Barrier layer based on MPMD.t cells

Abstract

The invention relates to a polyamide (PA), the repeat units (RPA) of which are formed by the polycondensation of a diamine component (A) and a diacid component (B), in which:-the diamine component (A) consists essentially of or consists of:-between 50.0 mol% (excluding this value) and 70.0 mol% 2-methylpentanediamine (MPMD); and-between 30.0 and 50.0 mol% of at least one further diamine (DA) having the formula 2HN-R1-NH2, wherein R1 is a linear or branched alkylene group of C8-C11; -these proportions in mol% are based on the total amount of diamines in diamine component (A); -the diacid component (B) consisting essentially of or consisting of:-between 90.0 and 100.0 mol.% of terephthalic acid; and between 0 and 10.0 mol.% of another diacid (DI) selected from the group consisting of isophthalic acid, adipic acid (AA) and combinations thereof; -these proportions in mol% are based on the total amount of diacids in the dicarboxylic acid component (B); -wherein the proportion of MPMD.T repeat units in the polyamide (PA) is greater than 50.0 mol% (gt; 50.0 mol%), given with respect to the total number of moles of repeat units in the polyamide (PA).

Description

[0001] This international application claims priority to U.S. Patent Application No. 63 / 579725, filed August 30, 2023, and European Patent Application No. 23196801.7, filed September 12, 2023, the contents of which are incorporated herein by reference in their entirety for all purposes. In the event of any inconsistency between this international application and those two priority applications that would affect the clarity of terminology or expression, reference should be made solely to this PCT application. Technical Field

[0002] This invention relates to a novel 2-methylpentanediamine (MPMD)-based semi-aromatic polyamide and its use as an H2 barrier layer, and to a multilayer structure comprising said polyamide. Background Technology

[0003] In recent years, environmentally friendly natural gas vehicles and fuel cell vehicles have become more popular. Fuel cell vehicles are powered by fuel cells, in which hydrogen is used as fuel.

[0004] When vehicle weight reduction is required, composite material-based H2 tanks are superior to those made of steel. These tanks need to withstand the internal pressure of H2 and should minimize H2 loss over time.

[0005] To meet this need, high-pressure gas storage tanks have been developed, including linings with barrier properties and outer layers containing fiber-reinforced composite materials. Type IV tanks were thus developed. These tanks are made with thermoplastic linings encased in composite materials.

[0006] For example, US 2023 / 0142635 discloses such a high-pressure gas storage tank in which the lining is made of thermoplastic polymers, especially polyamides as disclosed in WO 2016 / 084175.

[0007] JP 2023 / 058318 discloses a hydrogen tank liner that exhibits excellent gas barrier properties for hydrogen, the liner being formed from a resin composition comprising a copolymer containing conjugated diene units, non-conjugated olefin units, and aromatic vinyl units.

[0008] KR 102493982 B1 discloses a polymer membrane for hydrogen tank lining, the polymer membrane comprising a copolymer containing polyamide segments and polyether segments.

[0009] US 5,302,691 discloses a copolyamide based on a diamine component comprising MPMD and 1,6-hexamethylenediamine.

[0010] WO 2017 / 102385 discloses a pressure vessel comprising a hollow body containing continuous fibers embedded in a thermoplastic matrix. The polyamide of this invention is not disclosed.

[0011] WO 2022 / 069826 discloses a multilayer structure intended for containing hydrogen, comprising, from the inside to the outside, at least one barrier layer and at least one reinforcing layer. The barrier layer comprises 20.5 to 99.845 wt% polyamide, 0.005 to 0.5 wt% catalyst, 0.05 to 1 wt% heat stabilizer, and 0.1 to 3 wt% oligomer or polycarbodiimide. The polyamide of the barrier layer may be selected from the group consisting of: PA 10.10, PA 10.12, PA 11, PA12, 11 / 5T, 11.6T, 11.10T, MXD.T / 10.T, MPMD.T / 10.T, and BAC.T / 10.T. The copolyamide of claim 1 is not disclosed.

[0012] US 6,162,317 (D1) discloses several copolyamides based on MPMD and 1,6-hexanediamine (C6) in Table 2.

[0013] US 2023 / 0151255 (D2) discloses the use of a sealing layer comprising a composition containing at least one polyamide for preparing a multilayer structure intended for transporting, distributing, or storing hydrogen, said sealing layer being based on a polyamide selected from the group consisting of 11 / 5T, 11 / 6T, 11 / 10T, MXDT / 10T, MPMD.T / 10.T, and BAC.T / 10.T. The copolyamide of claim 1 is not disclosed.

[0014] WO 2023 / 083783 discloses a multilayer structure for storing or transporting H2, the multilayer structure comprising a sealing layer made of MPMD.T / 10.T with a Tg of 125°C. The copolyamide of claim 1 is not disclosed.

[0015] US 11,345,131 discloses a barrier structure selected from bottles, cans, and tubes, comprising a barrier layer containing an MPMD.T / XT copolyamide in the following proportions: 5 to 50 mol% MPMD.T units and 50 to 95 mol% XT units. Specifically, the sole example in US'131 discloses a polyamide having 41 mol% MPMD.T units and 59 mol% XT units. The polyamide of the present invention differs in that the proportion of MPMD.T units is strictly higher than 50.0 mol%.

[0016] US 8,338,561 B2 discloses a polyamide having a melting point Tm between 330°C and 370°C, the polyamide comprising a diamine component (a) and a dicarboxylic acid component (b), the diamine component (a) comprising at least 22 mol% and at most 28 mol% of at least one aliphatic diamine (selected from 1,9-nonanediamine and 2-methyl-1,8-octanediamine) having more than 6 carbon atoms and at least 72 mol% and at most 78 mol% of 1,6-hexanediamine, the dicarboxylic acid component (b) being substantially composed of terephthalic acid.

[0017] GB 1383757 discloses a polyamide comprising condensing a mixture of 2-methyl-pentamethylenediamine and 1,3-bis-(aminomethyl)-cyclohexane (the latter may be partially replaced by 1,4-bis-(aminomethyl)-cyclohexane if desired, wherein the proportion of 2-methyl-pentamethylenediamine is in the range of 20 to 80 mol% based on the total amount of diamine, preferably 40 to 60 mol%) with an aromatic dicarboxylic acid having 7 to 20 carbon atoms, preferably 8 to 14 carbon atoms, a mononuclear dicarboxylic acid advantageously carrying a meta or para carboxyl group, or a mixture of two or more of these acids.

[0018] JP 2014 / 240148 discloses a conductive laminated tubular body comprising at least three layers including: a layer composed of an aliphatic polyamide; a layer composed of a semi-aromatic polyamide having a specific structure comprising at least 80% C9-C. 13 The composition comprises a diamine unit of an aliphatic diamine unit and a dicarboxylic acid unit containing at least 80% terephthalic acid units and / or naphthalic acid units; and a layer composed of a conductive semi-aromatic polyamide copolymer composition, which consists of: a semi-aromatic polyamide copolymer having a specific structure; and a conductive filler. The following semi-aromatic polyamide containing 20 mol% MPMD.T units with a melting temperature of 217°C is disclosed: 9T / M8T / 6T / M5T = 30 / 30 / 20 / 20 mol%. Technical issues

[0019] A thermoplastic polymer is needed that exhibits good H2 barrier properties (low permeability) even at high temperatures, while also being easily processed into linings, especially by extrusion. Furthermore, this thermoplastic polymer should exhibit a combination of the following thermal properties: a high glass transition temperature Tg to withstand high temperatures, a low melting temperature Tm for easy processing, and a low crystallization temperature Tc to simplify the processing procedure.

[0020] The polyamide of this invention aims to solve this technical problem. Brief description of the invention

[0021] The invention is particularly disclosed in the appended claims.

[0022] The present invention relates to a polyamide as disclosed in any one of claims 1 to 20.

