Copolymers with hard polyamide blocks and soft blocks comprising polyethylene glycol

Abstract

The invention relates to a copolymer having a hard polyamide block and a soft block comprising polyethylene glycol. The invention relates to a copolymer having hard polyamide blocks and soft blocks, containing, relative to the total weight of the copolymer: between 55% and 90% by weight of soft blocks, at least 35% by weight of which is derived from polyethylene glycol; between 10% and 45% by weight of a hard polyamide block, wherein the average carbon content in the repeating units of the polyamide block is greater than or equal to 7. The invention also relates to a method for preparing such a copolymer, a membrane comprising such a copolymer and a method for preparing such a membrane.

Description

[0001] This application is a divisional application of the patent application with application number 202080062842.3, application date July 15, 2020, and invention name “Copolymer having hard polyamide blocks and soft blocks containing polyethylene glycol”. Technical Field

[0002] The present invention relates to copolymers containing rigid polyamide blocks and flexible blocks, processes for preparing such copolymers, and membranes formed from such copolymers. Background Art

[0003] Greenhouse gas emissions and their impact on global warming have become a major concern. Various technologies have been developed to recover greenhouse gases such as carbon dioxide and methane. Among them, polymer-based gas separation membranes have been developed due to their low environmental impact. Gas separation membranes can also be used in a variety of other applications, such as natural gas purification or in novel enthalpy heat exchangers.

[0004] WO 2018 / 222255 describes a gas separation process using a membrane comprising a crosslinked mixture of a polyetheramide copolymer and acrylate-terminated polyethylene glycol.

[0005] The paper by Scholes et al. (Crosslinked PEG and PEBAX Membranes for Concurrent Permeation of Water and Carbon Dioxide, Membranes, Vol. 6, No. 1, 0001 (2016)) describes membranes of copolymers containing blocks derived from PTMG and polyamide blocks or blocks of cross-linked polyethylene glycol diacrylate.

[0006] A paper by Car et al. (PEG modified poly(amide-b-ethylene oxide) membranes for CO2 separation, Journal of Membrane Science, Vol. 307, pp. 88-95 (2008)) describes membranes prepared from a blend of a copolymer containing polyamide 6 blocks and blocks derived from polyethylene glycol.

[0007] A paper by Alqaheem et al. (Polymeric Gas-Separation Membranes for PetroleumRefining, International Journal of Polymer Science, Vol. 2017, No. 117, pp. 1-19 (2017)) investigated various polymer membranes and their permeability to several gases.

[0008] The paper by Bondar et al. (Gas Transport Properties of Poly(ether-b-amide) Segmented Block Copolymers, Journal of Polymer Science: Part B: Polymer Physics, Vol. 38, No. 15, pp. 2051-2062 (2000)) relates to membranes containing copolymers of polyamide blocks and polyether blocks.

[0009] In certain applications, it is desirable to use a membrane that is highly permeable to water vapor and carbon dioxide, but nearly impermeable to molecular oxygen. In enthalpy heat exchangers, the polymer membranes used must be permeable to water vapor while at the same time impermeable to VOCs (volatile organic compounds). Liquid desiccant air conditioning applications may also require the use of a membrane that is permeable to water vapor to dehydrate the air before cooling it.

[0010] Increasing the membrane's permeability to water vapor and carbon dioxide can be achieved by increasing the polymer's hydrophilicity. However, the water uptake is also greatly increased, which leads to a deterioration of the membrane's mechanical properties in the water-saturated state.

[0011] It is therefore necessary to provide polymers that can be used to produce gas separation membranes having waterproof and gas-permeable properties as well as good permeability to carbon dioxide and low permeability to molecular oxygen, while at the same time conserving sufficient mechanical properties in the wet state. Summary of the Invention

[0012] The present invention firstly relates to a copolymer containing rigid polyamide blocks and flexible blocks, comprising, relative to the total weight of the copolymer:

[0013] - from 55 to 90% by weight of a soft block, at least 35% by weight of which comes from polyethylene glycol;

[0014] - from 10% to 45% by weight of rigid polyamide blocks, wherein the average carbon content of the repeating units of said polyamide blocks is greater than or equal to 7.

[0015] According to certain embodiments, the flexible block is a polyether block and / or a polyether and polyester block.

[0016] According to certain embodiments, the soft block is a block derived from polyethylene glycol.

[0017] According to certain embodiments, the soft blocks comprise, in addition to blocks derived from polyethylene glycol, blocks derived from further polyethers (such as polytetramethylene glycol and / or propylene glycol) and / or polyesters.

[0018] According to certain embodiments, the average carbon content of the repeating units of the polyamide blocks is from 8 to 14, preferably from 8 to 12.

[0019] According to certain embodiments, the rigid polyamide block is a block of polyamide 11, polyamide 12, polyamide 6.10, polyamide 6.12, polyamide 10.10, polyamide 10.12, copolyamide 6 / 11, copolyamide 6 / 12, copolyamide 11 / 12, or mixtures or copolymers thereof.

[0020] According to certain embodiments, the copolymer comprises from 56% to 90%, preferably from 57%, from 58%, or from 59% to 90% by weight of soft blocks relative to the total weight of the copolymer.

[0021] According to certain embodiments, the copolymer comprises from 10% to 44%, preferably from 10% to 43%, or from 10% to 42%, or from 10% to 41% by weight of rigid polyamide blocks relative to the total weight of the copolymer.

[0022] According to certain embodiments, the copolymer comprises from 60% to 90% by weight of flexible blocks and from 10% to 40% by weight of rigid polyamide blocks, relative to the total weight of the copolymer.

[0023] According to certain embodiments, the copolymer comprises at least 40% by weight of a soft block derived from polyethylene glycol, preferably from 50% to 90% by weight, or from 55% to 90% by weight, or from 56% to 90% by weight, more preferentially from 60% to 80% by weight, relative to the total weight of the copolymer.

[0024] According to certain embodiments, the copolymer is a copolymer containing polyamide 11 blocks and blocks derived from polyethylene glycol, a copolymer containing polyamide 11 blocks, blocks derived from polyethylene glycol, and blocks derived from polytetrahydrofuran, a copolymer containing polyamide 12 blocks and blocks derived from polyethylene glycol, a copolymer containing polyamide 12 blocks, blocks derived from polyethylene glycol, and blocks derived from polytetrahydrofuran, a copolymer containing copolyamide 6 / 11 blocks and blocks derived from polyethylene glycol, or a copolymer containing copolyamide 6 / 11 blocks, blocks derived from polyethylene glycol, and blocks derived from polytetrahydrofuran.

[0025] According to certain embodiments, the copolymer has an elongation at break in a water-saturated state of greater than or equal to 100%, preferably greater than or equal to 200%, more preferably greater than or equal to 300%.

[0026] According to certain embodiments, the copolymer has a water absorption (water absorption) reaching saturation at 23°C ranging from 50% to 160% by weight, preferably from 50% to 150% by weight, relative to the total weight of the copolymer.

[0027] The present invention also relates to a membrane comprising a copolymer as described above.

[0028] According to certain embodiments, the membrane is waterproof and breathable.

[0029] According to certain embodiments, the membrane has a selectivity greater than or equal to 10, preferably greater than or equal to 12, measured at a temperature of 23°C and at 0% relative humidity, the selectivity being defined as the ratio of the membrane's permeability to carbon dioxide relative to its permeability to molecular oxygen.

[0030] According to certain embodiments, the membrane has a water vapor permeability MVTR of at least 800 g / m per 24 hours at 23°C for a relative humidity level of 50% and a membrane thickness of 30 μm. 2 , preferably at least 900 g / m 2 , more preferably at least 1000 g / m 2 , more preferably from 1000 to 5000 g / m 2 .

[0031] According to certain embodiments, the membrane has a thickness of from 0.05 to 100 μm, preferably from 0.5 to 50 μm.

[0032] According to certain embodiments, the membrane further comprises at least one polymer or oligomer selected from the group consisting of polyolefins such as polyethylene, polypropylene, poly(3-methyl-1-butene), and poly(4-methyl-1-pentene); vinyl polymers such as polystyrene, poly(methyl methacrylate); polysulfones; fluorinated or chlorinated polymers such as poly(vinylidene fluoride), polytetrafluoroethylene, fluoroethylene / tetrafluoroethylene copolymers, polychloroprene; polyamides such as PA 6, PA 6.6, and PA 12; copolymers containing rigid blocks and flexible blocks, such as copolymers containing polyamide blocks and polyether blocks; polyesters, such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene 2,6-naphthalate; polycarbonates, such as poly-4,4′-dihydroxydiphenyl-2,2-propane carbonate; polyethers, such as polyoxymethylene and polymethylene sulfide; polyphenylene sulfide, such as polysulfide, polyphenylene oxide, and polyphenylene sulfide; polyetheretherketone; polyetherketoneketone; silicones, such as Such as polyvinyl trimethylsiloxane, polydimethylsiloxane, perfluoroalkoxy; polyethylene glycol; ethylene-vinyl acetate; ethylene-methyl acrylate; ethylene-(ethylene-butyl acrylate)-maleic anhydride, ethylene-(ethylene-methyl acrylate)-maleic anhydride, ethylene-methacrylate glycidyl-(ethylene-butyl acrylate), ethylene-(ethylene-methyl acrylate)-methacrylate glycidyl, ethylene-(ethylene-vinyl acetate)-maleic anhydride terpolymer; and mixtures thereof.

