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EP-4288481-B1 - PROCESS FOR MODIFYING AN AROMATIC POLYETHER BACKBONE AND A MODIFIED POLYETHER OBTAINED BY THIS PROCESS

EP4288481B1EP 4288481 B1EP4288481 B1EP 4288481B1EP-4288481-B1

Inventors

  • SÜßMUTH, Roderich
  • PRISYAZHNOY, VICTOR

Dates

Publication Date
20260506
Application Date
20220207

Claims (13)

  1. A process for modifying an aromatic moiety of an aromatic polyether backbone, for obtaining a modified polyether comprising the steps of: a) providing at least one aromatic polyether to be modified in dissolved state in an inert organic solvent, b) adding at least one modification reagent, c) adding at least one catalyst, wherein the at least one catalyst is a boron trifluoride complex, wherein no gaseous boron trifluoride is used d) carrying out the process until a desired degree of functionalization of said aromatic polyether backbone is reached, e) recovery of the modified aromatic polyether. Wherein said aromatic polyether comprises at least one of the following repeating units: wherin R a and R b represent substituents on the benzene ring and each independently comprises alkyl, -aryl, or -arylene-alkyl,
  2. Process according to claim 1, characterized in that after step b) at least one second modification reagent is added.
  3. Process according to one of the preceding claims, characterized in that prior to step e) at least one catalyst quencher is added.
  4. Process according to one of the preceding claims, characterized in that at least one catalyst scavenger is added prior to step e).
  5. Process according to one of the preceding claims, characterized in that prior to step e) both catalyst quencher and catalyst scavenger are added.
  6. Process according to one of the preceding claims, characterized in that prior to step e) the reaction solvent replaced by workup solvent.
  7. Process according to one of the preceding claims, characterized in that the inert organic solvent is selected from the group consisting of halogenated hydrocarbons, halogenated aromatics, nitroalkanes, nitroaromatics or mixture thereof.
  8. Process according to one of the preceding claims, characterized in that the catalyst is selected from the group consisting of complexes of boron trifuoride with: ethers (dimethyl ether, diethyl ether, di-n-butyl ether, tetrahydrofuran, dioxane, etc.), esters (ethyl acetate, isopropyl acetate, methyl benzoate, ethyl benzoate, dimethyl succinate, methyl p-toluate, etc.), alcohols (methanol, ethanol, n-butanol, 2,2,2-trifluoroethanol, 1,1,1,3,3,3-hexafluoro-2-propanol, etc.), chloroalkanes (dichloromethane, 1,2-dichloroethane, etc.), nitroalkanes (nitromethane, nitroethane, 1-nitropropane, etc.), haloaromatics (chlorobenzene, chlorotoluene, bromobenzene, fluorobenzene, 1,2-difluorbenzene, hexafluorobenzene, alpha,alpha,alpha-trifluorotoluene, etc.), nitroaromatics (nitrobenzene, nitrotoluene, etc.), nitriles (acetonitrile, propionitrile, isobutyronitrile, benzonitrile, etc.), carboxylic acids (acetic acid, propionic acid, pivalic acid, benzoic acid, malonic acid, succinic acid, etc.), sulfonic acids (methanesulfonic acid, benzenesufonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, etc.), water (monohydrate, dihydrate), sulfones (tetramethylene sulfone, dimethyl sulfone, diethyl sulfone, etc.), sulfoxides (dimethyl sulfoxide, diethyl sulfoxide, etc.), thioethers (methyl sulfide, ethyl sulfide, propyl sulfide, isopropyl sulfide, tetrahydrothiophene), mineral acids (phosphoric acid, sulfuric acid, etc.) any derivative thereof, and any combination thereof.
  9. Process according to one of the preceding claims, characterized in that the catalyst is selected from the group consisting of complexes of boron trifuoride based on ethers, preferably dimethyl ether, diethyl ether, di-n-butyl ether, tetrahydrofuran, dioxane; esters, preferably ethyl acetate, isopropyl acetate, methyl benzoate, ethyl benzoate, dimethyl succinate, methyl p-toluate; carboxylic acids, preferably acetic acid, propionic acid, pivalic acid, benzoic acid, malonic acid, succinic acid, particularly preferred boron trifluoride diethyl etherate and boron trifluoride acetic acid complex.
  10. Process according to one of the preceding claims, characterized in that the catalyst quencher is selected from the group consisting of alkyl phosphates (trimethyl phosphate, triethyl phosphate, tributyl phosphate, etc.), carboxylic acid amides, (dimethyl formamide, dimethyl acetamide, N-methyl pyrrolidone, N-butyl pyrrolidone, etc.), ureas (dimethylethylene urea, tetramethyl urea, 1,3-dimethyl-2-imidazolidinone, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, etc.), any derivative thereof, and any combination thereof.
  11. Process according to one of the preceding claims, characterized in that the scavenger is selected from the group consisting of hydrofluoric acid salts (ammonium fluoride, lithium fluoride, sodium fluoride, potassium fluoride, cesium fluoride, rubidium fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, barium fluoride, etc.), sulfuric acid salts (sodium sulfate, potassium sulfate, etc.), phosphoric acid salts (trisodium phosphate, tripotassium phosphate, etc.), pyrophosphoric acid salts (sodium pyrophosphate, potassium pyrophosphate, etc.), .), any derivative thereof, and any combination thereof.
  12. Process according to one of the preceding claims, characterized in that the at least one modifying reagent is selected from a group of compounds of the general structure 1 ( GS1 ) Fn-Sp-Lg (GS1) wherein Fn is functional moiety selected from structures of General formula 1 (GF1), or General formula 2 (GF2), or General formula 3 (GF3), or General formula 4 (GF4), or General formula 5 (GF5): wherein Sp is spacing moiety selected from structure of General formula 6 (GF6): wherein Lg is a leaving group moiety selected from structures of General formula 7 ( GF7 ), or General formula 8 ( GF8 ), or General formula 9 ( GF9 ), or General formula 10 ( GF10 ), or General formula 5 ( GF5 ): in which: W comprises -CO- (carbonyl) or -SO 2 - (sulfonyl) group; X comprises -NR 111 - (R 111 selected from hydrogen or the group consisting of lower alkyl (C 1 - C 10 ), -O- (oxygen), or direct bond; R 11 - comprises (selected from) alkyl, heteroalkyl, -aryl, -arylene-alkyl, -alkylene-aryl, or - alkylene-arylene-alkyl (optionally substituted); R 12 - comprises hydrogen or the group consisting of lower alkyl (C 1 - C 10 ); Y comprises -NR 111 -, -O- (oxygen), or methylene group (optionally substituted); n represents an integer of 1 to 4; R 13 and R 14 independently each other comprises hydrogen, COOH, COOR 111 , CON(R 111 ) 2 , or the group consisting of lower alkyl (C 1 - C 10 ); R 21 - represents a substituent on the benzene ring and each independently comprises halo group, cyano group, trifluoromethylsulfonyl group, nitro group, trihalomethyl group, keto group, formyl group, carboxyl group, alkoxycarbonyl group, aminocarbonyl group, sulfonyl group, sulfonamide group; and m represents an integer of 0 to 4; Z comprises NH or O (oxygen);
  13. Modified polyether obtainable in a process according to one of the preceding claims wherein the at least one of the aromatic moieties in the polyether backbone is modified with at least one of the following groups having one of the general structure 2 ( GS2 ): Fn-Sp-Polyether (GS2) wherein Fn and Sp have the meanings as defined in claims 12.

