Flash spinning process for partially fluorinated polymers using flash spinning agents comprising a chlorinated solvent and a linear or branched hydrocarbon with 5 or more carbon atoms

Abstract

The present invention relates to (i) a spin fluid for flash spinning comprising (a) at least one partially fluorinated polymer and (b) a spin agent comprising at least one chlorinated solvent and at least one linear or branched hydrocarbon with 5 or more carbon atoms, and (ii) a process for the preparation of plexifilamentary fibrils of partially fluorinated polymers using the spin fluid.

Description

[0001] TITLE

[0002] FLASH SPINNING PROCESS FOR PARTIALLY FLUORINATED POLYMERS USING FLASH SPINNING AGENTS COMPRISING A CHLORINATED SOLVENT AND A LINEAR OR BRANCHED HYDROCARBON WITH 5 OR MORE CARBON ; ';ATOMS

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to (i) a spin fluid for flash spinning comprising (a) at least one partially fluorinated polymer and (b) a spin agent comprising at least one chlorinated solvent and at least one linear or branched hydrocarbon with 5 or more carbon atoms, and (ii) a process for the preparation of plexifilamentary fibrils of partially fluorinated polymers using the spin fluid.

[0005] BACKGROUND Poiyvmylidene fluoride (PVDF). poly(ethylene-co-tetrafluoroethyieoe) (ETFE) and poly(ethylene-co-chlorotrifluoroethylene) (ECTFE) are partially fluorinated polymers comprising a linear carbon chain in which up to about 50% of the carbon atoms have hydrogen substituents and about 50% of the carbon atoms have fluorine substituents. These polymers exhibit very good chemical, temperature, fire, weathering and fouling resistance, which are of benefit in many applications such as filtration, architectural surfaces, electrical insulation, and industrial components. Partially fluorinated polymers are frequently used in the form of fibrils, especially in filtration applications. Furthermore, PVDF may exhibit useful piezoelectric properties if it is induced to adopt a crystal phase known as the p crystal phase. However, the p phase is thermodynamically unstable and can only be formed by elaborate processing steps involving heating and / or stretching the material in a strong electric field, or by precipitating

[0006] PVDF polymer in a controlled manner fitom highly polar solvents. :

[0007] Flash spinning is a process for producing fibrils that involves the foilowing steps: (i) dissolving a polymer in a composition comprising one or more solvents (often called a spin agent), at elevated temperature and pressure to forme homogeneous solution (often called a spin fluid), (ii) reducing the pressure sufficiently below the spin fluid’s cloud point pressure (i.e., the pressure at which the spin fluid transitions from adear solution to a cloudy, two-phase dispersion), while still maintaining sufficient pressure to prevent the spin fluid from reaching its bubble point pressure (i e.. the pressure at which the spin agent in the spin fluid begins to boil), (iii) releasing the resulting dispersion continuously through one or more orifices into a lower pressure region at or near atmospheric temperature and pressure so that the spin agent flash evaporates as it emerges from the one or more orifices, (tv) collecting the polymer which remains as a stream of fibrils, e g., plexifilamentary fibrils, and (v) recovering the evaporated spin agent for re-use. Examples of flash spinning processes are disclosed in US 3,681,519 and US 3,227,794.

[0008] In a commercial flash spinning process, the spin agent's solvent properties and physical properties are critical. In particular, the solvent properties of the spin agent determine whether and under what conditions fibrils are produced in the flash spinning process, and the spin agent's physical properties impact the process for recovering and re-using the spin agent The process for recovering spin agents typically involves a step in which the spin agent is condensed from the gas state to the liquid state, and it is preferred that the composition of the spin agent remains essentially constant during this step. This is inherent when spin agents comprise only one solvent but not when they comprise two or more Solvents, which are often required to provide the necessary solvent properties for flash spinning the desired polymer. ' Accordingly, when using a spin agent that comprises two or more solvents, it is preferred to use a composition that is azeotropic or azeotrope-like which behaves similarly to a spin agent with only one solvent In many instances, however, it is not practical to use an azeotropic or azeotrope-like composition. For example, when the components of an azeotropic or azeotrope-like spin agent composition are at ratios "that; do not provide the necessary solvent properties for flash spinning the desired polymer, the spin agent recovery and re-use process becomes significantly more complicated. In such cases, / it is instead advantageous -to use a composition that is zeotropic.

[0009] Examples of solvents that can be used with polymers such as polyvinylidene fluoride (PVDF) or poly(ethylene-co-tetrafluoroethyiene) (ETFE) are dichloromethane (DCM) and 1,2- dichloroethylene (DCE). At practical operating temperatures, DCM and DCE are each too strong of a solvent and cannot be used as the only component in a spin agent composition for flash spinning because they dissolve polymers at relatively low pressures. In particular, because DCM and DCE dissolve polymers at relatively low pressures, the cloud point pressure of a spin fluid using a spin agent with these chlorinated solvents alone is so close to the bubble point pressure that use of such spin agent is not feasible. Weaker solvents such as hydrofluorocarbons can be mixed with DCM or DCE to reduce the solvent strength of the spin agent and increase the spin fluid's cloud point pressure such that flash spinning can be readily accomplished. WO2016 / 200873 A1 suggests spin agent compositions of dichloromethane or 1,2- dichloroethylene with 1 H.SH-perfluorohexane, 1 H-perfluorohexane, or 1 H-perfluoroheptane for spinning various polymers, including polyvinylidene fluoride (PVDF) or poly(ethylene-co- tetrafluoroethylene) (ETFE). US 7, 179413 describes that PVDF. ETFE. and ECTFE can be spun from a spin agent comprising DCM or DOE and the linear hydrofluorocarbon PFMCP (3,3,4,4,5,5,6,6,6-nonafluoro-1 -hexene). US 7,300,968 teaches flash spinning of PVDF, ETFE or ECTFE using mixtures of DOM or DOE and HFC-365mfc (1,1, 1,3, 3-pentafluorobutane) as a spin agent. However, use of such linear hydrofluorocarbons in combination with DCM or DCE results in spin agents that often exhibit undesirably high global warming potential (GWP). In view tof the growing concerns regarding climate change and increasing regulatory requirements, there is a need to find suitable low GWP replacements for spin agent compositions disclosed in the prior art. Such spin agent compositions should also form a homogeneous liquid phase at ambient temperatures and pressures, rather than a heterogeneous liquid phase where, due to low miscibility of the components of the spin agent composition, a:liquid-liquid phase separation occurs. Compositions forming heterogeneous liquid phases are usually undesired since processes involving such compositions are more complex and expensive due to the liquid-liquid phase separation.

[0010] US 6,136,911 suggests the flash spinning of partly fluorinated polymers, such as PVDF, ETFE arid ECTFE, using spin agents of n-pentane and acetone, but that acetone and similar ketones can undergo self-condensation at the temperatures and pressures employed in flash spinning, generating contaminants which must be continuously removed during spin agent recycling..

[0011] Accordingly, there is a need for, and the presentinventors have discovered, low GWP spin agent compositions of at least one chlorinated solvent and at least one non-cyclic hydrocarbon that provide suitable cloud point pressures for flash spinning partially fluorinated polymers. It is a further object of the present invention to provide a spin fluid comprising PVDFand spin agent compositions where the crystal phase present in the PVDF in the fibrils resulting from flash spinning is predominantly the |3 phase. SUMMARY OF THE INVENTION

[0012] In one embodiment, the invention is directed to a spin fluid for flash; spinning comprising (a) from about 12 to about 36 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises a composition:comprising at least one chlorinated solvent, selected from dichloromethane, trans-l,2-dichloroethylene, cis-i,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0013] In a further embodiment, the invention is directed to a process for the preparation of piexifilamentary fibrils of a partially fluorinated polymer. The process comprises the steps of: (i) generating a spin fluid comprising

[0014] (a) from about 12 to about 36 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and

[0015] (b) a spin agent, and

[0016] (ii) flash spinning the spin fluid at a pressure that is above the vapor pressure of the spin fluid into a region of essentially atmospheric pressure to form piexifilamentary fibrils of the partially fluorinated polymer, wherein t he spin agent comprises a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichioroethylene, cis-1,2- dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0017] BRIEF DESCRIPTION OF THE FIGURES

[0018] Fig. 1 shows the cloud point pressure curve of a spin fluid comprising 26 wt% polyvinylidene fluoride (PVDF) and a spin agent of dichloromethane (DCM) and n-pentane in a 92:8 ratio by weight, the cloud point pressure curve of a spin fluid comprising 26 wt% PVDF and a spin agent of DCM and n-pentane in a 95:5 ratio by weight, and the cloud point pressure curve of a spin fluid comprising 26 wt%. PVDF and a spin agent of DCM and n-pentane in a 98:2 ratio by weight.

[0019] Fig. 2 shows the cloud point pressure at 225 °C for different spin fluids comprising poly vinylidene fluoride (PVDF) at different concentrations.

[0020] Fig. 3 shows the cloud point pressure curve of a spin fluid comprising 28 wt% poly(ethylene-co-tetrafluoroethylene) (ETFE) and a spin agent of dichloromethane (DCM) and n-pentane in a 49 1 :05.9 ratio by weight, the cloud point pressure curve of a spin fluid comprising 26 wt% ETFE and a spin agent of DCM and n-pentane in a 40:60 ratio by weight, and the cloud point pressure curve of a spin fluid comprising 26 wt% ETFE and a spin agent of DCM and n-pentane in a 35:65 ratio by weight.

[0021] Fig. 4 shows the cloud point pressure curve of a spin fluid comprising 34 wt% poly(ethylene-co-tetrafluoroethylene) (ETFE) and a spin agent of trans-1.2-dichloroethylene (trans-1 ,2-DCE) and 2.2-dimethylbutane in a 35:65 ratio by weight.

[0022] Fig. 5 shows the cloud point pressure at 225 °C for different spin fluids comprising poly(ethylene-co-tetrafluoroethylene) (ETFE) at different concentrations. DETAILED DESCRIPTION

[0023] Definitions and Clarification of Terms

[0024] Before addressing details of embodiments, some terms and test methods are defined or clarified Unless otherwise mentioned, all tests were carried out without preconditioning of the samples When average values are indicated herein, this refers to the arithmetic average Density is determined according to the method described in ISO 1183 (Plastics -

[0025] Methods for determining the density of non-cellular plastics). Melting temperature is determined by differential scanning calorimetry, following the guidance provided in ASTM D3418 (Standard Test Method for Transition Temperatures and Enthalpies of Fusion and Crystallization of Polymers by Differential Scanning Calorimetry). For PVDF. heating and cooling is performed under inert gas at a rate of 10 ' C / minute, heating the sample first from room temperature to 230 °Crthen cooling the sample back to room temperature and subsequently heating the sample a second time to 230 °C. The melting point reported herein is the peak temperature of the endotherm of the second heating cycle For polyfethylene-co-tetrafluoroethylene) and poly(efoylene-cd-chlorotrifluoroethylene), the same procedures apply with a maximum temperature of 300°C.

[0026] The melt flow rate for polyvinylidene fluoride is determined according to the method described in ASTM D1238 (Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer) at a temperature of 230 °C and using a mass of 3.8 kg, 5.0 kg, or 12.5 kg. The melt flow rate for poly(ethylene-co-tetrafluoroethylene) (ETFE) is determined according to the method described in ASTM D3159 (Standard Specification for Modified ETFE Fluoropolymer Molding and Extrusion Materials) The melt flow rate for poly(ethylene-co- chlorotrifluoroethylene) (ECTFE) is determined according to the method described in ASTM D1238 (Standard Test Method for Melt Flow Rates of Thermoplastics by ExtrusionPlastometer) at a temperature of 275 °C and using a mass of 2.16 kg. The total crystallinity index is determined as follows. A diffractometer in reflection 0-29

[0027] Bragg-Brentano geometry

[0028] Ray%20Powder%20Diffraction pdf) is fitted with a Cu-K.-, x-ray tube source with a wavelength of 1.54 A and a 1-dimensional detector. A parabolic mirror with a 1 / 16Jfixed slit and 10mm mask is used to create a parallel incident x-ray beam while a fixed slit of 1 / 8°, Soller slits of 0.04 rad, and a nickel Cu-KPfilter are employed on the diffracted side before the detector Each sample Is mounted onto low background, flat silicon wafer holders. 'The sample holder is mounted horizontally at the center of the diffractometer and normal to the scattering vector. During the measurement, the sample rotates in this plane.

[0029] PVDF can crystallize in three different crystal phases - the a, p, and y. The different crystal phases have distinct scattering peaks (see ICDD Database ICDD PDF-4+ database - PDF - 00-061-1403. 00-061-1404, 00-061-1406. Gates-Rector. S.: Blanton, T. The Powder Diffraction File: A Quality Materials Characterization Database Powder Diffr 2019, 34 (4), 352-360) The strongest intensity peaks for each phase are summarized in the following table

[0030] The procedure as described below is used to determine the crystallinity index of the PVDF samples using MATLAB The scattering angle 29 of the diffraction peaks can vary by about + / - 0.2° due to instrumental differences and sample height / texture. 1. An empty background scan (Si wafer only) is scaled and subtracted from the sample data such that the height of the baseline (in counts) is equivalent at two points - 10 and 29 20.

[0031] 2. A local linear background, drawn from 29 - 10° to 29° in scatering angle, is then subtracted, to bring the baseline down to zero counts. 3; Next, based on comparison to known PVDF crystal XRD paterns, the predominant phase(s) present are chosen. Only these crystalline peaks will be fit.

[0032] 4. The full patern is fit in the range of 20 = 10° to 29bwith the chosen crystalline peaks and one amorphous peak, all of Pearson VII shape. In the examples, in the current case, no scatering peak is observed for a scatering angle of 28 ® 26 7 - 26.8°, indicating no significant portions of the a or y crystal phases are present. No significant portion means that the integrated intensity in the range of 20 = 26.7 - 26.8" is below 2 % of the total integrated intensity in the range of 2G = 10° to 29°. The scattering intensity is then:

[0033] 1) Amorphous peak: 18.6°, Pearson VII peak shape, iamorphous, and

[0034] 2) |3 110 / 200 superimposed peak: 20.5°, Pearson VII peak shape, Iwwoo-

[0035] The amorphous peak parameters are limited to FWHM >3° and 1<M<2, while the crystalline peak parameters are limited to FWHM<2<’ and 1<M<10, where FWHM is foil-width at half maximum and M is the Pearson VII shape parameter.

[0036] 5 The total crystallinity index is calculated from the ratio of crystalline scattering to total scatering. The crystalline Scattering is defined as the sum of the integrated intensities from the crystalline peaks of all phases present in the fit angle range. The total scatering is defined as the sum of the integrated intensity of crystalline and amorphous peaks. In this case, where no significant portions of the o or y crystal phases are found, it is justified to define a crystallinity index (Cl) as the quotient of the integrated intensity of the only crystal phase present, i.e., pure P phase, divided by the sum of the integrated intensity of the p phase and amorphous peaks: crys

[0037] The term, ‘‘polymer” is intended to embrace, Without limitation, homopolymers, copolymers (such as for example, block graft, random, and alternating copolymers), terpolymers, etc., and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymeH shall include all possible geometrical configurations of the material. These configurations include, but are not limited to, isotactic, syndiotactic, and random symmetries.

[0038] The term ‘ potyvinylidene fluoride' (PVDF) is intended to embrace not only homopolymers of vinylidene fluoride but also copolymers where at least 70% of the recurring units are vinylidene fluoride units. The .PVDF may contain up to 10 weight percent or up to 5 weight percent of other polymers, such as polyoiefins.

[0039] The terms •poly(ethylene-co-tetrafluoroethylene)" or "ethylene-tetrafluoroethylene' ("ETFE”) are intended to embrace not only copolymers of ethylene and tetrafluoroethylene but also copolymers where at least 70% of the recurring units are ethylene and tetrafluoroethylene units. The ratio of ethylene to tetrafluoroethylene units in the copolymer may vary over wide limits. For example, the mole ratio of tetrafluoroethylene to ethylene units may be from about 40 / 60 to about 70 / 30. The ETFE may contain up to 10 weight percent or up to 5 weight percent of other polymers, such as polyolefins.

[0040] The term "poly(ethylene-co-chlorotrifluoroethylene) (ECTFE) is intended to embrace not only copolymers of ethylene and chlorotrifluoroethylene but also copolymers where at l east

[0041] 70% of the recurring units are ethylene and chlorotrifluoroethylene units. The ECTFE may contain up to 10 weight percent or up to 5 weight percent of other polymers, such as polyolefins.

[0042] The term polymer" is intended to embrace, without limitation, homopolymers, copolymers (such as for example, block, graft, random, and alternating copolymers), terpolymers, etc., and blends and modifications thereof.

[0043] The term “plexifilamentary" refers to a three-dimensional integral network or web of a multitude of thin, ribbon-like, fibrils of random length and a median fibril width of less than about 25 microns, in plexifilamentary structures, the fibrils are generally coextensively aligned with the longitudinal axis of the structure, and they intermittently unite and separate at irregular intervals in var ious places throughout the length, width, and thickness of the structure to form a continuous three-dimensional network or web

[0044] The terms “spin agent’* or “spin agent composition” refer to a composition comprising one or more solvents and any additives that are used to initially dissolve the polymer(s) to form the spin fluid. Suitable additives include stabilizers, such as antioxidants or acid scavengers.