[0033] The invention also relates to the use of a copolymer as described above for producing a gas separation membrane, or a membrane for dehumidifying a gas, such as air, or an enthalpy heat exchanger membrane, or a textile membrane.

[0034] According to certain embodiments, the gas separation membrane is a greenhouse gas recovery membrane.

[0035] The present invention also relates to a process for preparing the copolymer as described above, comprising the following steps:

[0036] - Synthesis of rigid polyamide blocks from polyamide precursors;

[0037] - Adding flexible blocks;

[0038] - condensing the rigid polyamide blocks and the flexible blocks.

[0039] The present invention also relates to a process for preparing a copolymer as described above, which involves mixing the soft block with a polyamide precursor and a chain-limiting diacid.

[0040] The present invention also relates to a process for producing a membrane as described above, comprising the following steps:

[0041] - supplying a copolymer as described above;

[0042] - dissolving the copolymer in a solvent;

[0043] - depositing a polymer dissolved in said solvent on a substrate;

[0044] - Evaporate the solvent.

[0045] The present invention also relates to a process for producing a membrane as described above, comprising the following steps:

[0046] - supplying a copolymer as described above;

[0047] - melting the copolymer;

[0048] - forming a molten copolymer film;

[0049] - Allowing the film to solidify.

[0050] The present invention satisfies the needs expressed above. More particularly, it provides copolymers that can be used to prepare membranes that have high permeability to water vapor and carbon dioxide. In particular, the membranes also exhibit high selectivity for carbon dioxide relative to molecular oxygen, while at the same time maintaining good mechanical properties and good durability in the wet state.

[0051] This is achieved by means of a copolymer comprising specific proportions of rigid polyamide blocks, flexible blocks, and blocks derived from polyethylene glycol, and wherein the polyamide has repeating units having an average carbon content greater than or equal to a minimum value.

[0052] According to certain specific embodiments, the present invention also has one or preferably several of the following advantageous features: waterproof and breathable properties, high selectivity for water vapor relative to other gases, good selectivity for carbon dioxide relative to molecular nitrogen, good selectivity for hydrogen sulfide relative to methane, and good selectivity for VOC relative to molecular nitrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] [ Figure 1 The tensile curves obtained for PEBA No. 3 described in Example 1, in the transverse direction relative to the extrusion direction, are shown. The elongation (in mm) is given on the x-axis, and the stress (in MPa) is given on the y-axis. The black curve represents the tensile curve obtained before the MVTR measurement test, and the gray curve represents the tensile curve obtained after the MVTR measurement test.

[0054] [ Figure 2The tensile curves obtained for PEBA No. 3 described in Example 1, in the longitudinal direction relative to the extrusion process, are shown. The elongation (in mm) is given on the x-axis, and the stress (in MPa) is given on the y-axis. The black curve represents the tensile curve obtained before the MVTR measurement test, and the gray curve represents the tensile curve obtained after the MVTR measurement test.

[0055] [ Figure 3

[0026] The tensile curves obtained for PEBA No. 2 described in Example 1, in the transverse direction relative to the extrusion direction, are shown. The elongation (in mm) is given on the x-axis, and the stress (in MPa) is given on the y-axis. The black curve represents the tensile curve obtained before the MVTR measurement test, and the gray curve represents the tensile curve obtained after the MVTR measurement test.

[0056] [ Figure 4

[0026] The tensile curves obtained for PEBA No. 2 described in Example 1, in the longitudinal direction relative to the extrusion process, are shown. The elongation (in mm) is given on the x-axis, and the stress (in MPa) is given on the y-axis. The black curve represents the tensile curve obtained before the MVTR measurement test, and the gray curve represents the tensile curve obtained after the MVTR measurement test.

[0057] [ Figure 5 The tensile curves obtained for PEBA No. 7 described in Example 1, in the transverse direction relative to the extrusion direction, are shown. The elongation (in mm) is given on the x-axis, and the stress (in MPa) is given on the y-axis. The black curve represents the tensile curve obtained before the MVTR measurement test, and the gray curve represents the tensile curve obtained after the MVTR measurement test.

[0058] [ Figure 6 The tensile curve obtained for PEBA No. 7 described in Example 1, in the longitudinal direction relative to the extrusion direction, is shown. The elongation (in mm) is given on the x-axis, and the stress (in MPa) is given on the y-axis. The black curve represents the tensile curve obtained before the MVTR measurement test, and the gray curve represents the tensile curve obtained after the MVTR measurement test. DETAILED DESCRIPTION

[0059] The invention is now described in more detail and in a non-limiting manner in the following description.

[0060] Unless otherwise stated, all percentages are by mass.

[0061] The present invention relates to copolymers containing rigid and flexible blocks. These copolymers are thermoplastic elastomer (TPE) polymers that contain rigid (or hard, having rather thermoplastic behavior) blocks and flexible (or soft, having rather elastomeric behavior) blocks.

[0062] The term "rigid block" means a block having a melting point or glass transition temperature (in the case of an amorphous block) greater than 20° C. The presence of a melting point can be determined by differential scanning calorimetry according to standard ISO 11357-3 Plastics - Differential Scanning Calorimetry (DSC) Part 3.

[0063] The term "soft block" means a block having a glass transition temperature (Tg) less than or equal to 0° C. The glass transition temperature can be determined by differential scanning calorimetry according to standard ISO 11357-2 Plastics - Differential Scanning Calorimetry (DSC) Part 2.

[0064] The rigid blocks of the copolymers according to the invention are polyamide blocks.

[0065] Advantageously, three types of polyamide blocks can be used.

[0066] According to a first type, the polyamide blocks are derived from the condensation of dicarboxylic acids, in particular those containing from 4 to 36 carbon atoms, preferably those containing from 6 to 18 carbon atoms, and aliphatic or aromatic diamines, in particular those containing from 2 to 20 carbon atoms, preferably those containing from 6 to 14 carbon atoms.

[0067] As examples of dicarboxylic acids, mention may be made of 1,4-cyclohexanedicarboxylic acid, succinic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, terephthalic acid, and isophthalic acid, and also dimerized fatty acids.

[0068] As examples of diamines, mention may be made of tetramethylenediamine, hexamethylenediamine, 1,10-decamethylenediamine, dodecamethylenediamine, trimethylhexamethylenediamine, bis(4-aminocyclohexyl)methane (BACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM), and isomers of 2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), p-aminodicyclohexylmethane (PACM), isophoronediamine (IPDA), 2,6-bis(aminomethyl)norbornane (BAMN), and piperazine (Pip).

[0069] Advantageously, the polyamide blocks PA 4.12, PA 4.14, PA 4.18, PA 6.10, PA 6.12, PA 6.14, PA 6.18, PA 9.12, PA 10.10, PA 10.12, PA 10.14, and PA 10.18 are used. In the PAXY notation, X represents the number of carbon atoms from the diamine residues and Y represents the number of carbon atoms from the diacid residues, as is conventional.

[0070] According to a second type, the polyamide blocks are obtained by condensing one or more α,ω-aminocarboxylic acids containing from 7 to 12 carbon atoms and / or one or more lactams in the presence of dicarboxylic acids containing from 4 to 12 carbon atoms or in the presence of diamines. Examples of lactams include enantholactam and laurolactam. As examples of α,ω-aminocarboxylic acids, mention may be made of 7-aminoheptanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

[0071] Advantageously, said second type of polyamide blocks are blocks of PA 11 (polyundecylamide) or PA 12 (polydodecylamide).In the notation PA X, X represents the number of carbon atoms resulting from the amino acid residue.

[0072] According to a third type, the polyamide blocks are obtained from the condensation of at least one α,ω-aminocarboxylic acid (or lactam), at least one diamine, and at least one dicarboxylic acid.