Description

The present invention relates to a process for modifying / functionalizing a polymer backbone, in particular a polyether polysulfone backbone, and to a modified functionalized polymer obtained in this process. More specifically, the invention relates to an improved, economical, and environmentally friendlier method of chemical modification of a preformed polyether backbone, resulting in a modified polymer with improved consumer properties. Aromatic polyethers are attractive polymer materials for a range of applications, such as separation membranes, which have been developed for a wide variety of applications, e.g. in separation technology, biological processes, medical devices, and blood purification. In addition, due to superior thermal, chemical, and mechanical properties of aromatic polyethers, they are widely used as filtration membranes, coatings, composites, microelectronic devices, and fuel cells. The performance of aromatic polyethers in numerous applications relies largely on the combination of bulk (e.g. mechanical) properties together with the aromatic polyether based materials surface properties. However, despite outstanding progress in their synthesis and applications, these materials have limitations associated with mechanical stress, cracking in certain solvents, poor tracking resistance, and weathering properties. The chemical modification of the aromatic polyether backbone not only overcomes these limitations but also extends the range of potential applications of these high-performance materials through the specific properties gained, and thus provides broader scope of applications. Besides, the chemical modification of large-scale produced commodity aromatic polyethers might provide unique opportunities in the fabrication of advanced polymeric materials. In this sense, effective chemical functionalization methodologies are always of great importance in synthetic manipulations with polymer substrates to impart desired properties. Chemical modification of commercially available aromatic polyethers may be performed by treatments of the polymer by a certain modification (functionalization) reagent or a mixture of such reagents depending on the chemical structure of the polymer backbone or pendant groups. However, treating the aromatic polyether with one known modifying reagent that has previously been used successfully to modify a similar, but still slightly different polymer, can lead to unpredictable results. In other terms, a functionalization reagent that works well for one type of aromatic polyether will not necessarily work successfully for another type of aromatic polyethers, and vice versa. Different approaches for modifying aromatic polyethers and other polymers are described, For example in EP 2 152 780 A1 methods for increasing the solubility of polymeric materials based on aromatic polyethers in organic solvents for their subsequent processing are described. All chemical changes are carried out on the ketone functionality, which is part of the polymer backbone, but does not affect the C-H bonds of aromatic nuclei, which are also part of the backbone of the polymer. US 3,733,302 discloses a method for production of trimellitimido alkyl substituted aromatic carbocyclic organic polymers. The process for imidoalkylation of aromatic carbocyclic polymers is performed by incubation of the aromatic carbocyclic polymer, dissolved in an appropriate reaction solvent, imidoalkylation reagents, in the presence of gaseous boron trifluoride. EP 2725 050 A1 describes a method for producing a poly(phenylene ether ether ketone) by thermal ring opening of a cyclic poly(phenylene ether ether ketone). Thus, most of the methods that are supposed to be used for the chemical modification of an aromatic polyether backbone require careful selection and optimization of the reaction conditions, solvents, and modification reagents used for to avoid undesirable side reactions that can alter the molecular weight of the aromatic polyether (crosslinking or chain scission), polydispersity, non-uniform functionalization of polymer chains and thus reduce the favorable properties of the desired modified aromatic polyether. Hence, alternative mild, cost-effective and environmentally safe methods for chemical modification of aromatic polyethers are highly desired. Chemical modification of relatively low molecular weight compounds usually results in a mixture consisting of the desired modified low molecular weight compound and a number of by-products. The modified substance can be separated from side-products after each step of the chemical modification by using a plurality of well-known separation methods (like crystallization, distillation, chromatography, etc.). However, in the case of the chemical modification of polymers (high molecular substances, consisting of a sequence of many covalently linked low molecular weight repeating units), separation of polymer chains bearing only covalently attached desired function