Crosslinking polymers of vinyl and monocyclic organosiloxanes and methods

Abstract

A method is disclosed, comprising providing (A) an ethylene / MOCOS copolymer consisting of (i) units derived from ethylene, (ii) 0.01 wt% to 0.5 wt% of units derived from a comonomer, and (iii) optionally units derived from a terpolymer. The comonomer is of formula (I) [R 1 ,R 2 SiO 2 / 2 ] n Monocyclic organosiloxane (MOCOS), wherein n is an integer greater than or equal to 3, each R 1 are independently (C2-C4)alkenyl or H2C=C(R 1a )‑C(=O)‑O‑(CH2) m _, where R 1a is H or methyl; m is an integer from 1 to 4; and each R 2 are independently H, (C1-C4) alkyl, phenyl or R 1 The method comprises: mixing (B) a free radical initiator with (A) the ethylene / MOCOS copolymer to form a mixture; heating the mixture; and forming a crosslinkable ethylene / MOCOS copolymer composition having a gel content greater than 70%.

Description

Background Art

[0001] Polyethylene is the most widely used thermoplastic material today. In some applications, polyethylene must be modified to improve certain properties. For example, crosslinking between polymer chains forms a three-dimensional (3D) network that improves heat resistance, thereby providing crosslinked polyethylene with a higher operating temperature. Peroxide curing is widely used in industry to crosslink polyethylene. For example, crosslinkable polyethylene (XLPE) is widely used as an insulation material for medium voltage (MV), high voltage (HV) and extra-high voltage (EHV) wire and cable applications. The insulation material is composed of low-density polyethylene (LDPE), peroxide and antioxidant. In wire and cable applications, an inner semiconductive layer, an XLPE insulation layer and an outer semiconductive layer are usually applied to the conductor through a crosshead in a triple extrusion process. The cable core consisting of the conductor, the inner semiconductive layer, the XLPE insulation layer and the outer semiconductive layer is then passed through a vulcanizing tube with a 10 bar N2 pressure to induce peroxide crosslinking. After cooling by passing through a cooling tube, the cable core is placed in a chamber at an elevated temperature (e.g., 70°C) to remove byproducts from the decomposition of the peroxide.

[0002] Thus, the art recognizes a need for LDPE with an improved peroxide cure that provides improved productivity by increasing cure rate and reducing peroxide loading (and reducing by-products). Thus, the art also recognizes a need for LDPE with an improved peroxide cure response not only for XLPE insulation applications but also for other peroxide cross-linkable compositions. Summary of the Invention

[0003] The present disclosure provides a method. In one embodiment, the method includes providing (A) an ethylene / MOCOS copolymer consisting of (i) units derived from ethylene, (ii) 0.01 wt% to 0.5 wt% of units derived from a comonomer, and (iii) optionally units derived from a terpolymer. The comonomer is a monocyclic organosiloxane (MOCOS) of formula (I)

[0004] [R 1 ,R 2 SiO 2 / 2 ] n

[0005] Where n is an integer greater than or equal to 3,

[0006] Each R 1 are independently (C2-C4)alkenyl or H2C=C(R 1a )-C(=O)-O-(CH2) m -

[0007] where R 1a is H or methyl;

[0008] m is an integer from 1 to 4; and

[0009] Each R 2 are independently H, (C1-C4)alkyl, phenyl or R 1 The method comprises mixing (B) a free radical initiator with (A) the ethylene / MOCOS copolymer to form a mixture. The method comprises heating the mixture to form a crosslinkable ethylene / MOCOS copolymer composition. In one embodiment, the method comprises crosslinking the crosslinkable ethylene / MOCOS copolymer composition to form a crosslinked ethylene / MOCOS copolymer composition having a gel content greater than 70%.

[0010] The present disclosure provides a composition. In one embodiment, a crosslinkable composition is provided, and the crosslinkable composition comprises A) an ethylene copolymer consisting of: (i) units derived from ethylene,

[0011] (ii) 0.01 wt% to 0.5 wt% of units derived from a comonomer, and (iii) optionally units derived from a terpolymer comonomer. The comonomer is a monocyclic organosiloxane (MOCOS) of formula (I)

[0012] [R 1 ,R 2 SiO 2 / 2 ] n

[0013] Where n is an integer greater than or equal to 3,

[0014] Each R 1 are independently (C2-C4)alkenyl or H2C=C(R 1a )-C(=O)-O-(CH2) m -

[0015] where R 1a is H or methyl;

[0016] m is an integer from 1 to 4; and

[0017] Each R 2 are independently H, (C1-C4)alkyl, phenyl or R 1 ;as well as

[0018] (B) a free radical initiator. After crosslinking, the crosslinkable composition forms a crosslinked ethylene / MOCOS copolymer composition having a gel content greater than 70%.

[0019] definition

[0020] Any reference to the Periodic Table of the Elements is to the Periodic Table as published by CRC Press, Inc., 1990-1991. Groups of elements in this table are referred to by a new notation for numbering the groups.

[0021] For purposes of U.S. patent practice, the contents of any referenced patent, patent application, or publication are incorporated by reference in their entirety (or their equivalent U.S. versions are incorporated by reference), particularly with respect to the disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure).

[0022] The numerical ranges disclosed herein include all values from the lower limit to the upper limit, and include the lower limit and the upper limit. For ranges containing clear values (e.g., 1 or 2, or 3 to 5, or 6, or 7), any subrange between any two clear values is included (e.g., the above range 1 to 7 includes subranges of 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6, etc.).

[0023] Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percentages are based on weight, and all test methods are current as of the filing date of this disclosure.

[0024] As used herein, an "acrylate" is a monomer containing the following structure (A):

[0025] Structure (A)

[0026]

[0027] Where R1 is a hydroxyl group or a C1-C 18 Alkoxy group, and R2 is H or CH3. Acrylate-based monomers include acrylates and methacrylates.

[0028] As used herein, the term "blend" or "polymer blend" refers to a mixture of two or more polymers. A blend may be miscible or immiscible (not phase separated at the molecular level). A blend may or may not be phase separated. A blend may or may not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art. A blend may be effected by physically mixing two or more polymers at the macroscopic level (e.g., melt blending resins or compounding) or at the microscopic level (e.g., simultaneously forming in the same reactor).

[0029] The term "composition" refers to a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0030] The terms "comprising," "including," "having," and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not the components, steps, or procedures are specifically disclosed. For the avoidance of any doubt, all compositions claimed through use of the term "comprising" may include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless stated to the contrary. Conversely, the term "consisting essentially of excludes any other components, steps, or procedures (except those that are not essential for operability) from the scope of any subsequently stated content. The term "consisting of excludes any components, steps, or procedures that are not specifically described or listed. Unless otherwise stated, the term "or" refers to the listed members individually and in any combination. The use of the singular includes the use of the plural, and vice versa.

[0031] An "ethylene-based polymer" is a polymer that contains greater than 50 weight percent (wt%) polymerized ethylene monomer (based on the total amount of polymerizable monomers) and, optionally, may contain at least one comonomer. Ethylene-based polymers include ethylene homopolymers and ethylene copolymers (meaning units derived from ethylene and one or more comonomers). The terms "ethylene-based polymer" and "polyethylene" are used interchangeably.

[0032] As used herein, the term "ethylene monomer" or "ethylene" refers to a chemical unit having two carbon atoms with a double bond therebetween, and each carbon bonded to two hydrogen atoms, wherein the chemical unit is polymerized with other such chemical units to form an ethylene-based polymer composition.

[0033] A "hydrocarbon" is a compound containing only hydrogen and carbon atoms. A "hydrocarbyl" (or "hydrocarbyl group") is a hydrocarbon having a valence (usually a single valence). A hydrocarbon can have a linear, cyclic, or branched structure.

[0034] As used herein, the term "linear low density polyethylene" (or "LLDPE") refers to a linear ethylene / α-olefin copolymer comprising a heterogeneous distribution of short chain branching, comprising units derived from ethylene and units derived from at least one C3-C 10 Units of α-olefins or C4-C8 α-olefin comonomers. LLDPE is characterized by minimal long chain branching (if any) compared to conventional LDPE. LLDPE has a density of 0.910 g / cc to less than 0.940 g / cc. Non-limiting examples of LLDPE include TUFLIN TM Linear low density polyethylene resin (available from The Dow Chemical Company), DOWLEX TMPolyethylene resin (available from The Dow Chemical Company) and MARLEX TM Polyethylene (available from Chevron Phillips).

[0035] As used herein, the term "low density polyethylene" (or LDPE) refers to a polyethylene having a density of 0.910 g / cc to less than 0.940 g / cc, or 0.918 g / cc to 0.930 g / cc, and long chain branching with a broad molecular weight distribution (MWD) (i.e., a "broad MWD" of 4.0 to 20.0).

[0036] An "olefin" is an unsaturated aliphatic hydrocarbon having a carbon-carbon double bond.

[0037] The term "phenyl" (or "phenyl group") is a C6H5 aromatic hydrocarbon ring having a valence (usually monovalent).