[0073] In this case, the polyamide PA blocks are prepared by the following polycondensation:

[0074] - linear aliphatic or aromatic diamines containing X carbon atoms;

[0075] - a dicarboxylic acid containing Y carbon atoms; and

[0076] - a comonomer {Z} selected from lactams and α,ω-aminocarboxylic acids containing Z carbon atoms, and an equimolar mixture of at least one diamine containing X1 carbon atoms and at least one dicarboxylic acid containing Y1 carbon atoms, (X1, Y1) being different from (X, Y),

[0077] - the comonomer {Z} is incorporated in a weight proportion advantageously ranging up to 50%, preferably up to 20%, even more advantageously up to 10%, relative to the total amount of polyamide-precursor monomers;

[0078] - in the presence of a chain limiter selected from dicarboxylic acids.

[0079] Advantageously, a dicarboxylic acid containing Y carbon atoms is used as chain limiter, which is introduced in a stoichiometric excess relative to the diamine.

[0080] According to a variant of this third type, the polyamide blocks are obtained from the condensation of at least two α,ω-aminocarboxylic acids or at least two lactams containing from 6 to 12 carbon atoms, or from the condensation of a lactam and an aminocarboxylic acid having different numbers of carbon atoms, optionally in the presence of a chain limiter. Examples of aliphatic α,ω-aminocarboxylic acids include aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples of lactams include caprolactam, enantholactam, and laurolactam. Examples of aliphatic diamines include hexamethylenediamine, dodecamethylenediamine, and trimethylhexamethylenediamine. Examples of cycloaliphatic diacids include 1,4-cyclohexanedicarboxylic acid. Examples of aliphatic diacids include succinic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, and dimerized fatty acids. These dimerized fatty acids preferably have a dimer content of at least 98%; preferably they are hydrogenated; they are, for example, the products sold under the brand name Pripol by Croda, or the products sold under the brand name Empol by BASF, or the products sold under the brand name Radiacid by Oleon, as well as polyoxyalkylene α,ω-diacids. As examples of aromatic diacids, terephthalic acid (T) and isophthalic acid (I) may be mentioned. As examples of alicyclic diamines, bis(4-aminocyclohexyl)methane (BACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM), and isomers of 2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), as well as para-aminodicyclohexylmethane (PACM) may be mentioned. Other commonly used diamines may be isophoronediamine (IPDA), 2,6-bis(aminomethyl)norbornane (BAMN), and piperazine.

[0081] As examples of said third type of polyamide blocks, the following may be mentioned:

[0082] PA 6.6 / 6.10 / 11 / 12, wherein 6.6 represents the condensation of hexamethylenediamine with adipic acid, 6.10 represents the condensation of hexamethylenediamine with sebacic acid, 11 represents the unit resulting from the condensation of aminoundecanoic acid, and 12 represents the unit resulting from the condensation of laurolactam;

[0083] PA 6 / 11, in which 6 represents a unit resulting from the condensation of caprolactam and 11 represents a unit resulting from the condensation of aminoundecanoic acid;

[0084] PA 6 / 12, in which 6 represents a unit resulting from the condensation of caprolactam and 12 represents a unit resulting from the condensation of laurolactam;

[0085] - PA 11 / 12, wherein 11 represents a unit resulting from the condensation of aminoundecanoic acid and 12 represents a unit resulting from the condensation of laurolactam.

[0086] The notations PA X / Y, PA X / Y / Z etc. relate to copolyamides in which X, Y, Z etc. represent homopolyamide units as described above.

[0087] The repeating units of the polyamide blocks of the copolymer according to the invention have an average carbon content greater than or equal to 7.

[0088] The term "average carbon content of the repeating units" means the average of the number of carbon atoms of each repeating unit present in the polyamide block of the copolymer, weighted by the molar proportion of the repeating unit relative to the total amount of polyamide block. For example, for PAX / Y, as defined above, comprising a mol% of PAX and b mol% of PAY (a% + b% representing 100 mol% of polyamide), the average carbon content is (a × X + b × Y) / 100. When the polyamide block comprises a single repeating unit (as in the case of a block PAX or a block PAXY, as defined above), the average carbon content of the repeating units of the polyamide block is equal to the number of carbon atoms of the repeating unit, provided that the polyamide repeating unit (in a known manner) contains only one amide function. In the case of a PAX block, the number of carbon atoms of the repeating unit is X. In the case of a PAXY block, the number of carbon atoms of the repeating unit is (X + Y) / 2, since the unit XY contains two amide functions.

[0089] Advantageously, the polyamide blocks of the copolymer according to the invention comprise or consist of blocks of the polyamides PA 11, PA 12, PA 5.4, PA 5.9, PA 5.10, PA 5.12, PA 5.13, PA 5.14, PA 5.16, PA 5.18, PA 5.36, PA 6.4, PA 6.9, PA 6.10, PA 6.12, PA 6.13, PA 6.14, PA 6.16, PA 6.18, PA 6.36, PA 10.4, PA 10.9, PA 10.10, PA 10.12, PA 10.13, PA 10.14, PA 10.16, PA 10.18, PA 10.36, PA 10.4, PA 10.9, PA 10.10, PA 10.12, PA 10.13, PA 10.14, PA 10.16, PA 10.18, PA 10.36, PA 10.4, PA 10.9. 12.9, PA 12.10, PA 12.12, PA 12.13, PA 12.14, PA 12.16, PA 12.18, PA 12.36, PA 12.T, or mixtures or copolymers thereof.

[0090] Particularly preferably, the polyamide blocks of the copolymer comprise or consist of blocks of polyamides PA 11, PA 12, PA 6.10, PA 6.12, PA 10.10, PA 10.12 or copolyamides PA 6 / 11, PA 6 / 12, PA 11 / 12 or mixtures or copolymers thereof.

[0091] Preferably, the average carbon content of the repeating units of the polyamide blocks according to the present invention is from 8 to 14, more preferentially from 8 to 12. In certain embodiments, the carbon content of the repeating units is from 7 to 8, or from 8 to 9, or from 9 to 10, or from 10 to 11, or from 11 to 12, or from 12 to 13, or from 13 to 14, or from 14 to 15, or from 15 to 18, or from 18 to 22, or from 22 to 25, or from 25 to 30, or from 30 to 40.

[0092] Advantageously, the flexible blocks of the copolymer are polyether blocks (the copolymer is then PEBA or a copolymer containing polyamide blocks and polyether blocks) or polyether and polyester blocks. The polyether blocks are formed from oxyalkylene units.

[0093] The flexible block of the copolymer according to the present invention comprises a block derived from polyethylene glycol (PEG). The mass ratio of the block derived from polyethylene glycol in the copolymer is at least 35%, relative to the total weight of the copolymer. Preferably, the copolymer according to the present invention comprises a block derived from PEG of at least 40% by weight, more preferably the copolymer comprises a block derived from PEG of from 50% to 90% by weight, more preferably from 60% to 80% by weight, relative to the total weight of the copolymer. In certain embodiments, the copolymer comprises by weight 35 to 40%, or 40 to 45%, or 45 to 50%, or 50 to 55%, or 55 to 60%, or 60 to 65%, or from 65% to 70% by weight, or from 70% to 75% by weight, or from 75% to 80%, or from 80% to 85%, or from 85% to 90% of the block derived from PEG, relative to the total weight of the copolymer.

[0094] In certain embodiments, the soft blocks of the copolymers according to the present invention consist of blocks derived from PEG.

[0095] Alternatively, the soft block of the copolymer may contain at least one other block in addition to the block derived from PEG.

[0096] The soft blocks of the copolymers may comprise, in addition to the blocks derived from PEG, one or more other polyethers and / or polyesters and / or polysiloxanes and / or polydimethylsiloxanes (or PDMS) and / or polyolefins and / or polycarbonates. Possible soft blocks are described, for example, in French patent application FR 2941700 A1 (from page 32, line 3 to page 33, line 8, from page 34, line 16 to page 37, line 13, and on page 38, lines 6 to 23).

[0097] Preferably, this further block is a polyether block and / or a polyester block different from the block derived from PEG.

[0098] The copolymers may comprise in their chains several types of polyethers other than blocks derived from PEG, the corresponding copolyethers being either block or random copolyethers.

[0099] As polyether blocks suitable for the present invention, other than blocks derived from PEG, there may be mentioned blocks derived from PPG (polypropylene glycol) (composed of propylene oxide units), blocks derived from PO3G (polytrimethylene glycol) (composed of polytrimethylene glycol ether units), and blocks derived from PTMG (polytetramethylene glycol), also known as polytetrahydrofuran (composed of tetramethylene glycol units), or any combination thereof. Particularly preferably, the polyether blocks are blocks derived from polypropylene glycol and / or polytetrahydrofuran. As polyethers other than PEG, blocks obtained by oxyethylation of bisphenols (e.g., bisphenol A) may also be used. These latter products are described, inter alia, in EP 613919.