[0045] The term spin fluid' refers to a solution for spinning in a flash spinning process comprising a polymer and a spin agent. The solution may also include one or more additives.

[0046] The term “dew point pressure” refers to the pressure at which, at constant temperature, liquid starts condensing from a vapor, vapor mixture, or vapor-gas mixture. The;term “bubble point pressure” refers to the pressure at which, at constant temperature, a liquid, liquid mixture, or liquid-solution begins to boil.

[0047] The term azeotropic composition" refers to a composition comprising two or more fluids wherein the bubble point pressure equals the dew point pressure. An azeotropic composition boils without change of the composition and behaves as a single substance. The azeotropic compositions described herein comprising dichloromethane are determined in a temperature range of -20 °C to 100 °C and expressed in mass fractions.

[0048] The term azeotrope-like composition" refers to a composition comprising two or more fluids which exhibit only small differences between the dew point pressure and the bubble point pressure, i.e . the dew point pressure is different by 5% or less from the bubble point pressure (both expressed in absolute pressure). An azeotrope-like composition boils without substantial change of the composition and behaves substantially as a single substance. The azeotrope-like compositions described herein are determined in a temperature range of -20 °C to 100 °C and expressed in mass fractions. The term “cloud point pressure” refers to the pressure at which, at constant temperature, a clear single phase spin fluid transitions from a clear solution to a cloudy, two- phase dispersion. At the cloud point pressure, a clear spin fluid becomes turbid.

[0049] Atmospheric pressure means 101.325 kPa. Essentially atmospheric pressure means 101.325 kPa ± 5 % Theterm “normal boiling point” refers to the temperature that is reached when the liquid vapor pressure equals 101.325 kPa (1 atm). As used herein, the singular forms "a," "an" and "the" include the plural, and reference toa particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. When a range of values is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood tihat the particular value forms another embodiment. All ranges are inclusive and combinable.

[0050] Spin Agents and Spin Fluids for Flash Spinning

[0051] Provided herein are spin fluids for flash spinning partially fluorinated polymers. The spin fluid comprises (a) from about 12 to about 35 weight percent of partially fluorinated polymer, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises, consists essentially of or consists of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1.2- dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0052] In some embodiments, the spin fluid comprises (a) from about 14 to about 30 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises,, consists essentially of Or consists of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms. In other embodiments, the spin fluid comprises (a) from about 18 to about 28 weight percent of a partially fluorinated polymer. based on the total amount of the spin fluid* and (b) a spin agent, wherein the spin agent comprises, consists essentially of or consists of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2- dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms. in other embodiments, the spin fluid comprises (a) from about 12 to about 19 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises, consists essentially of or consists of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene. cis-1 ,2-dichloroethylene. and trichloromethane. and at least one linear or branched hydrocarbon with 5 or more carbon atoms In other embodiments, toe spin fluid comprises (a) from about 22 to about 34 weight percent, or from about 26 to about 34 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises, consists essentially of or consists of a composition comprising at feast one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroetoylene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0053] In some embodiments, the spin fluid comprises from about 64 to about 88 weight percent of the spin agent, based on the total amount of the spin fluid, in other embodiments, the spin fluid comprises from about 70 to about 86 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 72 to about 82 weight percent of the spin agent, based on the total amount of the spin fluid In some embodiments, the spin fluid comprises from about 81 to about 88 weight percent of the spin agent, based on the total amount of the spin fluid. In some embodiments, the spin fluid comprises from about 64 to about 78 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 64 to about 74 weight percent of the spin agent, based on the total amount of the spin fluid.

[0054] In some embodiments, the spin agent comprises, consists essentially of. or consists of at least one chlorinated solvent, selected from dichloromethane, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbonatoms.

[0055] In some embodiments, the at least one linear or branched hydrocarbon with 5 or more carbon atoms has a normal boiling point of about 27 C to about 126;C. In some embodiments, the at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane. 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane. 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2- methyl-2-butene, 2-methyl-1-butene, 1-hexene, n-heptane, and n-octane, In some embodiments, the spin agent comprises, consists essentially of, or consists of didiloromethane and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane. 2.3-dimethylbutane. 2-methyl-2- butene. 2-methyl-1-butene, 1-hexene. n-heptane, and n-octane. In some embodiments, the spin agent comprises, consists essentially of, or consists of trans-1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2- methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane. In some embodiments, the spin agent comprises, consists essentially of, or consists of cis-1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane. n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2- methyl-2-butenel2-methyl-1-butene, 1-hexene, n-heptane, and n-octane. In some embodiments, the spin agent comprises, consists essentially of, or consists of cis-1 ,2-dichloroethylene and trans- 1,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n- heptane; and n-octane.

[0056] In some embodiments, the spin agent comprises, consists essentially of, or consists of trichloromethane and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane.

[0057] In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 84 to about 98 weight percent, or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from dichloromethane, cis-1 ,2-dichloroethylene. and trichloromethane, and from about 16 to about

[0058] 141 2 weight percent, or from about 12 to about 2 weight percent, or from about 8 to about 3 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms. In some embodiments, the spin agent comprises, consists essentially of. or consists of from about 84 to about 98 weight percent, or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from dichloromethane. cis-1, 2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent, or from about 12 to about 2 weight percent, or from about 8 to about 3 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane. 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2.3-dimethylbutane. 2-methyl-2-butene, 2-methyl-1- butene, 1 -hexene, n-heptane, and n-octane.

[0059] In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from: about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylehe, cis-1 ,2- dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms, in some embodiments, the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2- dichloroethylene, cis-1 , 2-dichloroethylene, and trichloromethane, and from about 86 to about 45 wight percent, or from about 80 to about 45 weight percent, or from about 80 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1, 2-dichloroethylene, cis-1 ,2- dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0060] In some embodiments the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 , 2-dichloroethylene, cis-1 ,2- dichloroethylene, and tnchloromethane. and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane. n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl- 1- butene, 1 -hexene, n-heptane. and n-octane In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 , 2- dichloroethylene, and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, or from about 80 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, 1 -hexene, n-heptane, and n-octane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene. and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2.3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, 1-hexene, n-heptane, and n-octane.

[0061] In some embodiments, the spin agent comprises, consists essentially of. or consists of an azeotropic or azeotrope-like composition comprising a chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1 , 2-dichloroethylene, and trichloromethane and a linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 2-methylbutane, 2-methylpentane, 3-methylpentane. 2,2- dimethylbutane, and 2,3-dimethylbutane. In some embodiments, the spin agent comprises, consists essentially of, or consists of an azeotropic or azeotrope-like composition comprising an azeotropic or azeotrope-like composition comprising dichloromethane and 2-methylpentarie, or an azeotropic or azeotrope- like composition comprising dichloromethane and 3-methylpentane. or an azeotropic or azeotrope-like composition comprising trichloromethane and 2-methylpentane, or an azeotropic or azeotrope-like composition comprising trichloromethane and 3-methylpentane, or comprising or an azeotropic or azeotrope-iike composition comprising dichloromethane and n- pentane, or comprising or an azeotropic or azeotrope-iike composition comprising dichloromethane and 2-methylbutane, or an azeotropic or azeotrope-iike composition comprising trans-1 ,2-dichloroethylene and 2,2-dimethylbutane, or an azeotropic azeotrope- iike composition comprising cis-1 ,2-dichloroethylene and 2-methylpentane, or an azeotropic or azeotrope-iike composition comprising cis-1 ,2-dichloroethylene and 3-methylpentane, or an azeotropic or azeotrope-iike composition comprising cis-1 ,2-dichloroethylene and 2,2- dimethylbutane, or an azeotropic or azeotrope-iike composition comprising cis-1.2- dichloroethylene and 2,3-dimethylbutane.

[0062] In some embodiments, the azeotropic or azeotrope-iike composition comprises, consists essentially of, or consists of from about 84 to about 98 weight percent dichloromethane and from about 16 to about 2 weight percent 2-methylpentane, in other embodiments from about 88 to about 98 weight percent dichloromethane and from about 12 to about 2 weight percent 2-methylpentane and in other embodiments from about 92 to about 9T weight percent dichloromethane arid from about 8 to about 3 weight percent 2- methylpentahe. These azeotropic or azeotrope-iike compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 6 kPa to about.591 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 84 to about 95 weight percent dichloromethane and from about 16 to about 5 weight percent 2-methylpentane. These azeotropic compositions boil at a temperature of about 20 °C to about 100 *C arid at a boiling pressure of about 49 kPa to about 591 kPa In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of about 87.0 weight percent dichloromethane and about 13.0 weight percent 2-methylpentane at a pressure of about 104.8 kPa and at a boiling temperature of about 40 °CT

[0063] In some embodiments, the azeotropic or azeotrope-iike composition comprises, consists essentially of. or consists of from about 84 to about 98 weight percent dichloromethane and from about 16 to about 2 weight percent 3-methylpentane. in other embodiments from about 88 to about 98 weight percent dichloromethane and from about 12 to about 2 weight percent 3-methylpentane, and in other embodiments from about 92 to about 97 weight percent dichloromethane and from about 8 to about 3 weight percent 3- methy I pentane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 6 kPa to about 590 kPa. In some embodiments, the azeotropic composition comprises, consists essentially ok or consists of from about 85 to about 95 weight percent dichloromethane and from about 15 to about 5 weight percent 3-methylpentane. These azeotropic compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 6 kPa to about 590 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of. or consists of about 90.0 weight percent dichloromethane and about 10.0 weight percent 3-methylpentane at a pressure of about 103.7 kPa and at a boiling temperature of about 40 °C.

[0064] In some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent trichloromethane and from about 90 to about 33 weight percent 2-methylpentane, or from about 36 to about 67 weight percent tnchloromethane and from about 64 to about 33 weight percent 2-methylpentane. These:azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 °C and at « boiling pressure of about 3 kPa to about 340 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 54 to about 63 weight percent trichloromethane and from about 46 to about 37 weight percent 2-methylpentane These azeotropic compositions boil at a temperature of about -20 “C to about TOO °C and at a boiling pressure of about 3 kPa to about 340 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 56.0 weight percent trichloromethane and about 440 weight percent 2-methylpentane at a pressure of about 56,6 kPa and at a boiling temperature of about 40 °C.

[0065] In some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 Weight percent trichloromethane and from about 90 to about 33 weight percent 3-methylpentane, or from about 46 to about 67 weight percent trichloromethane and from about 54 to about 33 weight percent 3-methylpentane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20;°C to about 100 °C and at a boiling pressure of about 2 kPa to about 326 kPa In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 58 to about 67 weight percent tnchloromethane and from about 42 to about 33 weight percent 3-methylpentane. These azeotropic compositions boil at a temperature of about -20 °C to about 60 X and at a boiling pressure of about 3 kPa to about 107 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 66.0 weight percent trichlorometfiane and about 34.0 weight percent 3-methylpentane at a pressure of about 53.6 kPa and at a boiling temperature of about 40 X.

[0066] In some embodiments, the azeotropic or azeotrope-iike compositions comprise, consist essentially of, or consist of from about 10 to about 67 weight percent dichloromethahe and from about 33 to about 90 weight percent n-pentane, or from about 31 to about 67 weight percent dichloromethane and from about 69 to about 33 weight percent n-pentane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 X to about 100 X and at a boiling pressure of about 10 kPa to about 703 kPa. In some embodiments, the azeotropic or azeotrope-iike compositions comprise, consist essentially of, or consist of from about 31 to about 63 weight percent dichloromethane and from about 69 to about 37 weight percent n-pentane. These azeotropic or azeotrope-like compositions boil at a temperature of about 40 X and at a boiling pressure of about 132 kPa to about 139 kPa. In some embodiments, the azeotropic compositions comprise, consist essentially of. or consist of from about 43 to about 58 weight percent dicnloromethane and from about 57 to about 42 weight percent n-pentane. These azeotropic compositions boil at a temperature of about - 20 °C to about 100 X and at a boiling pressure of about 11 kPa to about 703 kPa. In some embodiments, the azeotropic composition consists essentially of or consists of about 50.9 weight percent dichloromethane and about 49.1 weight percent n-pentane at a pressure of about 82 kPa and at fa boiling 'temperature of about 25 X. In some embodiments, the azeotropic composition consists essentially of or consists of about 51.0 weight percent dichloromethane and about 49.0 weight percent n-pentane at a pressure of about 1389 kPa and at a boiling temperature of about 40 °C.

[0067] In some embodiments, the azeotropic or azeotrope-iike compositions comprise, consist essentially of, or consist of from about 10 to about 67 weight percent dichloromethane and from about 33 to about 90 weight percent 2 -methylbutane, or from about 24 to about 67 weight percent dichloromethane and from about 76 to about 33 weight percent 2-methylbutane. These azeotropic or azeotrope-like compositions boil at a temperature ofabout -20 X to about 100 X and at a boiling pressure of about 13 kPa to about 775 kPa. In some embodiments, the azeotropic or azeotrope-iike compositions comprise, consist essentially of, or consist of tom about 15 to about 56 weight percent dichloromethane and from about 85 to about 44 weight percent 2-methylbutane or from about 25 to about 51 weight percent dichloromethane and from about 75 to about 49 weight percent 2-methylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about 40 C and at a boiling pressure of about 157 kPa to about 163 kPa. In some embodiments, the azeotropic compositions comprise, consist essentially of, or consist of from about 26 to about 42 weight percent dichloromethane and from about 74 to about 58 weight percent 2-methylbutane.

[0068] These azeotropic compositions boil at a temperature of about -20 *C to about 100 ’C and at a boiling pressure of about 14 kPa to about 775 kPa. In some embodiments, the azeotropic composition consists essentially of or consists of about 35.0 weight percent dichloromethane and about 65.0 weight percent 2-methylbutane at a pressure of about 162 6 kPa and at a boiling temperature of about 40 °C.

[0069] In some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of , or consists of from about 10 to about 67 weight percent trans-1, 2- dichloroethylene and from about 90 to about 33 weight percent 2,2-dimethylbutane, or from about 34 to about 67 weight percent trans-1 ,2-dtchloroethylene and from about 66 to about 33 weight percent 2,2-dimethylbutane. or from about 44 to about 67 weight percent trans-

[0070] 1 ,2-dichloroethylene and from about 56 to about 33 weight percent 2,2-dimethylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to . about 100 °C and at a boiling pressure of about 5 kPa to about 460 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 52 to about 67 weight percent trans-1 ,2-dichloroethylene and from about 48 to about 40 weight percent 2,2-dimethylbutane These azeotropic compositions boil at atemperature of about -20 °C to about 60 °C and at a boiling pressure of about 5 kPa to about 161 kPa. In Some embodiments, toe azeotropic composition comprises, consists essentially of or consists of about 63.0 weight percent trans-1 ,2-dichloroethylene and about 37.0 weight percent 2,2-dimethylbutane at a pressure of about 84.6 kPa and at a boiling temperature of about 40 °C.