[0038] As used herein, the term "polymer" or "polymeric material" refers to a compound prepared by polymerizing monomers, whether of the same or different types, which, in polymerized form, provide multiple and / or repeating "units" or "monomer units" that constitute the polymer. Thus, the general term polymer encompasses the term homopolymer, which is typically used to refer to polymers prepared from only one type of monomer, and the term copolymer, which is typically used to refer to polymers prepared from at least two types of monomers. It also encompasses all forms of copolymers, such as random copolymers, block copolymers, etc. The terms "ethylene / α-olefin polymer" and "propylene / α-olefin polymer" refer to copolymers prepared by polymerizing ethylene or propylene, respectively, and one or more additional polymerizable α-olefin monomers, as described above. It should be noted that although polymers are often referred to as being "made from" one or more specified monomers, "based on" a specified monomer or monomer type, "containing" a specified monomer content, etc., in this context, the term "monomer" should be understood to refer to the polymerized residue of the specified monomer rather than the unpolymerized substance. Generally, the polymers herein are referred to as being based on "units" that are the polymerized form of the corresponding monomer.

[0039] Test Method

[0040] Density is measured according to ASTM D792, Method B. Results are reported in grams per cubic centimeter (g / cc).

[0041] Fourier Transform Infrared Analysis ("FTIR")

[0042] The amount of terminal and internal trans double bonds per 1000 carbons (or "1000C") was determined by Fourier transform infrared analysis ("FTIR"). Sample films (approximately 250 to 300 microns thick) for FTIR analysis were compression molded by pressing approximately 0.5 g of sample pellets in a Carver hydraulic press with heated platens set to 190°C. The amount of terminal and internal olefins per 1000 carbons was measured following a procedure similar to that outlined in ASTM method D6248. FTIR measures internal olefin bonds in the trans configuration; FTIR cannot detect internal olefin bonds in the cis configuration.

[0043] Gel content

[0044] Gel content was measured according to ASTM D 2765-01. Samples were hand-cut into small pellets (approximately 1 mm x 1 mm x 1 mm cubes) from 1 mm thick polymer plaques prepared on a hot press (preheated at 120°C for 10 minutes (min), followed by preheating at 180°C / 10 MPa for 20 minutes, and then cooling to room temperature (RT) for 10 minutes under 10 MPa pressure). These samples were refluxed in xylene for 12 hours (h). After 6 hours, the hot xylene was removed, and then new fresh xylene was added to continue reflux for another 6 hours. Gel content results are reported as a percentage (%). Higher gel content indicates a higher level of crosslinking.

[0045] Gel Permeation Chromatography (GPC)

[0046] The chromatography system consisted of a PolymerChar GPC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5) and 4 capillary viscometers (DV) connected to a Precision Detectors (now Agilent Technologies) 2-angle laser light scattering (LS) detector model 2040. For all absolute light scattering measurements, a 15-degree angle was used for measurement. The autosampler oven chamber was set to 160 degrees Celsius, and the column chamber was set to 150 degrees Celsius. The columns used were 4 Agilent "MixedA" 30 cm 20 micron linear mixed bed columns. The chromatographic solvent used was 1,2,4 trichlorobenzene (CAS 120-82-1, HPLC grade, from Fisher Scientific) and contained 200 ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 μl and the flow rate was 1.0 ml / min.

[0047] The GPC column set was calibrated with at least 20 narrow molecular weight distribution polystyrene standards with molecular weights ranging from 580 to 8,400,000, and arranged in 6 "cocktail" mixtures with at least ten times of spacing between the individual molecular weights. Standards were purchased from Agilent Technologies. For molecular weights equal to or greater than 1,000,000, 0.025 grams of polystyrene standards were prepared in 50 milliliters of solvent, and for molecular weights less than 1,000,000, 0.05 grams of polystyrene standards were prepared in 50 milliliters of solvent. The polystyrene standards were dissolved at 80 degrees Celsius and gently stirred for 30 minutes. The polystyrene standard peak molecular weight was converted to polyethylene molecular weight using equation 1 (as described by Williams and Ward, J. Polym. Sci., Polym. Let., 6, 621 (1968)):

[0048] M 聚乙烯 =A×(M 聚苯乙烯 ) B (Equation 1)

[0049] Wherein M is the molecular weight, A has a value of 0.4315, and B equals 1.0.

[0050] A polynomial between order 3 and 5 was used to fit the corresponding polyethylene equivalent calibration points.A small adjustment was made to A (from approximately 0.375 to 0.440) to correct for column resolution and band broadening effects such that the homopolymer polyethylene standard had a molecular weight of 120,000.

[0051] Plate counts were performed on the GPC column set using eicosane (prepared at 0.04 g in 50 mL of TCB and dissolved under slow stirring for 20 minutes). Plate counts (Equation 2) and symmetry (Equation 3) were measured at a 200 μL injection according to the following equations:

[0052]

[0053] where RV is the retention volume in milliliters, peak width is in milliliters, peak maximum is the maximum height of the peak, and 1 / 2 height is the height of 1 / 2 the peak maximum.

[0054]

[0055] Where RV is the retention volume in milliliters, and peak width is in milliliters, peak maximum is the maximum position of the peak, tenth height is 1 / 10 of the height of the peak maximum, and where post-peak is the tail of the peak with a retention volume later than the peak maximum, and where front-peak is the front of the peak with a retention volume earlier than the peak maximum. The plate count of the chromatography system should be greater than 24,000,

[0056] And the symmetry should be between 0.98 and 1.22.

[0057] The samples were prepared semi-automatically using the PolymerChar "Instrument Control" software, with a target sample weight of 2 mg / ml and solvent (containing 200 ppm BHT) added to a septum-capped vial previously sparged with nitrogen using a PolymerChar high-temperature autosampler. The samples were dissolved at 160 degrees Celsius for 2 hours with "low speed" shaking.

[0058] Based on the GPC results, using the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR spectrometer, according to equations 4-6, the PolymerChar GPCOne TM The software, the baseline-subtracted IR chromatogram at each equally spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve at point (i) according to Equation 1 were used to determine the Mn (GPC) 、Mw (GPC) and Mz (GPC) Calculation.

[0059]

[0060]

[0061]

[0062] To monitor the deviation over time, a flow rate marker (decane) was introduced into each sample via a micropump controlled by the PolymerChar GPC-IR system. This flow rate marker (FM) was used to linearly correct the pump flow rate for each sample (Flow Rate (Nominal)) by comparing the RV of the corresponding decane peak in the sample (RV (FM Sample)) with the RV of the decane peak in the narrow standard calibration (RV (FM Calibrated)). It was then assumed that any change in the decane marker peak time was related to a linear change in flow rate (Flow Rate (Effective)) throughout the run. To facilitate the highest accuracy in the RV measurement of the flow marker peak, a least squares fitting procedure was used to fit the peak of the flow marker concentration chromatogram to a quadratic equation. The first derivative of the quadratic equation was then used to solve for the true peak position. After calibrating the system based on the flow marker peak, the effective flow rate (relative to the narrow standard calibration) was calculated as Equation 7. TM The software completes the processing of the flow marker peaks.An acceptable flow rate correction is such that the effective flow rate should be within + / - 2% of the nominal flow rate.

[0063] Flow rate (effective) = flow rate (nominal) * (RV (FM calibrated) / RV (FM sample)) (Equation 7)

[0064] Triple Detector GPC (TDGPC)

[0065] The chromatography system, run conditions, column setup, column calibration, and calculation of conventional molecular weight moments and distributions were performed according to the methods described in Gel Permeation Chromatography (GPC).

[0066] To determine the offset of the viscometer and light scattering detectors relative to the IR5 detector, a systematic method for determining multi-detector offset was performed in a manner consistent with that published by Balke, Mourey et al. (Mourey and Balke, Chromatography Polym., Chapter 12, (1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey, Chromatography Polym., Chapter 13, (1992)) using the PolymerChar GPCOne TM The software optimizes triple detector logarithmic (MW and IV) results from broad homopolymer polyethylene standards (Mw / Mn>3) with narrow standards column calibration results from a narrow standards calibration curve.

[0067] Absolute molecular weight data were obtained using PolymerChar GPCOne TMThe software was obtained in a manner consistent with that published by Zimm (Zimm, BH, Journal of Physical Chemistry, 16, 1099 (1948)) and Kratochvil (Kratochvil, P., Classical Light Scattering from Polymer Solutions, Elsevier, Oxford, NY (1987)). The total injected concentration used to determine the molecular weight was obtained from the mass detector area and the mass detector constant, which was derived from a suitable linear polyethylene homopolymer or one of the polyethylene standards of known weight average molecular weight. The calculated molecular weight (using GPCOne TM ) are obtained using the light scattering constants from one or more polyethylene standards mentioned below and a refractive index concentration coefficient dn / dc of 0.104. Typically, the mass detector response (IR5) and the light scattering constant (using GPCOne TM Viscometer calibration (using GPCOne TM The viscometer constant (measured using GPCOne) can be calculated using the method described by the manufacturer, or alternatively, by using the published value of a suitable linear standard such as Standard Reference Material (SRM) 1475a (available from the National Institute of Standards and Technology, NIST). TM The specific viscosity area (DV) and injected mass of the calibration standard are related to their intrinsic viscosity. The chromatographic concentration is assumed to be low enough to eliminate the effect of the second viral coefficient (the effect of concentration on molecular weight).

