Polyphenylene sulfone

Abstract

A polyphenylene sulfone (PPSU) consisting essentially of benzophenone-coupled polyphenylene sulfone segments A and B of formula I, where segments A and B may be the same or different and are of formula II, where x is from 4.5 to 8.

Description

[0001] The present invention relates to polyphenylenesulfones based on phenylenesulfone segments, which are connected to each other by benzophenone groups.

[0002] Polyarylethersulfones and polyaryletherketones are classified as high-performance thermoplastics. Some preparation methods and some properties of copolymers of polyarylethersulfones and polyaryletherketones have been disclosed.

[0003] Thus, EP 278 720 A2 discloses crystalline copolymers having a molar content of 50 to 92 mol% of ketone units and polyphenylsulfone (PPSU) units with a chain length of 1 to 3.5. They are obtained by a method in which the block containing ketone units is polymerized first.

[0004] CN 106167548 A discloses the reaction of DCDPS, adding 3-fluoro-4-chloro-benzophenone to DCDPS in ppm amounts, and then adding biphenyl. It also discloses stopping the reaction by adding 3-fluoro-4-chloro-benzophenone.

[0005] For example, US 4268635 describes the preparation of block copolymers in which a suspension of crystalline polyetherketone or etherketone / sulfone copolymer is used.

[0006] EP 2 225 328 describes polyphenylenesulfone ketones prepared from a mixture of 4,4'-diphenol, 4,4'-dichlorodiphenylsulfone (DCDPS), and benzophenone substituted at the 4,4'-position with fluorine, chlorine, or a hydroxyl group.

[0007] In EP 332 012, block polycondensates prepared from 4,4'-diphenol, DCDPS, 4,4'-difluoro and / or dihydroxybenzophenone are disclosed as components of high-temperature thermoplastic compositions.

[0008] The problem to be solved by the present disclosure is to provide a novel polyphenylenesulfone that exhibits good tolerance to hydraulic fluids, gasoline, and / or fuels, particularly to flame-retardant hydraulic fluids. In addition, the novel polyphenylenesulfone should provide good processing stability at high temperatures, and particularly good corrosion resistance to flame-retardant hydraulic fluids. Furthermore, the polyphenylenesulfone should support the manufacture of coatings, fibers, films, foams, and molded articles. One motivation is to propose a novel polyphenylenesulfone suitable for the manufacture of membranes. It is intended to be applicable to membranes for purifying produced water, particularly for fuel and oil production. In addition, a method for manufacturing the novel polyphenylenesulfone should be provided, which is simple and thus particularly suitable for industrial-scale production, for example, salt separation should be achievable within a short filtration time.

[0009] Disclosed below is a polyphenylene sulfone (PPSU) which consists essentially of benzophenone-coupled polyphenylene sulfone segments A and B of formula I

[0010]

[0011] wherein segments A and B may be the same or different and are of formula II

[0012]

[0013] wherein x is from 4.5 to 9.

[0014] Also disclosed is a solution comprising PPSU. Additionally, a method for preparing PPSU is disclosed, which method comprises reacting at least one dihalodiphenyl sulfone with at least one dihydroxybiphenyl to obtain a polyphenylene sulfone oligomer having a number average degree of polymerization of from 4.5 to 9 (hereinafter also referred to as chain length x), and then reacting the oligomer with at least one dihalobenzophenone. The use of the PPSU and the solution comprising PPSU, respectively, thus obtained in the manufacture of coatings, fibers, films, foams, moldings and / or membranes is also disclosed. At the same time, membranes comprising the PPSU or the PPSU thus obtained and articles comprising such membranes are disclosed. Additionally, the use of such membranes in water purification is disclosed.

[0015] "At least one" hereinafter generally means one or two or more, such as three or four or five or more, where more may mean a large amount or uncountable. For example, "at least one" may mean one, or a mixture of two or more. If used with a compound, "at least one" means one or two or more compounds having different chemical compositions (i.e., chemical properties).

[0016] "Polymer" hereinafter may mean a homopolymer or a copolymer or a mixture thereof. Those skilled in the art will understand that any polymer, which may be a homopolymer or a copolymer, is essentially usually a mixture of polymer individuals having different constitutions (such as number average degree of polymerization, degree of branching or end group properties). This fact is also often described as a distribution. Thus, "at least one" as a prefix to a polymer means that different types of polymers may be included, and thus each type of polymer may have the specific distribution described above.

[0017] Those skilled in the art can further understand that any polymer is derived from monomers or their oligomers or mixtures, and thus polymers contain the reacted and polymerized forms.

[0018] Hereinafter

[0019] The starting compounds are at least one dihalodiphenyl sulfone and at least one dihydroxybiphenyl

[0020] The coupling agent is at least one dihalodibenzophenone

[0021] The solvent L is at least one solvent

[0022] Compound C is at least one compound having a functional group reactive with a reactive group in the polymer chain

[0023] The polyphenylene sulfone (PPSU) consists essentially of the benzophenone-coupled polyphenylene sulfone chain segments A and B of formula I. Thus, the PPSU consists entirely or substantially entirely of the said coupled chain segments. Optionally, the PPSU may contain a small amount of units with different structures. If the PPSU contains such units with different structures, it is generally preferably not more than 10 moL%, for example not more than 5 moL%, and more preferably it is not more than 1 mol% or 2 mol%, based on the number of moles of the starting compounds contained. Usually, it may be most preferred that the PPSU does not contain such units with different structures.

[0024] The chain segments A and B may be the same or different. For example, the chain lengths x of the chain segments A and B may be different, ranging from 4.5 to 9, for example 4.5 to 8, 4.5 to 7 or 4.5 to 6 or 4.5 to 5. For the PPSU consisting essentially of the benzophenone-coupled polyphenylene sulfone chain segments A and B of formula I, very good results regarding the target properties are obtained, where the chain segments A and B may be the same or different and the chain length x is from 4.5 to 7.