[0023] The present invention also relates to a method for preparing polyamide as disclosed in claim 21 or 22.

[0024] The present invention also relates to a polymer composition as disclosed in any one of claims 23 to 27.

[0025] The present invention also relates to the uses disclosed in claim 28 or 29.

[0026] The present invention also relates to a hydrogen barrier layer as disclosed in any one of claims 30 to 32.

[0027] The present invention also relates to a multilayer structure as disclosed in any one of claims 33 to 36, intended for storing or transporting H2.

[0028] The present invention also relates to a container or tube as disclosed in claim 37.

[0029] The present invention also relates to a thermoplastic composite material as described in claim 38.

[0030] More precise information and details on these topics are now provided below. definition

[0031] wt% means percentage by weight. mol% means percentage by mole.

[0032] Unless otherwise specified, this applies to all numerical ranges (including those without upper or lower limits), including the endpoints.

[0033] In this application, unless otherwise indicated, any particular embodiment or technical feature related to the subject matter is applicable to and interchangeable with another embodiment or technical feature that is also related to the same subject matter and disclosed elsewhere in this application.

[0034] The proportion of diamine in diamine component (A) is given in mol% and relative to the total amount of diamine in diamine component (A).

[0035] The proportion of dicarboxylic acids in dicarboxylic acid component (B) is given as mol% and relative to the total amount of dicarboxylic acids (also called diacids) in dicarboxylic acid component (B).

[0036] Dicarboxylic acids are organic compounds containing two carboxylic acid functional groups (-COOH). Terephthalic acid, isophthalic acid, and adipic acid are examples of dicarboxylic acids.

[0037] The proportion of repeating units in polyamide is expressed in mol% relative to the total amount of repeating units. Detailed Implementation

[0038] As a first aspect, the present invention relates to a polyamide (PA) having repeating units (R... PA It is formed by the condensation polymerization of a diamine component (A) and a dicarboxylic acid component (B), wherein:

[0039] - The diamine component (A) contains, is substantially composed of, or is composed of the following:

[0040] ■ 2-Methylpentanediamine (MPMD) between 50.0 mol% (excluding this value) and 70.0 mol%; and

[0041] ■ At least one other diamine (DA) having the formula 2HN-R1-NH2, with a concentration between 30.0 and 50.0 mol%, wherein R1 is C8-C 11 Straight-chain or branched alkylene groups;

[0042] ■ These percentages, expressed in mol%, are based on the total amount of diamine in diamine component (A);

[0043] - The dicarboxylic acid component (B) contains, is substantially composed of, or is composed of the following:

[0044] ■Terephthalic acid between 90.0 and 100.0 mol.%; and

[0045] ■ Another diacid (DI) selected from isophthalic acid, adipic acid (AA), and combinations thereof, between 0 and 10.0 mol.%.

[0046] ■ These percentages, expressed in mol%, are based on the total amount of dicarboxylic acid in the dicarboxylic acid component (B);

[0047] - The proportion of MPMD.T repeating units in the polyamide (PA) is greater than 50.0 mol% (> 50.0 mol%), which is given relative to the total number of repeating units in the polyamide (PA).

[0048] All monomers of the diamine component (A) and the dicarboxylic acid component (B) are present in the polyamide in essentially polymeric form.

[0049] Diamine component (A)

[0050] The diamine component (A) comprises, is substantially composed of, or consists of: 2-methylpentanediamine (MPMD) in amounts between 50.0 mol% (excluding this value) and 70.0 mol% and at least one other diamine (DA) having the formula 2HN-R1-NH2 in amounts between 30.0 and 50.0 mol%, wherein R1 is C8-C 11 A straight-chain or branched alkylene group. The diamine component (A) is more particularly composed essentially of either 2-methylpentanediamine (MPMD) in amounts between 50.0 mol% (excluding this value) and 70.0 mol% or at least one other diamine (DA) having the formula 2HN-R1-NH2 in amounts between 30.0 and 50.0 mol%, wherein R1 is C8-C 11 Straight-chain or branched alkylene groups. These percentages, expressed in mol%, are based on the total amount of diamine in the diamine component (A).

[0051] The phrase “consistently composed of” in the context of this invention in relation to the diamine component means that the diamine component (A) consists of MPMD, at least one diamine (DA), and up to 1.0 mol%, more preferably up to 0.5 mol%, of one or more diamines other than MPMD and diamine (DA), the percentage in mol% being based on the total amount of diamine in the diamine component (A).

[0052] MPMD (or 2-methylpentane-1,5-diamine) is a diamine having the following formula:

[0053] [CAS No.: 15520-10-2]

[0054] Diamine (DA) has the formula 2HN-R1-NH2, where R1 is C8-C. 11 Straight-chain or branched alkylene groups.

[0055] One or more other diamines (DA) having the formula 2HN-R1-NH2 (where R1 is C8-C) 11 The proportion of straight-chain or branched alkylene groups is between 30.0 and 50.0 mol%. This proportion in mol% is based on the total amount of diamine in the diamine component (A).

[0056] The proportion of MPMD and the total proportion of one or more diamines (DA) can be more specifically between 53.0 and 63.0 mol% and between 37.0 and 47.0 mol%, respectively.

[0057] R1 is even more special because it's C8-C10 Straight-chain or branched alkylene groups.

[0058] R1 is even more special because it's C8-C 10 Straight-chain alkylene groups.

[0059] The diamine (DA) may more particularly be selected from the group consisting of 1,8-octanediamine, 1,9-diaminononane, 1,10-diaminodecane, 2-methyl-1,8-octanediamine, and combinations of two or more of these diamines. If the diamine (DA) corresponds to 2-methyl-1,8-octanediamine and at least one diamine selected from the group consisting of 1,8-octanediamine, 1,9-diaminononane, and 1,10-diaminodecane, then the proportion of 2-methyl-1,8-octanediamine in the diamine component (A) is preferably less than or equal to 10.0 mol% (≤ 10.0 mol%), more preferably less than or equal to 5.0 mol% (≤ 5.0 mol%).

[0060] The diamine (DA) can be more specifically selected from the group consisting of: 1,8-octanediamine, 1,9-diaminononane, 1,10-diaminodecane, and combinations of two or more of these diamines.

[0061] The diamine (DA) can be more specifically selected from the group consisting of: 1,9-diaminononane, 1,10-diaminodecane, and 1,9-diaminononane and 1,10-diaminodecane (2HN-(CH2)). 10 The combination of -NH2).

[0062] The diamine (DA) can be more specifically 1,9-diaminononane (2HN-(CH2)9-NH2).

[0063] The diamine (DA) can be any of the diamines disclosed in this document.

[0064] Dicarboxylic acid component (B)

[0065] The dicarboxylic acid component (B) comprises, is substantially composed of, or is composed of: terephthalic acid in the range of 90.0 to 100.0 mol%; and another diacid (DI) selected from the group consisting of isophthalic acid, adipic acid (AA), and combinations thereof in the range of 0 to 10.0 mol.%. More particularly, the dicarboxylic acid component (B) is substantially composed of, or is composed of: terephthalic acid in the range of 90.0 to 100.0 mol%; and another diacid (DI) selected from the group consisting of isophthalic acid, adipic acid (AA), and combinations thereof in the range of 0 to 10.0 mol.%. These mol% percentages are based on the total amount of diacid in the dicarboxylic acid component (B).

[0066] Dicarboxylic acid (DI) can be isophthalic acid, adipic acid, or a combination of isophthalic acid and adipic acid.

[0067] The phrase "consistently composed of" in the context of this invention in relation to the dicarboxylic acid component means that the dicarboxylic acid component (B) consists of: terephthalic acid, optionally another diacid (DI) selected from the group consisting of isophthalic acid, adipic acid (AA), and combinations thereof, and up to 1.0 mol%, more preferably up to 0.5 mol%, of one or more diacids other than terephthalic acid and one or more diacids (DI), the percentage in mol% being based on the total amount of dicarboxylic acid in the dicarboxylic acid component (B).