[0068] Absolute weight average molecular weight (MW (Abs) )Yes(Using GPCOne TM ) is obtained by dividing the area of the light scattering (LS) integrated chromatogram (calculated from the light scattering constant) by the mass recovered from the mass constant and the mass detector (IR5) area. Molecular weight and intrinsic viscosity responses are at the end of the chromatogram where the signal-to-noise ratio becomes low (using GPCOne TM ) linear extrapolation. The other corresponding moments Mn are calculated according to equations 8-9 as follows (Abs) and Mz (Abs) :

[0069]

[0070]

[0071] gpcBR branching index by triple detector GPC (3D-GPC)

[0072] The gpcBR branching index is determined by first calibrating the light scattering, viscosity, and concentration detectors as described above. The baseline is then subtracted from the light scattering, viscometer, and concentration chromatograms. The integration window is then set to ensure integration of all low molecular weight retention volume ranges in the light scattering and viscometer chromatograms, which indicate the presence of detectable polymer from the infrared (IR5) chromatogram. Linear polyethylene standards are then used to establish polyethylene and polystyrene Mark-Houwink constants. After obtaining the constants, these two values are used to construct two linear reference conventional calibrations of polyethylene molecular weight and polyethylene intrinsic viscosity as a function of elution volume, as shown in Equations (10) and (11):

[0073] M PE =(K PS / K PE ) 1 / α PE +1 ·M PS αPS+1 / αPE+1 (Equation 10)

[0074] [η] PE =K PS ·M PS α+1 / M PE (Equation 11)

[0075] The gpcBR branching index is a robust method for characterizing long chain branching, as described in Yau, Wallace W., "Examples of Using 3D-GPC—TREF for Polyolefin Characterization," Macromol. Symp., 2007, 257, 29-45. This index avoids the "slice-by-slice" 3D-GPC calculations and branching frequency calculations traditionally used to determine g' values, favoring the entire polymer detector area. From 3D-GPC data, the peak area method can be used to obtain the absolute weight average molecular weight (Mw, Abs) of the sample bulk using a light scattering (LS) detector. This method avoids the "slice-by-slice" ratio of the light scattering detector signal to the concentration detector signal required in traditional g' determinations.

[0076] In the case of 3D-GPC, the sample intrinsic viscosity is also obtained independently using equation (8). The area calculation in equations (5) and (8) provides higher accuracy because, as the total sample area, it is less sensitive to changes caused by detector noise and the 3D-GPC settings on the baseline and integration limits. More importantly, the peak area calculation is not affected by detector volume offset. Similarly, the sample intrinsic viscosity (IV) is obtained with high accuracy by the area method shown in equation (12):

[0077]

[0078] where η spi represents the specific viscosity obtained from the viscometer detector.

[0079] To determine the gpcBR branching index, the light scattering elution area of the sample polymer is used to determine the molecular weight of the sample. The viscosity detector elution area of the sample polymer is used to determine the intrinsic viscosity (IV or [η]) of the sample.

[0080] First, the molecular weight and intrinsic viscosity of a linear polyethylene standard (e.g., SRM 1475a) or equivalent are determined using conventional calibration ("cc") for both molecular weight and intrinsic viscosity as a function of elution volume:

[0081]

[0082] Equation (14) Used for Determine g pcBR Branching index:

[0083]

[0084] where [η] is the measured intrinsic viscosity, [η] cc is the intrinsic viscosity from conventional calibration, Mw is the measured weight average molecular weight, and Mw ,cc The weight average molecular weight determined by light scattering (LS) is often referred to as the "absolute weight average molecular weight" or

[0085] "Mw, Abs". Mw,cc using a conventional GPC molecular weight calibration curve ("conventional calibration") is often referred to as the "polymer chain backbone molecular weight", "conventional weight average molecular weight" and

[0086] “Mw, GPC ”.

[0087] All statistical values with a "cc" subscript were determined using their respective elution volumes, corresponding conventional calibrations, and concentrations (Ci) as described previously. Non-subscripted values are based on measurements of mass detector, LALLS, and viscometer areas. Iteratively adjusted K PEThe values of α and Log K were adjusted until the gpcBR measurement for the linear reference sample reached zero. For example, the final values of α and Log K for gpcBR in this particular case were determined to be 0.725 and -3.391 for polyethylene, and 0.722 and -3.993 for polystyrene, respectively. These polyethylene coefficients were then entered into Equation 13.

[0088] Once the K and α values were determined using the previously discussed procedure, the procedure was repeated using the branched samples. Since the best "cc" calibration values were applied, the final Mark-Houwink constants obtained from the linear reference were used to analyze the branched samples.

[0089] The interpretation of gpcBR is straightforward. For linear polymers, the gpcBR calculated by equation (14) will be close to zero because the values measured by LS and viscometry will be close to conventional calibration standards. For branched polymers, gpcBR will be higher than zero, especially for high levels of long chain branching, because the measured polymer molecular weight will be higher than the calculated Mw,cc, and the calculated IVcc will be higher than the measured polymer IV. In effect, the gpcBR value represents the fractional IV change due to the molecular size shrinkage effect as a result of polymer branching. A gpcBR value of 0.5 or 2.0 means that the molecular size shrinkage effect on IV is 50% and 200%, respectively, relative to an equivalent linear polymer molecule.

[0090] For these specific examples, the advantage of using gpcBR compared to traditional "g' index" and branching frequency calculations is due to the higher precision of gpcBR. All parameters used in the gpcBR index determination are obtained with good precision and are not adversely affected by the low 3D-GPC detector response at high molecular weights from the concentration detector. Errors in detector volume alignment also do not affect the accuracy of the gpcBR index determination.

[0091] Thermal creep

[0092] The conditions from IEC 60811-2-1, part 9.1 were followed. Dumbbells as specified in Figure 12 of IEC 60811-1-1 were cut from 1 mm thick crosslinked compression molded plaques. The dumbbells were tested at 200°C after 20 min at 20 N / cm 2 Thermal Creep Under Load. Thermal creep measures the extension under load, with results reported as a percentage (%). The value indicates the degree of crosslinking, with lower values indicating a higher level of crosslinking.

[0093] Melt index

[0094] As used herein, the term "melt index" or "MI" refers to a measure of how easily a thermoplastic polymer flows when in a molten state. Melt index, or I2, is measured according to ASTM D 1238, Condition 190°C / 2.16 kg and is reported in grams eluted per 10 minutes (g / 10 min). I10 is measured according to ASTM D 1238, Condition 190°C / 10 kg and is reported in grams eluted per 10 minutes (g / 10 min).

[0095] Moving Die Rheometer (MDR) Testing

[0096] According to ASTM D5289-12, Standard Test Method for Rubber Property--Vulcanization Using Rotorless CureMeters, an MDR test was performed on an MDR2000 (Alpha Technologies) at 180°C for 20 minutes while monitoring the change in torque. The lowest measured torque value is designated as "ML" and is expressed in deciNewton-meters (dN-m). As curing or crosslinking proceeds, the measured torque value increases, eventually reaching a maximum torque value. The maximum or highest measured torque value is designated as "MH" and is expressed in dN-m. All other things being equal, the greater the MH torque value, the greater the degree of crosslinking. The T90 crosslinking time is determined as the number of minutes required to reach a torque value equal to 90% of the difference MH minus ML (MH-ML) (i.e., 90% of the distance from ML to MH). The shorter the T90 crosslinking time, that is, the earlier 90% of the way the torque value changes from ML to MH, the faster the cure rate of the test sample. On the contrary, the longer the T90 crosslinking time, ie the longer the time required for the torque value to reach 90% on the way from ML to MH, the slower the curing speed of the test sample.

[0097] Nuclear magnetic resonance (NMR) 1 H NMR)

[0098] As used herein, the term "nuclear magnetic resonance" or "NMR" or "proton NMR" refers to a spectroscopic analysis of a material or compound that provides information about the chemical composition and structure of the material or compound. Samples for proton NMR were prepared using 0.1 to 0.2 g of sample in 3.25 g of 30 / 70 wt / wt o-dichlorobenzene-d4 / perchloroethylene (ODCB-d4 / PCE) containing 0.001 M chromium (III) acetylacetonate Cr(AcAc)3 in a 10 mm tube. The sample was heated and vortexed at 115°C to ensure homogeneity. Single pulse proton spectra were obtained on a Bruker AVANCE 600 MHz spectrometer equipped with a Bruker CryoProbe and a sample temperature of 120°C. Spectra were collected using a ZG pulse P1 = 20 us (90° PW), 64 scans, AQ 1.82s, D1 15s.