[0025] The linearity of the chain segments A and B may also be different. Thus, both chain segments may be linear. One or both chain segments may be non-linear. A and B may be different in terms of both the chain length x and the linearity. Usually, it may be preferably that both chain segments A and B are linear and have the same or different chain lengths x.

[0026] The units structurally different from the coupled chain segments are not particularly limited, provided that they support the technical properties sought for the PPSU, in particular good tolerance to hydraulic fluids, oils and / or fuels, processing stability, and ease of production. Such units may for example be derived from monomers commonly used for preparing polyarylether sulfones and / or polyarylether ketones.

[0027] There are no particular restrictions on the nature of the end groups of PPSU. Generally, it depends on whether reactive or non-reactive end groups are required as end groups. For example, if it is desired to polymerize PPSU with at least one other monomer or polymer to produce a copolymer, such as a block copolymer or a polymer network, reactive end groups may be preferred, for example. Feasible end groups are phenolic OH end groups or phenolic end groups, phenolic alkoxy end groups (where -OCH3 end groups are preferred), amino end groups (where -NH2 end groups are preferred), halogen end groups (where especially -F or -Cl), and among the halogen end groups, Cl is most preferred. The end group can also be a phthalic anhydride end group. The end groups can be of one type or different from each other. Generally, preferred end groups are Cl-, OH-, and / or -OCH3. Usually, inert end groups can be obtained by capping reactive end groups. If PPSU is intended for applications obtainable by solution production methods (such as solution spinning or casting from solution), capping may not be required. Uncapped PPSU can be used especially for the preparation of composite membranes. In this case, PPSU having Cl and / or OH end groups may be advantageous. For PPSU containing -OCH3 end groups, very good results are obtained in the preparation of membranes or membrane-containing articles, especially in water treatment, more specifically, in the treatment of the produced water, where the end groups consist essentially of -OCH3, for example, 98% of all end groups, for example, 99% or more are -OCH3 end groups, and PPSU is generally more preferred.

[0028] PPSU preferably may have a relative viscosity of 0.20 to 1.30 dl / g, especially 0.30 to 0.95. Depending on the solubility of PPSU, the relative viscosity can be measured in a 1 wt% solution of N-methylpyrrolidone or in a mixture of phenol and dichlorobenzene, in each case at 20 °C or 25 °C.

[0029] The number-average molecular weight Mn of PPSU may preferably be 7500 to 60000 g / mol, especially 8000 to 45000 g / mol, as determined by gel permeation chromatography (GPC). The weight-average molar mass Mw of PPSU may preferably be 14000 to 120000 g / mol, especially it may be 18000 to 100000 g / mol, and may be particularly preferably 25000 to 80000 g / mol, as determined by GPC. Thus, Mn and Mw can be determined by GPC, using dimethylacetamide as the solvent, narrow-distribution polymethyl methacrylate as the standard (calibrated between 800 and 1820000 g / mol), using 4 columns (a pre-column, 3 separation columns based on polyester copolymers), operating at 80 °C and a flow rate set to 1 ml / min, with an injection volume of 100 μl. For detection, an RI detector can be used.

[0030] Taking into account the ease of preparation from a PPSU solution, it is preferable that the PPSU consists essentially of linearly linked segments A and B coupled by benzophenone, where segments A and B may be the same or different and where x is from 4.5 to 9 and Mw is from 25,000 to 80,000 g / mol (measured as described above), and it is preferable that the PPSU contains -OCH3 and -Cl end groups, where it contains no more than 1 mol% of other units, based on the molar amount of the starting compounds contained, and where it may more preferably contain no other units.

[0031] Taking into account the ease of PPSU extrusion or injection molding, it is advantageous that it has good melt stability. The melt stability can be determined by comparing the apparent melt viscosity at a given time with the apparent melt viscosity after a period of time. Then, the ratio Q of the two is a measure of the melt stability. Preferably, the Q value of the PPSU is 1.5 or lower, more preferably less than 1.5, where Q can be determined in the manner given in the examples.

[0032] The disclosed PPSU can be advantageously prepared by a method which comprises - where it may preferably consist essentially of - reacting at least one dihalodiphenyl sulfone with at least one dihydroxybiphenyl to obtain a phenylene sulfone oligomer with a chain length x of from 4.5 to 9, and reacting the oligomer with at least one dihalobenzophenone. Thereby, the structure of the phenylene sulfone oligomer chain can be schematically represented by formula (II).

[0033] Taking into account the ease of industrial scale production, it is preferably to react one or two, especially one dihalophenyl sulfone with one or two, especially one dihydroxybiphenyl to obtain a phenylene sulfone oligomer. For the same reason, it is preferably to react the phenylene sulfone oligomer with one or two, especially one dihalobenzophenone. Therefore, reacting a phenylene sulfone oligomer - which is obtained by reacting one dihalodiphenyl sulfone with one dihydroxybiphenyl - with one dihalobenzophenone to obtain PPSU can observe very good results.

[0034] At least one dihalophenyl sulfone can be a 4,4'-substituted phenyl sulfone. Dihalophenyl sulfones with other substitution patterns can also be used, such as 2,4'- or 2,2'-substituted dihalophenyl sulfones. At least one dihydroxybiphenyl can be a 4,4'-substituted biphenyl. Dihydroxybiphenyls with other substitution patterns can also be used, such as 2,4'- or 2,2'-substituted dihydroxybiphenyls. Reacting at least one 4,4'-substituted dihalophenyl sulfone with at least one 4,4'-substituted biphenyl gives a linear phenylene sulfone oligomer. Those skilled in the art should understand that non-linear phenylene sulfone oligomers can be obtained in other cases. Those skilled in the art should further understand that the linearity of the phenylene sulfone oligomer can vary according to the combination and amount of the dihalophenyl sulfone and the dihydroxybiphenyl with other substitution patterns.