[0071] In some embodiments, toe azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent cis-1,2- dichloroethyiene and from about 90 to about 33 weight percent 2-methylpentane, or from about 26 to about 67 weight percent cis-1,2-dichloroethylene and from about 74 to about 33 weight percent 2-methylpentane, or from about 36 to about 67 weight percent cis-1 ,2- dichloroethylene and from about 64 to about 33 weight percent 2-methylpentane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 C and at a boiling pressure of about 3 kPa to about 361 kPa. In some embodiments. the azeotropic composition comprises, consists essentially of, or consists of from about 52 to about 60 weight percent cis-1 ,2-dichloroethylene and from about 48 to about 40 weight percent 2-methylpentane. These azeotropic compositions boil at a temperature of about -20 *0 to about 100 °C and at a boiling pressure of about 3 kPa to about 361 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 54.5 weight percent cis-1 ,2-dichloroethylene and about 45.5 weight percent

[0072] 2-methylpentane at a pressure of about 60.4 kPa and at a boiling temperature of about

[0073] 40 °C. ' in some embodiments, the azeotropic or azeotrope- like composition comprises. consists essentially of, or consists of from about 10 to about 67 weight percent cis- 1 ,2- didtloroethylene and from about 90 to about 33 weight percent 3-methylpentane, or from about 33 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 67 to about 33 weight percent 3-methylpentane, or from about 43 to about 67 weight percent cis-1 ,2- dichloroethylene and from about 57 to about 33 weight percent 3-methylpentane. These , azeotropic or azeotrope-like compositions boil at a temperature of about -20 ”C to about

[0074] 100 C and at a boiling pressure of about 3 kPa to about 348 kPa In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 59 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 41 to about 33 weight percent 3-methylpentane. These azeotropic compositions boil at a temperature of about -20 C to about 100 ' C and at a boiling pressure of about 3 kPa to about 348 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 60 6 weight percent cis-1.2-dichloroethylene and about 39.4 weight percent

[0075] 3-methylpentane at a pressure of about 57.3 kPa and at a boiling temperature of about 40 °G. In some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent cis-1.2- dichloroethylene and from about 90 to about 33 weight percent 2,2-dimethylbutane, or from about 10 to about 64 weight percent cis-1, 2-dichloroefriyiene and from about 90 to about 36 weight percent 2,2-dimethylbutane, or from about 15 to about 64 weight percent cis-1 ,2- dichloroethylene and from about 85 to about 36 weight percent 2,2-dimethylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 C and at a boiling pressure of about 5 kPa to about 414 kPa. In some embodiments, the azeotropic cbmpositiori comprises, consists essentially of, or consists of from about 21 to about 36 weight percent cis-1.2-dichloroethylene and from about 79 to about 64 weight percent 2,2-dimethylbutane. These azeotropic compositions boil at a temperature of about - 20 ' C to about 100 'C and at a boiling pressure of about 5 kPa to about 414 kPa In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 25 5 weight percent cis-1 ,2-dichloroethyiene and about 74 5 weight percent 2,2-dimethylbutane at a pressure of about 76.2 kPa and at a boiling temperature of about

[0076] 40 °G. in some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about W to about 67;weight percent cis-1, 2- dichloroethylene and from about 90 to about 33 weight percent 2.3-dimethylbutane. or from about 19 to about 67 weight percent cis-1.2-dichloroethylene and from about 81 to about 33 weight percent 2.3-dimethylbutane, or from about 29 to about 67 weight percent cis-1 , 2- dichloroethylene and from about 71 to about 33 weight percent 2,3-dimethylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 C and at a boiling pressure of about 3 kPa to about 367 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 43 to about 55 weight percent cis-1 ,2-dichloroethylene and from about 57 to about 45 weight percent 2,3-dimethylbutane. These azeotropic compositions boil at a temperature of about -20 "C to about 100 °C and ata boiling pressure of about4 kPa to about 367 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 47.0 weight percent cis-1 ,2-dichloroethylene and about 53.0 weight percent 2,3-dimethylbutane at a pressure of about 62.7 kPa and at a boiling temperature of about 40 C

[0077] The spin fluid may include additives, such as antioxidants or acid scavengers, in minor amounts. In some embodiments, the spin fluid comprises additives in an amount of about 1.5 weight percent or less of the total amount of the spin agent, and in other embodiments in an amount of about 01 weight percent or less of the total amount of the spin agent.

[0078] The spin agent can be used for a broad range of different partially fluorinated polymers and blends / mixtures thereof. ,

[0079] In some embodiments, the partially fluorinated polymer is selected from polyvinylidene fluoride (PVDF) poly(ethylene-co-tetrafluoroethylene) (ETFE), and poly(ethylene-co-chlorotrifluoroethylene) (ECTFE).

[0080] In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a polyvinylidene fluoride (PVDF), each based on the total amount of the spin W fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 84 to about 98 weight percent, or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from / dichloromethane, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent, or from about 12 to about 2 we^ht percent, or from about 8 to about 3 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methy I pentane, 3-methylpentane, 2.2-dimethylbutane. 2,3-dimethylbutane, 2-methyl-2- butene. 2-methyl-1 -butene, 1 -hexene, n-heptane, and n-octane.

[0081] In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-tetrafluoroethylene) (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 Weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 90 to about 45 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting Of n- pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methytpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1-butene, 1-hexene, n- heptane, and n-octane. In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-tetrafluoroethylene) (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight / percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2- dichloroethylene, and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, or from about 70 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane. 2-methyipentane, 3- methylpentane, 2,2-dimethylbutane, 2.3-dimethylbutane. 2-methyl-2-butene. 2-methyl-1- butene, 1-hexene, n-heptane, and n-octane. In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co- tetrafluoroethylene) (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more Carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2.2-dimethylbutane, 2.3-dimethylbutane. 2-methyi-2- butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane.

[0082] In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-chlorotrifluoroethylene) (ECTFE). each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 might percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane. trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 90 to about 45 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n- pentane. 1-pentene, 2-methylbutane, n-hexane, 2-methyipentane, 3-methylpentane, 2,2- dimethylbutane. 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n- heptane, and n-octane In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-chiorotrifiuoroethylene) (ECTFE), each based on the total amount of the spin fluid, and a sp n agent, wherein the spin agent comprises, consists essentially Of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one .chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1 ,2* dichloroethylene, and trichloromethane, and from about 86 to about 45 'weight percent, or from about 80 to about 45 weight percent, or from about 70 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, 1-hexene, n-heptane, and n-octane. In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co- chlorotrifluoroethylene) (ECTFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of , or consists of from about 10 to about 30 weight percent, or from about 20 to about 30;weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis^l,2- dichloroethylene. and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2- methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene, 2-methyl-1-butene, 1-hexene, n-heptane, and n-octane.

[0083] In some embodiments, the spin fluid as described herein exhibits a cloud point pressure in the range of about 45 to about 300 bar, in other embodiments in the range of about 50 to about 300 bar. and in other embodiments in the range of about 70 to about 300 bar In some embodiments, the spin fluid as described herein exhibits a cloud point pressure in the range of about 45 to about 250 bar, in other embodiments in the range of about 50 to about 250 bar, and in other embodiments in the range of about 70 to;about 250 bar. In some embodiments, the spin fluid as described herein exhibits a cloud point pressure in the range of about 45 to about 200 bar, in other embodiments in the range of about 50 to about 200 bar, and in other embodiments in the range of about 70 to about 200 bar. The flash spinning process must take place at an operating pressure below the spin fluid's cloud point pressure but above the spin fluid’s bubble point pressure. If the pressure becomes lower than the spin fluid’s bubble point pressure, premature and unwanted boiling occurs. If the cloud point pressure is above about 300 bar, the flash spinning equipment must be built to withstand very high pressure which increases costs and operational constraints.

[0084] Properties of the spin fluids comprising the spin agent compositions

[0085] The compound dichloromethane (DCM) has reported GWP-100 ^global warming potential over a 100-year period) of 11 2 (IPCC 2021 report) and the compound trichloromethane (TCM, chloroform) has a reported GWP-100 of 20 6 (IPCC 2021 report) No calculated GWP value is available for trans-1,2-dichloroethylene and for cis-1,2- dichioroefoylene. However, these compounds are expected:to have short atmospheric lifetimes due to their relatively high reactivity, so a very low GWP-100 of essentially zero may be assumed While no specific data is available for linear or branched hydrocarbons, such as n-pentane, 1 -pentene, 2-methylbutane, hexane, 2-methylpentane, 3-mefoylpentane, 2,2- dimefoylbutane, 1-hexene, 2-mefoyl-2-butene, and 2-mefoyl-l -butene, and 2,3- dimethylbutane, values reported for hydrocarbons with up to four carbon atoms show a rapid decline in GWP-100 as the number of carbon atoms increases, so it is reasonable to assume a GWP-100 of at or close to zero for these compounds . Accordingly, foe spin agent compositions disclosed herein combining the chlorinated compounds dichloromefoane. trichloromefoane, and / or dichloroefoylene and one or more of linear or branched hydrocarbons with 5 or more carbon atoms have a very low global warming potential (GWP). In some embodiments, spin agent compositions comprising trans / cis-1 ,2- dichloroethylene and one or more of linear or branched hydrocarbons with 5 or more carbon atoms have a GWP-100 of at or close to zero.

[0086] The spin agent compositions as described herein have the advantage of being homogeneous compositions For homogenous spin agent compositions, the components of the composition at ambient temperatures and pressures form a single liquid phase. This is to be contrasted with heterogeneous spin agent compositions, where, due to low miscibility of the components of the composition, the components of the composition undergo phaseseparation in foe liquid phase. Phase separation is usually undesired since processes involving the composition are more complex and expensive The homogeneous nature of the spin agent compositions is achievable over a broad range of practical conditions including ambient pressure and temperature. Preparation of Plexifilamentary Film-fibril Strands of partially fluorinated polymer

[0087] In some embodiments, there is provided a process for the preparation of plexifilamentary fibrils of a partially fluorinated polymer. The process comprises the steps of:

[0088] (i) generating a spin fluid comprising

[0089] (a) about 12 to about 36 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and

[0090] (b) a spin agent, and (ii) flash spinning the spin fluid at a pressure that is above the vapor pressure of the spin fluid into a region of essentially atmospheric pressure to form plexifilamentary fibrils of the partially fluorinated polymer, wherein the spin agent comprises a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans- 1.2-dichloroethylene, cis-1.2- dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0091] In some embodiments, the flash-spinning is performed at a pressure in the range of about 45 to about 300 bar, in other embodiments in the range of about 50 to about 300 bar, or in other embodiments in the range of about 70 to about 300 bar. In some embodiments, the flash-spinning is performed at a pressure in the range of about 45 to about 250 bar, in other embodiments in the range of about 50 toabout 250 bar, and in other embodiments in the range of about 70 to about 250 bar. In some embodiments, the flash-spinning is performed at a pressure in the range of about 45 to about 200 bar, in other embodiments in the range of about 50 to about 200 bar, and in other embodiments in the range of about 70 to about 200 bar. The region of lower pressure into which flash spinning occurs is usually at or around atmospheric pressure.

[0092] In some embodiments, the spin fluid comprises (a) from about 14 to about 30 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises, consists essentially of or consists of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene. cis-1.2-dichloroethylene. and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms In other embodiments, the spin fluid comprises (a) from about 48 to about 28 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises, consists essentially of or consists of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 , 2- dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms In other embodiments the spin fluid comprises (a) from about 12 to about 19 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises, consists essentially of or consists of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms In other embodiments, the spin fluid comprises (a) from about 22 to about 34 weight percent, or from about 26 to about 34 Weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid , and (b) a spin agent, wherein the spin agent comprises, consists essentially of or consists of a composittoni comprising at least one chlorinated solvent, selected from dichloromethane, trans-l,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms..

[0093] In some embodiments, the spin fluid comprises from about 64 to about 88 weight percent of the spin agent, based on the total amount of the spin fluid, in other embodiments, the spin fluid comprises from about 70 to about 86 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 72 to about 82 weight percent of the spin agent, based on the total amount of the spin fluid. In some embodiments the spin fluid comprises from about 81 to about 88 weight percent of the spin agent, based on the total amount of the spin fluid. In some embodiments, the spin fluid comprises from about 64 to about 78 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 64 to about 74 weight percent of the spin agent, based on the total amount of the spin fluid.

[0094] In some embodiments, the spin agent comprises, consists essentially of, or consists of at least one chlorinated solvent, selected from dichloromethane, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0095] In some embodiments, the at least one linear or branched hydrocarbon with 5 or more carbon atoms has a normal boiling point of about 27 C to about 126 ’C.

[0096] In some embodiments, the at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane. 1 -pentene, 2-methylbutane. n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2- methyl-2-butene, 2-methyl-1-butene, 1-hexene, n-heptane, and n-octane.

[0097] In some embodimente, the spin agent comprises, consists essentially of, or consists of dichloromethane and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane. n-hexane, 2- methylpentane, 3-methylpentane, 2;2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane.

[0098] In some embodiments, the spin agent comprises, consists essentially of. or consists of trans- 1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane. n-hexane, 2-methyfpentane 3-methylpentane. 2,2-dimethylbutane. 2.3-dimethylbutane, 2- methyl-2-butene, 2-methyl-1-butene, 1-hexene, n-heptane, and n-octane.

[0099] In some embodiments, the spin agent comprises, consists essentially of, or consists of cis-1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane 1 -pentene, 2-methylbutane n-hexane, 2-methylpentane. 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane 2- methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane.

[0100] In some embodiments, the spin agent comprises, consists essentially of, or consists of cis-1,2-dichloroethylene and trans-1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene. 2-methylbutane, n-hexane. 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n- heptane, and n-octane.

[0101] In some embodiments, the spin agent comprises, consists essentially of, or consists of trichloromethane and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutarie, 2-methyl-2- butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane.

[0102] In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 84 to about 98 weight percent^ or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from dichioromethane. cis-1 ,2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent, or from about 12 to about 2 weight percent, or from about 8 to about 3 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms. In some

[0103] ; » embodiments, the spin agent comprises, consists essentially of, or consists of from about 84 to about 98 weight percent, or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from dichloromethane. cis-1 ,2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent, or from about 12 to about 2 weight percent, or from about 8 to about 3 weight percent Of at leastone linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of mpentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3* methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene. 1-hexene. n-heptane, and n-octane.

[0104] In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2- dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, frans-1,2- dichloroethylene, cis-1 ,2-dichlbroethylene, and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, or from about 80 to about 45 weight percent of at feast one linear or branched hydrocarbon with 5 or more carbon atoms. In some embodiments, the spin agent comprises, consists essentially o^ or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, Selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2- dichloroethylene. and trichloromethane. and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0105] In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1, 2- dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-< methyl pentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, 1-hexene, n-heptane, and n-octane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1, 2- dichloroethylene, and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, ar from about 80 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene. 2-methylbutane. n-hexane. 2-methylpentane. 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, 1-hexene, n-heptane, and n-octane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, 1-hexene, n-heptane, and ri-octane.

[0106] In some embodiments, the spin agent comprises, consists essentially of, or consists of;an azeotropic or azeotrope-like composition comprising a chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane and a linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 2-methylbutane,;2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, and 2,3-dimethylbutane.

[0107] In some embodiments, the spin agent comprises, consists essentially of, or consists of an azeotropic or azeotrope-like composition comprising an azeotropic or azeotrope-like composition comprising dichloromethane and 2-methylpentane. or an azeotropic or azeotrope- like composition comprising dichloromethane and 3-methylpentane, or an azeotropic or azeotrope-like composition comprising trichloromethane and 2-methylpentane, or an azeotropic or azeotrope-like composition comprising trichloromethane and 3-methylpentane or comprising or an azeotropic or azeotrope-hke composition comprising dichloromethane and n-pentane, or comprising or an azeotropic or azeotrope-like composition comprising dichloromethane and 2-methylbutane, or an azeotropic or azeotrope-like composition comprising trans-1 ,2-dichloroethylene and 2,2-dimethylbutane, or an azeotropic azeotropelike composition comprising cis-1 ,2-dichloroethylene and 2-methylpentane. or an azeotropic or azeotrope-iike composition comprising cis-1 ,2-dichloroethylene and 3-methylpentane. or an azeotropic or azeotrope-hke composition comprising cis-1 ,2-dichloroethylene and 2,2- dimethylbutane, or an azeotropic or azeotrope-like composition comprising cis-1 ,2- dichloroethylene and 2,3-dimethylbutane.

[0108] In some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 84 to about 98 weight percent dichloromethane and from about 16 to about 2 weight percent 2-methylpentane, in other embodiments from about 88 to about 98 weight percent dichloromethane and from about 12 to about 2 weight percent 2-methylpentane. and in other embodiments from about 92 to about 97 weight percent dichloromethane and from about 8 to about 3 weight percent 2- methylpentane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 C to about 100 ' C and at a boiling pressure of about 6 kPa to about 591 kPa. In some embodiments the azeotropic composition comprises, consists essentially of, or consists of from about 84 to about 95 weight percent dichloromethane and from about 16 to about 5 weight percent 2-methylpentane. These azeotropic compositions boil at a temperature of about 20 °C to about 100 “C and at a boiling pressure of about 49 kPa to about 591 kPa, In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of about 87.0 weight percent dichloromethane and about 13.0 weight percent 2-methylpentane at a pressu re of about 104.8 kPa and at a boiling temperature of about 40 °C.

[0109] In some embodiments, the azeotropic or azeotrope- like composition comprises, consists essentially of , or consists of from about 84 to about 98 weight percent dichloromethane and from about 16 to about 2 weight percent 3-methylpentane, in other embodiments from about 88 to about 98 weight percent dichloromethane and from about 12 to about 2 weight percent 3-methylpentane. and in other embodiments from about 92 to about 97 weight percent dichloromethane and from about 8 to about 3 weight percent 3- methylpentane. These azeotropic or azeotrope-hke compositions boil at a temperature of about -20 “C toabout 100 °C and at a boiling pressure of about 6 kPa to about 590 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 85 to about 95 weight percent dichloromethane and from about 15 to about 5 weight percent 3-methylpentane. These azeotropic compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 6 kPa to about 590 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of about 90.0 weight percent dichloromethane and about 10.0 ■weight percent 3-methylpentane at a pressure of about 103.7 kPa and at a boiling temperature of about 40 °C. In some embodirhents, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent trichloromethane and from about 90 to about 33 weight percent 2-methylpentane, or from about 36 to about 67 weight percent tri chloromethane and from about 64 to about 33 weight percent 2-methylpentane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 3 kPa to about 340 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 54 to about 63 weight percent trichloromethane and from about 46 to about 37 weight percent 2-methylpentane. These azeotropic compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 3 kPa to about 340 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 56.0 weight percent trichloromethane and about 44 0 weight percent 2-methylpentane at a pressure of about 56.6 kPa and at a boiling temperature of about 40 “C.