[0068] The proportion of terephthalic acid and the total proportion of one or more diacids (DI) may particularly be between 95.0 and 100.0 mol% and between 0 and 5.0 mol%, respectively; preferably between 97.0 and 100.0 mol% and between 0 and 3.0 mol%, respectively; and more preferably between 99.0 and 100.0 mol% and between 0 and 1.0 mol%, respectively.

[0069] According to a preferred embodiment (E), the dicarboxylic acid component (B) is substantially composed of or consisting of terephthalic acid. The expression "substantially composed of" here means that the dicarboxylic acid component (B) consists of terephthalic acid and up to 1.0 mol%, more preferably up to 0.5 mol%, of one or more diacids other than terephthalic acid, the mol% percentage being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B).

[0070] The copolyamide (PA) of the present invention is particularly selected from the group consisting of MPMD.T / 10.T and MPMD.T / 9.T copolyamides.

[0071] Repeating unit (R) PA )

[0072] Repeating units (R) of polyamide (PA) PA It is basically composed of or consists of the following units:

[0073]

[0074] The phrase "consistent with essentially..." in the context of this invention and in relation to repeating units means that the repeating units of polyamide (PA) consist of repeating units (R... PA1 )-(R PA4 The composition consists of repeating units other than the repeating units, up to 1.0 mol%, more preferably up to 0.50 mol%, more preferably up to 0.25 mol%, and more preferably up to 0.10 mol%, the percentage in mol% being based on the total amount of repeating units in the polyamide (PA).

[0075] As shown in the table above (R) PA1 As can be seen, MPMD is an asymmetric molecule, which means that the repeating unit derived from this diamine can be based on two configurations.

[0076] The unit (R) in polyamide (PA) PA1 The proportion of ) is > 50.0 mol%.

[0077] According to the preferred embodiment (E), the repeating unit of polyamide (PA) is essentially composed of unit (R) PA1 ) and (R PA2 It is composed of or consists of. The ratio of these two units corresponds to the ratio of MPMD and diamine (DA) as disclosed herein. Therefore, (R PA1 The proportion of ) is between 50.0 mol% (excluding this value) and 70.0 mol%, and (R PA2 The proportion of (R) is between 30.0 and 50.0 mol%. More specifically, (R) PA1 The proportion of ) was between 53.0 mol% and 63.0 mol%, and (R PA2 The proportion of ) is between 37.0 and 47.0 mol%.

[0078] The polyamide (PA) (i) preferably does not contain or (ii) preferably does not contain repeating units derived from 1,6-hexamethylenediamine.

[0079] The polyamide (PA) (i) preferably does not contain or (ii) preferably does not contain repeating units derived from 2-methyl-1,8-octanediamine.

[0080] The polyamide (PA) (i) preferably does not contain or (ii) preferably does not contain repeating units derived from m-phenylenediamine or p-phenylenediamine.

[0081] The polyamide (PA) (i) preferably does not contain or (ii) preferably does not contain repeating units derived from 1,3-bis(aminomethyl)cyclohexane or 1,4-bis(aminomethyl)cyclohexane.

[0082] Polyamide (PA) (i) preferably does not contain or (ii) preferably does not contain repeating units derived from lactams or amino acids.

[0083] The expression “free of” in relation to a specific repeating unit means that the proportion of the repeating unit in the polyamide (PA) is less than or equal to 1.0 mol% (≤ 1.0 mol%), preferably less than or equal to 0.50 mol% (≤ 0.50 mol%), preferably less than or equal to 0.25 mol% (≤ 0.25 mol%), and preferably less than or equal to 0.10 mol% (≤ 0.10 mol%).

[0084] End groups of polyamide (PA)

[0085] The end groups of polyamides (PAs) are selected from the group consisting of -NH2, -COOH, and amide end groups. In fact, the end groups in polyamides (PAs) can be either -NH2 or -COOH. However, when polycondensation involves the addition of end-capping agents, these end groups can be partially or completely converted to amide end groups.

[0086] The amide terminal group has the formula -NH-C(=O)-R, where R is alkyl, aryl, or cycloalkyl, and / or has the formula -C(=O)-NH-R', where R' is alkyl or cycloalkyl. R is more particularly a straight-chain or branched C1-C group. 18 Alkyl or C5-C 10 Cycloalkyl. R' is more particularly a straight-chain or branched C2-C. 18 alkyl.

[0087] Amide end groups with the formula -NH-C(=O)-R are produced by the reaction of the end group -NH2 with a monocarboxylic acid (end capping agent) having the formula R-COOH.

[0088] Monocarboxylic acids (capping agents) can be advantageously selected from the group consisting of: benzoic acid; cyclohexanoic acid; R-COOH, where R is a straight-chain or branched C1-C. 18 Alkyl groups; and combinations of two or more of these acids. R is a group derived from an acid having the formula R-COOH.

[0089] Monocarboxylic acids (capping agents) may be more specifically selected from the group consisting of: acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, lauric acid, stearic acid, 2-ethylhexanoic acid, cyclohexanoic acid, benzoic acid, and combinations of two or more of these acids.

[0090] Monocarboxylic acids (capping agents) are more specifically those with the formula CH3-(CH2). m -COOH, where m is an integer between 0 and 16. The amide terminal group has the formula -NH-C(=O)-(CH2). m -CH3.

[0091] The amide end group with the formula -C(=O)-NH-R' is generated by the reaction of the end group -COOH with a primary amine (end capping agent) having the formula R'-NH2.

[0092] Primary amines (capping agents) can be advantageously selected from the group consisting of amines having the formula R'-NH2, wherein R' is a straight-chain or branched C2-C. 18 Alkyl group. R' is a group derived from an amine having the formula R'-NH2.

[0093] Primary amines (capping agents) are more specifically those with the formula CH3-(CH2). m' -NH2, where m' is an integer between 2 and 18. The amide terminal group has the formula -C(=O)-NH-(CH2). m' -CH3.

[0094] Primary amines (capping agents) may be more specifically selected from the group consisting of: propylamine, butylamine, pentylamine, hexylamine, 2-ethylhexylamine, n-octylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, stearylamine, cyclohexylamine, and combinations of two or more of these amines.

[0095] The ratio of end groups can be determined by... 1 Quantification can be achieved using 1H NMR spectroscopy or potentiometric techniques.

[0096] Properties of polyamide (PA)

[0097] The polyamides (PAs) of the present invention typically have a number-average molecular weight (“Mn”) ranging from 1,000 g / mol to 40,000 g / mol, for example 2,000 g / mol to 35,000 g / mol, 4,000 to 30,000 g / mol, or 5,000 g / mol to 20,000 g / mol. Mn can be determined using the following formula (1): Mn = 2,000,000 / [EG] (1), where [EG] is the proportion of end groups in the PA, expressed in mmol / kg.

[0098] The polyamide (PA) preferably exhibits a specific logarithmic viscosity (IV) of at least 0.9 dL / g, which is measured according to ASTM D5336-22 using a mixture of phenol / 1,1,2,2-trichloroethane (60 / 40 by weight). It should be noted that this mixture is commercially available from Sigma-Aldrich (https: / / www.sigmaaldrich.com / FR / fr / product / aldrich / 33514).

[0099] IV is typically between 0.9 and 1.3 dL / g (measured under the same conditions).

[0100] Glass transition temperature (Tg)

[0101] Polyamides exhibit a Tg of at least 115°C. The Tg of polyamide (PA) is preferably at least 120°C, more preferably at least 125°C. The Tg is preferably strictly higher than 125°C (> 125°C).

[0102] Polyamides (PA) typically exhibit a Tg of up to 150°C.

[0103] Tg can be more specifically between 115°C and 150°C.

[0104] Tg is measured according to ASTM D3418 by differential scanning calorimetry (“DSC”), specifically using a heating and cooling rate of 20°C / min.