[0035] At least one dihalodibenzophenone can be a 2,2'- or 2,4'- or 4,4'-substituted benzophenone. Reacting a linear polyphenylene sulfone oligomer with a 4,4'-substituted benzophenone produces PPSU, which is substantially composed of diphenylene-coupled linear polyphenylene sulfoxide segments A and B and is linear. Those skilled in the art should understand that nonlinear PPSU can be obtained in other cases. Those skilled in the art should further understand that depending on the combination and amount of nonlinear polyphenylene oligomers and / or dihalodibenzophenones having a 2,2'- or 2,4'-substitution pattern, PPSU with different degrees of linearity can be obtained. Compared with the corresponding linear PPSU with a comparable molecular weight, they can have a lower solution viscosity and thus can generally be processed better from solution, especially for manufacturing films. Linear PPSU can be preferred, especially considering ease of production (especially on an industrial scale) and the observable good overall technical effects. In this regard, it can be even more preferred that the PPSU is linear, where x is from 4.5 to 7, Mw is from 25,000 to 80,000 g / mol (determined as described above), and the end groups are substantially composed of -OCH3 and Cl, where preferably 60% to 90%, especially 70% to 85% of the end groups are -OCH3, and where no other units are contained in the PPSU.

[0036] While other halogen groups are feasible, fluorine and / or chlorine are generally preferred halogens in at least one dihalodiphenyl sulfone and at least one dihalodibenzophenone, respectively.

[0037] Examples of dihalodiphenyl sulfones are 4,4'-dichlorodiphenyl sulfone, 4,4'-difluorodiphenyl sulfone, 4,4'-dibromodiphenyl sulfone, 2,2'-dichlorodiphenyl sulfone, 2,2'-difluorodiphenyl sulfone, and if linear PPSU is pursued, 4,4'-dichlorodiphenyl sulfone (DCDPS) and / or 4,4'-difluorodiphenyl sulfone are particularly preferred. Examples of dihalodibenzophenones are 4,4'-dichlorobenzophenone, 4,4'-difluorobenzophenone, 2,2-dichlorobenzophenone, 2,4-dichlorobenzophenone, 2,2'-difluorobenzophenone, and / or 2,4'-difluorobenzophenone, and if linear PPSU is pursued, 4,4'-dichlorobenzophenone and / or 4,4'-difluorobenzophenone are particularly preferred.

[0038] The method for preparing PPSU comprises - where it may preferably consist essentially of - reacting starting compounds to obtain a phenylene sulfone oligomer of the above-specified chain length and reacting said oligomer with a coupling agent. The method may include being carried out using preformed oligomers, such as oligomers formed in a separate reaction apparatus or oligomers isolated before their reaction with the coupling agent. Most preferably, the following method is used, which comprises - where it may preferably be the case that the method consists essentially of - the reaction being carried out in a one-pot reaction. Generally, such a one-pot reaction is a convenient and robust method. In this case, the starting compounds react with the oligomer until the desired chain length is reached, and they react with the coupling agent without separating the oligomer.

[0039] The starting compounds undergo a polycondensation reaction to obtain a phenylene sulfone oligomer, which can generally be carried out in the presence of at least a catalytic amount of a base. It can be carried out in the absence of solvent L or, as is preferably the case, in the presence of solvent L. A reaction mixture is formed. The components of the reaction mixture generally react simultaneously. The components can be mixed in an upstream step and then reacted. It is also possible to feed each starting component into a reactor, where these components are mixed and then reacted. The polycondensation reaction to obtain a phenylene sulfone oligomer is preferably carried out in a one-step process. This means that the deprotonation of the starting compound having an OH group and its condensation reaction with the starting compound having a halogen group are carried out in a single reaction step without separation of the intermediate product.

[0040] Common general knowledge in the preparation of polymers in the field of polyarylether sulfones with simultaneous control can be applied to phenylene sulfone oligomers and is described in more detail hereinafter. For phenylene sulfone oligomers, for example, it can be achieved by controlling the amount of functional groups of the starting compounds, i.e., the amount they have before polymerization. The ratio of the starting compounds to be used is in principle determined by the stoichiometry of the polycondensation reaction for the theoretical elimination of hydrogen halide (such as hydrogen chloride) and is constructed in a known manner by those skilled in the art.

[0041] Generally preferably, the molar ratio of the functional groups of the starting compounds that are reactive with each other can be controlled or adjusted. Thus, the molar ratio of the halogen group and the hydroxyl group can vary depending on factors such as the control of the end groups or the reaction rate and the chain length x of the phenylene sulfone oligomer.

[0042] Therefore, for example, the chain length x of a phenylene sulfone oligomer containing phenolate end groups can be adjusted using a defined deviation from the stoichiometric ratio between the starting compounds having a halogen group and a hydroxyl group. Generally, the molar ratio does not exceed 0.80:1 to 0.895:1, for example 0.80:1 to 0.85:1.

[0043] Phenylene sulfone oligomers having phenolic end groups can react with dihalodibenzophenones. Depending on factors such as the control of the end groups or the control of the reaction rate and the molecular weight of PPSU, the molar ratio of the phenylene sulfone oligomer and the dihalodibenzophenone can vary. Thus, generally, a defined deviation in the number of moles of the phenylene sulfone oligomer and the dihalodibenzophenone is determined. From the perspective of ease of production, it is generally preferred to prepare the phenylene sulfone oligomer using an excess of the starting compound having a hydroxyl group and to react the phenylene sulfone oligomer with the dihalodibenzophenone. In this case, the ratio of the OH groups of the phenylene sulfone oligomer to the halogen groups of the benzophenone, based on moles, can be from 0.70:1 to 1:1, especially from 0.75:1 to 0.95:1, and most preferably from 0.75:1 to 0.90:1.

[0044] In principle, the method can be carried out in the absence of a solvent. Especially in cases where a very light-colored PPSU is aimed to be obtained, the method can be carried out more advantageously in the presence of at least one solvent (solvent L).