[0100] The polyether blocks may also consist of ethoxylated primary amines. As examples of ethoxylated primary amines, mention may be made of products having the formula:

[0101]

[0102] wherein m and n are integers between 1 and 20, and x is an integer between 8 and 18. These products are commercially available, for example, from the company CECA under the brand name Noramox® and from the company Clariant under the brand name Genamin®.

[0103] The soft block may comprise a polyoxyalkylene polyether block with NH2 chain ends, such blocks being obtainable by cyanoacetylation of aliphatic α,ω-dihydroxylated polyoxyalkylene blocks (also known as polyether diols). More particularly, the commercial products Jeffamine or Elastamine (e.g., Jeffamine® D400, 2000, ED 2003, XTJ 542, which are commercial products from Huntsman and are also described in JP 2004 / 346274, JP 2004 / 352794, and EP 1482011) may be used.

[0104] The polyetherdiol blocks are either used in unmodified form and co-polycondensed with the rigid blocks bearing carboxyl end groups, or are aminated to convert them into polyetherdiamines and condensed with the rigid blocks bearing carboxyl end groups.

[0105] The copolymers according to the invention include copolymers comprising three, four (or even more) different blocks selected from the blocks described in this specification, since these blocks include at least polyamide blocks and blocks derived from polyethylene glycol.

[0106] For example, the copolymer according to the present invention may be a multi-block block copolymer (or "triblock" copolymer) comprising three different types of blocks, which is obtained by condensation of several of the blocks described above. The triblock may be, for example, a copolymer comprising a polyamide block, a polyester block, and a block derived from PEG, or a copolymer comprising a polyamide block and two different polyether blocks (e.g., a block derived from PEG and a block derived from PTMG).

[0107] In a particularly advantageous manner, the copolymer according to the invention comprises or consists of PA11, PA 12, PA 6, PEG-derived, PTMG-derived blocks, or any mixture or combination thereof, provided that the average carbon content of the repeating units of the polyamide blocks of the copolymer is greater than or equal to 7 and that the copolymer comprises at least 35% by weight of blocks derived from polyethylene glycol.

[0108] In the context of the present invention, particularly preferred copolymers are copolymers comprising (or consisting of) the following blocks:

[0109] - PA 11 and those derived from PEG;

[0110] - PA 11, those derived from PEG, and those derived from PTMG;

[0111] - PA 12 and those derived from PEG;

[0112] - PA 12, those derived from PEG, and those derived from PTMG;

[0113] - PA 6 / 11 and those derived from PEG;

[0114] - PA 6 / 11, those derived from PEG, and those derived from PTMG;

[0115] - PA 6.10 and those derived from PEG;

[0116] - PA 6.10, and those derived from PEG, and those derived from PTMG;

[0117] - PA 6 / 12 and those derived from PEG;

[0118] - PA 6 / 12, and those derived from PEG, and those derived from PTMG.

[0119] The number-average molar mass of the rigid polyamide blocks of the copolymer according to the invention is preferably from 400 to 20 000 g / mol, more preferentially from 500 to 10 000 g / mol, even more preferentially from 600 to 6000 g / mol. In certain embodiments, the number average molar mass of the rigid polyamide block in the copolymer is from 400 to 500 g / mol, or from 500 to 1000 g / mol, or from 1000 to 1500 g / mol, or from 1500 to 2000 g / mol, or from 2000 to 2500 g / mol, or from 2500 to 3000 g / mol, or from 3000 to 3500 g / mol, or from 3500 to 4000 g / mol, or from 4000 to 5000 g / mol, or from 5000 to 6000 g / mol, or from 6000 to 7000 g / mol, or from 7000 to 8000 g / mol, or from 8000 to 9000 g / mol, or from 9000 to 10000 g / mol, or from 10000 to 11000 g / mol, or from 11000 to 12000 g / mol, or from 11000 to 13000 g / mol. 000 to 12 000 g / mol, or from 12 000 to 13 000 g / mol, or from 13 000 to 14 000 g / mol, or from 14 000 to 15 000 g / mol, or from 15 000 to 16 000 g / mol, or from 16 000 to 17 000 g / mol, or from 17 000 to 18 000 g / mol, or from 18 000 to 19 000 g / mol, or from 19 000 to 20 000 g / mol.

[0120] The number-average molar mass of the soft block is preferably from 100 to 6000 g / mol, more preferentially from 200 to 3000 g / mol. In certain embodiments, the number average molar mass of the soft block is from 100 to 200 g / mol, or from 200 to 500 g / mol, or from 500 to 800 g / mol, or from 800 to 1000 g / mol, or from 1000 to 1500 g / mol, or from 1500 to 2000 g / mol, or from 2000 to 2500 g / mol, or from 2500 to 3000 g / mol, or from 3000 to 3500 g / mol, or from 3500 to 4000 g / mol, or from 4000 to 4500 g / mol, or from 4500 to 5000 g / mol, or from 5000 to 5500 g / mol, or from 5500 to 6000 g / mol.

[0121] The number-average molar mass is set by the content of chain limiters. It can be calculated according to the following equation:

[0122] M n = n 单体 × MW 重复单元 / n 链限制剂 + MW 链限制剂

[0123] In this formula, n 单体 represents the number of moles of monomer, n 链限制剂 represents the number of moles of excess limiting agent (e.g., diacid), MW 重复单元 represents the molar mass of the repeating unit, and MW 链限制剂 represents the molar mass of the excess limiting agent (eg, diacid).

[0124] The number average molar mass of the hard blocks and the soft blocks can be measured by gel permeation chromatography (GPC) before copolymerization of the blocks.The number average molar mass of the polyol blocks can be determined by measuring the hydroxyl number.

[0125] The copolymers according to the present invention may be linear or branched copolymers. For example, the copolymers may be branched copolymers in which the branching is achieved by polyol residues having a functionality greater than 2 (i.e., the polyol comprises at least three hydroxyl groups) bound to the polyamide rigid blocks of the copolymer.

[0126] The copolymer according to the invention comprises from 55% to 90% by weight of the flexible block and from 10% to 45% by weight of the rigid polyamide block, relative to the total weight of the copolymer. The mass ratio of the flexible block to the rigid block in the copolymer can be determined by DSC (Differential Scanning Calorimetry). Advantageously, the copolymer comprises from 60% to 90% by weight of the flexible block and from 10% to 40% by weight of the rigid polyamide block, relative to the total weight of the copolymer.

[0127] The copolymer may comprise, relative to the total weight of the copolymer, from 55% to 60% by weight of the flexible block and from 40% to 45% by weight of the rigid polyamide block; or from 60% to 65% by weight of the flexible block and from 35% to 40% by weight of the rigid polyamide block; or from 65% to 70% by weight of the flexible block and from 30% to 35% by weight of the rigid polyamide block; or from 70% to 75% by weight of the flexible block and from 25% to 30% by weight of the rigid polyamide block; or from 75% to 80% by weight of the flexible block and from 20% to 25% by weight of the rigid polyamide block; or from 80% to 85% by weight of the flexible block and from 15% to 20% by weight of the rigid polyamide block; or from 85% to 90% by weight of the flexible block and from 10% to 15% by weight of the rigid polyamide block.

[0128] In certain embodiments, the copolymer consists essentially of or consists of soft block and hard block polyamide in the proportions as indicated above.

[0129] Advantageously, the copolymer according to the invention has an elongation at break of greater than or equal to 100% in the water-saturated state (i.e., under water saturation). Preferably, the copolymer has an elongation at break of greater than or equal to 150%, more preferably greater than or equal to 200%, even more preferably greater than or equal to 250%, even more preferably greater than or equal to 300%, even more preferably greater than or equal to 350% in the water-saturated state. The elongation at break in the water-saturated state can be measured according to standard ISO 527 1BA: 2012.

[0130] The term "water-saturated state" or "having water saturation" means a state in which the water absorption rate of the copolymer is maximum (the copolymer cannot absorb additional water). This water-saturated state can be achieved by immersing a sample of the copolymer in water and periodically measuring the mass of the sample. The water-saturated state is reached when the mass of the sample stabilizes (it no longer changes).

[0131] Preferably, the copolymer according to the invention has an elongation at break in the dry state of greater than or equal to 400%, preferably greater than or equal to 450%, more preferably greater than or equal to 500%, even more preferably greater than or equal to 550%, even more preferably greater than or equal to 600%. The elongation at break in the dry state can be measured according to standard ISO 527 1 BA: 2012.

[0132] The copolymer according to the invention preferably has a tensile stress in the water-saturated state of greater than or equal to 1 MPa, preferably greater than or equal to 2 MPa, more preferentially greater than or equal to 3 MPa, even more preferentially greater than or equal to 4 MPa. The tensile stress in the water-saturated state can be measured according to standard ISO 527 1 BA: 2012.