[0099] By obtaining as described above 1 H NMR spectroscopy was performed to determine the amount of Si-CH3 per 1000 carbons and Si-CH=CH2 (interchangeably referred to as "Si-vinyl") groups per 1000 carbons. The total polymer protons were quantified by integrating from about -0.5 ppm to 3 ppm, and the integral was set to a value of 2000 and therefore represents 1000 carbons. The signals from the three Si-vinyl protons appeared as three separate multiplets from about 5.8 ppm to 6.1 ppm. The (D Vi The )4 multiplet partially overlaps with one of the LDPE chain end vinyl protons at about 5.76 ppm. Therefore, only the two multiplets at about 5.92 ppm and 6.02 ppm were integrated and averaged to give the moles of Si-vinyl per 1000 carbons. DETAILED DESCRIPTION

[0100] 1. method

[0101] The present disclosure provides a method. In one embodiment, the method includes providing (A) an ethylene / MOCOS copolymer. The ethylene / MOCOS copolymer comprises (i) units derived from ethylene, (ii) 0.01 wt% to 0.5 wt% of units derived from a comonomer, and (iii) optionally units derived from a terpolymer comonomer. The comonomer is a monocyclic organosiloxane (MOCOS) of formula (I)

[0102] [R 1 ,R 2 SiO 2 / 2 ] n

[0103] Where n is an integer greater than or equal to 3,

[0104] Each R 1 are independently (C2-C4)alkenyl or H2C=C(R 1a )-C(=O)-O-(CH2) m -

[0105] where R 1a is H or methyl;

[0106] m is an integer from 1 to 4; and

[0107] Each R 2 are independently H, (C1-C4)alkyl, phenyl or R 1 .

[0108] The method comprises mixing (B) a free radical initiator with (A) the ethylene / MOCOS copolymer to form a mixture. The method comprises heating the mixture for a certain period of time and forming a crosslinkable ethylene / MOCOS copolymer composition.

[0109] In one embodiment, the method includes heating the crosslinkable composition at a curing temperature for a period of time and forming a crosslinked ethylene / MOCOS copolymer composition having a gel content greater than 70%.

[0110] The method comprises providing an ethylene / MOCOS copolymer. The ethylene / MOCOS copolymer is an ethylene-based polymer and comprises (i) units derived from ethylene, (ii) units derived from a comonomer, and (iii) optionally units derived from a terpolymer. The comonomer is a monocyclic organosiloxane (MOCOS) of formula (I)

[0111] [R 1 ,R 2 SiO 2 / 2 ] n

[0112] Where n is an integer greater than or equal to 3,

[0113] Each R 1 are independently (C2-C4)alkenyl or H2C=C(R 1a )-C(=O)-O-(CH2) m-

[0114] where R 1a is H or methyl,

[0115] m is an integer from 1 to 4, and

[0116] Each R 2are independently H, (C1-C4)alkyl, phenyl or R 1 .

[0117] Ethylene-based polymers of monocyclic organosiloxanes (MOCOS) of formula (I) are interchangeably referred to as "ethylene / MOCOS copolymers", and when a terpolymer is present, ethylene-based polymers of monocyclic organosiloxanes (MOCOS) of formula (I) are interchangeably referred to as "ethylene / MOCOS / terpolymers", wherein ethylene units constitute the majority (wt%) of the monomers present in the polymer. In other words, the ethylene-based polymer composition comprises ethylene monomer, MOCOS comonomer (and optional terpolymer), each of these two monomers (or each of these three monomers when a terpolymer is present) polymerized into the polymer backbone. In this way, the ethylene / MOCOS copolymers (and / or ethylene / MOCOS / terpolymers) of the present invention are structurally different from polyethylene having a functional adjuvant grafted to the polymer chain in a side chain manner. The weight percent of the MOCOS comonomer is based on the total weight of the ethylene / MOCOS copolymer (or the total weight of the ethylene / MOCOS / terpolymer when a termonomer is present).

[0118] In addition to ethylene, the ethylene / MOCOS copolymer comprises units derived from a comonomer. The comonomer is of formula (I) [R 1 ,R 2 SiO 2 / 2 ] n A monocyclic organosiloxane (interchangeably referred to as "MOCOS" or "MOCOS comonomer") of formula (I) is a molecule containing a monocyclic substructure composed of silicon and oxygen atoms arranged in an alternating arrangement; and formula (I) contains an unsaturated organic (hydrocarbyl) group; and optionally hydrogen ("H"), a saturated substituent group, or an aromatic substituent group. At least two unsaturated organic groups, and each of the at least two silicon atoms in the cyclic substructure has at least one unsaturated organic group bonded thereto, and wherein any remaining valences of the silicon atoms, after taking into account the unsaturated organic groups and the oxygen atoms, are bonded to hydrogen atoms, saturated substituent groups, or aromatic substituent groups; or a collection of such molecules.

[0119] MOCOS can be a monocyclic organosiloxane consisting of a 6-membered ring (n=3), an 8-membered ring (n=4), a 10-membered ring (n=-5), or a 12-membered ring (n=6). The ring substructure is composed of units of the following formula (I):

[0120] [R 1 ,R 2 SiO 2 / 2 ] n ,

[0121] wherein n is an integer greater than or equal to 3, or n is 3, or 4 to 5, or 6,

[0122] Each R 1 are independently (C2-C4)alkenyl or H2C=C(R 1a )-C(=O)-O-(CH2) m- , where R 1a is H or methyl,

[0123] Each R 2 are independently H, (C1-C4)alkyl, phenyl or R 1 (as defined above).

[0124] In each [R 1 ,R 2 SiO 2 / 2 ] unit, R 1 Group and R 2 The groups are bonded to their corresponding silicon atoms.

[0125] These units may be simply designated D using conventional organosiloxane shorthand notation. R1,R2 ,

[0126] So that formula (I) becomes [D R1,R2 ] n . R 1 With R 2 Can be the same or different.

[0127] Non-limiting examples of compounds suitable for use in MOCOS of formula (I) include: Vi,Et , R 1 It is vinyl and R 2 is ethyl, where Vi is vinyl and Et is ethyl; for MOCOS shorthand name D 烯丙基，Et , R 1 is allyl and R 2 is ethyl; for MOCOS shorthand name D 丁烯基，Et , R 1 is a butenyl group (H2C=C(H)CH2CH2-) and R 2 is ethyl; for MOCOS shorthand name D Vi,Vi , R 1 It is vinyl and R 2 is vinyl; shorthand name for MOCOS D 烯丙基，烯丙基 , R 1 is allyl and R 2 is allyl; for MOCOS shorthand name D 丁烯基，丁烯基 , R1 is a butenyl group (H2C=C(H)CH2CH2-) and R 2 is a butenyl group; for MOCOS the shorthand name is D Vi,Ph , R 1 It is vinyl and R 2 is phenyl; for MOCOS shorthand name D 烯丙基 , Ph , R 1 is allyl and R 2 is benzene; for MOCOS shorthand name D 丁烯基 , Ph , R 1 is a butenyl group (H2C=C(H)CH2CH2-) and R 2 It is phenyl.

[0128] When R 2 When it is a methyl group (CH3), the unit can be more simply named D R1 , so that formula (I) becomes [D R1 ] n Additional non-limiting examples of compounds suitable for use in MOCOS of formula (I) include: For the MOCOS shorthand name D Vi , R 1 It is vinyl and R 2 is a methyl group; for MOCOS, the shorthand name is D 烯丙基 , R 1 is allyl and R 2 is a methyl group; for MOCOS, the shorthand name is D 丁烯基 , R 1 is a butenyl group (H2C=C(H)CH2CH2-) and R 2 It's methyl.

[0129] In one embodiment, the MOCOS of formula (I), each R 1 are independently H2C=C(R 1a )-C(=O)-O-(CH2) m -, where R 1a is H or methyl, and the subscript m is an integer from 1 or 2 to 3 or to 4 and any range or individual value therein. In further embodiments, each R 2 is independently (C1-C2)alkyl or (C2-C3)alkenyl; or each R 2 is independently (C1-C2)alkyl; or each R 2 is independently methyl.

[0130] In one embodiment, the MOCOS of formula (I) is 2,4,6-trimethyl-2,4,6-trivinyl-cyclotrisiloxane "(D Vi )3" (CAS No. 3901-77-7):

[0131] Structure (B)

[0132]

[0133] In one embodiment, the MOCOS of formula (I) is 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-cyclotetrasiloxane "(D Vi )4" (CAS No. 2554-06-5):

[0134] Structure (C)

[0135]

[0136] In one embodiment, the MOCOS of formula (I) is 2,4,6,8,10-pentamethyl-2,4,6,8,10-pentavinyl-cyclopentasiloxane (D Vi )5.

[0137] The MOCOS comonomer of formula (I) is present in the ethylene-based polymer in an amount of 0.01 wt% to 2 wt%, or 0.01 wt% to 0.5 wt%, or 0.05 wt% to 0.45 wt%, or 0.1 wt% to 0.40 wt%, or 0.3 wt% to 0.5 wt%, or 0.15 wt% to 0.30 wt%, or 0.05 wt% to 0.15 wt%. The weight percentages are based on the total weight of the ethylene-based polymer composition, i.e., the ethylene / MOCOS copolymer.