[0045] In this method, solvent L can preferably be N-methyl-2-pyrrolidone (NMP) or N-ethyl-2-pyrrolidone (NEP), dimethylacetamide (DMAC), sulfolane, or any combination thereof. To improve solubility, solvent L can be, for example, a mixture of 2 to 3 solvents. In most cases, using two or more, preferably only one solvent is sufficient. Solvent L can especially be DMAC, NMP, NEP, or any mixture thereof. For industrial production purposes, it is often easier to use only one of the preferred solvents.

[0046] To separate the water released during the reaction to obtain the phenylene oligomer and / or PPSU, an azeotropic cosolvent such as toluene or chlorobenzene can be used. Generally, it is preferred not to use such azeotropic cosolvents. It is generally preferred to separate the water together with solvent L during the heating process. The loss of solvent L can be addressed, for example, by using a larger amount of solvent L at the beginning or by adding solvent L during the reaction. Controlling the increase in viscosity during the reaction can also be a means of controlling the molecular weight of PPSU.

[0047] The disclosed method generally comprises—or preferably consists essentially of—the step of reacting a starting compound and / or a phenylene oligomer with a coupling agent in the presence of at least one base. Those of ordinary skill in the art should understand that the phenolic hydroxyl group preferably reacts in the presence of at least one base to increase the reactivity towards halogen substituents. The at least one base can generally be a hydroxide, carbonate or bicarbonate. Thus, it can be a mixture of at least one hydroxide and at least one carbonate or a mixture of at least one carbonate and at least one bicarbonate. At least one anhydrous alkali metal carbonate can be preferred. A mixture of different hydroxides or different carbonates or different bicarbonates can also be used, for example. It is preferred to use one base. It is preferred that the one base is an alkali metal carbonate. In particular, sodium carbonate, potassium carbonate, calcium carbonate or a mixture thereof can be preferred, and very particularly, potassium carbonate can be preferably used as the base. From the perspective of reaction rate and reduction of by-product amount, potassium carbonate with a volume-weighted average particle size less than 100 microns is especially preferred, such as 5 to 80 μm, preferably 10 to 60 μm, such as 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm or 55 μm or any different μm sizes between 5 and 100 μm, determined in a solid suspension of chlorobenzene / sulfolane 60 / 40 (by weight) using a Malvern Mastersizer 2000 instrument.

[0048] In the composition, DMAC, NMP or NEP or any mixture thereof is particularly preferably used as the solvent, and potassium carbonate is used as the base, especially potassium carbonate with a size less than 100 μm. In a composition, NMP is particularly preferably used as the solvent, and potassium carbonate is used as the base, especially potassium carbonate with a size less than 100 μm, such as 5 to 80 μm, preferably 10 to 60 μm, such as 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm or 55 μm or any different μm sizes between 5 and 100 μm, determined in the manner described above.

[0049] The reaction of the starting compound to obtain a phenylene sulfone oligomer and their reaction with a coupling agent can be carried out at a temperature at which the reaction proceeds at an acceptable rate and respectively obtain a phenylene sulfone oligomer and PPSU with an acceptable quality (such as having the desired molecular weight and molecular weight distribution). Generally, the method is carried out at 80 to 250 °C, preferably at 100 to 220 °C. When the method is carried out in the presence of solvent L and under ambient pressure, the upper temperature limit is generally determined by the boiling point of solvent L. In particular, when the reaction is carried out in the absence of solvent, the stability of the reactants may be a factor limiting the reaction temperature.

[0050] While those skilled in the art can adapt the reaction temperature and time to the specific PPSU to be produced, a reaction temperature in the range of 180 to 205 °C can be applicable, and the temperature can preferably be 185 to 195 °C. At the latter temperature, the reaction of the starting compounds to form the phenylsulfone oligomers is usually quite fast. Therefore, the initial reaction time should be in the range of about 1 hour to about 2 hours. It can be less than 2 hours and is usually more than 1 hour. The reaction of the oligomers with the coupling agent may require an additional 2 to 20 hours at this temperature, for example 3 to 18 hours, for example 3 to 15 hours. In particular, if the method is carried out in solvent L (such as NMP), the said conditions can be preferred conditions.

[0051] At least one compound (Compound C) having one functional group reactive with the reactive groups contained in the polymer chain can be used in the method. Preferably, one Compound C is used. Thereby, it can control the chain length of the PPSU. Generally, it can be preferred to react with Compound C after the polycondensation reaction, for example after reaching at least 90% conversion. Preferably, Compound C is at least one aliphatic organic halide. This causes the reactive end groups, especially the hydroxyl end groups, to react further. Then the PPSU contains Compound C in the reacted form. Such PPSU is usually stabilized etc. to prevent further extension of the polymer chains during further processing.

[0052] The preferred at least one aliphatic organic halide is at least one alkyl halide, especially an alkyl chloride having a linear or branched alkyl group with 1 to 10 carbon atoms, which can especially be a primary alkyl chloride, particularly preferably a methyl halide, especially methyl chloride.

[0053] The reaction with Compound C can preferably be carried out at a temperature of 90 °C to 160 °C, where a temperature of 100 °C to 150 °C can be preferred. The time can vary within a wide range and is usually at least 5 minutes, especially at least 15 minutes. The reaction time can usually preferably be 15 minutes to 8 hours, where the reaction time can especially be 30 minutes to 4 hours.

[0054] Different methods can be used for the reaction of Compound C (more specifically, at least one aliphatic organic halide). In addition, the amount of Compound C (more specifically, at least one aliphatic organic halide) can be stoichiometric or present in excess, where the excess can be up to 5-fold excess for example. For example, it can be preferred to add at least one aliphatic organic halide continuously, especially by continuous introduction in the form of a gas stream.

[0055] The reaction of Compound C can be carried out in a separate process unit or preferably directly in the polycondensation reactor.