[0105] Tg can be measured more specifically as described in the experimental section.

[0106] Tg can be measured according to ASTM D3418 by differential scanning calorimetry (“DSC”) using a heating and cooling rate of 20°C / min. Three scans are used for each DSC test: a first heating to 350°C, followed by a first cooling to 30°C, and then a second heating to 360°C. Tg is determined by the second heating.

[0107] Melting point (Tm)

[0108] Polyamide (PA) exhibits a Tm of up to 270°C. Tm is preferably up to 250°C, more preferably up to 245°C.

[0109] Tm is typically at least 230°C. Tm is preferably at least 238°C.

[0110] Tm can be between 230°C and 270°C.

[0111] Tm is measured according to ASTM D3418 by differential scanning calorimetry (“DSC”), specifically using a heating and cooling rate of 20°C / min.

[0112] Tm can be measured more specifically as described in the experimental section.

[0113] Tm can be measured according to ASTM D3418 by differential scanning calorimetry (“DSC”) using a heating and cooling rate of 20°C / min. Three scans are used for each DSC test: a first heating to 350°C, followed by a first cooling to 30°C, and then a second heating to 360°C. Tm is determined by the second heating.

[0114] Crystallization temperature (Tc)

[0115] The polyamide (PA) exhibits a temperature tc of up to 200°C. Preferably, the temperature tc is up to 190°C.

[0116] Tc is typically at least 170°C.

[0117] Tm can be between 170°C and 200°C.

[0118] Tc is measured according to ASTM D3418 by differential scanning calorimetry (“DSC”), specifically using a heating and cooling rate of 20°C / min.

[0119] Tc can be measured according to ASTM D3418 by differential scanning calorimetry (“DSC”) using a heating and cooling rate of 20°C / min. Three scans are used for each DSC test: a first heating to 350°C, followed by a first cooling to 30°C, and then a second heating to 360°C. Tc is determined from the first cooling.

[0120] Heat of fusion (Hm)

[0121] Polyamide (PA) is semi-crystalline.

[0122] Polyamide (PA) exhibits an Hm of at least 20.0 J / g, preferably at least 25.0 J / g.

[0123] Hm is typically up to 50.0 J / g.

[0124] Hm can be between 20.0 J / g and 50.0 J / g.

[0125] Hm is measured according to ASTM D3418 by differential scanning calorimetry (“DSC”), specifically using a heating and cooling rate of 20°C / min.

[0126] Hm can be measured more specifically as described in the experimental section.

[0127] Hm can be measured according to ASTM D3418 using differential scanning calorimetry (“DSC”) with a heating and cooling rate of 20°C / min. Three scans are used for each DSC test: a first heating to 350°C, followed by a first cooling to 30°C, and then a second heating to 360°C. Hm is measured from the second heating.

[0128] In the context of this invention, the Tm, Tg, Tc, and Hm of polyamide (PA) can be measured according to the scheme disclosed in the experimental section.

[0129] Methods for preparing polyamide (PA)

[0130] The polyamide (PA) described herein can be prepared by any conventional method suitable for the synthesis of polyamides and polyphthalamides. The polyamide (PA) is prepared by the method claimed.

[0131] Polyamide (PA) is prepared by polycondensation of a reaction mixture (RM) containing monomers by heating, preferably in the presence of less than 60 wt.%, preferably less than 30 wt.%, preferably less than 20 wt.%, preferably less than 10 wt.% of water, based on the total weight of the reaction mixture, with water preferably not added.

[0132] Polyamide (PA) is more specifically prepared by polycondensation of a reaction mixture (RM) containing, substantially consisting of, or consisting of the following:

[0133] - A monomer mixture (MM) comprising, substantially consisting of, or consisting of: a diamine component (A) and a dicarboxylic acid component (B);

[0134] - The catalyst may be selected, particularly from the group consisting of phosphorous acid, orthophosphoric acid, metaphosphoric acid, alkali metal hypophosphite (such as sodium hypophosphite) and phenylphosphine;

[0135] - Optionally at least one end-capping agent;

[0136] - Optionally, water, preferably less than 80.0 wt.% or more preferably less than 50.0 wt.%, is used, the proportion of which is based on the total weight of the reaction mixture (RM).

[0137] The reaction mixture (RM) contains a monomer mixture (MM) comprising all diamines and all dicarboxylic acids as monomers of polyamide (PA). The monomer mixture (MM) preferably contains no lactams or any amino acids; the expression "containing no lactams" means that the total proportion of one or more lactams and the total proportion of one or more amino acids are each less than or equal to 1.0 wt% (≤1.0 wt%), these proportions being relative to the total weight of the mixture (MM). The proportion of the one or more lactams is preferably less than or equal to 0.5 wt% (≤0.5 wt%), preferably less than or equal to 0.1 wt% (≤0.1 wt%), and preferably less than or equal to 0.05 wt% (≤0.05 wt%). The proportion of the one or more amino acids is preferably less than or equal to 0.5 wt% (≤0.5 wt%), preferably less than or equal to 0.1 wt% (≤0.1 wt%), and preferably less than or equal to 0.05 wt% (≤0.05 wt%).

[0138] As is well known in polycondensation, the reaction mixture contains a certain amount of the aforementioned diamine and diacid, such that the ratio of -COOH groups from the diacid to the ratio of -NH2 groups from the diamine is substantially equimolar. The ratio of -NH2 / -COOH, and especially the ratio of -NH2 / -COOH, is particularly important. 2来自二胺组分 (A) 的二胺 / -COOH 来自二羧酸组分 (B) 的二羧酸 Typically, these values ​​range from 0.9 to 1.1, preferably from 0.95 to 1.05, and even more preferably from 0.98 to 1.02.

[0139] The reaction mixture (RM) typically contains a catalyst. The catalyst can be selected from the group consisting of phosphorous acid, orthophosphoric acid, metaphosphoric acid, alkali metal hypophosphite (such as sodium hypophosphite), and phenylphosphine. A convenient catalyst used is phosphorous acid.

[0140] To control the molecular weight of polyamide (PA), the reaction mixture (RM) may further contain at least one capping agent, particularly as disclosed above.

[0141] The end-capping agents that can be used in the polycondensation process are selected from the group consisting of monocarboxylic acids having the formula R-COOH, primary amines having the formula R'-NH2, and combinations thereof, where R and R' are as disclosed herein.

[0142] The end-capping agent that can be used in the polycondensation process can be selected from one or more of the lists disclosed herein, or can be any of the end-capping agents disclosed herein.

[0143] The temperature of the heating reaction mixture (RM) must be high enough to initiate the reaction between the amine groups of the diamine and the carboxyl groups of the dicarboxylic acid and to reduce the viscosity of the reaction mixture. This temperature is typically at least 140°C, preferably at least 200°C. Polycondensation leads to the formation of amide bonds and the release of water as a byproduct.

[0144] The temperature can be gradually increased during the polycondensation process. An example of gradual temperature increase is given in Example 1, and this example can be followed to prepare the polyamide (PA) of the present invention.

[0145] Polycondensation is advantageously carried out in a well-stirred vessel equipped with a device for removing volatile products of the reaction. As the viscosity of the reaction mixture increases over time, the stirrer is adapted to provide adequate stirring of the reaction mixture at the beginning of polymerization and when the conversion of polycondensation is nearing completion.

[0146] The experimental conditions disclosed in the experimental section can be conveniently used to prepare polyamides (PA).

[0147] Polyamide (PA) can be part of a polymer composition (PC) or a thermoplastic composite (TPC). See below for details.

[0148] Polymer composition (PC)

[0149] The present invention also relates to a polymer composition (PC) comprising at least 50.0 wt% of at least one polyamide (PA) as disclosed herein and optionally up to 20.0 wt% of at least one inorganic filler and / or at least one plastic additive other than an inorganic filler, the proportions being based on the total weight of the polymer composition (PC), wherein these components of the polymer composition (PC) are preferably blended together.