[0110] In some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent trichloromethane and from about 90 to about 33 weight percent 3-methylpentane, or from about 46 to about 67 weight percent trichloromethane and from about 54 to about 33 weight percent 3-methylpentane These azeotropic or azeotrope-like compositions boil at a temperature of about -20<JC to about 100 C and at a boiling pressure of about 2 kPa to about 326 kPa . I n some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 58 to about 67 weight percent trichloromethane and from about 42 to about 33 weight percent 3-methylpentane. These, azeotropic compositions boil at a temperature of about -20 °C to about 60 °Cand at a boiling pressure of about 3 kPa to about 107 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 66 0 weight percent trichloromethane and about 34.0 weight percent 3-methylpentane at a pressure of about 53.6 kPa and at aboiling temperature of about 40 °C.

[0111] In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 10 to about 67 weight percent dichloromethane and from about 33 to about 90 weight percent n-pentane, or from about 31 to about 67 weight percent dichioromethane and from about 69 to about 33 weight percent n-pentane. these azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 10 kPa to about 703 kPa. In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 31 to about 63 weight percent dichloromethane and from about 69 to about 37 weight percent n-pentane. These azeotropic or azeotrope-like compositions boil at a temperature of about 40 and at a boiling pressure of about 132 kPa to about 139 kPa. In some embodiments, the azeotropic compositions comprise, consist essentially of, or consist of from about 43 to about 58 weight percent dichioromethane and from about 57 to about 42 weight percent n-pentane. These azeotropic compositions boil at a temperature of about - 20 C to about 100 ‘ C and at a boiling pressure of about 11 kPa to about 703 kPa. In some embodiments, the azeotropic composition consists essentially of or consists of about 50.9 weight percent dichioromethane and about 49.1 weight percent n-pentane at a pressure of about 82 kPa and at a boiling temperature of about 25 °C. In some embodiments, the azeotropic composition consists essentially of or consists of about 51.0 weight percent dichioromethane and about 49.0 weight percent n-pentane at a pressure of about 138.9 kPa and at a boiling temperature of about 40 °C.

[0112] In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 10 to about 67 weight percent dichioromethane and from about 33 to about 90 weight percent 2-methylbutane, or from about 24 to about 67 weight percent dichioromethane and from about 76 to about 33 weight percent 2-methylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 13 kPa to about 775 kPa. In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 15 to about 56 weight percent dichioromethane and from about 85 to about 44 weight percent 2-methylbutane or from about 25 to about 51 weight percent dichioromethane and from about 75 to about 49 weight percent 2-methylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about 40 C and at a boiling pressure of about 157 kPa to about 163 kPa. In some embodiments, the azeotropic compositions comprise, consist essentially of, or consist of from about 26 to about 42 weight percent dichloromethane arid from about 74 to about 58 weight percent 2-methylbutane. These azeotropic compositions boil at a temperature of about -20 C to about 100 ' C and at a boiling pressure of about 14 kPa to about 775 kPa In some embodiments, the azeotropic composition consists essentially of or consists of about 35,0 weight percent dichloromethane and about 65^0 weight percent 2-methylbutane at a pressure of about 162.6 kPa and at a boiling temperature of about 40 °C.

[0113] In some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent trans- 1 ,2- dichloroethylene and from about 90 to about 33 weight percent 2,2-dimethylbutane, or from about 34 to about 67 weight percent trans-1 ,2-dichloroethylene and from about 66 to about 33 weight percent 2,2-dimethylbutane, or from about 44 to about 67 weight percent trans- 1 ,2-dichloroethylene and from about 56 to about 33 weight percent 2,2-dimethylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 C to about 100 °C and at a boiling pressure of about 5 kPa to about 460 kPa. In some ' embodiments, the azeotropic composition comprises, consists essentially of, or consists Of from about 52 to about 67 weight percent trans-1, 2-dichloroethylene and from about 48 to about 40 weight percent 2,2-dimethylbutane. These azeotropic compositions boil at a temperature of about -20 °C to about 60 "C and at a boiling pressure of about 5 kPa to about 161 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 63.0 weight percent trans-1 ,2-dichloroethylene and about 37.0 weight percent 2,2-dimethylbutane at a pressure of about 84 6 kPa and at a boiling temperature of about 40 °'C.

[0114] In some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent cis-1, 2- dichloroethylene and from about 90 to about 33 weight percent 2-methylpentane, or from about 26 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 74 to about 33 weight percent 2-methylpentane, or from about 36 to about 67 weight percent cis-1 ,2- dichloroethylene and from about 64 to about 33 weight percent 2-methylpentane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about TOOcC and at a boiling pressure of about 3 kPa to about 361 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 52 to about 60 weight percent cis-1 ,2-dichloroethylene and from about 48 to about 40 weight percent 2-methylpentane. These azeotropic compositions boil at a temperature of about -20 “C to about 100 °C and at a boiling pressure of about 3 kPa to about361 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 54.5 weight percent cis-1.2-dichloroethylene and about 45.5 weight percent

[0115] 2-methylpentane at a pressure of about 60 4 kPa and at a boiling temperature of about 40 °C.

[0116] In some embodiments, the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent cis-1, 2- dichloroethylene and from about 90 to about 33 weight percent 3-methylpentane. or from about 33 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 67 to about 33 weight percent 3-methylpentane. or from about 43 to about 67 weight percent cis-1 ,2- dichloroethylene and from about 57 to about 33 weight percent 3-methylpentane These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 “C and at a boiling pressure of about 3 kPa to about 348 kPa In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from, about 59 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 41 to about 33 weight percent 3-methylpentane These azeotropic compositions boil at a temperature of about -20 ’C to about 100 'C and at a boiling pressure of about 3 kPa to about 348 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 60.6 weight percent cis-1, 2-dichloroethylene and about 39.4 weight percent

[0117] 3-methylpentane at a pressure of about 57 3 kPa and at a boiling temperature of about 40 °G.

[0118] In some embodiments, the azeotropic dr azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent cis-1 ,2- dichloroethylene and from about 90 to about 33 weight percent 2,2-dimethylbutane, or from about 10 to about 64 weight percent cis-1 ,2-dichloroethylene and from about 90 to about 36 weight percent 2,2-dimethylbutane, or from about 15 to about 64 weight percent cis-1 ,2- dichloroethylene and from about 85 to about 36 weight percent 2,2-dimethylbutane These azeotropic or azeotropelike compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 5 kPa to about 414 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 21 to about 36 weight percent cis-1, 2-dichloroethylene and from about 79 to about 64 weight percent 2,2-dimethylbutane. These azeotropic compositions boil at a temperature of about - 20 °C to about 100 °C and at a boiling pressure of about 5 kPa to about 444 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of or consists of about 25.5 weight percent cis-1 ,2-dichloroethylene and about 74.5 weight percent

[0119] 2.2-dimethylbutane at a pressure of about 76.2 kPa and at a boiling temperature of about 40 °C.

[0120] In some embodiments, the azeotropic or azeotrope-like composition comprises consists essentially of, or consists of from about 10 to about 67 weight percent cis-1 ,2- dichloroethylene and from about 90 to about 33 weight percent 2,3-dimethylbutane, or from about 19 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 81 to about 33 weight percent 2i3-dirnethylbutane, or from about 29 to about 67 weight percent cis-1, 2- dichloroethylene and from about 71 to about 33 weight percent 2,3-dimethylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about -2Q C to about 100 °C and at a boiling pressure of about 3 kPa to about 367 kPa. In some embodiments, the azeotropic composition comprises, consists essentially of, or consists of from about 43 to about 55 weight percent cis-i,2-dichloroethylene and from about 57 to about 45 weight percent

[0121] 2.3-dimethylbutane These azeotropic compositions boil at a temperature of about -20 C to about TOO °C and at a boiling pressure of about4 kPa to about 367 kPa. In some embodiments, the azeotropic composition comprises consists essentially of or consists of about 47.0 weight percent cis-1 ,2-dichloroethylene and about 53.0 weight percent 2,3-dimethylbutane at a pressure of about 62.7 kPa and at a boiling temperature of about 40 °C.

[0122] The spin fluid may include additives, such as antioxidants or acid scavengers, in minor amounts. In some embodiments, the spin fluid comprises additives in an amount of about 1.5 weight percent or less of the total amount of the spin agent, and in other embodiments in an amount of about 0 1 weight percent or less of the total amount of the spin agent

[0123] The spin agent can be used for a broad range of different partially fluorinated polymers and blends / mixtures thereof. In some embodiments, the partially fluorinated polymer is selected from polyvinylidene fluoride (PVDF) poly(ethylene-co4etrafluoroethylene) (ETFE), and poly(ethylene-co-chlorotrifluoroethylene) (ECTFE).

[0124] In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a pblyvinylidene fluoride (PVDF), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 84 to about 98 weight percent, or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from dichloromethane , cis-1 ,2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent, or from about 12 to about 2 weight percent, or from about 8 to about3 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane. 1 -pentene, 2-methylbutane. n-hexane. 2- methylpentane. 3-methylpentane, 2,2-dimethylbutane. 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, 1 -hexene, n-heptane, and n-octane

[0125] In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-tetrafluoroethylene) (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane. trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 90 to about 45 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 'weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n- pentane, 1-pentene, 2-methylbutane, n-hexane. 2-methylpentane, 3-methylpentane, 2.2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1-butene, 1-hexene, n- heptane, and n-octane. In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 36 weight percent, or about 18 to about 28weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethyiene-co-tetrafluoroethylene) (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1 ,2- didfloroethylene, and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to abbut 45 weight percent, or from about 70 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyM- butene. 1 -hexene, n-heptane, and n-octane. In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co- tetrafiuoroethylene) (ETFE), each based on frie totel amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1.2-dichloroethylene. and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about

[0126] 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-l -butene, 1-hexene, n-heptane, and n-octane. In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-chlorotrifluoroethylene) (ECTFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 90 to about 45 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n- pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n- heptane, and n-octane. In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-chlorotrifluoroethylene) (ECTFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of , or consists Of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane. trans-1 ,2-dichloroethylene, cis-1.2- dichloroethylene, and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, or from about 70 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutarie, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2 3-dimethylbutane 2-methyl-2-butene, 2-methyl-1- butene, 1 -hexene, n-heptane, and n-octane. In some embodiments, the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co- chlorotrifluoroethylene) (ECTFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent Of at least one chlorinated solvent, selected from dichloromethane. trans-1 ,2-dichloroethylene, cis-1 ,2- dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched -hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2- methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 23- dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1 -hexene, mheptane, and n-octane.

[0127] In some embodiments, there is provided plexifilamentary fibrils of a partially fluorinated polymer obtainable by the process described herein. In some embodiments, there is provided plexifilamentary fibrils of polyvinylidene fluoride (PVDF) obtainable by the process described herein. In some embodiments, the plexifilamentary fibrils obtainable by the process described herein are characterized in that the only detectable PVDF crystal phase, i.e., the only PVDF crystal phase having significant intensities in the range of 29 = 10° to 29°, is the p crystal phase, whereas no significant portions of the o or y crystal phases are detectable. This is advantageous in electrical applications. In some embodiments, the crystallinity index (p phase) is about 32 % or more, or 34 % or more, or 35 % or more .

[0128] In some embodiments, there is provided plexifilamentary fibrils of poly(ethylene-co- tetrafluoroethylene) (ETFE) obtainable by the process described herein. In some embodiments, there is provided piexifilamentary fibrils of poly(ethylene-co- chlorotrifluoroethylene) (ECTFE) obtainable by the process described herein.

[0129] The shape of the assembly of piexifilamentary fibrils of partially fluorinated polymer discharged from each spin orifice may be modified by any methods known in the art. In some embodiments, the piexifilamentary fibrils of polyvinylidene fluoride discharged from each spin orifice may be modified by passing into a shroud such as descnbed on US 3,387,326, in other embodiments by passing into a slotted outlet such as described in US 3,467,744 or US 5,788,993, and in other embodiments passing into a slot fen jet as described in US 8, 114, 325. In some embodiments, streams of fibrils from multiple orifices may exit via a common slot as described in US 3,564,088.

[0130] Preparation of Sheets of Nonwoven Flash-spun Piexifilamentary Fibrils by Collection, Consolidation, Bonding, Softening, and Articles Made from Sheets of Nonwoven Flash-spun Piexifilamentary Fibrils

[0131] Sheets comprising piexifilamentary fibrils of partially fluorinated polymer can be formed by any method known in the art. In some embodiments, the stream of fibrils discharged from each spin orifice is directed towards a deflector device which alternately directs the stream of fibrils to the left and right onto a moving collecting device such that the fibrils accumulate in the form of a collected sheet of nonwoven flash-spun piexifilamentary fibrils, formed from fibrils oriented in an overlapping, multi-directional configuration. Deflection of the stream of fibrils may be achieved by any suitable means known in the art, including, but not limited to, tiose described in US 3,277,526 and US 3,387,326, US 3,169,899, US 3,497,918, US 3,456,156, US 3,593,074, US 3, 851, 023 and US 3,860,369, US 4, 148,595, US 5,045,258, US 5,643,524, US 5,731.011. US 5,750,152 and WO92 / 20511. The stream of fibrils may also be laid down to form a collected sheet of nonwoven flash-spun piexifilamentary fibrils without deflection as described in US 5,788,993 and US 8,114,325. The method of forming a collected sheet of nonwoven flash-spun piexifilamentary fibrils may further utilize structures in the spin cell such as those described in US 5, 123, 983, US 5, 296, 172, and WO92 / 20511.

[0132] In some embodiments, the streams of fibrils are discharged from spin orifices located on a rotating support, and the fibrils are collected on a collecting belt which surrounds the rotating arrangement circumferentially as described in US 7,118.698, US 7.621 ,731 , US 7,786,034, and US 7,998,388. "

[0133] In some embodiments, the collected sheet of nonwoven flash-spun piexifilamentary fibrils formed by flash-spinning as described herein may be consolidated by applying a small amount of pressure to the sheet to form a consolidated sheet of nonwoven flash-spun plexifilamentary fibrils. In some embodiments, tne sheet may be passed under a roller which applies pressure to the sheet to form a consolidated sheet.

[0134] In some embodiments, a consolidated sheet as described herein is subjected to thermal or mechanical bonding as known in the art to form a thermally or mechanically bonded sheet. Bonding may also be achieved by impregnation of a consolidated sheet with a chemical bonding agent, either throughout the entire sheet, or at isolated points distributed over the sheet, or pattern-wise.

[0135] In some embodiments, the bonded sheet is subjected to a mechanical softening process to obtain a softened sheet of nonwoven flash-spun plexifilamentary fibrils.

[0136] In some embodiments, an antistatic treatment is applied to the bonded or softened sheet. In some embodiments, the antistatic treatment is applied by applying a coating, composition comprising an antistatic compound.

[0137] Further embodiments relate to a multilayer structure comprising at least one sheet of nonwoven flash-spuh plexifilamentary fibrils as described herein, and at least one further sheet or a film. In some embodiments, the sheet of nonwoven flash-spun plexifilamentary fibrils as described herein is a collected sheet, a consolidated sheet, a bonded sheet or a softened sheet.

[0138] The sheet of nonwoven flash-spun plexifilamentary fibrils as described herein has many uses and may be used in a variety of articles and applications, including, but not limited to, multilayer structures packaging material, filtration media, print media, tags and labels accessories, and electronic devices such as .pressure sensors, strain gauges, microphones, actuators, energy harvesters, and nanogenerators.

[0139] EXAMPLES

[0140] A study has been performed for the phase behavior and flash spinning of polyvinylidene fluoride (PVDF) and of poly(ethylene-co-tetrafluoroethylene) (ETFE) for different compositions. The experimental procedure and results are provided below These examples are given to illustrate exemplary embodiments of the invention and should not be interpreted as limiting in any way.

[0141] Materials Used

[0142] Dichloromethane (DCM), GAS No. of 75-09-2 has an atmospheric boiling point Of 40oC and a molecular weight of 84.93 g / mol. The dichloromethane used had a purity level above 995 percent by weight.

[0143] Trans-1,2-dichlorbethylene (trans-1,2-DCE), CAS No. 156-60-5, has an atmospheric boiling point of 48 C and a molecular weight of 96.94 g / mol. The trans- 1 ,2-dichloroethylene used had a purity level above 98 percent by weight

[0144] Cis-1,2-dichloroethylene(cis-1,2-DCE), GAS No. 156-59-2, has an atmospheric boiling point of 60 °C and a molecular weight of 96.94 g / mol. The cis*1,2-dichloroethylene used had a purity level above 97 percent by weight

[0145] Trichloromethane (TOM). CAS No. 67-66-3, has an atmospheric boiling point of 61 C and a molecular weight of 119.38 g / mol. The trichloromethane used had a purity level above 99 percent by weight.

[0146] N-pentane, GAS No. 109-66-0, has an atmospheric boiling point of 36 °G and a molecular weight of 72.15 g / mol. The n-pentane used had a purity level above 99 percent by weight.

[0147] 2-Methylpentane (2-MP), CAS No. 107-83-5, has an atmospheric boiling point of

[0148] 60 C and a molecular weight of 86.18 g / mol. The 2-methyfpentane used had a purity level above 99 %.