[0133] The copolymer according to the invention preferably has a tensile stress in the dry state of greater than or equal to 10 MPa, preferably greater than or equal to 12 MPa, more preferentially greater than or equal to 15 MPa. The tensile stress in the dry state can be measured according to standard ISO 527 1 BA: 2012.

[0134] Advantageously, the copolymers according to the invention have a water absorption at saturation of from 50% to 160% by weight, relative to the weight of the copolymer, preferably from 50% to 150% by weight, for example from 50% to 100% by weight, or from 100% to 125% by weight, or from 125% to 150% by weight, or from 150% to 160% by weight at 23° C. The water absorption at saturation of the copolymers at 23° C. can be determined according to standard ISO 62: 2008.

[0135] Synthesis of copolymers

[0136] The present invention also relates to a process for preparing the copolymers as described above.

[0137] In a general and known manner, polymers containing rigid polyamide blocks and flexible blocks can be prepared according to a "two-step" preparation process (comprising a first step of synthesizing the polyamide blocks followed by a second step of condensing the polyamide blocks and the flexible blocks) or by a "one-step" preparation process.

[0138] In certain embodiments, the copolymer is prepared according to a two-step process. This process comprises the following steps:

[0139] - Synthesis of rigid polyamide blocks from polyamide precursors;

[0140] - Adding flexible blocks;

[0141] - condensing the rigid polyamide blocks and the flexible blocks.

[0142] Alternatively, the copolymers according to the invention can be prepared according to a one-step process involving mixing the soft block with the polyamide precursor and the chain-limiting diacid.

[0143] A general process for the two-step preparation (i.e., a first step of synthesizing the polyamide blocks, followed by a second step of condensing the polyamide and polyether blocks) of copolymers containing polyamide blocks and polyether blocks (also known as PEBAs or polyether-block-amides according to IUPAC) with ester bonds between the PA and PE blocks is known and is described, for example, in FR 2 846 332. A general process for the preparation of PEBA copolymers with amide bonds between the PA and PE blocks is known and is described, for example, in EP 1 482 011. The polyether blocks can also be mixed with a polyamide precursor and a chain-limiting diacid to produce polymers containing polyamide blocks and polyether blocks with randomly distributed units (one-step process).

[0144] Regardless of the preparation method (in one or two steps), the copolymers with polyamide rigid blocks and flexible blocks are obtained by polycondensation of polyamide blocks with reactive ends with flexible blocks with reactive ends, such as in particular:

[0145] 1) Polyamide blocks with diamine chain ends and flexible blocks with dicarboxylic acid chain ends;

[0146] 2) polyamide blocks with dicarboxylic acid chain ends and flexible blocks with diamine chain ends (obtained, for example, by cyanoethylation and hydrogenation of aliphatic α,ω-dihydroxylated polyoxyalkylene blocks (also known as polyetherdiols);

[0147] 3) Polyamide blocks with dicarboxylic acid chain ends and polyether diols, the resulting products (in this particular case) being polyetheresteramides.

[0148] The polyamide blocks with dicarboxylic acid chain ends originate, for example, from the condensation of polyamide precursors in the presence of a chain-limiting dicarboxylic acid. The polyamide blocks with diamine chain ends originate, for example, from the condensation of polyamide precursors in the presence of a chain-limiting diamine.

[0149] When the copolymer is a branched copolymer, it can be prepared by adding one or more polyols comprising at least three hydroxyl groups as branching agents during its synthesis. In the one-step or two-step process described above, the polyol is added together with the polyamide precursor. Advantageously, the polyol is added in an amount ranging from 0.01% to 10% by weight, preferably from 0.01% to 5% by weight, more preferably from 0.05% to 0.5% by weight, relative to the total weight of the polyol, polyamide precursor, and the flexible block. Adding the polyol comprising at least three hydroxyl groups produces bridging bonds that connect the rigid polyamide blocks of the copolymer (preferably via ester bonds). The polyol may in particular be:

[0150] - monomeric polyols, especially monomeric aliphatic triols, such as glycerol, trimethylolpropane, pentaerythritol, and / or

[0151] - Polymer polyols, in particular triols containing polyether chains, polycaprolactone triols, mixed polyether-polyester polyols comprising at least three hydroxyl groups.

[0152] Advantageously, the polyol is selected from the group consisting of pentaerythritol, trimethylolpropane, trimethylolethane, hexanetriol, diglycerol, methyl glucoside, tetraethanol, sorbitol, dipentaerythritol, cyclodextrin, polyether polyols comprising at least three hydroxyl groups, and mixtures thereof. Preferably, the weight-average molar mass of the polyol is not greater than 3000 g / mol, more preferably not greater than 2000 g / mol.

[0153] diaphragm

[0154] The present invention also relates to a membrane (or film) comprising the copolymer as described above.

[0155] Preferably, the thickness of the membrane according to the present invention is from 0.05 to 100 μm. Particularly preferably, the thickness is from 0.5 to 50 μm. The membrane may have a thickness of from 0.05 to 0.5 μm, or from 0.5 to 1 μm, or from 1 to 2 μm, or from 2 to 5 μm, or from 5 to 10 μm, or from 10 to 20 μm, or from 20 to 30 μm, or from 30 to 40 μm, or from 40 to 50 μm, or from 50 to 60 μm, or from 60 to 70 μm, or from 70 to 80 μm, or from 80 to 90 μm, or from 90 to 100 μm.

[0156] In certain embodiments, the membrane consists essentially of, or consists of, a copolymer as described above.

[0157] In other embodiments, the membrane according to the present invention further comprises at least one additional polymer or oligomer selected from the group consisting of polyolefins such as polyethylene, polypropylene, poly(3-methyl-1-butene), and poly(4-methyl-1-pentene); vinyl polymers such as polystyrene, poly(methyl methacrylate); polysulfones; fluorinated or chlorinated polymers such as poly(vinylidene fluoride), polytetrafluoroethylene, fluoroethylene / tetrafluoroethylene copolymers, polychloroprene; polyamides such as PA 6, PA 6.6, and PA 12; copolymers containing rigid blocks and flexible blocks, such as copolymers containing polyamide blocks and polyether blocks; polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene 2,6-naphthalate; polycarbonates such as poly-4,4′-dihydroxydiphenyl-2,2-propane carbonate; polyethers such as polyoxymethylene and polymethylene sulfide; polyphenylene sulfide such as polysulfide, polyphenylene oxide, and polyphenylene sulfide; polyetheretherketone; polyetherketone Ketones; silicones such as polyvinyl trimethylsiloxane, polydimethylsiloxane; perfluoroalkoxy; polyethylene glycol; ethylene vinyl acetate (EVA); ethylene methyl acrylate (EMA); ethylene-EBA (ethylene butyl acrylate)-MAH (maleic anhydride), ethylene-EMA-MAH, ethylene-GMA (glycidyl methacrylate)-EBA, ethylene-EMA-GMA, ethylene-EVA-MAH terpolymers; and mixtures thereof.

[0158] Advantageously, the membrane comprises at least 50% by weight of a copolymer containing rigid polyamide blocks and flexible blocks as described above, and no more than 50% by weight of another polymer or oligomer, relative to the total weight of the membrane.

[0159] The membrane may further comprise one or more additives selected from the group consisting of UV stabilizers, crosslinking agents, pigments, metal oxides, zeolites, and mixtures thereof, preferably in an amount of from 0.01% to 30% by weight relative to the total weight of the membrane.

[0160] The membrane according to the invention may be a composite membrane, ie a membrane comprising at least one polymer layer as described above deposited on at least one porous, microporous or nanoporous support layer, such as nonwoven polypropylene or any polymeric framework.

[0161] Advantageously, the membrane is a waterproof and breathable membrane. The term "waterproof and breathable" means permeable to water vapor and impermeable to liquid water.

[0162] Preferably, the membrane according to the invention has a water vapor permeability (MVTR, standing for "Moisture Vapor Transmission Rate") of at least 800 g / m2 per 24 hours at 23°C and 50% relative humidity for a membrane thickness of 30 μm. 2 More preferably, the membrane has a water vapor permeability MVTR of at least 900 g / m at 23°C and 50% relative humidity for a membrane thickness of 30 μm. 2 / 24 h, more preferably at least 1000 g / m 2 / 24 h, even more preferably from 1000 to 5000 g / m 2 In particular, the MVTR membrane permeability (at 23°C, at 50% relative humidity, for a membrane thickness of 30 µm) can range from 800 to 900 g / m 2 / 24 hr, or from 900 to 1000 g / m 2 / 24 hr, or from 1000 to 1200 g / m 2 / 24 h, or 1200 to 1500 g / m 2 / 24 hr, or from 1500 to 2000 g / m 2 / 24 h, or 2000 to 2500 g / m 2 / 24 hr, or from 2500 to 3000 g / m 2 / 24 h, or 3000 to 3500 g / m 2 / 24 h, or 3500 to 4000 g / m 2 / 24 hr, or from 4000 to 4500 g / m 2 / 24 hr, or from 4500 to 5000 g / m 2 The water vapor permeability (MVTR) of the membrane (at 23°C, at 50% relative humidity, for a membrane thickness of 30 µm) can be measured according to standard ASTM E96 B.