[0150] Inorganic fillers are typically selected from the following groups: talc, clay, mica, kaolin, calcium carbonate, calcium silicate, magnesium carbonate, glass fiber, carbon fiber, and combinations thereof.

[0151] Inorganic fillers may be more specifically clay. The clay may be selected from the group consisting of montmorillonite, lithium montmorillonite, soapstone, vermiculite, and combinations of two or more of the clays mentioned above.

[0152] The plastic additives, excluding inorganic fillers, are typically selected from the group consisting of: toughening agents, plasticizers, colorants, pigments, antistatic agents, dyes, lubricants, heat stabilizers, light stabilizers, flame retardants, nucleating agents, antioxidants, UV absorbers, acid scavengers, and combinations thereof.

[0153] The polymer composition (PC) may contain at least one aliphatic polyamide. The proportion of the one or more aliphatic polyamides in the polymer composition (PC) is typically at least 10.0 wt%, based on the total weight of the polymer composition (PC).

[0154] The total proportion of fillers and plastic additives in the polymer composition (PC) relative to the total weight of the PC can be 20.0 wt% or less, even 15.0 wt% or less, even 10.0 wt% or less, even 5.0 wt% or less. When present, the one or more additives are at least 0.1 wt% or even at least 0.5 wt% relative to the total weight of the polymer composition (PC).

[0155] The proportion of one or more polyamides (PA) in the polymer composition (PC) is preferably at least 95.0 wt%, more preferably at least 97.0 wt%, and more preferably at least 99.0 wt%.

[0156] The polymer composition (PC) is prepared by method M1, which includes the step of introducing the components of the polymer composition (PC) into a mixer, such as a single-screw extruder or twin-screw extruder, a stirrer, a single-screw or twin-screw kneader, or a Banbury mixer. The mixer is conveniently an extruder.

[0157] Method M1 includes at least one step in which the polymer composition (PC) is in molten form.

[0158] Method M1 ensures that the one or more plastic additives and / or the one or more fillers are blended with the one or more polyamides (PA) using a mixer as disclosed.

[0159] In particular, the polymer composition (PC) prepared by method M1 can be in the form of powder or granules.

[0160] Thermoplastic composites (TPC)

[0161] The present invention also relates to a thermoplastic composite material (TPC) comprising:

[0162] - A matrix comprising at least 40.0 wt% of at least one polyamide (PA) as disclosed herein and optionally at least one plastic additive as disclosed above, the proportions being given relative to the total weight of the TPC;

[0163] - Continuous fibers embedded in the matrix and selected from the group consisting of continuous glass fibers, continuous carbon fibers and combinations thereof.

[0164] Thermoplastic composites (TPCs) are prepared by method M2, which includes the following steps: impregnating fibers with a composition in molten form forming matrix and comprising at least 40.0 wt% of at least one polyamide (PA) as disclosed herein and optionally at least one plastic additive as disclosed above. Pressure is typically applied to the structural fibers / composition.

[0165] Impregnation can be carried out by a slurry method, particularly as disclosed in US 4,894,105, in which the composition is in the form of particles dispersed in an aqueous medium, thereby bringing these particles into contact with the fibers.

[0166] Thermoplastic composites (TPCs) can also be used as hydrogen barrier layers.

[0167] Uses of polyamide (PA) or polymeric compositions (PC)

[0168] Polyamides (PA) as disclosed herein, or polymer compositions (PC) as disclosed herein, can be used to prepare hydrogen barrier layers (L). b For example, polyamide (PA) can be used as polyphthalamide in the preparation of barrier layers as disclosed in US 2019 / 0242525.

[0169] A "hydrogen barrier layer" is a layer that prevents or hinders the migration of hydrogen through itself.

[0170] Hydrogen barrier layer (L b It may be (i) a single layer or (ii) a multilayer, wherein at least one layer comprises at least one polyamide (PA) as disclosed herein or a polymer composition (PC) as disclosed herein.

[0171] Hydrogen barrier layer (L b It is made of or contains at least one polyamide (PA) or polymer composition (PC) as disclosed herein.

[0172] Layer (L) b It has a thickness that provides the required gas permeability value for the application. Layer (L) b Typically, it has a thickness of at least 100 micrometers, and usually at least 250 micrometers. Layer (L) b It can have a thickness of up to 10.0 mm, or even up to 8.5 mm, or even up to 7.5 mm. Layer (L) bIt can have a thickness of 100 micrometers to 10.0 mm, typically 250 micrometers to 10.0 mm, even 300 micrometers to 8.5 mm, and 500 micrometers to 6.0 mm.

[0173] Penetration P

[0174] The hydrogen barrier layer (L) of the present invention b Typically exhibiting up to 90.0 Ncm 3 .mm / m 2 .Ba.Tian, ​​with a maximum of 70.0 Ncm. 3 .mm / m 2 .Ba.Tian, ​​with a maximum of 50.0 Ncm. 3 .mm / m 2 .Ba.Tian, ​​with a maximum of 40.0 Ncm 3 .mm / m 2 The penetration rate P of .ba.tian.

[0175] The permeability P (or permeability coefficient) of a sample measures its sensitivity to penetration and transmission by H2. P is obtained by measuring steady-state permeation using a carrier gas method and a sensor. This method is more accurate than pressure testing.

[0176] The method for measuring P is defined in the experimental section (p2).

[0177] A sample in the form of a circular membrane is mounted in the test cell, thus creating a barrier between two chambers. One chamber contains the test gas (H2), and the other chamber is purged with a purge gas (synthetic air). The feed side is pressurized with H2, and during measurement, the concentration of H2 in the purge gas stream is measured (typically using an electrochemical H2 sensor). The permeability coefficient (P) is calculated according to the following formula (eq. 1):

[0178] P = (CDd / Ap p ).(T°.p / Tp°) (eq. 1)

[0179] P = permeability coefficient, typically expressed in N / cm³. 3 .mm.d -1 .bar -1 .m -2 express

[0180] C = Penetrant concentration, expressed in ppm

[0181] D = purge gas flow rate (typically expressed in mL.min) -1 Measurement

[0182] d = Sample thickness (mm)

[0183] A = Test area in contact with gas (m²) 2 )

[0184] p p = Penetrant partial pressure (bar)

[0185] T = Ambient temperature (K)

[0186] p = Environmental pressure (bars)

[0187] T° = Standard temperature (273.15 K)

[0188] p° = Standard pressure (10¹³ bar)

[0189] Further normalization was performed to standard temperature and pressure (273.15 K and 1013 bar).

[0190] The membrane to be tested can be prepared in particular according to the protocol (p1) in the experimental section.

[0191] The permeability P can be measured by following the conditions provided in the experimental section.

[0192] Multi-layer structure

[0193] The present invention also relates to a multilayer structure comprising at least one hydrogen barrier layer (L) as disclosed herein. b The multi-layered structure is designed for storing or transporting H2 and is selected from containers and tubes.

[0194] Therefore, the multi-layered structure includes, from the inside to the outside:

[0195] - At least one hydrogen barrier layer (L) as disclosed herein b );

[0196] - At least one structural layer (L s ).

[0197] Advantageously, the barrier layer (L b ) or barrier layer (L b One of them is in contact with the contained fluid (H2) or is intended to be in contact with the contained fluid (H2).

[0198] According to an embodiment, the multilayer structure includes only one barrier layer (L b The multilayer structure may include another barrier layer made of or containing a polymer that is not a polyamide having the composition disclosed in claim 1.

[0199] Structural layer (L) sThe function of ) is to provide structural stiffness and to provide a hydrogen barrier layer (L) b Protection of the structural layer (L) s Selected from the group consisting of metal layers and layers made of composite materials.

[0200] A multilayer structure may include two or more reinforcing layers. For example, a multilayer structure may include, from the inside to the outside:

[0201] - At least one hydrogen barrier layer (L) as disclosed herein b );

[0202] - At least one structural layer made of composite material (L s1 );

[0203] - At least one metal structural layer (L s2 ).