[0138] In addition to ethylene and MOCOS comonomers, ethylene / MOCOS copolymers also include optional units derived from terpolymers, and are ethylene / MOCOS / terpolymers. When present, the terpolymers are olefins, unsaturated esters, functionalized olefins, silanes, and combinations thereof. The non-limiting examples of suitable terpolymers (when there are terpolymers) include propylene, C4-C8 α-olefins, acrylates, (meth) acrylates, vinyl acetate, vinyltrimethoxysilane, and combinations thereof. When terpolymers are present in ethylene-based polymers, the terpolymers are present in an amount of 0.5wt% to 50wt%, or 1wt% to 40wt%, or 1wt% to 30wt%, or 1wt% to 25wt%, or 1wt% to 20wt%, or 1wt% to 15wt%, or 3wt% to 12wt%, or 5wt% to 10wt%. Weight percentages are based on the total weight of the ethylene / MOCOS / terpolymer.

[0139] In one embodiment, the ethylene-based polymer composition of the present invention comprises an ethylene / MOCOS copolymer of formula (I) and further comprises a terpolymeric monomer of formula (II)

[0140] Formula (II)

[0141] [R 1 ,R 2 SiO 2 / 2 ] n

[0142] Where n is an integer greater than or equal to 3,

[0143] Each R 1 are independently methyl, (C2-C4)alkenyl or H2C=C(R 1a )-C(=O)-O-(CH2) m -, the prerequisite is at least two R 1 Not a methyl group,

[0144] where R 1a is H or methyl,

[0145] m is an integer from 1 to 4, and

[0146] Each R 2 are independently H, (C1-C4)alkyl, phenyl or R 1 .

[0147] In one embodiment, the ethylene / MOCOS copolymer (and / or ethylene / MOCOS / terpolymer) can be a component in an ethylene-based polymer composition that includes one or more optional additives. When additives are present, non-limiting examples of suitable additives include stabilizers, light stabilizers, UV absorbers, antioxidants, plasticizers, antistatic agents, voltage stabilizers, crosslinking aids and scorch retardants, pigments, dyes, carbon black, nanoparticles, nucleating agents, fillers, slip agents, flame retardants, processing aids, smoke suppressants, viscosity control agents, and anti-caking agents. Based on the weight of the ethylene-based polymer composition, the ethylene-based polymer composition can, for example, include less than 70% by combined weight of one or more additives and fillers.

[0148] In one embodiment, the ethylene-based polymer composition is compounded with one or more antioxidants. Non-limiting examples of suitable antioxidants are bis(4-(1-methyl-1-phenylethyl)phenyl)amine (e.g., NAUGARD 445); 2,2-methylene-bis(4-methyl-6-tert-butylphenol) (e.g., VANOX MBPC); 2,2'-thiobis(2-tert-butyl-5-methylphenol) (CAS No. 90-66-4, CAS No. 96-69-5, commercially available as LOWINOX TBM-6); 2,2'-thiobis(6-tert-butyl-4-methylphenol) (CAS No. 90-66-4, commercially available as LOWINOX TBP-6); tris[(4-tert-butyl-3-hydroxy-dimethylphenyl)methyl]-1,3,5-triazine-2,4,6-trione (e.g., CYANOX 1790); pentaerythritol tetrakis(3-(3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)propionate (e.g., IRGANOX 1010, CAS No. 6683-19-8); 2,2'-thiodiethyl 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropionate (e.g., IRGANOX 1035, CAS No. 41484-35-9); distearyl thiodipropionate ("DSTDP"); dilauryl thiodipropionate (e.g., IRGANOX PS800); stearyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (e.g., IRGANOX 1076); 2,4-bis(dodecylthiomethyl)-6-methylphenol (IRGANOX 1726); 4,6-bis(octylthiomethyl)-o-cresol (e.g., IRGANOX 1520); and 2',3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide (IRGANOX 1024); 4,4-thiobis(2-tert-butyl-5-methylphenol) (also known as 4,4'-thiobis(6-tert-butyl-m-cresol)); 2,2'-thiobis(6-tert-butyl-4-methylphenol); tris[(4-tert-butyl-3-hydroxy-2,6-dimethylphenyl)methyl]-1,3,5-triazine-2,4,6-trione; distearyl thiodipropionate; and combinations thereof. The antioxidant is present in an amount of 0.01 wt% to 1.5 wt%, or 0.05 wt% to 1.2 wt%, or 0.07 wt% to 1.0 wt%, or 0.1 wt% to 0.5 wt%, based on the total weight of the ethylene-based composition. The ethylene-based polymer composition is treated with an antioxidant prior to the heating step.

[0149] In one embodiment, the ethylene-based polymer composition is composed of (i) ethylene and (ii) 0.05 wt% to 0.5 wt% of a Vi )3、(DVi )4 and (D Vi )5, the ethylene / MOCOS copolymer having an Mw / Mn of 5.0 to 9.5 or 7.5 to 9.5, a vinyl content of 0.3600 / 1000 carbon atoms to 0.6200 / 1000 carbon atoms, a trans content of 0.1000 / 1000 carbon atoms to 0.3100 / 1000 carbon atoms and an MI of 2.0 g / 10 min to 5.0 g / 10 min.

[0150] In one embodiment, the ethylene-based polymer composition is composed of (i) ethylene and (ii) 0.05 wt% to 0.5 wt% of (D Vi )4, the ethylene / MOCOS copolymer composition has one, some or all of the following characteristics:

[0151] (i) an Mw / Mn of 5.0 to 9.5 or 7.5 to 9.5; and / or

[0152] (ii) a vinyl content of from 0.3600 / 1000 carbon atoms to 0.6200 / 1000 carbon atoms; and / or

[0153] (iii) a trans content of 0.1000 / 1000 carbon atoms to 0.3100 / 1000 carbon atoms; and / or

[0154] (iv) MI of 2.0 g / 10 min to 5.0 g / 10 min, or 2.5 g / 10 min to 4.7 g / 10 min.

[0155] In one embodiment, the ethylene-based polymer composition is composed of (i) ethylene and (ii) 0.1 wt% to 0.5 wt% of a Vi )4, wherein the ethylene / MOCOS copolymer has an Mw / Mn of 7.0 to 7.5, a vinyl content of 0.5800 / 1000 carbon to 0.6200 / 1000 carbon, a trans content of 0.2000 / 1000 carbon atoms to 0.2500 / 1000 carbon atoms and an MI of 35.0 g / 10 min to 42.0 g / 10 min.

[0156] In one embodiment, the ethylene-based polymer composition is an ethylene / MOCOS / MA terpolymer consisting of (i) ethylene, (ii) 0.01 wt% to 0.5 wt% MOCOS, and (iii) 1 wt% to 50 wt% MA or 8 wt% to 12 wt% MA. The weight percentages are based on the total weight of the ethylene / MOCOS / MA terpolymer.

[0157] The method includes mixing (B) a free radical initiator with (A) the ethylene / MOCOS copolymer to form a mixture. In one embodiment, the free radical initiator is an organic peroxide. The organic peroxide is a molecule containing carbon atoms, hydrogen atoms and two or more oxygen atoms and having at least one -OO- group, provided that when there are more than one -OO- groups, each -OO- group is indirectly bonded to another -OO- group via one or more carbon atoms; or a collection of such molecules. Non-limiting examples of suitable organic peroxides include diacyl peroxides, peroxycarbonates, peroxydicarbonates, peroxyesters, peroxyketals, cyclic ketone peroxides, dialkyl peroxides, ketone peroxides, and combinations thereof.

[0158] The organic peroxide may be of formula R O -OOR O A monoperoxide, where each R O Independently (C1-C 20 )alkyl group or (C6-C 20 ) aryl group. Each (C1-C 20 )alkyl groups are independently unsubstituted or substituted with 1 or 2 (C6-C 12 ) aryl group substituted. Each (C6-C 20 ) aryl groups are unsubstituted or substituted with 1 to 4 (C1-C 10 ) alkyl group substituted. Alternatively, the organic peroxide may be of formula R O -OOROOR O A diperoxide wherein R is a divalent hydrocarbon group, such as (C2-C 10 )alkylene, (C3-C 10 ) cycloalkylene or phenylene, and each R O As defined above.