[0163] Advantageously, the membrane according to the invention may have a permeability to carbon dioxide of CO2TR (standing for "CO2 transmission rate") greater than or equal to 100,000 cm at 23°C and 0% relative humidity. 3 .25 mm / m 2 .24 h.atm. Preferably, the membrane has a permeability to carbon dioxide (at 23°C and 0% relative humidity) greater than or equal to 120,000 cm3 .25 µm / m 2 .24 h.atm, more preferably greater than or equal to 150000 cm 3 .25 µm / m 2 .24 h.atm, even more preferably greater than or equal to 160000 cm 3 .25 µm / m 2 .24 h.atm, even more preferably greater than or equal to 180000 cm 3 .25 µm / m 2 .24 h.atm, even more preferably greater than or equal to 200000 cm 3 .25 µm / m 2 .24 h.atm. The permeability of a membrane to carbon dioxide (at 23°C, 0% relative humidity, for a membrane thickness of 25 µm) can be determined by the following method: In a permeation chamber, the upper side of the membrane to be tested is flushed with the test gas, and the flow through the membrane in the lower part of the membrane flushed with the carrier gas is analyzed by gas chromatography. The operating parameters are as follows:

[0164] - Test gas: O2 / CO2 gas mixture, ratio 80 / 20 mol%

[0165] - Osmometer equipment: LYSSY GPM 500 coupled with testing equipment;

[0166] - Detection equipment: Gas chromatograph equipped with TCD (thermal conductivity detector), reference Agilent 4890D;

[0167] - Gas injector with shut-off valve for chromatography (example: EMS injector, reference 008110 / 1 MR-V-GT);

[0168] - Aluminum surface reducing agent;

[0169] - Cryostat: one high-power (2.4 kW) for LYSSY GPM500, and two low-power (1.8 kW) for bubbler baths;

[0170] - Test temperature: 23°C;

[0171] - Relative humidity: 0%.

[0172] The permeability to gas is then calculated by the following formula:

[0173]

[0174] where "amount" is the volume of the gas of interest (in this case CO2) that has passed through the membrane, "e" is the thickness of the membrane, "area" is the area of ​​the membrane, "time" is the duration of flushing with the test gas, and p1 and p2 are the partial pressures on the upstream and downstream sides of the membrane, respectively.

[0175] Advantageously, the membrane according to the invention has a thermal conductivity (at 23°C and 0% relative humidity) less than or equal to 50,000 cm 3 .25 µm / m 2 .24 h.atm permeability to molecular oxygen ("oxygen transmission rate", OTR). Preferably, the membrane has a permeability to molecular oxygen (at 23°C and 0% relative humidity) less than or equal to 40,000 cm 3 .25 µm / m 2 .24 h.atm, more preferably less than or equal to 30000 cm 3 .25 µm / m 2 .24 h.atm, even more preferably less than or equal to 30000 cm 3 .25 µm / m 2 .24 h.atm, even more preferably less than or equal to 25 000cm 3 .25 µm / m 2 .24 h.atm, even more preferably less than or equal to 22 000 cm 3 .25 µm / m 2 .24 h.atm, even more preferably less than or equal to 20000 cm 3 .25 µm / m 2 .24 h.atm. The permeability of the membrane to molecular oxygen (at 23°C, at 0% relative humidity, for a membrane thickness of 25 µm) can be determined according to the method described above for the permeability to carbon dioxide (except that the gas concerned is O2).

[0176] Advantageously, the membrane according to the invention has a carbon dioxide / molecular oxygen selectivity P greater than or equal to 10. CO2 / P O2 The carbon dioxide / molecular oxygen selectivity of a membrane corresponds to the ratio of the membrane's permeability to carbon dioxide relative to the membrane's permeability to molecular oxygen, measured at a temperature of 23°C and 0% relative humidity. The membrane's permeability to carbon dioxide and molecular oxygen is determined under the same conditions and can be measured as described above. Preferably, the membrane's P CO2 / P O2The selectivity is greater than or equal to 12, more preferentially greater than or equal to 13, even more preferentially greater than or equal to 14, even more preferentially greater than or equal to 15. In other advantageous embodiments, it is greater than or equal to 16, or 17, or 18.

[0177] The present invention also relates to the use of the copolymers described above for the manufacture of membranes. In certain embodiments, the membranes are gas separation membranes, membranes for dehumidifying gases such as air, membranes for heat exchangers, or fabric membranes. The membranes may also be membranes for the recovery of greenhouse gases, particularly carbon dioxide and / or methane.

[0178] The membranes according to the invention can be produced in a known manner by any melt process, for example by flat film extrusion ("extrusion casting") or by extrusion coating on a support, or by a solvent process, for example by deposition in a solvent / evaporation process ("solvent casting").

[0179] In particular, the membrane can be manufactured by a process comprising the following steps:

[0180] - providing a copolymer as described above;

[0181] - dissolving the copolymer in a solvent;

[0182] - depositing the polymer dissolved in a solvent onto a substrate;

[0183] - Evaporate the solvent.

[0184] Alternatively, the membrane may be manufactured by a process comprising the following steps:

[0185] - providing a copolymer as described above;

[0186] - melting the copolymer;

[0187] - forming a molten copolymer film;

[0188] - Allowing the film to solidify.

[0189] When the membrane is a composite layer, the polymer layer can be deposited on the support layer by extrusion coating, extrusion lamination, adhesive lamination, deposition by solvent / evaporation ("solvent casting"), atomization ("spray coating"), welding, or sealing.

[0190] The present invention includes the following aspects / embodiments / features in any order and / or in any combination:

[0191] 1. A copolymer containing a rigid polyamide block and a flexible block, comprising, relative to the total weight of the copolymer:

[0192] - from 55 to 90% by weight of a soft block, at least 35% by weight of which comes from polyethylene glycol;

[0193] - from 10% to 45% by weight of rigid polyamide blocks, wherein the average carbon content of the repeating units of said polyamide blocks is greater than or equal to 7.

[0194] 2. The copolymer of the preceding or following embodiment / feature / aspect, wherein the soft block is a polyether block, and / or a polyether and polyester block.

[0195] 3. The copolymer of the preceding or following embodiment / feature / aspect, wherein the soft block is a block derived from polyethylene glycol, or the soft block comprises, in addition to the block derived from polyethylene glycol, a block derived from another polyether such as polytetrahydrofuran and / or propylene glycol, and / or polyester.

[0196] 4. The copolymer of the preceding or following embodiment / feature / aspect, wherein the average carbon content of the repeating units of the polyamide blocks is from 8 to 14, preferably from 8 to 12.

[0197] 5. The copolymer of the preceding or following embodiment / feature / aspect, wherein the rigid polyamide block is a block of polyamide 11, polyamide 12, polyamide 6.10, polyamide 6.12, polyamide 10.10, polyamide 10.12, copolyamide 6 / 11, copolyamide 6 / 12, copolyamide 11 / 12, or mixtures or copolymers thereof.

[0198] 6. The copolymer of the preceding or following embodiment / feature / aspect, comprising from 60 to 90 wt% of the soft blocks and from 10 to 40 wt% of the rigid polyamide blocks, relative to the total weight of the copolymer.

[0199] 7. The copolymer of the preceding or following embodiment / feature / aspect, comprising at least 40% by weight of a soft block derived from polyethylene glycol, preferably from 50% to 90% by weight, more preferentially from 60% to 80% by weight, relative to the total weight of the copolymer.

[0200] 8. The copolymer of any preceding or subsequent embodiment / feature / aspect, wherein the copolymer is a copolymer comprising polyamide 11 blocks and blocks derived from polyethylene glycol, a copolymer comprising polyamide 11 blocks, blocks derived from polyethylene glycol, and blocks derived from polytetrahydrofuran, a copolymer comprising polyamide 12 blocks and blocks derived from polyethylene glycol, a copolymer comprising polyamide 12 blocks, blocks derived from polyethylene glycol, and blocks derived from polytetrahydrofuran, a copolymer comprising copolyamide 6 / 11 blocks and blocks derived from polyethylene glycol, or a copolymer comprising copolyamide 6 / 11 blocks, blocks derived from polyethylene glycol, and blocks derived from polytetrahydrofuran.