[0204] Composite materials can be thermosetting composite materials or thermoplastic composite materials.

[0205] container

[0206] According to an embodiment, the multi-layered structure is a container.

[0207] The term "vessel" is used herein to refer to a hollow storage container. This container is particularly used for containing gases, preferably pressurized gases.

[0208] The length of the container depends on its end use and can range from, for example, 50.0 cm to a maximum of 10.0 m. These larger lengths are typically used for gas transport. As an example, for containers in trucks, the length is typically between 1.0 m and 3.0 m.

[0209] The container can have a diameter of 3.5 dm. 3 With 5.0 m 3 Between, or even 5.0 dm 3 and 1.0 m 3 The internal volume of the container can be at least 10.0 dm. 3 Even at least 15.0 dm 3 The internal volume can be up to 1.0 m³. 3 Even up to 0.5 m 3 .

[0210] The vessels typically exhibit a nominal pressure of at least 2.5 MPa, typically at least 20.0 MPa, or even at least 30.0 MPa. The nominal pressure can be up to 70.0 MPa, 100 MPa, or even 150.00 MPa and greater. Advantageously, the vessels have a nominal pressure of 20.0 to 70.0 MPa.

[0211] The container typically has a cylindrical shape with bosses at each end. Often, the container has two bosses at each end of this cylindrical shape.

[0212] The shape of a hollow body is determined by its intended use. It is usually, but not only, cylindrical; it typically has a diameter between 10.0 cm and 1.00 m.

[0213] Another object of the present invention is a container as disclosed herein and intended for containing H2 or a container for containing H2.

[0214] Another object of the present invention is a vehicle comprising a container as disclosed herein. The vehicle may be an automobile, truck, train, ship, urban mobility vehicle, aircraft, helicopter, or any other vehicle that can be powered by the conversion of gas into energy by any means.

[0215] Hydrogen barrier layer (L b It can be incorporated into a container, as shown below:

[0216] - US 2019 / 0242525: The container can therefore be, in particular, a container as disclosed in US 2019 / 0242525, comprising: a single-layer liner and a reinforcing structure disposed on the liner, wherein the liner includes a hydrogen barrier layer (L) as disclosed herein. b );or

[0217] - US 2010 / 0075200: The container may therefore be, in particular, a container as disclosed in US 2010 / 0075200, comprising: a lid; a liner; and a reinforcing layer disposed on the liner, wherein the liner includes a hydrogen barrier layer (L) as disclosed herein. b );or

[0218] - US 11,441,732 B2: The container can therefore be, in particular, a liner-containing container as disclosed in US 11,441,732 B2, wherein the liner includes a hydrogen barrier layer (L) as disclosed herein. b ).

[0219] Tube

[0220] According to the embodiment, the multi-layer structure is a tube.

[0221] The pipe is preferably not a three-layer pipe. Experimental Section

[0222] Examples of the present invention illustrate the present invention.

[0223] Raw materials used

[0224] The following raw materials were used to prepare polymer samples: 2-methylpentanediamine (MPMD; from Azelis); 1,9-diaminononane (C9; from Solvay); 1,10-diaminodecane (C10; from Hangzhou); m-xylenediamine (MXDA; from Mitsubishi Gas Chemical Company); terephthalic acid (TPA; from Sigma Aldrich); isophthalic acid (IA; from Sigma Aldrich); adipic acid (AA; from Invista); and phosphorous acid (from Sigma Aldrich).

[0225] All copolyamides disclosed in Table I were prepared in autoclave reactors equipped with distillate lines fitted with pressure control valves. All copolyamides were prepared following the procedures detailed in Example 1 (except for the monomer ratios).

[0226] Example 1

[0227] The polyamide in Example 1 was prepared by charging a reactor with 2.53 g of MPMD, 2.45 g of C10, 5.58 g of TPA, 5.21 g of deionized water, and 0.0035 g of phosphorous acid. The reactor was sealed, purged with N2 gas, and heated to 145°C and held for 45 min, then heated to 195°C and held for 45 min, then heated to 230°C and held for 35 min, and then heated to 270°C and held for 35 min. The generated vapors were slowly released to keep the internal pressure below 200 psig. Once the temperature was maintained at 270°C for 35 min, the reactor pressure was slowly reduced to atmospheric pressure over 45 min while maintaining 270°C ± 30°C. After holding for another 30 min under N2 gas purging, the reactor was cooled to room temperature, and the polymer was removed from the reactor.

[0228] thermal properties

[0229] Tg, Tm, and Hm were measured according to ASTM D3418 by differential scanning calorimetry (“DSC”) using a heating and cooling rate of 20°C / min. Three scans were used for each DSC test: a first heating to 350°C, followed by a first cooling to 30°C, and then a second heating to 360°C. Tg, Tm, and Hm were determined by the second heating. Tc was determined by the first cooling.

[0230] Penetration P

[0231] Preparation of samples for measuring permeability P

[0232] The samples were processed in the micro-mixing / extrusion machine Xplore and the injection unit (DSM).

[0233] Extruder used: Twin-screw co-rotating extruder

[0234] Extruder effective volume: 15 cc

[0235] Extruder temperature setting: 275°C

[0236] The extruder was filled with 18 g of the test material (e.g., polyamide), and the screw speed was set to 100 rpm. After the extruder was filled, the material was held in the extruder at 150 rpm in recirculation mode for 3 minutes. The melt was then transferred to a 12 cc barrel in the injection module, with the barrel temperature set to 275°C. The material was injected from the barrel into the die at a pressure of 8 bar and held at that pressure for 10 seconds. The die temperature was set to 125°C.

[0237] Square sheets of 30×30×1.3 mm are prepared using a specific mold cavity, from which circular films are obtained.

[0238] Scheme (p1): Preparation of circular membranes

[0239]

[0240] More specifically, follow these details:

[0241] - Place the sheet in the mold. Preferably, use a plastic film to prevent the sheet from sticking to the two inner sides of the mold;

[0242] - Place the mold on the lower pressure plate;

[0243] - The temperature of the upper and lower pressure plates is set to 255°C and the force is set to 15 kN;

[0244] - Raise the lower plate;

[0245] - Set the program temperature to remain unchanged for 5 minutes;

[0246] - Cool the plate to 40°C while maintaining pressure;

[0247] - Once the temperature reaches 40°C, the lower plate will be lowered.

[0248] Solution (p2): Method for determining penetration rate P

[0249]

[0250] The calibrated leak detector used was an Inficon Sentrac H2.

[0251] The permeability coefficient P is calculated using formula (eq. 1).

[0252] Table I

[0253]

[0254] The monomer proportions are given as mol% relative to the diamine in the diamine component (A) and the diacid in the diacid component (B).

[0255] P with Ncm 3 .mm.m -2 .bar -1 .sky -1 express

[0256] In the context of this invention, diacid is equivalent to dicarboxylic acid.

[0257] The polyamide of this invention is semi-crystalline and exhibits high Tg, high Tm, and low Tc. This combination of properties ensures that the polyamide can be processed into a lining with good permeability P.

[0258] Polyamide CE4 has a Tg of only 83°C. The melting temperatures Tm of polyamides E1 and E2 are also higher than that of polyamide CE4.