[0149] 3-Methylpentane (3-MP), CAS No 96-14-0, has an atmospheric boiling point of 63 "C and a molecular weight of 86 18 g / mol. The 3-methylpentane used had a purity level above 99 %.

[0150] 2,2-Dimethylbutane, CAS No. 75-83-2, has ah atmospheric boiling point of 50 X and a molecular weight of 86.18 g / mol. The 2.2-dimethylbutane used had a purity level above 98 %. N-hexane, CAS No. 110-54-3, has an atmospheric boiling point of 69 °C and a molecular weight of 86.16 g / mol. The n-hexane used had a purity level above 95 percent by weight.

[0151] 1-pentene, CAS No 109-67-1 , has an atmospheric boiling point of 30,JC and a molecular weight of 70.13 g / mol. The 1-pentene used had a purity level above 98.5 percent by weight.

[0152] N-octane, CAS No. 111-65-9, has an atmospheric boiling point of 126 °C and a molecular weight of 114.24 g / mol. The n-octane used had a purity level above 98 percent by weight. The polyvinylidene fluoride (PVDF) used was Kynar® 720 grade or Kynar® 740 grade from Arkema. The Kynar® 720 has a melt flow rate of 5.0-26.5 g / 10 min (ASTM D1238, 2306C / 3.8 kg) and a melting point of 165-172 ’G. The Kynar® 740 has a melt flow rate of 1.5 - 3.0 g / 10 min (ASTM D1238, 230 °C / 5 kg) and a melting point of 165-172 °C.

[0153] The poly(ethylene-co-tetrafluoroethene), also known as ethylene-tetrafluoroethylene (ETFE), used has a density of 1 .7 g / cm3(ISO 1183). a nominal melting point of 255 to 280 C (ASTM D3418). and a melt flow rate of 6 g / 10 min (ASTM D3159)

[0154] All polymers were dried during a minimum of 8 hours in a vacuum oven at about 45- 50 °C before use, Spinning Equipment

[0155] The apparatus used consisted of two high pressure cylindrical chambers, each equipped with apiston which was adapted to apply pressure to the contents of the vessel. The cylinders had an inside diameter of 1.0 inch (25.4 mm) and each had an internal capacity of 50 cubic centimeters. The cylinders were connected to each other at one end through a 3 / 32 inch (2.3 mm) diameter channel and a mixing chamber containing a series of fine mesh screens was used as a static mixer. In the channel, a Type J thermocouple was in contact with the spin fluid to record the temperature Mixing was accomplished by forcing the contents of the vessel back and forth between the two cylinders through the static mixer. A spinneret assembly with a quick-acting means for opening the orifice was attached to the channel through a tee. The spinneret assembly consisted of a lead hole with a diameter of 0.25 inch (6.3 mm) and a length of about 2 0 inch (50.8 mm), and a spinneret orifice with a diameter of 0 020 inch (0.508 mm) and a length of 0.020 inch (0.508 mm) A pressure transmitter calibrated at the spin temperature was mounted in the lead hole to measure the pressure of the spin fluid. The pistons were driven by a high-pressure hydraulic system. In operation, the apparatus was charged with polymer pellets and spin agent and a pressure of at least 50 bar was applied to the pistons to compress the charge and avoid the spin fluid from boiling during subsequent heating The contents were then heated to mixing temperature and held at that temperature for about 30 to 45 minutes during which time a differential pressure was alternatively established between the two cylinders to repeatedly force the contents through the mixing channel from one cylinder to the other to provide mixing and effective formation of a spin fluid. The spin fluid temperature was then increased to the final spin temperature and held there for about 10 to 20 minutes to equilibrate. The pressure of the spin fluid was kept above the cloud point pressure during mixing and during the increase in temperature from the mixing temperature to the spin temperature Mixing was continued throughout this period At the end of the mixing cycle, the accumulator was set to the pressure desired for spinning. Next, the valve between the accumulator and the twin piston assembly was opened to reduce the pressure of the spin fluid to the desired spin pressure, and about two to five seconds later, the spinneret orifice was opened to release the spin fluid into conditions of atmospheric pressure. The delay of about two to five seconds corresponds to the residence time in the letdown chamber in a continuous spinning process. The resultant stream of flash-spun fibrils was collected in a stainless-steel open mesh screen basket During spinning, the spin pressure was recorded just upstream of the spinneret.

[0156] For cloud point pressure determination, the spinneret assembly was replaced with a view cell assembly containing a 1 / 2 inch ( 12.3 mm) diameter high-pressure sight glass, through which the contents of the ceil could be viewed as they flow through the channel The window was lit by means of a fiber optic light guide, while the view through the sight glass was displayed using a digital camera. In the ceil, a Type J thermocouple was located about 5 mm behind the high-pressure sight glass. The Type J thermocouple and a pressure measuring device located in close proximity to the window measured the pressure and temperature inside the view cell behind the sight glass and the pressure and temperature were continuously monitored by a computer When, after a period of mixing, a clear, homogeneous spin fluid was established, the temperature was held constant and the differential pressure applied to the pistons was equalized so that the pistons stopped moving. Then, the pressure applied to the spin fluid in the view cell was gradually decreased until phase separation was observed through the sight glass, as the initially clear, homogeneous spin fluid became cloudy in appearance The temperature and pressure were recorded when the thermocouple became no longer visible. This pressure was the phase separation pressure or cloud point pressure for that spin fluid at that temperature. The pressure was then increased until the spin fluid returned to its transparent state, i.e., until the insoluble phase redissolved, and in this way, two or three repeat cloud point measurements could be mace at an approximately constant temperature. Once this data was recorded, mixing was resumed while the spin fluid was heated to the next temperature at which the cloud point pressure was to be measured.

[0157] Results

[0158] Examples 1 to 17: Cloud point study of polyvinylidene fluoride

[0159] Figure 1 shows the cloud point pressure curves of three different spin fluids (Examples 1-3) comprising 26 wt% of two different PVDF grades and spin agents of dichloromethane and n-pentane in different ratios by weight.

[0160] Example 1 concerns the cloud point pressure curve of a spin fluid comprising 26 wt% PVDF (Kynar® 740) and a spin agent of dichloromethane and n-pentane in a 98:2 ratio by weight. Example 2 concerns the cloud point pressure curve of a spin fluid comprising 26 wt% PVDF (Kynar® 720) and a spin agent of dichloromethane and n-pentane in a 95:5 ratio by weight.;

[0161] Example 3 concerns the cloud point pressure curve of a spin fluid comprising 26 wt% PVDF (Kynar® 740) and a spin agent of dichloromethane and n-pentane in a 92:8 ratio by weight

[0162] The Table 1 below shows for Examples 1 to 17 the cloud point pressure of different spin -fluids comprising PVDF in different concentrations and different spin agents at a temperature of 225 °C. The cloud point pressures for Examples 1 to 17 are additionally shown graphically in Figure 2.

[0163] Table 1: Summary of the cloud point pressure experiments of Examples 1 to 17. ;

[0164] (*) Calculated using in Example 17 the sum of 2,2-dimethylbutane and 1 -pentene of 8 wt% of hydrocarbon.

[0165] These spin fluids comprising from 22 wt% to 34 wt% PVDF show a cloud point pressure suitable for flash spinning.

[0166] The cloud point pressure increases with increasing amount of the hydrocarbon. For the spin fluid comprising 26 wt% PVDF (Kynar® 74C) and a spin agent of dichloromethane and n- pentane, the cloud point pressure at a temperature of 225:?C increases by about 7 to 8 bar for a 1 wt% percent increase in the concentration of n-pentane. A similar increase in the cloud point pressure with increasing amount of the hydrocarbon is seen for spin fluids comprising PVDF and a spin agent of dichloromethane or cis-1 ,2-dichloroethylene (cis-1 ,2-DCE) and a linear or branched hydrocarbon with 5 or more carbon atoms, as exemplified in Table 1 and Figure 2 for 2-mefliylbutane, 3-methylbutane, 1-pentene, 2,2-dimethylbutane n-octane and 2,2-dimethylbutane. Examples 18 to 31: Cloud point study of poly(ethylene-co-tetrafluoroethylene)

[0167] Figure 3 shows the cloud point pressure curves of three different spin fluids (Examples 18-20) comprising 26 wt% or 28 wt% poly(ethylene-co-tetrafluoroethylene) (ETFE) and spin agents of dichloromethane and n-pentane in different ratios by weight.

[0168] Example 18 concerns the cloud point pressure curve of a spin fluid comprising 28 wt% ETFE and a spin agent of dichloromethane and mpentane in <49.1:50(9 ratio by weight.

[0169] Example 19 concerns the cloud point pressure curve of a spin fluid comprising 26 wt% ETFE and a spin agent of dichloromethane and n-pentane in a 40 60 ratio by weight

[0170] Example 20 concerns the cloud point pressure curve of a spin fluid comprising 26 wt% ETFE and a spin agent of dichloromethane and n-pentane in a 35:65 ratio by weight. Figure 4 shows the cloud point pressure curve of a spin fluid (Example 25) comprising

[0171] 34 wt% poly(ethylene-co-tetrafluoroethylene) (ETFE) and a spin agent of trans-1.2- dichloroethylene (trans- 1 ,2-DCE) and 2,2-dimethylbutane in a 35:65 ratio by weight.

[0172] The Table 2 below shows for Examples 18 to 31 the cloud point pressure of different spin fluids comprising ETFE in different concentrations and different spin agents at a temperature of 2250C. The cloud point pressures for Examples 18to 31 are additionally shown graphically in Figure 5.

[0173] Table 2: Summary of the cloud point pressure experiments of Examples 18 to 3T;

[0174] These spin fluids comprising from 15 wt% to 34 wt% ETFE show a cloud point pressure suitable for flash spinning. The cloud point pressure increases with increasing amount of the hydrocarbon. For the spin fluid comprising 26 wt% or 28 wt% ETFE and a spin agent of dichloromethane and n- pentane, the cloud point pressure at a temperature of 225°C increases by about 3 bar for a 1 wt% percent increase in the concentration of n-pentane. A similar increase in the cloud pointpressure with increasing amount of the hydrocarbon is seen for spin fluids comprising ETFE and a spin agent of dichloromethane or cis-l^-dichloroethylene (cis-T2-DCE) and a linear or branched hydrocarbon with 5 or more carbon atoms, as exemplified in Table 2 and Figure 5 for 2-methylbutane or 2-methylbutane The cloud point pressures of spin fluids comprising ETFE are less sensitive to increases in the amount of the hydrocarbon compared to those comprising PVDF.

[0175] Examples 32 to 41 : Flash spinning performance of polyvinylidene fluoride

[0176] Flash spinning of PVDF was performed on the equipment described in the above for different spin fluids. The Tables 3 and 4 below show the conditions for flash spinning PVDF from spin fluids comprising PVDF in different concentrations and different spin agents at different temperatures. Table 3: Summary of the flash spinning experiments of Examples 32 to 36.

[0177] ‘ assuming a GWP of 11.2 for dichterornethane and a GWPof about zero for n-pentane, 1-pentene, 2-methylpentane “ based on the intensity level In the range 26 - 26.7° -26.8‘ Table 4: Summary of the flash spinning experiments of Examples 37 to 41. * assuming a GWP of 11.2 for the dichloromethane and a GW of about zero for the cis-1, 2- dfchloroethylene, the 2-methylpentane, the 3-methylpentane, the n-octane, and the 2.2-dimetylbutane

[0178] ** blend of Kynar® 720 and ETFE in a 75:25 weight rat o

[0179] *** based on the intensity level in the range 26 = 26.7' - 26.8'

[0180] The spin agents used in examples 32-41 exhibit a desirably low GWP value of less than 1 1 or less. This makes these compositions suitable as replacements for spin agents disclosed in the prior art.

[0181] In addition, the above examples illustrate that the compositions can be used as a spin agent for the flash spinning process of PVDF at different polymer concentrations, spin temperatures, and spin pressures. This allows an efficient preparation of plexifilamentary fibrils of PVDF In addition, the obtained fibrils contain high amounts of crystals in the B phase. This is advantageous in electrical applications. Examples 42 to 51: Flash spinning performance of poly(ethylene-co- tetrafluoroethylene)

[0182] Flash spinning of ETFE was performed on the equipment described in the above for different spin fluids. The Tables 5 and 6 below shows the conditions for flash spinning poly(ethylene-co-tetrafluoroethylene) (ETFE) from spin fluids comprising ETFE in different concentrations and different spin agents at different temperatures.

[0183] Table 5: Summary of the flash spinning experiments of Examples 42 to 46. * assuming a GWP of 11.2 for the dichloromethane, a GWP of 20.6 for the trichloromethane and a

[0184] GWP of about zero for the n-pentane, the 1-pentene, and fc 2-rnethylpentane

[0185] Table 6: Summary of the flash spinning experiments of Examples 47 to 51.

[0186] * assuming a GWP of 11 2 for the dichloromethane and a GWP of about zero for the trans-1.2- dichloroethylene (trans-1,2-DGE), the cis-l,2-dichloroethylene (cfs-1,2-QCE), tie 2-methylpentane>the 3- methyipentane, and the 2,2-dimetylbutane

[0187] The spin agents used in examples 42-51 exhibit a desirably low GWP value of 8 or less. This makes these compositions suitable as replacements for spin agents disclosed in the prior art.

[0188] In addition, the above examples illustrate that the compositions can be used as a spin agent for the flash spinning process of ETFE at different polymer concentrations, spin temperatures, and spin pressures This allows an efficient preparation of plexifilamentary fibrils of ETFE.

[0189] OTHER EMBODIMENTS

[0190] 1. In some embodiments, the present application provides a spin fluid for flash spinning comprising (a) from about 12 to about 36 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises a composition comprising at least one chlorinated solvent, selected from

[0191] -W dichloromethane, trans-1,2-dichloroetoylene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with S or more carbon atoms.

[0192] 2. The spin fluid of embodiment 1 comprising from about 14 to about 30 weight percent. or tort about 18 to about 28 weight percent, or from about 12 to about 19 weight percent of a partially fluorinated polymer, each based on the total amount of the spin fluid.

[0193] 3. The spin fluid of embodiment 1 or 2 comprising from about 22 to about 34 weight percent, or from about 26 to about 34 weight percent of a partially fluorinated polymer, each based on the total amount of the spin fluid.

[0194] 4. The spin fluid of any of embodiments 1 to 3 comprising from about 64 to about 88 weight percent of the spin agent, or from about 70 to about 86 weight percent of the spin agent, or from about 72 to about 82 weight percent of toe spin agent, or from about 81 to about 88 weight percent of the spin agent, or from about 64 to about 78 weight percent of the spin agent or from about 64 to about 74 weight percent ofthe spin agent* each based on the total amount of the spin fluid.

[0195] 5. The spin fluid of any of embodiments 1 to 4, wherein the spin agent comprises, consists essentially of. or consists of at least one chlorinated solvent, selected from dichloromethane, cis-1 ,2-dichloroethylene. and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0196] 6. The spin fluid of any of embodiments 1 to 5, wherein the at least one linear or branched hydrocarbon wito S or more carbon atoms has a normal boiling point of about 27 °C to about

[0197] 126 °C. 7. The spin fluid of any of embodiments 1 to 6, wherein the at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimetoylbutane, 2,3-dimethylbutane, 2-metoyl-2-butene, 2-methyl-1 -butene, 1-hexene, n- heptane, and n-octane.

[0198] SO 8. The spin fluid of any of embodiments 1 to7, wherein the spin agent comprises, consists essentially of, or consists of dichloromethane and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane. n-hexane. 2-methylpentane. 3-methylpentane. 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane.

[0199] 9 The spin fluid of any of embpdimente 1 to 4, 6 or 7, wherein the spin agent comprises, consists essentially of or consists of trans- 1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane. 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n- heptane, and n-octane.

[0200] 10. The Spin fluid of any of embodiments 1 to 7, wherein the spin agent comprises, consists essentially of, or consists of cis-1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane,

[0201] 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n- heptane, and n-octane.

[0202] 11. The spin fluid of any of embodiments 1 to 7, wherein the spin agent comprises, consists essentially of, or consists of trans-1;2-dichloroethylene and cis-1,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1-pentene, 2-metoylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, 1 -hexene, n-heptane, and n-octane.

[0203] 12. The spin fluid of any of embodiments Ito 7, wherein the spin agent comprises, consists essentially of, or consists of trichloromethane and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1-pentene,

[0204] 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene, 2-methy!-1 -butene, 1-hexene, n-heptane. and n-octane 13. The spin fluid of any of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of , or consists of from about 84 to about 98 weight percent, or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from dichloromethane, cis-1 , 2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent, or from about 12 to about 2 weight percent, or from about 8 to about 3 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0205] 14 The spin fluid of any of embodiments 1 to 12. wherein the spin agent comprises, consists essentially of. or consists of or consists of from about 10 to about 67 weight percent. or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene. cis-1 , 2-dichloroethylene, and trichloromethane. and from about 90 to about 33 weight percent or from about 90 to about 38 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms. 15. The spin fluid of any of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of, or consists of. from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1,2-dichloroethylene, cis-1, 2- dichloroethylene, and trichloromethane, and from about 86 to about 45 weight percent, orfrom about 80 to about;45 weight percent, or from about 80 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms. : ;

[0206] 16. The spin fluid of any of embodiments 1 to 12. wherein the spin agent comprises, consists essentially of, or consists of, from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from didiloromethane, trans-1, 2-dichloroethylene, cis-1 , 2-dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms 17. The spin fluid of any of embodiments 13 to 16, wherein the at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane n-hexane, 2-methylpentane. 3-methylpentane, 2,2- dimethylbutane. 2.3-dimethylbutane. 2-methyl-2-butene, 2-methyl-1 -butene, 1 -hexene, n- heptane, and h-octane.