[0056] If the method is carried out in the presence of solvent L, after the reaction is completed, additional solvent L can usually be added to cool the reaction mixture. The additional solvent L can be, for example, the solvent L in which the reaction is carried out, such as DMAC, NMP, NEP, sulfolane or any mixture thereof, such as DMAC, NMP, NEP or any mixture thereof, where NMP can be preferably used. For example, the reaction mixture can be cooled to a temperature range at which compound C can react with PPSU in a separate unit or the above polycondensation reactor. Thereafter, if necessary, the reaction mixture can be further cooled, preferably to about 80 °C. If PPSU does not react with compound C, the reaction mixture can be preferably cooled to about 80 °C. At this temperature, the reaction mixture (usually a suspension) is taken out from the respective reaction unit (usually including a reaction vessel) and transferred to at least one separation unit. The separation unit preferably comprises a filtration unit to separate the salt formed during the reaction, such as potassium chloride, from the reaction mixture.

[0057] Depending on the viscosity of the suspension, the method can take several minutes or hours, such as 30 minutes to 24 hours, preferably 1 to 24 hours. Then the product can be separated, for example, by precipitation by contacting the filtrate with a non-solvent. It can be, for example, a mixture of water and at least one polar aprotic solvent. Preferably, a mixture of water and solvent L (such as DMAC, NMP, NEP, sulfolane or any mixture thereof, such as DMAC, NMP, NEP or any mixture thereof, where NMP can be preferably used) is used. Thus, water can usually be used in an amount greater than solvent L (such as DMAC, NMP, NEP, sulfolane or any mixture thereof, such as DMAC, NMP, NEP or any mixture thereof, where NMP can be preferably used). It can be most preferably precipitated in a water / NMP mixture (80 / 20 by weight). The precipitation can also be carried out in an acidic medium, such as in a water / NMP mixture containing an acid. Suitable acids are, for example, organic or inorganic acids, such as carboxylic acids, such as acetic acid, propionic acid, succinic acid or citric acid, and inorganic acids, such as hydrochloric acid, sulfuric acid or phosphoric acid. The obtained precipitated solid, such as a powder or beads, can be collected, usually filtered, then usually washed and finally dried, where a temperature below the glass transition temperature, where 80 to 150 °C in vacuo can be advantageously used.

[0058] In addition to the above disclosure, those skilled in the art can adopt the methods available to them by applying their general knowledge. Preparation methods for producing polyarylethersulfone are described, for example, in Herman F. Mark, "Encyclopedia of Polymer Science and Technology", 3rd edition, Volume 4, 2003, chapter "Polysulfones", pages 2 to 8, and Hans R. Kricheldorf, "Aromatic Polyethers" in: Handbook of Polymer Synthesis, 2nd edition, 2005, pages 427 to 443. More details on the synthesis of OH-terminated polyarylethersulfone are given, for example, in R. Viswanathan, B. C. Johnson, J. E. McGrath, Polymer 25 (1984) 1827. Information on controlling the molecular weight is disclosed, for example, in A. Noshay, M. Matzner, C. N. Merriam, J. Polym. Sci. A-19 (1971) 3147.

[0059] The PPSU disclosed herein is substantially an amorphous polymer. Its advantage is that it is soluble in various solvents and can be processed at high temperatures.

[0060] Solutions comprising at least one PPSU are also disclosed. The solution comprises at least one liquid capable of dissolving at least one PPSU (hereinafter also referred to as the solute).

[0061] The solution can be produced by a preparation method of PPSU. In this case, the solution can contain certain solids. The method can include filtering the solution at a temperature above room temperature. Thus, the solution can be filtered at a temperature below the boiling point of the solute. The temperature can be constant or variable during the filtration time. Filtration can in principle be carried out in any filtration device suitable for the temperature conditions and the required pressure. The pore sizes that can be used range from μ to m, preferably 10 μm or smaller, for example 5 μm or smaller. The time required for filtration depends on factors such as temperature or the pore size used. Generally, the filtration of a solution comprising at least one PPSU can be achieved within a reasonable time for industrial-scale production. Generally preferably, the solvent comprises one PPSU - or as may be preferred, consists essentially of one PPSU and the solute. Thus, generally the filtrate is a solution consisting essentially of one PPSU and the solute. In particular, in the case where the solution is from this method, the solution generally only comprises one PPSU. It is also feasible to prepare the solution by bringing at least one PPSU, preferably one PPSU, into contact with the solute. With regard to removing the solvent after use, it is preferred to keep the amount of the solute to a minimum.

[0062] The amount of solute generally depends on the desired viscosity of the solution at the temperature at which the solution is processed and the intended use. The amount of solute needs to be sufficient to dissolve at least one PPSU at the temperature required to process the solution. Conveniently, the solute is at least one solvent L, such as DMAC, NMP, NEP, sulfolane or any mixture thereof, such as DMAC, NMP, NEP or any mixture thereof, where NMP may be preferred. The solution containing PPSU generally has a reduced tendency to gel. Accordingly, it generally has a convenient time span for processing.

[0063] The solution can in particular be used for the preparation of coatings, films, fibres or membranes. For this purpose, the solution can be mixed with other compounds, such as processing aids and / or other polymers. Thus, the solution can for example comprise at least one other polyarylene(ether)sulphone and / or at least one polyvinylpyrrolidone, the latter generally being preferred in terms of film formation. Accordingly, the solution can comprise the said other components or - as may preferably be the case - consist essentially of at least one PPSU, at least one solute and at least one other polyarylene(ether)sulphone and / or at least one polyvinylpyrrolidone.

[0064] Also disclosed herein is the use of at least one PPSU as disclosed herein or obtainable by the methods disclosed herein for the production of coatings, fibres, films, foams, moulded articles and / or membranes.