Claims

1. A polyamide (PA) whose repeat units (R PA ) are formed by polycondensation of a diamine component (A) and a dicarboxylic acid component (B), wherein: - The diamine component (A) contains, is substantially composed of, or is composed of the following: ■ 2-Methylpentanediamine (MPMD) between 50.0 mol% (excluding this value) and 70.0 mol%; and ■ between 30.0 and 50.0 mol% of at least one other diamine (DA) having the formula 2HN-R1-NH2, wherein R1is C8-C 11 linear or branched alkylene; ■ These percentages, expressed in mol%, are based on the total amount of diamine in the diamine component (A); ■ The statement "consistently composed of..." means that the diamine component (A) is composed of MPMD and at least one diamine (DA) in a specified proportion, and one or more diamines other than MPMD and diamine (DA) in a proportion of up to 1.0 mol%, more preferably up to 0.5 mol%, the proportion in mol% being based on the total amount of diamine in the diamine component (A); - The dicarboxylic acid component (B) contains, is substantially composed of, or is composed of the following: ■Terephthalic acid between 90.0 and 100.0 mol.%; and ■ Another diacid (DI) selected from isophthalic acid, adipic acid (AA), and combinations thereof, between 0 and 10.0 mol.%. ■ These percentages, expressed in mol%, are based on the total amount of diacid in the dicarboxylic acid component (B); ■ The statement "consistently composed of..." means that the dicarboxylic acid component (B) is composed of terephthalic acid and optionally other diacids (DI) and combinations thereof in a specified proportion, and up to 1.0 mol%, more preferably up to 0.5 mol%, of one or more dicarboxylic acids other than terephthalic acid and diacids (DI), the proportion in mol% being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B); - The proportion of MPMD.T repeating units in the polyamide (PA) is greater than 50.0 mol% (> 50.0 mol%), which is given relative to the total number of repeating units in the polyamide (PA).

2. The polyamide (PA) according to claim 1, wherein: - The diamine component (A) is essentially composed of the following or consists of the following: ■ 2-Methylpentanediamine (MPMD) between 50.0 mol% (excluding this value) and 70.0 mol%; and ■ between 30.0 and 50.0 mol% of at least one other diamine (DA) having the formula 2HN-R1-NH2, wherein R1is C8-C 11 linear or branched alkylene; ■ These percentages, expressed in mol%, are based on the total amount of diamine in the diamine component (A); The statement "consistently composed of..." means that the diamine component (A) consists of MPMD and at least one diamine (DA) in a specified proportion, and up to 1.0 mol%, more preferably up to 0.5 mol%, of one or more diamines other than MPMD and diamine (DA), wherein the proportion in mol% is based on the total amount of diamines in the diamine component (A); and / or - The dicarboxylic acid component (B) is essentially composed of the following or consists of the following: ■Terephthalic acid between 90.0 and 100.0 mol.%; and ■ Another diacid (DI) selected from isophthalic acid, adipic acid (AA), and combinations thereof, between 0 and 10.0 mol.%. ■ These percentages, expressed in mol%, are based on the total amount of diacid in the dicarboxylic acid component (B); The statement "consistently composed of..." means that the dicarboxylic acid component (B) consists of terephthalic acid and optionally other diacids (DI) and combinations thereof in a specified proportion, and up to 1.0 mol%, more preferably up to 0.5 mol%, of one or more dicarboxylic acids other than terephthalic acid and diacids (DI), the proportion in mol% being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B).

3. The polyamide (PA) according to claim 1 or 2, wherein, The proportion of MPMD in the diamine component (A) and the total proportion of one or more diamines (DA) are between 53.0 and 63.0 mol% and between 37.0 and 47.0 mol%, respectively.

4. The polyamide (PA) according to any one of the preceding claims, wherein, The proportion of terephthalic acid and the total proportion of one or more diacids (DI) in the dicarboxylic acid component (B) are between 95.0 and 100.0 mol% and between 0 and 5.0 mol%, respectively; preferably between 97.0 and 100.0 mol% and between 0 and 3.0 mol%, respectively; and more preferably between 99.0 and 100.0 mol% and between 0 and 1.0 mol%, respectively.

5. The polyamide (PA) as claimed in any one of the preceding claims, wherein, The diacid component (B) is essentially composed of or consists of terephthalic acid.

6. The polyamide (PA) according to any one of the preceding claims, wherein, These repeat units (R PA ) of polyamide (PA) essentially consist of or consist of the following units (R PA1 )-(R PA4 ) The expression "consisting essentially of means that the repeating units of the polyamide (PA) consist of the repeating units (R PA1 )-(R PA4 ) and up to 1.0 mol%, more preferably up to 0.50 mol%, more preferably up to 0.25 mol%, more preferably up to 0.10 mol% of repeating units other than the repeating units (R PA1 )-(R PA4 ), the proportion in mol% being based on the total amount of repeating units in the polyamide (PA).

7. A polyamide (PA), in particular according to any one of the preceding claims, whose repeat units consist essentially or consist of the repeat units (R PA1 ) and (R PA2 ). wherein R1is a C8-C30alkyl group derived from at least one diamine (DA) having the formula 2HN-R1-NH2 11 linear or branched alkylene group, Among them, unit (R) PA1 ) and (R PA2 The proportions relative to the total number of repeating units in the polyamide (PA) are as follows: - (R PA1 ): 50.0 mol% (excluding this value) and 70.0 mol% - (R PA2 (): Between 30.0 and 50.0 mol%; or the following proportions - (R PA1 ): 53.0 and 63.0 mol% - (R PA2 (): Between 37.0 and 47.0 mol%.

8. The polyamide (PA) according to any one of the preceding claims, wherein, The diamine (DA) is selected from the group consisting of the following: - 1,8-octanediamine, 1,9-diaminononane, 1,10-diaminodecane, and 2-methyl-1,8-octanediamine, and combinations of two or more of these diamines; or - 1,8-octanediamine, 1,9-diaminononane, 1,10-diaminodecane, and combinations of two or more of these diamines; or - 1,8-octanediamine, 1,9-diaminononane, 1,10-diaminodecane, and combinations of 1,9-diaminononane and 1,10-diaminodecane.

9. The polyamide (PA) according to any one of the preceding claims, wherein it (i) does not contain or (ii) does not contain units derived from: - 1,6-hexamethylenediamine; and / or - 2-Methyl-1,8-octanediamine; and / or - m-phenylenediamine or p-phenylenediamine; and / or - 1,3-bis(aminomethyl)cyclohexane or 1,4-bis(aminomethyl)cyclohexane; and / or - Lactams or amino acids; The expression "without" in relation to a specific repeating unit means that the proportion of the repeating unit in the polyamide (PA) is less than or equal to 1.0 mol%, preferably less than or equal to 0.50 mol%, preferably less than or equal to 0.25 mol%, and preferably less than or equal to 0.10 mol%.

10. The polyamide (PA) according to any one of the preceding claims, wherein, The end groups of this polyamide (PA) are selected from the group consisting of -NH2, -COOH and amide end groups.

11. A polyamide (PA) selected from the group consisting of MPMD.T / 10.T and MPMD.T / 9.T copolyamides.

12. The polyamide (PA) according to any one of the preceding claims, exhibiting a specific logarithmic viscosity (IV) of at least 0.9 dL / g, preferably between 0.9 and 1.3 dL / g, which is measured according to ASTM D5336-22 using a mixture of phenol / 1,1,2,2-trichloroethane (60 / 40 weight ratio).

13. The polyamide (PA) according to any one of the preceding claims, exhibiting a glass transition temperature (Tg) of at least 115°C, preferably at least 120°C, preferably at least 125°C, and preferably strictly above 125°C (> 125°C), Tg being measured according to ASTM D3418 by differential scanning calorimetry ("DSC"), particularly using a heating and cooling rate of 20°C / min.

14. The polyamide (PA) according to any one of the preceding claims, exhibiting the following melting temperature (Tm): - Up to 270°C, preferably up to 250°C, preferably up to 245°C; and / or - At least 230°C; Tm is measured according to ASTM D3418 by differential scanning calorimetry ("DSC"), specifically using a heating and cooling rate of 20°C / min; and / or.

15. The polyamide (PA) according to any one of the preceding claims, exhibiting a crystallization temperature (Tc) of up to 200°C, preferably up to 190°C, Tc being measured by differential scanning calorimetry ("DSC") according to ASTM D3418 using a heating and cooling rate of 20°C / min, Tc being measured by the first cooling.