[0201] 9. The copolymer of the preceding or following embodiment / feature / aspect, which has an elongation at break in the water-saturated state of greater than or equal to 100%, preferably greater than or equal to 200%, more preferentially greater than or equal to 300%, and / or a water absorption to saturation at 23°C ranging from 50% to 160% by weight, preferably from 50% to 150% by weight, relative to the total weight of the copolymer.

[0202] 10. A membrane comprising the copolymer of the preceding or following embodiment / feature / aspect, said membrane being preferably waterproof and breathable.

[0203] 11. The membrane of any preceding or subsequent embodiment / feature / aspect, having a selectivity greater than or equal to 10, preferably greater than or equal to 12, measured at a temperature of 23°C and 0% relative humidity, wherein the selectivity is defined as the ratio of the membrane's permeability to carbon dioxide relative to the membrane's permeability to molecular oxygen.

[0204] 12. The membrane of any preceding or following embodiment / feature / aspect, having a water vapor permeability MVTR of at least 800 g / m per 24 hours at 23°C, for a relative humidity level of 50% and a membrane thickness of 30 μm. 2 , preferably at least 900 g / m 2 , more preferably at least 1000 g / m 2 , more preferably from 1000 to 5000 g / m 2 .

[0205] 13. The membrane of the preceding or following embodiment / feature / aspect, having a thickness of from 0.05 to 100 μm, preferably from 0.5 to 50 μm.

[0206] 14. The membrane of any preceding or subsequent embodiment / feature / aspect, further comprising at least one polymer or oligomer selected from the group consisting of: polyolefins such as polyethylene, polypropylene, poly(3-methyl-1-butene), and poly(4-methyl-1-pentene); vinyl polymers such as polystyrene, poly(methyl methacrylate); polysulfones; fluorinated or chlorinated polymers such as poly(vinylidene fluoride), polytetrafluoroethylene, fluoroethylene / tetrafluoroethylene copolymers, polychloroprene; polyamides such as PA 6, PA 6.6, and PA 12; copolymers containing rigid blocks and flexible blocks, such as copolymers containing polyamide blocks and polyether blocks; polyesters, such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene 2,6-naphthalate; polycarbonates, such as poly-4,4′-dihydroxydiphenyl-2,2-propane carbonate; polyethers, such as polyoxymethylene and polymethylene sulfide; polyphenylene sulfide, such as polysulfide, polyphenylene oxide, and polyphenylene sulfide; polyetheretherketone; polyetherketoneketone; silicones, such as Such as polyvinyl trimethylsiloxane, polydimethylsiloxane, perfluoroalkoxy; polyethylene glycol; ethylene-vinyl acetate; ethylene-methyl acrylate; ethylene-(ethylene-butyl acrylate)-maleic anhydride, ethylene-(ethylene-methyl acrylate)-maleic anhydride, ethylene-methacrylate glycidyl-(ethylene-butyl acrylate), ethylene-(ethylene-methyl acrylate)-methacrylate glycidyl, ethylene-(ethylene-vinyl acetate)-maleic anhydride terpolymer; and mixtures thereof.

[0207] 15. Use of the copolymer of the preceding or subsequent embodiments / features / aspects for producing a gas separation membrane, or a membrane for dehumidifying a gas such as air, or an enthalpy heat exchanger membrane, or a fabric membrane; preferably, the gas separation membrane is a greenhouse gas recovery membrane.

[0208] 16. A process for preparing a copolymer of any preceding or subsequent embodiment / feature / aspect, comprising the steps of:

[0209] - Synthesis of rigid polyamide blocks from polyamide precursors;

[0210] - Adding flexible blocks;

[0211] - condensing the rigid polyamide blocks and the flexible blocks.

[0212] 17. A process for preparing a copolymer of the preceding or following embodiment / feature / aspect, comprising mixing a soft block with a polyamide precursor and a chain-limiting diacid.

[0213] 18. A process for manufacturing a membrane according to any preceding or subsequent embodiment / feature / aspect, comprising the following steps:

[0214] - supplying a copolymer of the preceding or subsequent embodiment / feature / aspect;

[0215] - dissolving the copolymer in a solvent;

[0216] - depositing the polymer dissolved in a solvent onto a substrate;

[0217] - Evaporate the solvent.

[0218] 19. A process for manufacturing a membrane according to any preceding or subsequent embodiment / feature / aspect, comprising the following steps:

[0219] - supplying a copolymer of the preceding or subsequent embodiment / feature / aspect;

[0220] - melting the copolymer;

[0221] - forming a molten copolymer film;

[0222] - Allowing the film to solidify.

[0223] Example

[0224] The following examples illustrate the invention without limiting it.

[0225] Example 1

[0226] Films were produced from various copolymers containing polyamide blocks and soft blocks via a flat film extrusion process ("extrusion casting") using an extruder with the following parameters:

[0227] - Screw diameter: 30 mm;

[0228] - L / D ratio: 25

[0229] - Profile: screw-barrier;

[0230] - Die: T-shaped, 250 µm width and 300 µm air gap.

[0231] Extrusion temperatures were between 180°C and 230°C and varied to suit the guard of the copolymer.

[0232] The characteristics of the copolymers and films are given in the following table:

[0233] [Table 1]

[0234]

[0235] The copolymer of membrane 8 is prepared from PEG diamine blocks.

[0236] Diaphragms 7 to 10 are according to the invention, and diaphragms 1 to 6 correspond to comparative examples.

[0237] These films were tested for various properties and the results are given below:

[0238] [Table 2]

[0239]

[0240] The permeability to water vapor, MVTR, is measured at 23° C. and 50% relative humidity according to standard ASTM E96B.

[0241] The permeability to molecular oxygen OTR and the permeability to carbon dioxide CO2TR were measured according to the method described above in the specification at 23°C and a relative humidity level of 0%. The values ​​shown are normalized for a 25 μm membrane.

[0242] P CO2 / P O2 Selectivity is calculated by dividing the permeance CO2TR by the permeance OTR.

[0243] It was observed that the membranes according to the invention (membranes 7 to 10) combined high permeability to water vapor, high permeability to CO2, and good P CO2 / P O2 Selective.

[0244] Compared to the membrane according to the invention, membranes 1, 2 and 3 have a lower permeability to carbon dioxide. Membrane 1 also has a low permeability to water vapor.

[0245] Membranes 4 and 5 have low permeability to water vapor and low P CO2 / P O2 Selective.

[0246] The membrane 6 has insufficient mechanical properties in the water-saturated state due to the very high water absorption. The elongation at break and the tensile stress in the water-saturated state show a very significant decrease compared to these characteristics measured in the dry state.

[0247] Several mechanical properties were also tested for the following copolymers: a copolymer containing PA 12 blocks / blocks derived from PEG (50 / 50) (PEBA No. 2), used to prepare membrane 2, a copolymer containing PA 6 blocks / blocks derived from PEG (50 / 50) (PEBA No. 3), used to prepare membrane 3, and a copolymer containing PA 11 blocks / blocks derived from PEG (40 / 60) (PEBA No. 7), used to prepare membrane 7.

[0248] 50 μm thick films were prepared from the three PEBAs as described above and tensile tests were performed on these films before and after they were subjected to the MVTR measurement test. For the measurements performed after the MVTR measurement test, the films were air-dried for a few minutes before the tensile test was performed.

[0249] Use a guillotine cutter (guillotine) to cut approximately 7 mm wide and 50 mm long samples (3 for each product). These samples were subjected to traction measurements as follows: according to standard ASTM-D 882, using a traction speed of 200 mm / min and a length (L0) between the grips of 25 mm. Measure tensile stress and elongation at break. These properties are determined in the longitudinal direction relative to the extrusion direction and in the transverse direction relative to the extrusion direction.

[0250] The results are shown in Figures 1 to 6 middle.

[0251] For PEBA No. 3, in the transverse direction, there is a very strong decrease in the elongation at break and the tensile stress after the MVTR measurement test relative to these characteristics measured before said test ( Figure 1 In the longitudinal direction, a decrease in elongation at break and tensile stress was also observed after the MVTR measurement test, although it was not as significant as in the transverse direction ( Figure 2 ).

[0252] Thus, PEBA No. 3 is sensitive to the MVTR measurement test, and its mechanical properties deteriorate after this test.

[0253] For PEBA No. 2, in the transverse direction, the polymer film had an elongation at break after the MVTR measurement test that was similar to that obtained before the test ( Figure 3 ). However, in the longitudinal direction, the elongation at break and the tensile stress after the test were lower than those before the test ( Figure 4 ).

[0254] PEBA No. 2 showed relatively good resistance in the MVTR measurement test, but its permeability to carbon dioxide was too low, as shown above.