[0207] 18. The spin fluid of any of embodiments 1 to 17, wherein the spin agent comprises, consists essentially of, or consists of an azeotropic or azeotrope-like composition comprising a chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 , 2- dichloroethylene. and trichioromethane and a linear or branched hydrocarbon with 5 or more carbon atoms selected from tie group consisting of n-pentane, 2’methylbutane, 2- methylpentane, 3-methylpentane, 2, 2-dimethylbutane, and 2,3-dimethylbutane.

[0208] 19. The spin fluid of embodiment 18, wherein the azeotropicor azeotrope-like composition comprises, consists essentially of or consists of:

[0209] (1 ) dichloromethane and 2-methylpentane, or

[0210] (2) dichloromethane and 3-methylpentane, or

[0211] (3) trichioromethane and 2-methylpentane, or

[0212] (4) trichioromethane and 3-methylpentane, or (5) dichloromethane and n-pentane, or

[0213] (6) dichloromethane and 2-methylbutane, or

[0214] (7)trans-1,2-dichloroethylene and 2, 2-dimethylbutane, or

[0215] (8) cis-1, 2-dichloroethylene and 2-methylpentane, or

[0216] (9) cis-1 ,2-dichloroethylene and 3-methylpentane, or (10) cis-1 ,2-dichloroethylene and 2, 2-dimethylbutane, or

[0217] (11) cis-1.2-dichloroethylene and 2,3-dimethylbutane.

[0218] 20. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of , or consists of from about 84 to about 98 weight percent dichloromethane and from about 16 to about 2 weight percent 2-methylpentane, or from about 88 to about 98 weight percent dichloromethane and from about 12 to about 2 weight percent 2-methylpentane, or from about 92 to about 97 weight percent dichloromethane and from about 8 to about 3 weight percent 2-methylpentane.

[0219] S3 21. The spin fluid of embodiment 20, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 6 kPa to about 591 kPa. 22. The spin fluid of any of embodiments 20 or 21, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 84 to about 95 weight percent dichloromethane and from about 16 to about 5 weight percent 2*methylpentane.

[0220] 23 The spin fluid of embodiment 22, wherein the azeotropic composition boils at a temperature of about 20 ' C to about 100 ‘ C and at a boiling pressure of about 49 kPa to about 591 kPa.

[0221] 24. The spin fluid of any of embodiments 20 to 23, wherein the azeotropic composition comprises, consists essentially of, or consists of about 87.0 weight percent dichloromethane and about 13.0 weight percent 2-methylpentane.

[0222] 25.:The spin fluid of embodiment 24, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 104.8 kPa. 26. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of. or consists of from about 84 to about 98 weight percent dichloromethane and from about 16 to about 2 weight percent 3-methyipentane, or from about 88 to about 98 weight percent dichloromethane and from about 12 to about 2 weight percent 3-methylpentane, or from about 92 to about 97 weight percent dichloromethane and from about 8 to about 3 weight percent 3-methylpentane

[0223] 27. The spin fluid of embodiment 26, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 C and at a boiling pressure of about 6 kPa to about 590 kPa.

[0224] 28. The spin fluid of any of embodiments 23 or 27. wherein the azeotropic composition comprises, consists essentially of, or consists of from about 85 to about 95 weight percent dichloromethane and from about 15 to about 5 weight percent 3-methylpentane. 29 The spin fluid of embodiment 28, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 6 kPa to about 591 kPa. 30. The spin fluid of any of embodiments 26 to 29, wherein the azeotropic composition comprises, consists essentially of, or consists of about 90.0 weight percent dichloromethane and about 10.0 weight percent 3-methylpentane.

[0225] 31 The spin fluid of embodiment 30, wherein the azeotropic composition boils at a temperature of about 40 C and at a boiling pressure of about 103 7 kPa.

[0226] 32. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists offrom about 10 to about 67 weight percent trichloromethane and from about 90 to about 33 weight percent 2-methylpentane, or from about 36 to about 67 weight percent tnchloromethane and from about 64 to about 33 weight percent 2-methylpentane.

[0227] 33. The spin fluid of embodiment 32, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °G to about 100 °G and at a boiling pressure of about 3 kPa to about 340 kPa.

[0228] 34. The spin fluid Of any of embodiments 32 or 33, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 54 to about 63 weight percent trichloromethane and from about 46 to about 37 weight percent 2-methylpentane.

[0229] 35. The spin fluid of embodiment 34, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 3 kPa to about 340 kPa. 36. The spin fluid of any of embodiments 32 to 35, wherein the azeotropic composition comprises, consists essentially of, or consists of about 56.0 weight percent trichloromethane and about 44.0 weight percent 2-methylpentane. 37. The spin fluid of embodiment 36, wherein -the azeotropic composition boils at a temperature < about 40 °G and at a boiling pressure of about 56.6 kPa.

[0230] 38. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent trichloromethane and from about 90 to about 33 weight percent 3-methylpentane, or from about 46 to about 67 weight percent trichloromethane and from about 54 to about 33 weight percent 3-methylpentane. 39. The spin fluid of embodiment 38, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 °G and at a boiling pressure of about 2 kPa to about 326 kPa.

[0231] 40. The spin fluid of any of embodiments 38 or 39, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 58 to about 67 weight percent trichloromethane and from about 42 to about 33 weight percent 3-methylpentane.

[0232] 41. The spin fluid of embodiment 40, wherein the azeotropic composition boils at a temperature of about -20 “G to about 60 °G and at a boiling pressure of about 3 kPa to about 107 kPa.

[0233] 42. The spin fluid of any of embodiments 38 to 41, wherein the azeotropic- composition comprises, consists essentially of, or consists of about 66.0 weight percent trichloromethane and about 34.0 weight percent 3-methylpentane.

[0234] 43. The spin fluid of embodiment 42, wherein the azeotropic composition boils at a temperature of about 40 °G and at a boiling pressure of about 53.6 kPa.

[0235] 44. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent dichloromethane and from about 33 to about 90 weight percent n-pentane, or from about 31 to about 67 weight percent dichloromethane and from about 69 to about 33 weight percent n-pentane. 45. The spin fluid of embodiment 44, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 10 kPa to about 703 kPa. 46. The spin fluid of embodiment 44 or 45, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 31 to about 63 weight percent dichloromethane and from about 69 to about 37 weight percent n-pentane.

[0236] 47 The spin fluid of embodiment 46, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 C and at a boiling pressure of about 132 kPa to about 139 kPa.:

[0237] 48 The spin fluid of embodiment 44 or 45, wherein tie azeotropic composition comprises, consists essentially of, or consists of from about 43 to about 58 weight percent dichloromethane and from about 57 to about 42 weight percent h-pentane 70 weight percent dichloromethane and from about 69 to about 30 weight percent n-pentane

[0238] 49. The spin fluid of embodiment 48, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 11 kPa to about 703 kPa.

[0239] 50. The spin fluid of embodiment 48 or 49, wherein the azeotropic compositions comprise, consists essentially of or Consists of about 50.9 weight percent dichloromethane and about 49.1 weight percent n-pentane.

[0240] 51. The spin fluid of embodiment 50. wherein the azeotropic composition boils at a temperature of about 25 °C and at a boiling pressure of pressure of about 82 kPa

[0241] 52. The spin fluid of embodiment 48 or 49, wherein the azeotropic compositions comprise, consists essentially of or consists of about 51.0 weight percent dichloromethane and about

[0242] 49.0 weight percent n-pentane.

[0243] 53. The spin fluid of embodiment 52, wherein the azeotropic composition boils at a:temperature of about 40 °C and at a baling pressure of pressure of about 138.9 kPa.

[0244] ST 54. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent dichloromethane and from about 33 to about 90 weight percent 2-methylbutane, or from about 24 to about 67 weight percent dichloromethane and from about 76 to about 33 weight percent 2-methylbutane.

[0245] 55. The spin fluid of embodiment 54. wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 C to about 100 C and at a boiling pressure of about 13 kPa to about 775 kPa.

[0246] 56. The spin fluid of any of embodiments 54 or 55, wherein the azeotropic or azeotropelike compositions comprises, consists essentially of, or consists of from about 15 to about 56 weight percent dichioromethane and from about 85 to about 44 weight percent 2-methylbutane or from about 25 to about 51 weight percent dichioromethane and from about 75 to about 49 weight percent 2-methylbutane.

[0247] 57. The spin fluid of embodiment 56, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 °C and at a boiling pressure of about 157 kPa to about 163 kPa.

[0248] 58. The spin fluid of any of embodiments 54 to 57, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 26 to about 42 weight percent dichioromethane and from about 74 to about 58 weight percent 2-methylbutane.

[0249] 59. The spin fluid of embodiment 58, wherein the azeotropic composition boils at a temperature Of about -20 °C to about 100 “G and at a boiling pressure of about 14 kPa to about 775 kPa.

[0250] 60. The spin fluid of any of embodiments 58 to 59, wherein the azeotropic composition comprises consists essentially of, or consists of about 35.0 weight percent dichioromethane and about 65.0 weight percent 2-methylbutane 61 , The spin fluid of embodiment 60, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 1626 kPa.

[0251] 62. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists offrom about 10 to about 67 weight percent trans-1,2-dichto 90 to about 33 weight percent 2,2- dimethylbutane, or from about 34 to about 67 weight percent trans-1 ,2-dichloroethylene and from about 66 to about 33 weight percent 2.2-dimethylbutane, or from about 44 to about 67 weight percent trans- 1 ,2-dichloroethylene and from about 56 to about 33 weight percent 2,2- dimethylbutane.

[0252] 63. The spin fluid of embodiment 62, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 5 kPa to about 460 kPa. ,

[0253] 64. The spin fluid of any of embodiments 62 or 63 wherein the azeotropic composition comprises, consists essentially of, or consists of from about 52 to about 67 weight percent trans- 1,2-dichloroethylene and from about 48 to about 40 weight percent 2,2-dimethylbutane. 65. The spin fluid of embodiment 64, wherein the azeotropic composition boils at a temperature of about -20 C to about 60 C and at a boiling pressure of about 5 kPa to about 161 kPa.

[0254] 66. The spin fluid of any of embodiments 62 to 65, wherein the azeotropic composition comprises, consists essentially of, or consists of about 63 0 weight percent trans-1,2- dichloroethylene and about 37.0 weight percent 2,2-dimethylbutane

[0255] 67. The spin fluid of embodiment 66, wherein the azeotropic composition boils. at a temperature of about 40 °C and at a boiling pressure of about 84.6 kPa.

[0256] 68. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises consists essentially of, or consists of from about 10 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 90 to about 33 weight percent 2- methylpentane, or from about 26 to about 67 weight percent cis- 1 ,2-dichloroethylene and from about 74 to about 33 weight percent 2-methylpentane, or from about 36 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 64 to about 33 weight percent 2- methylpentane. 69, The spin fluid of embodiment 68, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 3 kPa to about 361 kPa.

[0257] 70. The spin fluid of any of embodiments 63 or 69. wherein the azeotropic composition comprises, consists essentially of, dr consists of from about 52 to about 60 weight percent cis-

[0258] 1 ,2-dichloroethylene and from about 48 to about 40 weight percent 2-methylpentane.

[0259] 71. The spin fluid of embodiment 70, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 3 kPa to about361 kPa.

[0260] 72* The spin fluid of any of embodiments 68 to 71, wherein the azeotropic composition comprises, consists essentially of, or consists of about 54.5 weight percent cis-1 ,2- dichloroethylene and about 45.5 weight percent 2-methylpentane

[0261] 73 The spin fluid of embodiment 72, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 60.4 kPa.

[0262] 74. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-lite composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 90 to about 33 weight percent 3- methylpentane, or from about 33 to about 67 weight percent cis-1, 2-dichloroethylene and from about 67 to about 33 weight percent 3-methylpentane, or from about 43 to about 67 weight percent cts-1, 2-dichloroetiylene and from about 57 to about 33 weight percent 3- methylpentane.

[0263] 75. The spin fluid of embodiment 74, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 C to about 100 C and at a boiling pressure of about 3 kPa to about 348 kPa. 76 The spin fluid of any of embodiments 74 or 75, wherein the azeotropic composition comprises, consists essentially of. or consists of from about 59 to about 67 weight percent cis- 1 .2-dichloroethylene and from about 41 to about 33 weight percent 3-methylpentane

[0264] 77. The spin fluid of embodiment 76, wherein the azeotropic composition boils at a temperature of about -20 ‘ C to about 100 ‘ C and at a boiling pressure of about 3 kPa to about 348 kPa. 78. The spin fluid of any of embodiments 74 to 77, wherein the azeotropic composition comprises, consists essentially of, or consists of about 60.6 weight percent cis-1, 2- didiloroethylene and about 39.4 weight percent 3-methylpentane

[0265] 79. The spin fluid of embodiment 78, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 57.3 kPa.

[0266] 80. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent cis-1 , 2-dichloroethylene and from about 90 to about 33 weight percent 2,2- dimethylbutane, or from about 10 to about 64 Wight percent cis-1 , 2-dichloroethylene and from about 90 to about 36 weight percent 2.2-dimethylbutane. or from about 15 to about 64 weight percent cis-1, 2-dichloroethylene:and from about 85 to about 36 weight percent 2,2- dimethylbutane. 81. The spin fluid of embodiment 80, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 ' C to about 100 C and at a boiling pressure of about 5 kPa to about 414 kPa.

[0267] 82. The spin fluid of any of embodiments 80 or 81, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 21 to about 36 weight percent cis-

[0268] 1, 2-dichloroethylene and from about 79 to about 64 weight percent 2, 2-dimethylbutane. 83. The spin fluid of embodiment 82, wherein the azeotropic composition boils at a temperature of about -20 “C to about 100 °C and at a boiling pressure of about 5 kPa to about 414 kPa. 84. The spin fluid of any of embodiments 80 to 83, wherein the azeotropic composition comprises, consists essentially erf, or consists of about 255 weight percent cis-1 ,2- dichloroethylene and about 74.5 weight percent 2,2-dimethylbutane.

[0269] 85 The spin fluid of embodiment 84, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 76.2 kPa.

[0270] 86. The spin fluid of embodiment 18 or 19, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 wight percent cis-1 ,2-dichloroethylene and from about 90 to about 33 weight percent 2,3- dimethylbutane, or from about 19 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 81 to about 33 weight percent 2,3-dimethylbutane, or from about 29 to about 67 weight percent cis-l^-dichloroethylene and from about 71 to about 33 weight percent 2,3- dimethylbutane. 87. The spin fluid of embodiment 86, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 C to about 100 C and at a boiling pressure of about 3 kPa to about 367 kPa. J

[0271] 88. The spin fluid of any of embodiments 86 or 87, wherein the azeotropic composition comprises, consists essentially of, or consists offrom about 43 to about 55 weight percent cis-

[0272] 1 ,2-dichloroethylene and from about 57 to about 45 weight percent 2,3-dimethylbutane.

[0273] 89. The spin fluid of embodiment 88. wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 4 kPa to about 367 kPa.

[0274] 90. The Spin fluid of any of embodiments 86 to 89, wherein the azeotropic composition comprises, consists essentially of, or consists of about 47.0 weight percent cis-1 ,2- dichloroethyfene and about 53.0 weight percent 2.3-dimethyibutane 91. The spin fluid of embodiment 90, wherein the azeotropic composition boils at a temperature of about 40 C and at a boiling pressure of about 62.7 kPa 92. The spin fluid of any of embodiments 1 to 91, wherein the partially fluorinated polymer is selected from polyvinylidene fluoride (PVDF) and:polyfethylene-co^etrafluoroethylene) (ETFE), and poly(ethylene-co»chlorotrifluoroethylene) (ECTFE).

[0275] 93. The spin fluid of any of embodiments 1 to 92. wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about

[0276] 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a polyvinylidene fluoride (PVDF), each based on the total amount of the spin fluid , and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 84 to about 98 weight percent, or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from dichloromethane, cis-1,2-dichioroethyiene, and trichloromethane, and from about 16 to about 2 weight percent, or from about 12 to about 2 weight percent, or from about 8 to about 3 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, > pentene, 2-methylbutane, n-hexane, 2-methylpentane, S-methylpentane, 2,2-dimethylbutane, 2 3-dimethylbutane. 2-methyl-2-butene, 2-methyl-1 -butene. 1-hexene, n-heptane. and n- octane.