[0159] Non-limiting examples of suitable organic peroxides include dicumyl peroxide; dodecyl peroxide; benzoyl peroxide; t-butyl perbenzoate; di(t-butyl) peroxide; cumene hydroperoxide; 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3; 2,5-dimethyl-2,5-di(t-butylperoxy)hexane; t-butyl hydroperoxide; isopropyl percarbonate; α,α'-bis(t-butylperoxy)diisopropylbenzene tert-Butylperoxy-2-ethylhexyl monocarbonate; 1,1-bis(tert-butylperoxy)-3,5,5-trimethylcyclohexane; 2,5-dimethyl-2,5-dihydroxyperoxide; tert-butylcumyl peroxide; α,α'-bis(tert-butylperoxy)-p-diisopropylbenzene; bis(1,1-dimethylethyl) peroxide; bis(1,1-dimethylpropyl) peroxide; 2,5-dimethyl-2,5-bis(1,1-dimethyl 2,5-Dimethyl-2,5-bis(1,1-dimethylethylperoxy)hexyne; 4,4-bis(1,1-dimethylethylperoxy)pentanoic acid; butyl ester; 1,1-bis(1,1-dimethylethylperoxy)-3,3,5-trimethylcyclohexane; benzoyl peroxide; tert-butyl peroxybenzoate; di-tert-amyl peroxide ("DTAP"); bis(α-tert-butylperoxyisopropyl)benzene ("BIPB") ; Isopropylcumyl tert-butyl peroxide; tert-butyl cumyl peroxide; di-tert-butyl peroxide; 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane; 2,5-bis(tert-butylperoxy)-2,5-dimethylhexyne-3,1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane; isopropylcumyl cumyl peroxide; butyl 4,4-di(tert-butylperoxy)valerate; di(isopropylcumyl) peroxide; and the like.

[0160] Non-limiting examples of suitable commercially available organic peroxides include TRIGONOX from AkzoNobel and LUPEROX from Arkema.

[0161] In one embodiment, the free radical initiator is an organic peroxide, and the organic peroxide is dicumyl peroxide (DCP).

[0162] The mixing of ethylene / MOCOS copolymer (A) and radical initiator (B) is carried out by placing the pellets of ethylene / MOCOS copolymer and the radical initiator into a container optionally with an antioxidant. Subsequently, the container is shaken, rotated, tumbled or otherwise agitated so that the radical initiator contacts the pellets of ethylene / MOCOS copolymer and is retained by these pellets, or otherwise the radical initiator is absorbed into these pellets. The method is included in heating the mixture of (A) ethylene / MOCOS copolymer and (B) radical initiator at a temperature of 60°C, or 65°C to 70°C, or 75°C, or 80°C, or heating at a temperature higher than the melting temperature of peroxide. The mixture is heated for a duration of 1 minute, or 10 minutes, or 30 minutes to 1 hour, or 2 hours, or 3 hours, or 4 hours, or 5 hours, or 6 hours, or 7 hours, or 8 hours, thereby enabling the radical initiator to diffuse into the ethylene / MOCOS copolymer pellets.

[0163] In one embodiment, mixing and heating occur sequentially.

[0164] In one embodiment, mixing and heating occur simultaneously.

[0165] The method comprises crosslinking (interchangeably referred to as "curing") a crosslinkable ethylene / MOCOS copolymer composition to form a crosslinked ethylene / MOCOS copolymer composition having a gel content greater than 70%. In one embodiment, the gel content of the crosslinked ethylene / MOCOS copolymer is 71%, or 75%, or 80% to 85%, or 90%, or 95%, or 99%. In other embodiments, the gel content of the crosslinked ethylene / MOCOS copolymer is 71% to 99%, or 72% to 95%, or 73% to 90%.

[0166] The curing step (cross-linking step) comprises heating the cross-linkable ethylene / MOCOS copolymer composition at a curing temperature of greater than 100°C, or 110°C, or from 125°C to 150°C, or from 180°C, or from 200°C, for a duration of 1 minute, or 5 minutes, or 10 minutes, or 30 minutes, or from 1 hour to 2 hours, or 5 hours, or 7 hours, or more, to form a cross-linked ethylene / MOCOS copolymer composition having a gel content of 71% to 99%, or from 72% to 95%, or from 73% to 90%.

[0167] The crosslinking of ethylene / MOCOS copolymers can be accomplished by a procedure that does not utilize a peroxidic initiator. In one embodiment, the method includes subjecting the ethylene / MOCOS copolymer to radiation and forming a crosslinked ethylene / MOCOS copolymer having a gel content greater than 70%. The radiation can be electron beam radiation (E beam), ultraviolet (UV) radiation, photoinitiation, and combinations thereof. In this embodiment, the mixing step and heating step described are eliminated and replaced by the radiation step. The gel content of the crosslinked ethylene / MOCOS copolymer is greater than 70%, or 71%, or 75%, or 80% to 85%, or 90%, or 95%, or 99%. In another embodiment, the gel content of the crosslinked ethylene / MOCOS copolymer is 71% to 99%, or 72% to 95%, or 73% to 90%.

[0168] In one embodiment, the method comprises mixing 3 wt% to 0.05 wt% of a free radical initiator (B) with 97 wt% to 99.95 wt% of an ethylene / MOCOS copolymer (A). The method comprises heating the mixture at a temperature of 70°C to 90°C to form a crosslinkable ethylene / MOCOS copolymer. The method comprises curing the crosslinkable ethylene / MOCOS copolymer composition to form a crosslinked ethylene / MOCOS copolymer composition having a T90 of less than 5 minutes or a T90 of 3.0 minutes to 4.9 minutes and a gel content of 71% to 99% after curing.

[0169] In one embodiment, the method includes mixing 1.5wt% to 0.5wt% of a free radical initiator (B) with 98.5wt% to 99.5wt% of an ethylene / MOCOS copolymer (A). The ethylene / MOCOS copolymer (A) has 0.3wt% to 0.5wt% of units derived from a MOCOS comonomer (based on the total weight of the ethylene / MOCOS copolymer). The method includes heating the mixture at a temperature of 70°C to 90°C for 0.5 to 8 hours, and forming a crosslinkable ethylene / MOCOS copolymer composition. The method includes curing the crosslinkable ethylene / MOCOS copolymer composition to form a crosslinked ethylene / MOCOS copolymer composition having a gel content of 71% to 99% and a thermal creep elongation of 20% to 50%.

[0170] In one embodiment, the method includes mixing 1.5wt% to 0.5wt% of a free radical initiator (B) with 98.5wt% to 99.5wt% of an ethylene / MOCOS copolymer (A). The ethylene / MOCOS copolymer has 0.05wt% to 0.2wt% of units derived from a MOCOS comonomer (based on the total weight of the ethylene / MOCOS copolymer). The method includes heating the mixture at a temperature of 70°C to 90°C for 2 to 6 hours, and forming a crosslinkable ethylene / MOCOS copolymer composition. The method includes curing the crosslinkable ethylene / MOCOS copolymer composition to form a crosslinked ethylene / MOCOS copolymer composition having a gel content of 71% to 99% and a thermal creep elongation of 50% to 90%.

[0171] In one embodiment, the process comprises mixing 3 wt% to 0.3 wt% of a free radical initiator (B) with 97 wt% to 99.7 wt% of an ethylene / MOCOS copolymer (A) and 0.05 wt% to 0.3 wt% of one or more antioxidants (yielding a 100 wt% crosslinkable ethylene-based polymer composition). The process comprises heating the mixture at a temperature of 70°C to 90°C for 2 hours to 6 hours, and forming a crosslinkable ethylene-based polymer composition. After curing, the crosslinked ethylene / MOCOS copolymer composition formed has

[0172] (1) a gel content of 64% to 99% and a T90 of 3.0 minutes to 5.3 minutes, or

[0173] (2) Gel content of 71% to 99%, and T90 of less than 5 minutes, or T90 of 3.0 minutes to 4.9 minutes.

[0174] 2. Composition

[0175] The present disclosure provides a composition that is a crosslinkable ethylene-based polymer composition. As used herein, a "crosslinkable ethylene-based polymer composition" is a composition containing an ethylene-based polymer and one or more additives (e.g., a free radical initiator or an organic peroxide) that enhances the ability of the ethylene-based polymer to crosslink when subjected to crosslinking conditions (e.g., heat, radiation, and / or UV light). After being subjected to the crosslinking conditions (e.g., "after crosslinking" or "after curing"), the crosslinkable ethylene-based polymer composition becomes a "crosslinked ethylene-based polymer composition," which is structurally and physically different from the crosslinkable ethylene-based polymer composition.

[0176] In one embodiment, the crosslinked ethylene-based composition is formed by a peroxide-initiated process as previously disclosed herein.

[0177] In one embodiment, a crosslinkable ethylene-based polymer composition is provided, comprising (A) an ethylene copolymer consisting of (i) units derived from ethylene, (ii) 0.01 wt% to 0.5 wt% of units derived from a comonomer, and (iii) optionally units derived from a terpolymer. The comonomer is a monocyclic organosiloxane (MOCOS) of formula (I):

[0178] [R 1 ,R 2 SiO 2 / 2 ] n

[0179] Where n is an integer greater than or equal to 3,

[0180] Each R 1 are independently (C2-C4)alkenyl or H2C=C(R 1a )-C(=O)-O-(CH2) m -

[0181] where R 1a is H or methyl;

[0182] m is an integer from 1 to 4; and

[0183] Each R 2 are independently H, (C1-C4)alkyl, phenyl or R 1 (ethylene / MOCOS copolymer). The crosslinkable ethylene-based polymer composition further comprises (B) a free radical initiator. After crosslinking, the crosslinkable ethylene / MOCOS copolymer composition forms a crosslinked ethylene / MOCOS copolymer having a gel content greater than 70%. In one embodiment, the gel content of the crosslinked ethylene / MOCOS copolymer composition is 71%, or 75%, or 80% to 85%, or 9%, or 95%, or 99%. In other embodiments, the gel content of the crosslinked ethylene / MOCOS copolymer composition is 71% to 99%, or 72% to 95%, or 73% to 90%.