[0255] For PEBA No. 7, in the transverse direction, the films had similar mechanical properties before and after the MVTR measurement test, both in terms of tensile stress and elongation at break ( Figure 5 In the longitudinal direction, the elongation at break measured after the MVTR measurement test is reduced relative to the elongation at break measured before said test ( Figure 6 ).

[0256] PEBA No. 7 showed good resistance in the MVTR measurement test and maintained its mechanical properties after this test.

[0257] Example 2

[0258] The branched copolymers were prepared according to a two-step process, where polyamide blocks were first synthesized by mixing polyamide precursors with a branching agent, and then a soft block derived from PEG was added and condensed with the polyamide blocks.

[0259] These copolymers have the following characteristics:

[0260] [Table 3]

[0261]

[0262] The mass amount of branching agent corresponds to the mass percentage of branching agent added together with the polyamide precursor during the synthesis of the copolymer relative to the total weight of all copolymer reagents.

[0263] PEBA Nos. 11, 12, 13, and 14 were prepared from PEG diamine blocks.

[0264] In PEBA No. 15, the polyamide block comprises 70 mol % of PA 6 and 30 mol % of PA 11 and thus has an average carbon content of the repeating units of 7.5.

[0265] PEBA No. 15 is a copolymer according to the invention and PEBA Nos. 11 to 14 correspond to comparative examples.

[0266] The water absorption of the copolymers up to saturation at 23°C (or water absorption) and their mechanical properties in the dry state and in the water-saturated state were determined and are presented in the following table:

[0267] [Table 4]

[0268]

[0269] The water absorption is measured according to standard ISO 62: 2008. The tensile stress in the dry state and in the water-saturated state and the elongation at break in the dry state and in the water-saturated state are measured according to standard ISO 527 1 BA: 2012.

[0270] Copolymers containing polyamide blocks with an average carbon content of 6 repeating units (PEBA numbers 11 to 14) have very high water absorption and, therefore, very low tensile stress and elongation at break when saturated with water. Membranes formed from these copolymers will therefore have low durability.

[0271] In contrast, PEBA No. 15, which contains polyamide blocks having an average carbon content of recurring units equal to 7.5, has a high elongation at break and sufficient tensile stress in the water-saturated state.

[0272] The copolymer according to the present invention has good permeability to water vapor and carbon dioxide, good P CO2 / P O2 selectivity, and good mechanical properties in the dry and wet state.

Claims

1. A copolymer containing a rigid polyamide block and a flexible block, comprising, relative to the total weight of the copolymer: - from 55 to 90% by weight of a soft block, at least 35% by weight of which comes from polyethylene glycol; - from 10% to 45% by weight of rigid polyamide blocks, wherein the average carbon content of the repeating units of said polyamide blocks is greater than or equal to 7.

2. The copolymer as claimed in claim 1, wherein the soft block is a polyether block and / or a polyether and polyester block.

3. The copolymer as claimed in claim 1 or 2, wherein the soft block is a block derived from polyethylene glycol, or the soft block comprises, in addition to the block derived from polyethylene glycol, a block derived from another polyether such as polytetrahydrofuran and / or propylene glycol, and / or polyester. 4 . The copolymer as claimed in claim 1 , wherein the average carbon content of the repeating units of the polyamide blocks is from 8 to 14, preferably from 8 to 12. 5 .

5. The copolymer as claimed in claim 1, wherein the rigid polyamide block is a block of polyamide 11, polyamide 12, polyamide 6.10, polyamide 6.12, polyamide 10.10, polyamide 10.12, copolyamide 6 / 11, copolyamide 6 / 12, copolyamide 11 / 12, or a mixture or copolymer thereof. 6 . The copolymer as claimed in claim 1 , comprising from 60% to 90% by weight of flexible blocks and from 10% to 40% by weight of rigid polyamide blocks, relative to the total weight of the copolymer.

7. The copolymer as claimed in claim 1, comprising at least 40% by weight of soft blocks derived from polyethylene glycol, preferably from 50% to 90% by weight, more preferentially from 60% to 80% by weight, relative to the total weight of the copolymer.

8. The copolymer according to any one of claims 1 to 7, which is a copolymer comprising polyamide 11 blocks and blocks derived from polyethylene glycol, a copolymer comprising polyamide 11 blocks, blocks derived from polyethylene glycol, and blocks derived from polytetrahydrofuran, a copolymer comprising polyamide 12 blocks and blocks derived from polyethylene glycol, a copolymer comprising polyamide 12 blocks, blocks derived from polyethylene glycol, and blocks derived from polytetrahydrofuran, a copolymer comprising copolyamide 6 / 11 blocks and blocks derived from polyethylene glycol, or a copolymer comprising copolyamide 6 / 11 blocks, blocks derived from polyethylene glycol, and blocks derived from polytetrahydrofuran.

9. The copolymer as claimed in claim 1 , having an elongation at break in the water-saturated state of greater than or equal to 100%, preferably greater than or equal to 200%, more preferentially greater than or equal to 300%, and / or a water absorption up to saturation at 23° C. ranging from 50% to 160% by weight, preferably from 50% to 150% by weight, relative to the total weight of the copolymer.

10. A membrane comprising a copolymer as claimed in any one of claims 1 to 9, said membrane being preferably waterproof and breathable.

11. The membrane as claimed in claim 10, having a selectivity greater than or equal to 10, preferably greater than or equal to 12, measured at a temperature of 23°C and 0% relative humidity, said selectivity being defined as the ratio of the membrane's permeability to carbon dioxide to the membrane's permeability to molecular oxygen.

12. The membrane of any one of claims 10 and 11, having a water vapor permeability MVTR of at least 800 g / m per 24 hours at 23°C, for a relative humidity level of 50% and a membrane thickness of 30 μm. 2 , preferably at least 900 g / m 2 , more preferably at least 1000 g / m 2 , more preferably from 1000 to 5000 g / m 2 .

13. The membrane as claimed in one of claims 10 to 12, having a thickness of from 0.05 to 100 μm, preferably from 0.5 to 50 μm.

14. The membrane of any one of claims 10 to 13, further comprising at least one polymer or oligomer selected from the group consisting of polyolefins such as polyethylene, polypropylene, poly(3-methyl-1-butene), and poly(4-methyl-1-pentene); vinyl polymers such as polystyrene, poly(methyl methacrylate); polysulfones; fluorinated or chlorinated polymers such as poly(vinylidene fluoride), polytetrafluoroethylene, fluoroethylene / tetrafluoroethylene copolymers, polychloroprene; polyamides such as PA 6, PA 6.6, and PA 12; copolymers containing rigid blocks and flexible blocks, such as copolymers containing polyamide blocks and polyether blocks; polyesters, such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene 2,6-naphthalate; polycarbonates, such as poly-4,4′-dihydroxydiphenyl-2,2-propane carbonate; polyethers, such as polyoxymethylene and polymethylene sulfide; polyphenylene sulfide, such as polysulfide, polyphenylene oxide, and polyphenylene sulfide; polyetheretherketone; polyetherketoneketone; silicones, such as Such as polyvinyl trimethylsiloxane, polydimethylsiloxane, perfluoroalkoxy; polyethylene glycol; ethylene-vinyl acetate; ethylene-methyl acrylate; ethylene-(ethylene-butyl acrylate)-maleic anhydride, ethylene-(ethylene-methyl acrylate)-maleic anhydride, ethylene-methacrylate glycidyl-(ethylene-butyl acrylate), ethylene-(ethylene-methyl acrylate)-methacrylate glycidyl, ethylene-(ethylene-vinyl acetate)-maleic anhydride terpolymer; and mixtures thereof.

15. Use of the copolymer according to any one of claims 1 to 9 for producing a gas separation membrane, or a membrane for dehumidifying a gas such as air, or an enthalpy heat exchanger membrane, or a textile membrane; preferably, the gas separation membrane is a greenhouse gas recovery membrane.

16. A process for preparing a copolymer as claimed in any one of claims 1 to 9, comprising the following steps: - Synthesis of rigid polyamide blocks from polyamide precursors; - Adding flexible blocks; - condensing the rigid polyamide blocks and the flexible blocks.

17. Process for preparing a copolymer as claimed in any one of claims 1 to 9, which involves mixing a soft block with a polyamide precursor and a chain-limiting diacid.

18. A process for producing a membrane as claimed in any one of claims 10 to 14, comprising the following steps: - supplying a copolymer as claimed in one of claims 1 to 9; - dissolving the copolymer in a solvent; - depositing the polymer dissolved in a solvent onto a substrate; - Evaporate the solvent.

19. A process for producing a membrane as claimed in any one of claims 10 to 14, comprising the following steps: - supplying a copolymer as claimed in one of claims 1 to 9; - melting the copolymer; - forming a molten copolymer film; - Allowing the film to solidify.

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