[0277] 94. The spin fluid of any of embodiments I to 92, wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about

[0278] 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-tetrafluoroethylene) (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, : consists essentially of, or consists of from about 10 to about 67:weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene. cis-1.2-dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 90 to about 45 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, 1 -hexene, n-heptane, and n-octane,

[0279] 95. The spin fluid of any of embodiments 1 to 92. wherein the spin fluid comprises about 12 to about 36 weight percent or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-tefrafluoroethylene)(ETFE), each based on the total amount of tie spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 2- dichloroethylene. cis-1 ,2-dichloroethylene, and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, or from about 70 to about 45 weight percent of at least one linear or:branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane. 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-l -butene, 1-hexene, n-heptane, and n-octane.

[0280] 96. The spin fluid of any of embodiments 1 to 92, wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-tetrafluoroethylene) (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentare 1-pentene. 2-methylbutane, n-hexane. 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane

[0281] 97. In some embodiments the present application provides for the preparation of plexifilamentary fibrils of partially fluorinated polymer which comprises the steps of:

[0282] (i) generating a spin fluid comprising

[0283] (a) from about 12 to about 36 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and:

[0284] (b) a spin agent, and

[0285] (ii) flash spinning the spin fluid at a pressure that is above the vapor pressure of the spin fluid into a region of essentially atmospheric pressure to form plexifilamentary fibrils of the partially fluorinated polymer, wherein the spin agent comprises a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene. cis-1 ,2-dich!oroethylene. and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0286] 98. The process of embodiment 2, wherein the spin fluid comprises from about 14 to about 30 weight percent, or from about 18 to about 28 weight percent, or from about 12 to about 19 weight percent of a partially fluorinated polymer, each based on the total amount of the spin fluid.

[0287] 99. The process of embodiment 97 or 98 wherein the spin fluid comprises from about 22 to about 34 weight percent, or from about 26 to about: 34 weight percent of a partially fluorinated polymer, each based on the total amount of the spin fluid. :

[0288] 100 The process of any of embodiments 97 to 99 wherein the spin fluid comprises from about 64 to about 88 weight percent of the spin agent, or from about 70 to about 86 weight percent of the spin agent, cw from about 72 to about 82 weight percent of the spin agent, or from about 81 to about 88 weight percent of the spin agent, or from about 64 to about 78 weight percent of the spin agent, or from about 64 to about 74 weight percent of the spin agent, each based on the total amount ofthe spin fluid. 101. The process of any of embodiments 97 to 100, wherein the spin agent comprises, consists essentially of, or consists of at least one chlorinated solvent,;selected from dichloromethane. cis-1 ,2-dichloroethylene. and trichloromethane, and at least one linear or branched hydrocarbon with S or more carbon atoms.

[0289] 102. The process of any of embodiments 97 to 101, wherein the at least one linear or branched hydrocarbon with 5 or more carbon atoms has a normal boiling point of about 27 °C to about 126 *(x<:103. The process of any of embodiments 97 to 102, wherein the at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1 -hexene, n- heptane, and n-octane.

[0290] 104. The process of any of embodiments 97 to 103, wherein the spin agent comprises, consists essentially of, or consists of dichloromethane and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane. 2,3-dimethylbutane. 2-methyl-2-butene, 2-methyl-1 -butene, 1 -hexene, n- heptahe, and n-octane.

[0291] 105. The process of any of embodiments 97 to 100, 102 or 103, wherein the spin agent comprises, consists essentially of, or consists of trans-1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane. 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2.2-dimethylbutane. 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, 1-hexene, n-heptane, and n-octane. 106. The process of any of embodiments 97 to 103, wherein the spin agent comprises,consists essentially of, or consists of cis-1,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane. 1-pentene. 2-methylbutane. n-hexane, 2-methylpentane. 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n- heptane, and n-octane.

[0292] 107. The process of any of embodiments 97 to 103, wherein the spin agent comprises, consists essentially of, or consists of trans-1 ,2-dichloroethylene and cis-1 ,2-dichloroethylene and at least one linear<orbranched :hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methyl pentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, 1 -hexene, n-heptane. and n-octane.

[0293] 108. The process of any of embodiments 97 to 103, wherein the spin agent comprises, consists essentially of, or consists of trichloromethane and at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, ; 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2.3-dimethylbutane, 2-methyl-2-butene. 2-methyi-l -butene, 1-hexene, n- heptane, and n-octane.

[0294] 109. The process of any of embodiments 97 to 108, wherein the spin agent comprises, consists essentially of, or consists of from about 84 to about 98 weight percent, or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from dichloromethane, cis-i,2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent, or from about 12 to about 2 weight percent, or from about 8 to about 3 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0295] 110. The process of any of embodiments 97 to 108, wherein the spin agent comprises, consists essentially of, or consists of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroetiylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms.

[0296] 111. The process of any of embodiments 97 to 108, wherein the spin agent comprises consists essentially of, or consists of, from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from didiloromethane, trans-1,2-dichloroetoylene, cis-1,2- dichloroethylene. and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, or from about 80 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms

[0297] 112. The process of any of embodiments 97 to 108, wherein the spin agent comprises, consists essentially of, or consists of, from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from:dichloromethane, trans-1,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms..

[0298] 113. The process of any of embodiments 109 to 112, wherein the at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1-pentene:2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane. 2,2- dimethylbutane, 2,3-dimethylbutane. 2-methyl-2-butene, 2-methyl-1 -butene. 1-hexene, n- heptane, and n-octane. 114. The process of any of embodiments 97 to 113, wherein the spin agent comprises, consists essentially of, or consists of an azeotropic or azeotrope-like composition comprising a chlorinated solvent, selected from dichloromethane, trans-1,2-dichlordethylene, cis-1,2- dichloroethylene, and trichloromethane and a linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 2-methylbutane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, and 2,3-dimethylbutane,

[0299] 1 15. The process of embodiment 114, wherein the azeotropic or azeotrope- like composition comprises, consists essentially of or consists of:

[0300] (1) dichloromethane and 2-methylpentane, or (2) dichloromethane and 3-methylpentane, or

[0301] (3) trichloromethane and 2-methylpentane. or

[0302] (4) trichloromethane and 3-methylpentane, or

[0303] (5) dichloromethane and n-pentane. or (6) dichloromethane and 2-methylbutane, or

[0304] (7) trans-1 ,2-dichloroethylene and 2,2-dimethylbutane, or

[0305] (8) cis-1 ,2-dichloroethylene and 2-methylpentane, or

[0306] (9) cis-1 ,2-dichloroethylene and 3-methylpentane. or

[0307] (10) cis-1 ,2-dichloroethylene and 2,2-dimethylbutane. or (11) cis-1 ,2-dichloroetoyfene and 2,3-dimetoylbutane.

[0308] 116. The process of embodiment 114 or 115, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 84 to about 98 weight percent dichloromethane and from about 16 to about 2 weight percent 2-methylpentane, or from about 88 to about 98 weight percent dichloromethane and from; about 12 to about2 weight percent 2-methylpentane or from about 92 to about 97 weight percent dichloromethane and from about 8 to about 3 weight percent 2-methylpentane.

[0309] 117. The process of embodiment 116^ wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 6 kPa to about 591 kPa.

[0310] 118. The process of any of embodiments 116 Or 117, wherein toe azeotropic composition comprises, consists essentially of, or consists of from about 84 to about 95 weight percent dichloromethane and from about 16 to about 5 weight percent 2-methylpentane.

[0311] 119. The process of embodiment 118, wherein the azeotropic composition boils at a temperature of about 20 C to about 100 ' C and at a boiling pressure of about 49 kPa to about 591 kPa.

[0312] 120. The process of any of embodiments 116 to 119, wherein the azeotropic composition comprises, consists essentially of, or consists of about 87.0 weight percent dichloromethane and about 13.0 weight percent 2-methylpentane. 121. The process of embodiment 120, wherein the azeotropic composition boils at a temperature of about 40 “G and at a boiling pressure of about 1048 kPa.

[0313] 122. The process of embodiment 114 or 115, wherein the azeotropic or azeotrope-like composition comprises consists essentially of. or consists of from about 84 to about 98 weight percent dichloromethane and from about 16 to about 2 weight percent 3-methylpentane, or from about 88 to about 98 weight percent dichloromethane and from about 12 to about 2 weight percent 3-methylpentane, or from about 92 to about 97 weight percent dichloromethane and from about 8 to about 3 weight percent 3-methylpentane.

[0314] 123. The process of embodiment 122, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 6 kPa to about 690 kPa. 124. The process of any of embodiments 122 or 123, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 85 to about 95 weight percent dichloromethane and from about 15 to about 5 weight percent 3-methylpentane.

[0315] 126. The process of embodiment 124, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 6 kPa to about

[0316] 591 kPa.

[0317] 126. The process of any of embodiments 122 to 125, wherein the azeotropic composition comprises, consists essentially of, or consists of about 90.0 weight percent dichloromethane and about 10.0 weight percent 3-methylpentane.

[0318] 127. The process of embodiment 126, wherein the azeotropic composition boils at a temperature of about 40 “G and at a boiling pressure of about 103.7 kPa. 128. The process of embodiment 114 or 115, wherein frie azeotropic or azeofrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent trichloromethane and from about 90 to about 33 weight percent 2-methylpentane, or from about 36 to about 67 weight percent trichloromethane and from about 64 to about 33 weight percent 2-methylpentane. , 129 The process of embodiment 128, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 C to about 100 C and at a boiling pressure of about 3 kPa to about 340 kPa.

[0319] 130. The process of any of embodiments 128 or 129, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 54 to about 63 weight percent triditoromethane and from about 46 to about 37 weight percent 2-methylpentane. 131. The process of embodiment 130, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 3 kPa to about 340 kPa.

[0320] 132. The process of any of embodiments 128 to 131, wherein the azeotropic composition comprises, consists essentially of, or consists of about 56 0 weight percent trichloromethane and about 44.0 weight percent 2-methylpentane.

[0321] 133. The process of embodiment 132, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 56.6 kPa.

[0322] 134. The process of embodiment 114 or 115, wherein the azeotropic or azeotrppe-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent trichioromethane and from about 90 to about 33 weight percent 3-methylpentane, or from about 46 to about 67 weight percent trichioromethane and from about 54 to about 33 weight percent 3-methylpentane.

[0323] 135. The process of embodiment 134. wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 and at a boiling pressure of about 2 kPa to about 326 kPa.

[0324] 136. The process of any of embodiments 134 or 135, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 58 to about 67 weight percent trichioromethane and from about 42 to about 33 weight percent 3-methylpentane 137. The process of embodiment 136, wherein the azeotropic composition boils at a temperature of about -20 X to about 60 C and at a boiling pressure of about 3 kPa to about

[0325] 107 kPa. 138. The process of any of embodiments 134 to 137, wherein the azeotropic composition comprises, consists essentially of, or consists of about 66.0 weight percent trichloromethane and about 34.0 weight percent 3-methylpentane.

[0326] 139. The process of embodiment 138, wherein the azeotropic composition boils at a temperature of about 40 C and at a boiling pressure of about 53 6 kPa

[0327] 140. The process of embodiment 114 or 115, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent dichloromethane and from about 33 to about 90 weight percent n-pentane, or from about 31 to about 67 weight percent dichloromethane and from about 69 to about 33 weight percent h-pentane.

[0328] 141. The process of embodiment 140, wherein the azeotropic or azeotrope-li ke composition boils at a temperature of about -20 *C to about 100 "C and at a boiling pressure of about 10 kPa to about 703 kPa.

[0329] 142. The process of embodiment 140 or 141 , wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 31 to about 63 weight percent dichloromethane and from about 69 to about 37 weight percent n-pentane.

[0330] 143. The process of embodiment 142, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 °C and at a boiling pressure of about 132 kPa to about 139 kPa. 144. The process of embodiment 142 or 143, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 43 to about 58 weight percent dichloromethane and from about 57 to about 42 weight percent n-pentane 70 weight percent dichloromethane and from about 69 to about 30 weight percent n-pentane. 145. The process of embodiment 144, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 11 kPa to about 703 kPa. 146. The process of embodiment 144 or 145^ wherein the azeotropic compositions comprise, consists essentially of or consists of about 50.9 weight percent dichioromethane and about 49.1 weight percent n-pentane.

[0331] 147. The process of embodiment 146. wherein the azeotropic composition boils at a temperature of about 25 °C and at a boiling pressure of pressure of about 82 kPa.

[0332] 148. The process of embodiment 144 or 145, wherein the azeotropic compositions comprise, consists essentially of or consists of about 51 0 weight percent dichioromethane and about 49.0 weight percent n-pentane.

[0333] 149. The process of embodiment 148. wherein the azeotropic composition boils at a temperature of about 40C’C and at a boiling pressure of pressure of about 138.9 kPa.

[0334] 150 The process of embodiment 114 or 115, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent dichioromethane and from about 33 to about 90 weight percent 2-methylbutane. or from about 24 to about 67 weight percent dichioromethane and from about 76 to about 33 weight percent 2-methylbutane. 151. The process of embodiment 150, wherein the azeotropic or azeotrope-like composition boils at a temperature of about *20 °C to about 100 °C and at a boiling pressure of about 13 kPa to about 775 kPa.

[0335] 152. The process of any of embodiments 150 or 151, wherein the azeotropic or azeotrope- like compositions comprises, consists essentially of, or consists of from about 15 to about 56 weight percent dichioromethane and from about 85 to about 44 weight percent 2-methylbutane or from about 25 to about 51 weight percent dichioromethane and from about 75 to about 49 weight percent 2-methylbutane. 153; The process of embodiment 152, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 °C and at a boiling pressure of about 157 kPa to about 163 kPa.

[0336] 154. The process of any of embodiments 150 to 153, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 26 to about 42 weight percent dichloromethane and from about 74 to about 58 weight percent 2-methylbutane. 155. The process of embodiment 154, wherein the azeotropic composition boils at a temperature of about -20 "C to about 100 °C and at a boiling pressure of about 14 kPa to about 775 kPa.

[0337] 156. The process of any of embodiments 154 to 155, wherein the azeotropic composition comprises, consists essentially of, Or consists of about 35.0 weight percent dichloromethane and about 65.0 weight percent 2-methylbutane.

[0338] 157. The process of embodiment 156, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 162.6 kPa.

[0339] 158. The process of embodiment 114 or 115. wherein the azeotropic or azeotrope-like compostion comprises, consists essentially of, or consists of from about 10 to about 67 weightpercent trans- 1,2-dichloroethylene and from about 90 to about 33 weight percent 2,2- dimethylbutane, or from about 34 to about 67 weight percent trans-1 ,2-dichloroethylene and from about 66 to about 33 weight percent 2,2-dimethylbutane, or from about 44 to about 67 weight percent trans- 1.2-dichloroethylene and from about 56 to about 33 weight percent 2,2- dimethylbutane.

[0340] 159. The processof embodiment 158, wherein theazeotropicorazeotrope-likecomposition boils at a temperature of about -20 "C to about 100 C and at a boiling pressure of about 5 kPa to about 460 kPa. 160- The process of any of embodiments 158 or 159, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 52 to about 67 weight percent trans-1,2-dichloroethylene and from about 48 to about 40 weight percent 2.2-dimethylbutane.

[0341] 161. The process of embodiment 160, wherein the azeotropic composition boils at a temperature of about -20 °C to about 60 °C and at a boiling pressure of about 5 kPa to about 161 kPa.

[0342] 162. The process of any of embodiments 158 to 161 , wherein the azeotropic composition comprises, consists essentially of, or consists of about 63 0 weight percent trans-1 ,2- dichloroethylene and about 37.0 weight percent 2, 2-dirnethylbutane.

[0343] 163. The process of embodiment 162, wherein the azeotropic composition boils at a temperature of about 40 C and at a boiling pressure of about 84.6 kPa.

[0344] 164. The process of embodiment 114 or 115, wherein the azeotropic or azeotrope-like compositipn comprises, consists essentially of, or consists of from about 10 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 90 to about 33 weight percent 2- methylpentane, or from about 26 to about 67 weight percent cis-T,2-dichloroethylene and from about 74 to about 33 weight percent 2-methylpentane, or from about 36 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 64 to about 33 weight percent 2- methylpentane.

[0345] 165. The process of embodiment 164, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20!'C to about 100 C and at a boiling pressure of about 3 kPa to about 361 kPa.

[0346] 166. The process of any of embodiments 164 or 165, wherein the azeotropic composition comprises, consists essentially of, or consists of from about 52 to about 60 weight percent cis- 1 ,2-dichloroethylene and from about 48 to about 40 weight percent 2-methylpentane.

[0347] 167 The process of embodiment 166, wherein the azeotropic composition boiis at a temperature of about -20 ' C to about 100 ‘ C and at a boiling pressure of about 3 kPa to about 361 kPa. 168. The process of any of embodiments 164 to 167, wherein the azeotropic composition comprises, consists essentially of, or consists of about 54.5 weight percent cis-1, 2- dichloroethylene and about 45 5 weight percent 2-methylpentane.

[0348] 169. The process of embodiment 168, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 60.4 KPa.