[0065] For example, a fiber is a more or less flexible structure that is relatively thin with respect to its length. The fiber can be dense or hollow. The fiber can be circular or nearly circular, or can have different cross-sectional shapes. For example, it can be flat. The fiber can also be tubular. The fiber can have a smooth surface, or can have pores or holes. The fiber can be obtained, for example, by an extrusion method. More preferably, the fiber derived from at least one PPSU (wherein usually one PPSU is preferred) is obtained by a spinning method. If the thermal stress on at least one PPSU is considered, solution spinning may be advantageous. For example, spinning can be carried out directly after the separation of PPSU from the salt. It is also possible to first separate the PPSU and then dissolve it in a solvent for spinning. In order to improve the mechanical strength of the fiber, it is advantageous to spin at least one PPSU (which is usually preferably one PPSU), which - as can be preferably - is spun from a solution by an electrospinning method, including magneto-electrospinning. For example, in the case of producing nanofibers, electrospinning can be most preferred. Magneto-electrospinning can be used to produce nonwoven materials from at least one PPSU, where usually one PPSU is preferred. Since the electrospinning method requires the melt or (which can be preferred) the solution to be conductive, it may not be necessary to separate the salt (all or substantially all of the salt) from the reaction mixture after the reaction. A solution containing one PPSU can preferably be used by an electrospinning method to prepare fibers, the PPSU consisting essentially of diphenyl ketone-coupled phenylene sulfone chain segments A and B of formula I and not containing structurally different units.

[0066] The molded article can be substantially a solid geometric body, which can be produced, for example, by a molding process, injection molding, extrusion, calendering, rotational molding, foaming, blow molding process, forming process or joining process. The molded article can be prepared using PPSU. Similarly, the molded article can be prepared from a mixture containing at least one PPSU, where the mixture can also contain at least one other polymer resin. Generally, in addition to at least one PPSU and optionally at least one other polymer resin, the mixture for manufacturing the molded article includes at least one processing aid and / or filler. The molded article containing at least one PPSU generally exhibits good flame retardancy and good tolerance to hydraulic fluids. Examples of preferred molded articles are aircraft connectors and spacers on the exterior of the aircraft fuselage, usually aluminum housings.

[0067] The membrane is, for example, a separation layer. The membrane can be understood to refer to an impermeable, partially impermeable or selectively permeable membrane, or a membrane permeable in one direction or a permeable membrane. The type of the membrane is generally not limited. Additionally, the membrane can be, for example, a reverse osmosis (RO) membrane, forward osmosis (FO) membrane, nanofiltration (NF) membrane, ultrafiltration (UF) membrane, microfiltration (MF) membrane. In many cases, it is preferred that the membrane is a UF membrane, NF membrane or MF membrane.

[0068] The PPSU disclosed in this article can be used in different filter membrane geometries. It can be used for flat membranes and / or capillary hollow fiber membranes. The fluid flowing to these membranes can take the form of dead-end flow or cross-flow.

[0069] The membrane can be produced using at least one PPSU, preferably one PPSU. Generally, the membrane can be prepared according to methods known to those of ordinary skill in the art. The membrane can be manufactured, for example, by solution casting. Thus, a casting solution can be prepared. The casting solution generally contains at least one (preferably one in many cases) compound that can be washed off the membrane. The compound is generally called a pore former. Therefore, in this case, the solution also contains the pore former. For the purpose of manufacturing the membrane from at least one PPSU, polyvinylpyrrolidone and / or polyethylene glycol (PEG) can generally be used as the pore former in the casting solution.

[0070] The membrane can be used in contact with water. In particular, the membrane can be used in water purification. More specifically, the membrane can be used to purify hydraulic fluids, gasoline, and / or water contaminated with or carrying fuel, such as water generated from daily life spills or industrial processing environments.

[0071] Advantageously, the membrane can be particularly used to purify the generated water, such as water from oil and gas manufacturing processes, which can be a hydraulic fracturing process or the recovery of desalinated water on an oil platform.

[0072] An article containing at least one membrane can be, for example, a filtration system, such as a filtration device, a component column, or a component bracket. Examples:

[0073] The following examples provide further explanation of the present invention but do not limit the present invention.

[0074] Definitions and abbreviations:

[0075] Reaction time: The time the reaction mixture is maintained at 190 °C.

[0076] DCDPS: 4,4′-Dichlorodiphenyl sulfone

[0077] BP: 4,4′-Dihydroxybiphenyl

[0078] NMP: N-Methyl-2-pyrrolidone

[0079] The particle size of potassium carbonate was measured in a solid suspension of chlorobenzene / sulfolane 60 / 40 (by weight) using the Malvern Mastersizer 2000 instrument as described above.

[0080] The chain length x of the oligomer was determined by potentiometric titration of the OH groups and elemental analysis of the organic Cl content of a precipitate taken from the reactor and dried before the addition of 4,4′-dichlorobenzophenone. The calculated value corresponds to the number-average molecular weight of the oligomer.

[0081] Determine the time required to filter the polymer solution.

[0082] The resulting polymer was processed into pellets using a ZSK 18 extruder. The throughput at 300 rpm was 2.5 kg / h, and the melt temperature (measured directly with a thermometer in the melt) was below 385 °C. From the pellets thus obtained, ISO bars (80 mm × 10 mm × 4 mm) and S2 tensile bars were prepared at a mass temperature of 370 °C and a tool temperature of 140 °C.

[0083] The solution viscosity (V.N.) was measured at 25 °C using an N-methylpyrrolidone solution of 0.01 g / ml of the polymer (DIN EN ISO 1628-1 (October 2012)).

[0084] The glass transition temperature (Tg) and melting point (Tm) of the polymer were determined by DSC analysis at a heating rate of 20 K / min. The reported values of the glass transition temperature, melting point, and heat of fusion are the values measured in the second heating run.