16. The polyamide (PA) according to any one of the preceding claims, wherein, The polyamide (PA) is semi-crystalline.

17. The polyamide (PA) according to any one of the preceding claims, exhibiting a heat of fusion (Hm) of at least 20.0 J / g, preferably at least 25.0 J / g, which is measured according to ASTM D3418 by differential scanning calorimetry ("DSC"), in particular using a heating and cooling rate of 20°C / min.

18. The polyamide (PA) according to any one of the preceding claims, prepared by polycondensation of a reaction mixture (RM) containing the monomers by heating, preferably in the presence of less than 60 wt.%, preferably less than 30 wt.%, preferably less than 20 wt.%, preferably less than 10 wt.% of water, based on the total weight of the reaction mixture, preferably without the addition of water.

19. The polyamide (PA) according to any one of the preceding claims, prepared by polycondensation of a reaction mixture (RM) comprising, substantially comprising, or comprising: - Monomer mixtures (MM) that contain, consist essentially of, or consist of the following: The diamine component (A) and the dicarboxylic acid component (B); - The catalyst may be selected, particularly from the group consisting of phosphorous acid, orthophosphoric acid, metaphosphoric acid, alkali metal hypophosphite such as sodium hypophosphite, and phenylphosphine; - Optionally, at least one capping agent, particularly selected from the group consisting of: monocarboxylic acids having the formula R-COOH, primary amines having the formula R'-NH2, wherein R is alkyl, aryl, or cycloalkyl, and R' is a straight-chain or branched C2-C... 18 alkyl; - Optionally, water, preferably less than 80.0 wt.% or more preferably less than 50.0 wt.%, is used, the proportion of which is based on the total weight of the reaction mixture (RM).

20. The polyamide (PA) according to claim 18 or 20, wherein, The reaction mixture (RM) contains a monomer mixture (MM) comprising all diamines and all dicarboxylic acids as monomers of the polyamide (PA), the monomer mixture (MM) preferably being free of any lactams or any amino acids, the expression "free of" meaning that the total proportion of one or more lactams and the total proportion of one or more amino acids are each less than or equal to 1.0 wt% (≤ 1.0 wt%), these proportions being relative to the total weight of the mixture (MM).

21. A method for preparing polyamide (PA) as disclosed in any one of claims 1 to 20 by polycondensation, the method comprising the step of heating a reaction mixture (RM) containing the monomers, the heating preferably being carried out in the presence of less than 60 wt.%, preferably less than 30 wt.%, preferably less than 20 wt.%, preferably less than 10 wt.% of water, the proportion being based on the total weight of the reaction mixture, preferably without the addition of water.

22. A method for preparing polyamide (PA) as disclosed in any one of claims 1 to 20 by polycondensation, the method comprising the step of heating a reaction mixture (RM) comprising, substantially comprising, or comprising: - Monomer mixtures (MM) that contain, consist essentially of, or consist of the following: The diamine component (A) and the dicarboxylic acid component (B); - The catalyst may be selected, particularly from the group consisting of phosphorous acid, orthophosphoric acid, metaphosphoric acid, alkali metal hypophosphite such as sodium hypophosphite, and phenylphosphine; - Optionally, at least one capping agent, particularly selected from the group consisting of: monocarboxylic acids having the formula R-COOH, primary amines having the formula R'-NH2, wherein R is alkyl, aryl, or cycloalkyl, and R' is a straight-chain or branched C2-C... 18 alkyl; - Optionally, water, preferably less than 80.0 wt.% or more preferably less than 50.0 wt.%, is used, the proportion of which is based on the total weight of the reaction mixture (RM).

23. A polymer composition (PC) comprising at least 50.0 wt% of at least one polyamide (PA) according to any one of claims 1 to 20 and optionally up to 20.0 wt% of at least one inorganic filler and / or at least one plastic additive other than an inorganic filler, the proportions being based on the total weight of the polymer composition (PC), wherein these components of the polymer composition (PC) are preferably blended together.

24. The polymer composition (PC) according to claim 23, wherein, The inorganic filler is selected from the group consisting of: talc, clay, mica, kaolin, calcium carbonate, calcium silicate, magnesium carbonate, glass fiber, carbon fiber, and combinations thereof.

25. The polymer composition (PC) according to claim 23, wherein, The inorganic filler is clay, particularly selected from the group consisting of montmorillonite, lithium montmorillonite, soapstone, vermiculite, and combinations of two or more of the clays.

26. The polymer composition (PC) according to any one of claims 23 to 25, wherein, The plastic additive is selected from the group consisting of: toughening agents, plasticizers, colorants, pigments, antistatic agents, dyes, lubricants, heat stabilizers, light stabilizers, flame retardants, nucleating agents, antioxidants, UV absorbers, acid scavengers, and combinations thereof.

27. The polymer composition (PC) according to any one of claims 23 to 25, wherein it is in the form of powder or granules.

28. The polyamide (PA) according to any one of claims 1 to 20 or the polymer composition (PC) according to any one of claims 22 to 27 is used to prepare a hydrogen barrier layer (L). b Or for use in the preparation of containers or tubes intended for containing H2 or for containing H2.

29. The use according to claim 28, wherein, The hydrogen barrier layer (L) b It is (i) a single layer or (ii) a multilayer, wherein at least one layer comprises the polyamide (PA) or the polymer composition (PC).

30. A hydrogen barrier layer (L b It is made of or contains at least one polyamide (PA) as disclosed in any one of claims 1 to 20 or a polymer composition as disclosed in any one of claims 23 to 27.

31. The hydrogen barrier layer (L) according to claim 30 b It exhibits a maximum of 90 Ncm 3 .mm / m 2 .Ba.Tian, ​​with a maximum of 70.0 Ncm. 3 .mm / m 2 .Ba.Tian, ​​with a maximum of 50.0 Ncm. 3 .mm / m 2 .Ba.Tian, ​​with a maximum of 40.0 Ncm 3 .mm / m 2 The permeability P of .bar.day, the measurement conditions of which are defined in scheme (p2) in the experimental section or in the experimental section.

32. The hydrogen barrier layer (L) according to claim 30 or 31 b It has a thickness of 100 µm to 10.0 mm.

33. A multilayer structure intended for storing or transporting H2 and selected from containers and tubes, the multilayer structure comprising at least one hydrogen barrier layer (L) disclosed in any one of claims 30 to 32. b ).

34. A multi-layer structure intended for storing or transporting H2 and selected from containers and pipes, the multi-layer structure comprising, from the inside to the outside: - At least one hydrogen barrier layer (L) as disclosed in any one of claims 30 to 32 b ); - At least one structural layer (L s ).

35. The multilayer structure according to claim 33 or 34, wherein, The barrier layer (L) b ) or the barrier layer (L b One of them is in contact with the contained fluid (H2) or is intended to be in contact with the contained fluid (H2).

36. The multilayer structure according to any one of claims 33 to 35, wherein, This multi-layer structure includes only one barrier layer (L b It should be understood that the multilayer structure may include another barrier layer made of or containing a polymer that is not a polyamide having the composition disclosed in claim 1.

37. A container or tube having a multi-layered structure as disclosed in any one of claims 33 to 36 and intended for containing H2 or for containing H2.

38. A thermoplastic composite material (TPC) comprising: - A matrix comprising at least 40.0 wt% of at least one polyamide (PA) as disclosed in any one of claims 1 to 20 and optionally at least one plastic additive, wherein the at least one plastic additive is particularly selected from the group consisting of toughening agents, plasticizers, colorants, pigments, antistatic agents, dyes, lubricants, heat stabilizers, light stabilizers, flame retardants, nucleating agents, antioxidants, UV absorbers, acid scavengers, and combinations thereof, the proportion being given relative to the total weight of the TPC; - Continuous fibers embedded in the matrix and selected from the group consisting of continuous glass fibers, continuous carbon fibers and combinations thereof.

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