[0184] In one embodiment, the MOCOS comonomer used in the ethylene / MOCOS copolymer is selected from 2,4,6-trimethyl-2,4,6-trivinyl-cyclotrisiloxane (D Vi )3, 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-cyclotetrasiloxane (D Vi)4、2,4,6,8,10-pentamethyl-2,4,6,8,10-pentavinyl-cyclotrisiloxane (D Vi )5 and their combinations.

[0185] In one embodiment, the MOCOS comonomer used in the ethylene / MOCOS copolymer is (D Vi ) 4. The crosslinked ethylene / MOCOS copolymer composition comprises 0.01 wt% to 0.5 wt% of (D Vi )4 (based on the total weight of the ethylene / MOCOS copolymer), and the crosslinked ethylene / MOCOS copolymer composition has one, some or all of the following characteristics:

[0186] (i) Mw / Mn of 7.5 to 9.5, and / or

[0187] (ii) a vinyl content of 0.3600 / 1000 carbons to 0.6200 / 1000 carbons, and / or

[0188] (iii) a trans content of 0.1000 / 1000 carbon atoms to 0.3100 / 1000 carbon atoms.

[0189] In one embodiment, the crosslinkable ethylene-based polymer composition comprises (A) 97 wt% to 99.95 wt% of an ethylene / MOCOS copolymer; and (B) 3 wt% to 0.05 wt% of a free radical initiator. The weight percentages are based on the total weight of the crosslinked ethylene / MOCOS copolymer composition.

[0190] In one embodiment, the crosslinkable ethylene-based polymer composition comprises 98.5wt% to 99.5wt% ethylene / MOCOS copolymer (A). The ethylene / MOCOS copolymer has 0.3wt% to 0.5wt% units derived from MOCOS comonomers (based on the total weight of the ethylene / MOCOS copolymer). The crosslinkable ethylene-based polymer composition further comprises 1.5wt% to 0.5wt% of a free radical initiator (B). After crosslinking, the crosslinkable ethylene / MOCOS copolymer composition forms a crosslinked ethylene / MOCOS copolymer composition having a gel content of 71% to 99%, or 72% to 95%, or 73% to 90%, and has a thermal creep elongation of 20% to 50%.

[0191] In one embodiment, the crosslinkable ethylene-based polymer composition comprises 98.5wt% to 99.5wt% ethylene / MOCOS copolymer (A). The ethylene / MOCOS copolymer has 0.05wt% to 0.2wt% units derived from MOCOS comonomers (based on the total weight of the ethylene / MOCOS copolymer). The crosslinkable ethylene-based polymer composition further comprises 1.5wt% to 0.5wt% of a free radical initiator (B). After crosslinking, the crosslinkable ethylene / MOCOS copolymer composition forms a crosslinked ethylene / MOCOS copolymer composition having a gel content of 71% to 99%, or 72% to 95%, or 73% to 90%, and has a hot creep elongation of 50% to 90%.

[0192] In one embodiment, the crosslinkable ethylene-based polymer composition comprises 98.5wt% to 99.5wt% ethylene / MOCOS copolymer (A). The ethylene / MOCOS copolymer has 0.05wt% to 0.2wt% units derived from MOCOS comonomers (based on the gross weight of the ethylene / MOCOS copolymer). The crosslinkable ethylene-based polymer composition also comprises 1.5wt% to 0.5wt% free radical initiators (B). The crosslinkable ethylene-based polymer composition comprises 0.05wt% to 0.3wt% one or more antioxidants (producing 100wt% crosslinkable ethylene-based polymer composition). The crosslinkable ethylene-based polymer composition forms a crosslinked ethylene / MOCOS copolymer composition having one, some or all of the following characteristics after crosslinking:

[0193] (i) a gel content of 64% to 99%, or 71% to 99%, or 72% to 95% or 73% to 90%; and / or

[0194] (ii) a T90 of 3.0 minutes to 5.3 minutes or 3.0 minutes to 4.9 minutes; and / or

[0195] (iii) Hot creep elongation of 50% to 90%.

[0196] application

[0197] The crosslinked ethylene / MOCOS copolymer compositions can be used in a variety of applications including, but not limited to, wire and cable applications such as insulation layers for MV / HV / EHV cables for AC (alternating current) and DC (direct current), carbon black filled semiconductive layers for MV / HV / EHV cables, accessories for power distribution transmission lines, insulation layers, insulating encapsulation films for photovoltaic (PV) modules.

[0198] By way of example and not limitation, some embodiments of the present disclosure will now be described in detail in the following examples.

[0199] Example

[0200] The materials used in the examples are set forth in Table 1 below.

[0201] Table 1

[0202]

[0203] 1. Polymerization of ethylene and MOCOS comonomer

[0204] The amounts of each material used in the samples and comparative samples (controls) are provided in Table 2 below. To a 545 milliliter (ml) stirred autoclave were added ethylene, MOCOS ((D Vi ) 4) a mixture of propylene (as a chain transfer agent). An organic peroxide (Luperox 26) was added to the mixture as a polymerization initiator in the form of a 0.5 wt%, 1 wt% or 2 wt% solution in odorless mineral spirits. The mixture was subjected to approximately 28,000 psi (1,969 kg / cm 2 ) set pressure. The reactor temperature was set to a target temperature of 220°C. Under the polymerization conditions shown in Table 2, ethylene / MOCOS copolymers were continuously synthesized and subsequently converted into pellet form by melt extrusion. The conditions listed in Table 2 are average values over the time span over which the samples were collected. The "autoclave-prepared" experimental reactor copolymers thus formed were found to have the properties shown in Table 3.

[0205] Table 2: Polymerization conditions

[0206]

[0207] The properties of the resulting ethylene / MOCOS copolymers are provided in Table 3 below.

[0208] Table 3 - Properties of Ethylene / MOCOS Copolymers

[0209]

[0210] NM = not measured, * - wt% (D Vi )4 and wt% MA, based on the total weight of the ethylene-based polymer composition, + Vinyl and trans are in mole %

[0211] Table 4: GPC properties of ethylene / MOCOS copolymers

[0212]

[0213]

[0214] *ID = identification, wt% in closed brackets (D Vi )4 is the first value and MI is the second value

[0215] Proton NMR was used to characterize (D Vi )4 incorporation / conversion in the selected samples. Proton NMR detected the presence of Si-CH3 and Si-vinyl groups. The average per molecule (D Vi )4 has 2.5 double bonds incorporated into the polyethylene backbone (Table 5). Without being bound by a particular theory, it is believed that (D Vi The copolymerization of )4 with ethylene and the incorporation of two double bonds produces an H-branched structure, which unexpectedly increases the melt strength.

[0216] Table 5 - NMR data of ethylene / MOCOS copolymers

[0217]

[0218] 2. Crosslinked ethylene-based polymer compositions

[0219] For Inventive Example (IE), pellets of dicumyl peroxide (DCP) and ethylene / MOCOS copolymer (and optional antioxidant) were weighed into a 250 mL fluorinated HDPE bottle. The bottle was then shaken for approximately 5 seconds (s) to mix. The bottle was then placed in an 80°C oven. The bottle was then removed and shaken every 5 minutes (min) (each shake having a duration of approximately 5 seconds), for a total of 6 times at 0 min, 5 min, 10 min, 15 min, 20 min, and 25 min. The bottle was then shaken 5 times and then placed in an oven for 6.5 hours. The MDR was then measured.

[0220] For comparative samples (CS), DCP, LDPE pellets and free (D Vi )4 was weighed into a 250 mL fluorinated HDPE bottle. The bottle was then shaken for about 5 seconds (s) to mix. The bottle was then placed in an oven at 80°C. The bottle was then taken out and shaken every 5 minutes (min) (each shake had a duration of about 5 seconds), for a total of 6 times at 0 min, 5 min, 10 min, 15 min, 20 min, and 25 min. The bottle was then shaken 5 times and then placed in the oven for 6.5 hours. The MDR was then measured. In the comparative sample, Vi )4 No bonding occurs between LDPE.

[0221] Table 6A - Crosslinked Ethylene-Based Polymer Compositions

[0222]

[0223]

[0224] *ID = identification, wt% in closed brackets (D Vi )4 is the first value and MI is the second value, C=control,

[0225] Table 6B - Crosslinked Ethylene-Based Polymer Compositions (Continued)

[0226]

[0227] *ID = identification, wt% in closed brackets (D Vi )4 is the first value and MI is the second value, C=control, S=sample

[0228] Tables 6A and 6B show the ethylene / (D Vi )4 copolymers have a higher crosslinking level (greater than 70% gel content) than copolymers using an equivalent amount of free (D Vi )4 (vi-d4 in the data table) as an LDPE additive to achieve a higher level of crosslinking. In Tables 6A to 6B, 7A to 7B, 8 and 9, a side-by-side comparison is provided whereby a LDPE containing a given (D Vi )4 wt% comonomer content ethylene / (D Vi )4 copolymer of each embodiment of the present invention and composed of LDPE and free (D Vi )4 constitutes a comparative sample pairing - wt% (D Vi )4 comonomer and free (D Vi )4 are the same or substantially the same by weight. The peroxide content is the same in each side-by-side comparison. For each side-by-side comparison, the inventive examples have (i) higher MH-ML values, and / or (ii) shorter T90 times, and / or (iii) greater percent gel content, and / or (iv) lower hot creep values than the comparative samples.