[0085] The melt stability of the sample was determined using a capillary rheometer at a mass temperature of 400 °C for 60 minutes. Subsequently, the apparent viscosity of the melt was measured at a shear rate of 55 s−1 every 5 minutes. The quotient (Q) of the apparent viscosity measured at 60 minutes and the apparent viscosity measured at 5 minutes is a measure of the melt stability. -1 The quotient (Q) of the apparent viscosity measured at 60 minutes and the apparent viscosity measured at 5 minutes is a measure of the melt stability.

[0086] The tolerance of the product to hydraulic fluids, gasoline, and / or fuel was determined as the tolerance to LD4 (58 wt% tributyl phosphate, 20 to 30 wt% phenyl dibutyl phosphate, 5 to 10 wt% butyl diphenyl phosphate, 1 to 5 wt% 2,6-di-tert-butyl-p-cresol, less than 10 wt% carboxylic acid esters). The S2 tensile bars were stored in LD4 for 24 hours. In each case, two of the S2 tensile bars were bent to a bending radius of 132 mm using a template before storing them. Using a camera, a photo was taken every minute to determine the time until breakage.

[0087] The results of the determination are shown in Table 1.

[0088] Preparation of the polymer - General procedural measures used in each case

[0089] Use a container equipped with a stir bar, a Dean-Stark trap, a nitrogen inlet, and temperature control. Use 304.05 g (2.20 mol) of potassium carbonate with a volume-average particle size of 34.5 μm. Continuously remove the water formed in the reaction by distillation. Do not use an azeotrope-forming agent. Replace the lost NMP.

[0090] After the reaction time, add 1500 ml of NMP to the container and adjust the temperature of the reaction mixture to 135 °C. Then, add chloromethane to the container over 60 minutes. Then purge the reaction mixture with nitrogen for an additional 30 minutes. Then cool the reaction mixture to 80 °C and transfer it to a heated pressure filter (80 °C), and separate the potassium chloride formed in the reaction mixture by filtration.

[0091] Filtration is carried out under a nitrogen pressure of 2.0 bar using a filter with a pore size of 3 μm.

[0092] Separate the polymer from the filtrate by precipitating the filtrate into a deionized water bath at room temperature (settling distance 0.5 m, throughput approximately 2.5 liters per hour). Collect the obtained beads and wash them with water at 85 °C for 20 hours (water throughput 160 liters per hour). Subsequently, dry the beads at a temperature below the glass transition temperature. The residual moisture content is less than 0.1 wt%.

[0093] For those samples that cannot be filtered, a small amount of material is precipitated. Then wash it with water and dry it at 120 °C for 24 hours. The residual moisture content is less than 0.1 wt%.

[0094] Comparative copolymer C1

[0095] In a container, dissolve and suspend 522.63 g (1.82 mol) of DCDPS, 372.41 g (2.00 moL) of BP, 50.22 g (0.20 mol) of 4,4'-dichlorobenzophenone, and potassium carbonate in 1152 ml of NMP respectively under a nitrogen atmosphere.

[0096] Heat the mixture to 190 °C within 1 hour. Subsequently, the reaction time is 5 hours.

[0097] Filter for 8 hours.

[0098] Then separate the polymer from the filtrate and dry it.

[0099] Comparative copolymer C2

[0100] In a container, dissolve and suspend 522.63 g (1.82 mol) of DCDPS, 372.41 g (2.00 mol) of BP, and potassium carbonate in 952 ml of NMP respectively under a nitrogen atmosphere.

[0101] Heat the mixture to 190 °C within 1 hour. The initial reaction time is 70 minutes.

[0102] Subsequently, separate 20 ml of the suspension. Then, add 50.22 g (0.200 mol) of 4,4′-dichlorobenzophenone dissolved in 200 ml of NMP to the container. Continue the reaction at 190 °C for 4 hours.

[0103] Filter for 8.5 hours.

[0104] Then separate the obtained polymer and dry it.

[0105] Comparative copolymer C3

[0106] In a container, dissolve and suspend 508.28 g (1.77 mol) of DCDPS, 372.41 g (2.00 mol) of BP, 62.78 g (0.25 mol) of 4,4′-dichlorobenzophenone, and potassium carbonate in 1152 ml of NMP under a nitrogen atmosphere.

[0107] Heat the mixture to 190 °C within 1 hour. The reaction time is 5 hours.

[0108] Filter for 10 hours.

[0109] Then separate the polymer from the filtrate and dry it.

[0110] PPSU 1

[0111] In a container, dissolve and suspend 508.28 g (1.77 mol) of DCDPS, 372.41 g (2.00 mol) of BP, and potassium carbonate in 952 ml of NMP under a nitrogen atmosphere.

[0112] Heat the mixture to 190 °C within 1 hour. The initial reaction time is 70 minutes.

[0113] Subsequently, separate 20 ml of the suspension. Then, add 62.78 g (0.250 mol) of 4,4′-dichlorobenzophenone dissolved in 200 ml of NMP to the container.

[0114] Continue the reaction at 190 °C. The reaction time is 4 hours.

[0115] Filter for 7.5 hours.

[0116] Then separate the polymer from the filtrate and dry it.

[0117] Comparative Example C4

[0118] In a container, 493.92 g (1.72 mol) of DCDPS, 372.41 g (2.00 mol) of BP, 75.33 g (0.3 mol) of 4,4'-dichlorobenzophenone and potassium carbonate were respectively dissolved and suspended in 1152 ml of NMP under a nitrogen atmosphere.

[0119] The mixture was heated to 190 °C within 1 hour. The reaction time was 5.5 hours.

[0120] Filter for 12 hours.

[0121] Then, the polymer was separated from the filtrate and dried.

[0122] PPSU 2

[0123] In a container, 493.92 g (1.72 mol) of DCDPS, 372.41 g (2.00 mol) of BP and potassium carbonate were respectively dissolved and suspended in 952 ml of NMP under a nitrogen atmosphere.

[0124] The mixture was heated to 190 °C within 1 hour. The preliminary reaction time was 70 minutes.