[0349] 170. The process of embodiment 114 or 115. wherein the azeotropic or azeotrope-like composition comprises, consists essentially of. or consists of from about 10 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 90 to about 33 weight percent 3- methylpentane, or from about 33 to about 67 weight percent cis-1, 2-dichloroethylene and from about 67 to about 33 weight percent 3-methylpentane, or from about 43 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 57 to about 33 weight percent 3- methylpentane.

[0350] 171. The process of embodiment 170, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °G to about 100 °C and at a boiling pressure of about 3 kPa to about 348 kPa.

[0351] 172. The process of any of embodiments 170 or 171 , wherein the azeotropic composition comprises, consists essentially of, or consists of from about 59 to about 67 Weight percent cis- 1 ,2-dichloroethylene and from about 41 to about 33 weight percent 3-methylpentane 173. The process of embodiment 172, wherein the azeotropic composition boils at a temperature of about -20 ‘ C to about 100 ‘ C and at a boiling pressure of about 3 kPa to about 348 kPa.

[0352] 174. The process of any of embodiments 170 to 173, wherein the azeotropic composition comprises, consists essentially of, or consists of about 60.6 weight percent cis-1 ,2- dichloroethylene and about 39.4 weight percent 3-methylpentane.

[0353] 175. The process of embodiment 174, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 57.3 kPa. 176. The process of embodiment 114 or 115, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of. or consists of from about 10 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 90 to about 33 weight percent 2,2- dimethylbutane, or from about 10 to about 64 weight percent cis-1 ,2-dichloroethylene and from about 90 to about 36 weight percent 2,2-dimethylbutane, or from about 15 to about 64 weight percent cis-1, 2-dichloroethylene and from about 85 to about 36 weight percent. 2,2- dimethylbutane. ';177. The process of embodiment 176, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 ’C and at a boiling pressure of about 5 kPa to about 414 kPa.

[0354] 178. The process of any of embodiments 176 or 177, wherein the azeotropic composition comprises, consists essentially of. or consists of from about 21 to about 36 weight percent os-

[0355] 1.2-dichloroethylene and from about 79 fo about 64 weight percent 2,2-dimethylbutane

[0356] 179. The process of embodiment 178, wherein the azeotropic composition boils at a temperature of about -20 ' C to about 100rC and at a boiling pressure of about 5 kPa to about 414 kPa.

[0357] 180. The process of any of embodiments 176 to 182, wherein the azeotropic composition comprises, consists essentially of, or consists of about 25.5 weight percent cis-1, 2- dichloroethylene and about 74.5 weight percent 2,2-dimethylbutane.

[0358] 181. The process of embodiment 180, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of about 76.2 kPa.

[0359] 182. The process of embodiment 114 or 115, wherein the azeotropic or azeotrope-like composition comprises, consists essentially of, or consists of from about 10 to about 67 weight percent cis-1 , 2-dichloroethylene and from about 90 to about 33 weight percent 2,3- dimethylbutane, or from about 19 to about 67 weight percent cis-1 ,2-dichloroethylene and from about 81 to about 33 weight percent 2,3-dimethylbutane, or from about 29 to about 67 weight percent cis-1, 2-dichloroethylene and from about 71 to about 33 weight percent 2,3- dimethylbutane.

[0360] 183. The process of embodiment 182 wherein the azeotropic or azeotrope-like compositions boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 3 kPa to about 367 kPa.

[0361] 184. The process of any of embodiments 182 or 183, wherein the azeotropic composition comprises, consists essentially of. or consists of from about 43 to about 55 weight percent cis- 1 ,2-dichloroethylene and from about 57 to about 45 weight percent 2.3-dimethylbutane.

[0362] 185. The process of embodiment 184, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 “Cand at a boiling pressure of about 4 kPa to about 367 kPa. \ ;

[0363] 186. The process of any of embodiments 182 to 185 wherein the azeotropic composition comprises, consists essentially of, or consists of about 47.0 weight percent cis-1 ,2- dichloroethylene and about 53.0 weight percent 2,3-dimethylbutane. 187. The process of embodiment 186. wherein the azeotropic composition boils at a temperature of about 40 C and at a boiling pressure of about 62.7 kPa

[0364] 188. The process of any of embodiments 97 to 187, wherein the partially fluorinated polymer is selected from polyvinylidene fluoride (PVDF) and poly(ethylene-co-tetrafluoroethylene) (ETFE), and poly(ethylene-co-chlorotrifluoroethylene) (ECTFE).

[0365] 189. The process of any of embodiments 97 to 188, wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 Weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a polyvinylidene fluoride (PVDF), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 84 to about 98 weight percent, or from about 88 to about 98 weight percent, or from about 92 to about 97 weight percent of at least one chlorinated solvent, selected from dichloromethane, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent, or from about 12 to about 2 weight percent, or from about 8 to about 3 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1- pentene, 2-rnethylbutane. n-hexane. 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane. 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-l-butene, 1 -hexene, n-heptane, and n- octane.

[0366] 190. The process of any of embodiments 97 to 188, wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-tetrafluoroethylene) (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, ciS’1,2-dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 90 to about 45 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl*2- butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane.

[0367] 191. The process of any of embodiments 97 to 188, wherein the spin fluid compnses about 12 to about 36 weight percent, Or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 we ght percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-tetrafluoroethylene) (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1.2- dichloroethylene. cis-1 ,2-dichloroethylene, and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, or from about 70 to about45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentare. 1 -pentene, 2-methylbutane. n-hexane, 2- methylpentane, 3-methylpentane;2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene 2-methyl-1-butene, 1-hexene. n-heptane, and n-octane

[0368] 192. The process of any of embodiments 97 to 188, wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 we ght percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-tetrafluoroethylene)

[0369] (ETFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichioroethylene, ciS"1,2-dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70

[0370] Weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentare, 1 -pentene, 2-methylbutane, n-hexane, 2- methyl pentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane.

[0371] 193. The process of any of embodiments 97 to 188, wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 we ght percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-chlorotrifluoroethylene) (ECTFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of. or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dfchloroethylene, cis-l^-dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 90 to about 45 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, 1 -hexene, n-heptane, and n-octane. 194. The process of any of embodiments 97 to 188, wherein the spin fluid comprises about

[0372] 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 weight percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-chlorotrifiuoroethylene) (ECTFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2- dichloroethylene, cis-1 ,2-didiloroethylene, and frichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, or from about 70 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentare 1 -pentene. 2-methylbutane. n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1-butene, 1-hexene, n-heptane, and n-octane. 195. The process of any of embodiments 97 to 188. wherein the spin fluid comprises about

[0373] 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 we ght percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethylene-co-chlorotrifluoroethylene) (ECTFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent, or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2.2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene. 2-methyl-1 -butene, 1-hexene, n-heptane, and n-octane. 196. The spin fluid of any of embodiments 1 to 92, wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 we ght percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethyiene-co-chlorotrifluoroethyiene) (ECTFE) each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 67 weight percent, or from about 10 to about 62 weight percent, or from about 10 to about 55 weight percent, or from about 14 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent. selected from dichloromethane. trans-1.2-dichloroethylene, cis-1.2-dichloroethylene. and trichloromethane, and from about 90 to about 33 weight percent, or from about 90 to about 38 weight percent, or from about 90 to about 45 weight percent, or from about 86 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentare. 1 -pentene, 2-methylbutane, n-hexane. 2- methylpentane, 3-methylpentane. 2.2-dimethylbutane, 2.3-dimethylbutane. 2-methyl-2- butene, 2-methyl-1-butene, 1 -hexene, n-heptane, and n-octane.

[0374] 197. The spin fluid of any of embodiments 1 to 92, wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about

[0375] 28 weight percent, or about 12 to about 19 we ght percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethyiene-co-chlorotrifluoroethylene) (ECTFE), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 14 to about 55 weight percent, or from about 20 to about 55 weight percent, or from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1.2- dichioroethylene, cis- 1 ,2-dichloroethylene, and trichloromethane, and from about 86 to about 45 weight percent, or from about 80 to about 45 weight percent, or from about 70 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentare, 1 -pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3- methyl pentane, 2.2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene. 2-methyi-1 -butene. 1 -hexene, n-heptane, and n-octane 198. The spin fluid of any of embodiments 1 to 92, wherein the spin fluid comprises about 12 to about 36 weight percent, or about 14 to about 30 weight percent, or about 18 to about 28 weight percent, or about 12 to about 19 we ght percent, or about 22 to about 34 weight percent, or about 26 to about 34 weight percent of a poly(ethyiene-co-chlorotrifluoroethyiene) (ECTFE), each based on the total amount of the spin fluid and a spin agent wherein the spin agent comprises, consists essentially of. or consists of from about 10 to about 30 weight percent, or from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1.2-dichloroethylene, and trichloromethane, and from about 90 to about 70 weight percent or from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms selected from the group consisting of n-pentare. 1 -pentene. 2-methylbutane. n-hexane. 2- methylpentane, 3-methylpentane, 2.2-dimethylbutane. 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, 1 -hexene, n-heptane, and n-octane. 199. In some embodiments, the present application provides a use of the spin fluid of any of embodiments 1 to 96 or 196 to 198 for preparing plexifilamentary fibrils of partially fluorinated polymers by flash spinning.

[0376] 200. The plexifilamentary fibrils of polyvinylidene fluoride (PVDF) or of poly(ethylene-co- tetrafluoroethylene) (ETFE) or of poly(ethylene-co-clilorotrifluoroethylene) (ECTFE) obtainable or obtained by the process of any one of embodiments 97 to 195.

[0377] 201 The plexifilamentary fibrils of polyvinyhdene fluoride of embodiment 200 wherein the only detectable PVDF crystal phase is the p crystal phase whereas no significant portions of the a or y crystal phases are detectable.

[0378] 202. The plexifilamentary fibrils of polyvinyhdene fluoride of embodiment 201 having a crystallinity index (p phase) of about 32 % or more, or about 34 % or more or about 35 % or more.

[0379] 203. A sheet of nonwoven flash-spun plexifilamentary comprising plexifilamentary fibrils of polyvinyhdene fluoride (PVDF) or of poly(ethylene-co-tetrafluoroethylene) (ETFE) or of poly(ethylene-co-chlorotrif)uoroethylene) (ECTFE) of any of embodiments 200 to 202. 204. The sheet of embodiment 203, wherein the sheet is a collected sheet, a consolidated sheet, a bonded sheet, or a softened sheet.

[0380] 205 A bonded sheet obtainable by thermally or mechanically bonding the consolidated sheet of embodiment 204.

[0381] 206 A softened sheet obtainable by softening the consolidated sheet of embodiment 204 or by softening the bonded sheet of embodiment 205. 207 An article comprising plexifilamentary fibrils of polyvinylidene fluoride (PVDF) or of poly(ethylene-co-tetrafluoroethylene) (ETFE) or of poly(ethylene-co-chlorotrifluoroethylene) (ECTFE) of any of embodiments 200 to 202 and / or a sheet of any one of embodiments 203 to 206. 208. The article of embodiment 207 which is selected from packaging material, filtration media, print media, tags and labels, accessories, and electronic devices.

[0382] 209. The article of embodiment 208, wherem the electronic devices are selected from pressure sensors, strain gauges, microphones, actuators, energy harvesters, and nanogenerators.

[0383] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope of the present invention. Thus, it should be appreciated that, while the invention has been described with reference to the above exemplary embodiments, other embodiments are within the scope of the claims. Moreover, it should be understood that the exemplary embodiments described herein may be combined to form other embodiments. After reading the above description, it will be apparent to one skilled in the relevant art(s) how to implement the invention in alternative embodiments. Thus, the present invention should not be limited by any of the above-described exemplary embodiments.

Claims

1. CLAIMS1. A spin fluid for flash spinning comprising(a) from about 12 to about 36 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and(b) a spin agent, wherein the spin agent comprises a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms2. The spin fluid of claim 1 , wherein the partially fluorinated polymer is selected from the group consisting of polyvinylidene:fluoride (FVDF), poly(ethylene-co-tetrafluoroethylene) (ETFE>, poly(emylene-co-chlorotriflUoroethylene) (EGTFE), and blends / mixtures thereof.

3. The spin fluid of any one of claims 1 to 2, wherein the at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2 -methylpentane. 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, 1-hexene, n- heptane, and n-octane.

4. The spin fluid of any one of claims 1 to 3, wherein the spin agent comprises from about 84 to about 98 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms.

5. The spin fluid of any one of claims 1 to 3. wherein the spin agent comprises from about 10 to about 67 weight percent of at .least one chlorinated solvent, selected from dichloromethane, frans’1,2-dichtoroethyleneicis-1, 2-dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms.6.;The spin fluid of any one of claims 1 to 5, wherein the spin agent comprises an azeotropic or azeotrope-like composition comprising(1) dichloromethane and 2-methylpentane, or(2) dichloromethane and 3-methylpentane, or(3) trichloromethane and 2-methylpentane, or(4) trichloromethane and 3-methylpentane. or (5) dichloromethane and n-pentane, or(6) dichloromethane and 2-methylbutane, or(7) trans-1 ,2-dichloroethylene and 2,2-dimethylbutane, or(8) cis-1 ,2-dichloroethylene and 2-methylpentane, or(9 J cis-1 ,2-dichloroethylene and 3-methylpentane, or (10)cis-1 ,2-dichloroethylene and 2.2-dimethylbutane. or(11 ) cis-1 , 2-dichloroethylene and 2.3-dimethylbutane.

7. A process for the preparation of plexifilamentary fibrils of partially fluorinated polymer which comprises the steps of: (i) generating a spin fluid comprising(a) from about 12 to about 36 weight percent of a partially fluorinated polymer, based on the total amount of the spin fluid, and(b) a spin agent, and(ii) flash spinning the spin fluid at a pressure that is above the vapor pressure of the spin fluid into a region of essentially atmospheric pressure to form plexifilamentary fibrils of the partially fluorinated polymer, wherein the spin agent comprises a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1, 2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 or more carbon atoms,8. The process of claim 7, Wherein the partially fluorinated polymer is selected from the group consisting of polyvinylidene fluoride (PVDF), poly(ethylene-co-tetrafluoroethylene) (ETFE), poly(etoylene-co-Ghlorotrifluoroethylene) (ECTFE) and blends / mixtures thereof,9. The process of any one of claims 7 to 8, wherein the at least one linear or branched hydrocarbon with 5 or more carbon atoms is selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane. 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-metoyl-1 -butene, 1-hexene, n- heptane, and n-octane.

10. The process of any one of claims 7 to 9, wherein the spin agent comprises from about 84 to about 98 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroetoylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 16 to about 2 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms.

11. The process of any one of claims 7 to 9, wherein the spin- agent comprises from about10 to about 67 -weight percent of at least one chlorinated solvent, selected from dichlorornethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 90 to about 33 weight percent of at least one linear or branched hydrocarbon with 5 or more carbon atoms.

12. The -process of any one of claims 7 to 11, wherein toe spin agent comprises an azeotropic or azeotrope-like composition comprising(1) dichlorornethane and 2-methylpentane, or(2) dichlorornethane and 3-methylpentane, or (3) trichloromethane and / 2-methylpentane, or(4) trichloromethane and 3-methylpentane. or(5) dichlorornethane and n-pentane, or(6) dichlorornethane and 2-metoylbutane, or(7) trans-1 ,2-dichloroethylene and 2,2-dimethylbutane, or (8> cis-1 ,2-dichloroethylene -and 2-methylpentane, or(9) cis-1 ,2-dichloroethylene and 3-methylpentane, or(10)cis-1 ,2-dichlordethylene and 2,2-dimethylbutane, or(11 ) cis-1 ,2-dichioroethylene and 2.3-dimethylbutane.

13. Use of the spin fluid of any one of claims 1 to 6 for preparing of plexifilamentary fibrils of partially fluorinated polymers by flash spinning.

14. Plexifilamentary fibrils of polyvinylidene fluoride (PVDF) or of poly(ethylene-co- tetrafluoroethylene) (ETFE) or of poly(ethylene-co-chlorotrifluoroethylene):(ECTFE) obtainable by the process of any one of claims 7 to 12.

15. The plexifilamentary fibrils of polyvinylidene fluoride of claim 14 wherein the only detectable PVDF crystal phase is the ^ crystal phase whereas no significant portions of the a or y crystal phases are detectable, wherein no significant portion means that the integrated intensity in the range of 2© - 26-7 - 26,8’ is below 2 % of the total integrated intensity in the range of 2H = 10:to 29’16. A sheet of nonwoven flash-spun plexifilamentary fibrils. comprising- plexifilamentary fibrils of polyvinylidene fluoride (PVDF) or of poly(ethylene-co-tetrafluoroethylene) (ETFE) or of poly(ethylene-co-chlorotrifluoroethylene) (ECTFE) of claim 14 or 15.

17. An article comprising the plexifilamentary' fibrils of polyvinylidene fluoride (PVDF) or of polyfethy lene-co-tetrafluoroethylene) (ETFE) or of poly(ethylene-co-chlorotrifluoroethylene) (ECTFE) of claim 14 or 15 and / or the sheet of claim 16.;18, The article of claim 17 which is selected from packaging material, filtration media, print media, tags and labels, accessories, and electronic devices

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