[0229] Tables 7A-7B (below) show crosslinked compositions containing the antioxidant Irganox 1076 (shown as 1076 in the data tables).

[0230] Table 7A: Crosslinked Ethylene-Based Polymer Compositions with Antioxidants

[0231]

[0232] *ID = identification, wt% in closed brackets (D Vi )4 is the first value and MI is the second value, C=control, S=sample

[0233] Table 7B: Crosslinked Ethylene-Based Polymer Compositions with Antioxidants (Continued)

[0234]

[0235]

[0236] *ID = identification, wt% in closed brackets (D Vi )4 is the first value and MI is the second value, C=control

[0237] Table 8: Thermal creep data of crosslinked compositions

[0238]

[0239]

[0240] Table 9: Thermal creep data of crosslinked compositions (continued)

[0241]

[0242] *0.15% AO blend = Antioxidant blend 0.06% Cyanox 1790, 0.09% DSTDP and 19ppm Uvinul

[0243] 4050 (0.15 wt% aggregate based on the total weight of the crosslinkable ethylene-based polymer composition)

[0244] The hot creep data from Tables 8 to 9 (above) show that the crosslinked ethylene-based polymer compositions with ethylene / MOCOS copolymers exhibit improved hot creep properties (i.e., less % hot creep elongation) compared to the comparative sample (control formulation). These data demonstrate the advantages of using ethylene / MOCOS copolymer compositions to achieve the desired level of crosslinking.

[0245] Comparison of IE34 (with 0.6 wt% free (D Vi 4) ethylene / (0.15 wt%) MOCOS copolymer) to CS32 (LDPE and 0.75 wt% free (D Vi )4) shows that IE34 is in the same (D Vi )4. A better curing response was achieved with a higher weight percentage (0.15wt%) and the same amount of DCP (0.3wt%), which had a shorter T90 time (5.25 vs. 5.55), lower thermal creep (85% vs. 143%), and higher MH-ML (2.50 vs. 2.41).

[0246] It is particularly intended that the present disclosure is not limited to the embodiments and descriptions contained herein, but rather includes modifications of those embodiments including portions of the embodiments and combinations of elements of different embodiments as appear within the scope of the following claims.

Claims

1. A method comprising: Providing (A) an ethylene / MOCOS copolymer, the ethylene / MOCOS copolymer comprising (i) units derived from ethylene, (ii) 0.01 wt% to 0.5 wt% of units derived from comonomers, and (iii) optionally units derived from termonomers, and The comonomer is a monocyclic organosiloxane MOCOS of the following formula (I): [R 1 ,R 2 SiO 2 / 2 n Formula (I)​ Where n is an integer greater than or equal to 3, Each R 1 are independently C2-C4 alkenyl or H2C=C(R 1a )-C(=O)-O-(CH2)m - , where R 1a is H or methyl; m is an integer from 1 to 4; and Each R 2 are independently H, C1-C4 alkyl, phenyl or R 1 ; mixing (B) a free radical initiator with (A) the ethylene / MOCOS copolymer to form a mixture; heating the mixture; and A cross-linkable ethylene / MOCOS copolymer composition is formed.

2. The method of claim 1 , comprising crosslinking the crosslinkable ethylene / MOCOS copolymer composition; and A crosslinked ethylene / MOCOS copolymer composition is formed having a gel content greater than 70%.

3. The method according to claim 1 or 2, comprising: Ethylene / MOCOS copolymers are provided, wherein the MOCOS comonomer is selected from the group consisting of 2,4,6-trimethyl-2,4,6-trivinyl-cyclotrisiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-cyclotetrasiloxane, 2,4,6,8,10-pentamethyl-2,4,6,8,10-pentaveinyl-cyclopentasiloxane, and combinations thereof.

4. The method according to claim 1 or 2, comprising: mixing 3 wt% to 0.3 wt% of the free radical initiator (B) with 97 wt% to 99.7 wt% of the ethylene / MOCOS copolymer (A); heating the mixture at a temperature of 70° C. to 90° C.; curing the cross-linkable ethylene / MOCOS copolymer composition; and A crosslinked ethylene / MOCOS copolymer composition is formed having a T90 of less than 5 minutes.

5. The method according to claim 1 or 2, comprising: mixing 1.5 wt% to 0.5 wt% of the free radical initiator (B) with 98.5 wt% to 99.5 wt% of an ethylene / MOCOS copolymer (A) having 0.3 wt% to 0.5 wt% of units derived from the MOCOS comonomer; heating the mixture at a temperature of 70° C. to 90° C.; forming a cross-linkable ethylene / MOCOS copolymer composition; curing the cross-linkable ethylene / MOCOS copolymer composition; as well as A cross-linked ethylene / MOCOS copolymer composition is formed having a hot creep elongation of 20% to 50%.

6. The method according to claim 1 or 2, comprising: mixing 1.5 wt% to 0.5 wt% of the free radical initiator (B) with 98.5 wt% to 99.5 wt% of an ethylene / MOCOS copolymer (A) having 0.05 wt% to 0.2 wt% of units derived from the MOCOS comonomer; heating the mixture at a temperature of 70°C to 90°C; and forming a cross-linkable ethylene / MOCOS copolymer composition; curing the cross-linkable ethylene / MOCOS copolymer composition; as well as A cross-linked ethylene / MOCOS copolymer composition is formed having a hot creep elongation of 50% to 90%.

7. A crosslinkable ethylene-based polymer composition comprising: (A) an ethylene copolymer comprising (i) units derived from ethylene, (ii) 0.01 wt% to 0.5 wt% of units derived from comonomers, (iii) optionally units derived from termonomers; and The comonomer is a monocyclic organosiloxane MOCOS of the following formula (I): [R 1 ,R 2 SiO 2 / 2 n Formula (I)​ Where n is an integer greater than or equal to 3, Each R 1 are independently C2-C4 alkenyl or H2C=C(R 1a )-C(=O)-O-(CH2)m - where R 1a is H or methyl; m is an integer from 1 to 4; and Each R 2 are independently H, C1-C4 alkyl, phenyl or R 1 ; (B) a free radical initiator; and The gel content of the ethylene / MOCOS copolymer composition after cross-linking is greater than 70%.

8. The crosslinkable ethylene-based polymer composition of claim 7, wherein the MOCOS comonomer is selected from the group consisting of 2,4,6-trimethyl-2,4,6-trivinyl-cyclotrisiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-cyclotetrasiloxane, 2,4,6,8,10-pentamethyl-2,4,6,8,10-pentaveinyl-cyclopentasiloxane, and combinations thereof.

9. The crosslinkable ethylene-based polymer composition according to claim 7 or 8, comprising (A) 97 wt% to 99.95 wt% of said ethylene / MOCOS copolymer; and (B) 3 wt% to 0.05 wt% of the free radical initiator.

10. The crosslinkable ethylene-based polymer composition according to claim 7 or 8, comprising 98.5 wt% to 99.5 wt% of an ethylene / MOCOS copolymer (A) having 0.3 wt% to 0.5 wt% of units derived from the MOCOS comonomer; 1.5 wt% to 0.5 wt% of the free radical initiator (B); and The thermal creep elongation of the ethylene / MOCOS copolymer composition after cross-linking is 20% to 50%.

11. The crosslinkable ethylene-based polymer composition according to claim 7 or 8, comprising 98.5 wt% to 99.5 wt% of an ethylene / MOCOS copolymer (A) having 0.05 wt% to 0.2 wt% of units derived from the MOCOS comonomer; 1.5 wt% to 0.5 wt% of the free radical initiator (B); The thermal creep elongation of the ethylene / MOCOS copolymer composition after cross-linking is 50% to 90%.

12. The crosslinkable ethylene-based polymer composition of claim 7 or 8, wherein the MOCOS comonomer is 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-cyclotetrasiloxane, and the ethylene / MOCOS copolymer has (i) Mw / Mn of 7.5 to 9.5, (ii) a vinyl content of 0.3600 / 1000 carbons to 0.6200 / 1000 carbons, and (iii) a trans content of 0.1000 / 1000 carbon atoms to 0.3100 / 1000 carbon atoms.

13. The crosslinkable ethylene-based polymer composition of claim 7 or 8, comprising an antioxidant.

14. A crosslinked ethylene-based polymer composition formed from the crosslinkable composition of claim 7 or 8.

15. An article comprising the crosslinked ethylene-based polymer composition of claim 14.

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