[0125] Subsequently, 20 ml of the suspension was separated. Then, 75.33 g (0.30 moL) of 4,4'-dichlorobenzophenone dissolved in 200 ml of NMP was added to the container. The reaction was continued at 190 °C for 5 hours.

[0126] Filter for 8 hours.

[0127] Then, the polymer was separated from the filtrate and dried.

[0128] Comparative copolymer C5

[0129] In a container, 465.20 g (1.62 moL) of DCDPS, 372.41 g (2.00 moL) of BP, 100.44 g (0.4 moL) of 4,4'-dichlorobenzophenone were respectively dissolved and suspended in 1152 ml of NMP under a nitrogen atmosphere.

[0130] The mixture was heated to 190 °C within 1 hour. The reaction time was 6 hours.

[0131] Filter for 14 hours.

[0132] Then, the obtained polymer was separated from the filtrate and dried.

[0133] PPSU 3

[0134] In a container, 465.20 g (1.62 mol) of DCDPS, 372.41 g (2.00 mol) of BP, and potassium carbonate were respectively dissolved and suspended in 952 ml of NMP under a nitrogen atmosphere.

[0135] The mixture was heated to 190 °C within 1 hour. The initial reaction time was 70 minutes.

[0136] Subsequently, 20 ml of the suspension was separated. Then, 100.44 g (0.40 moL) of 4,4′-dichlorobenzophenone dissolved in 200 ml of NMP was added to the container. The reaction was continued at 190 °C for 5.5 hours.

[0137] Filtration was carried out for 10 hours.

[0138] Then the polymer was separated from the filtrate and dried.

[0139] Comparative copolymer C6

[0140] In a container, 450.86 g (1.57 mol) of DCDPS, 372.41 g (2.00 mol) of BP, and potassium carbonate were respectively dissolved and suspended in 952 ml of NMP under a nitrogen atmosphere.

[0141] The mixture was heated to 190 °C within 1 hour. The initial reaction time was 70 minutes.

[0142] Subsequently, 20 ml of the suspension was separated. Then, 113.00 g (0.45 mol) of 4,4′-dichlorobenzophenone dissolved in 200 ml of NMP was added to the container. The reaction was continued at 190 °C for 6 hours.

[0143] Even after 24 hours of filtration time, only a small portion of the solution was filtered.

[0144] After 24 hours, the solution became a gel, and precipitation could only occur after diluting 20 ml of the solution / gel with 20 ml of NMP and heating to 120 °C.

[0145] Then the obtained polymer was separated from the filtrate and dried.

[0146] Comparative copolymer C7

[0147] In a container, 450.86 g (1.57 mol) of DCDPS, 372.41 g (2.00 mol) of BP, 113.00 g (0.45 mol) of 4,4′-dichlorobenzophenone were respectively dissolved and suspended in 1152 ml of NMP under a nitrogen atmosphere.

[0148] The mixture was heated to 190 °C within 1 hour. The reaction time was 6 hours.

[0149] Even after 24 hours of filtration time, only a small portion of the solution was filtered. After 24 hours, the solution became a gel and could only be precipitated after diluting 20 ml of the solution / gel with 20 ml of NMP and heating to 120 °C.

[0150] The polymer obtained was then separated from the filtrate and dried.

[0151] As can be seen from the measurement results given in Table 1 below, for PPSU substantially composed of benzophenone-coupled chain segments with a chain length x of 4.5 to 9, the target properties could be observed. At larger chain lengths, no tolerance for was given. At lower chain lengths, the samples could not be processed in a simple manner.

[0152]

Claims

1. A polyphenylene sulfone, which consists essentially of benzophenone-coupled polyphenylene sulfone segments A and B of formula I wherein segments A and B may be the same or different and are of formula II wherein x is from 4.5 to 9, and wherein the benzophenone group in formula I, the diphenylsulfone group in formula II, and the biphenyl group are all 4-4'-substituted.

2. The polyphenylene sulfone according to claim 1, wherein x is from 4.5 to 7.

3. The polyphenylene sulfone according to claim 1 or 2, which is linear.

4. A solution comprising the polyphenylene sulfone according to any one of claims 1 to 3.

5. The solution according to claim 4, which comprises N-methyl-2-pyrrolidone, dimethylacetamide, and / or sulfolane.

6. A method for preparing the polyphenylene sulfone according to any one of claims 1 to 3, which comprises reacting at least one dihalodiphenyl sulfone with at least one dihydroxybiphenyl to obtain a polyphenylene sulfone oligomer having a number average degree of polymerization of from 4.5 to 9, and then reacting the oligomer with at least one dihalobenzophenone, wherein the dihalodiphenyl sulfone, the dihydroxybiphenyl, and the dihalobenzophenone are all 4-4'-substituted.

7. The method according to claim 6, wherein the reaction is carried out in a one-pot reaction manner.

8. The method according to claim 6 or 7, wherein the reaction is carried out in the presence of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylacetamide, and / or sulfolane.

9. The method according to claim 8, which comprises filtering the solution according to claim 4 at a temperature above room temperature.

10. Use of the polyphenylene sulfone according to any one of claims 1 to 3 or the polyphenylene sulfone obtained by the method according to any one of claims 6 to 9 in the manufacture of coatings, fibers, foams, membranes, or molded articles.

11. The use according to claim 10, wherein the membrane is a thin film.

12. Use of the solution according to claim 4 or 5 in the manufacture of coatings, fibers, or membranes.

13. The use according to claim 12, wherein the membrane is a thin film.

14. The use according to claim 10 or 12 for the manufacture of membranes.

15. A membrane comprising at least one polyphenylene sulfone according to any one of claims 1 to 3.

16. An article comprising the membrane according to claim 15.

17. Use of the membrane according to claim 15 or the article according to claim 16 in water purification.

18. The use according to claim 17, which is for water produced during a fracturing process or for the recovery of desalted water on an oil platform.

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