A foam comprising a thermoplastic polyurethane and a copolymer having polyamide blocks and polyether blocks together with amine-terminated groups.

Abstract

The present invention relates to a polymer foam comprising at least one thermoplastic polyurethane and at least one amine chain-terminated polyamide block-polyether block copolymer. The present invention also relates to a method for preparing such a foam and an article comprising such a foam.

Description

[Technical Field]

[0001] The present invention relates to a polymer foam comprising a thermoplastic polyurethane and an amine chain-terminated polyamide block-polyether block copolymer, and to a method for preparing the same. [Background technology]

[0002] Various polymer foams are used particularly in the field of sports equipment, such as shoe soles or sole components, gloves, rackets or golf balls, and especially in personal protective equipment for sports practice (jackets, helmet linings, shells, etc.).

[0003] Such applications require a set of specific physical properties that ensure resilience, low compression set, and the ability to withstand repeated impacts without deformation and return to their original shape.

[0004] WO2022 / 162048 relates to an expandable particle comprising a first thermoplastic elastomer having a Shore D hardness of 20 to 90 and a second thermoplastic elastomer. The first thermoplastic elastomer is in particular a thermoplastic polyurethane, thermoplastic polyetheramide, thermoplastic copolyester, polyether ester, or polyester ester, and the second thermoplastic elastomer is in particular a thermoplastic polyurethane, thermoplastic polyetheramide, polyether ester, or polyester ester, or a thermoplastic styrene-butadiene copolymer.

[0005] There is a need to provide a polymer foam that has a fine and homogeneous cell structure, low density, good rebound elasticity, and improved flexibility and tear resistance. [Overview of the Initiative]

[0006] The present invention first, - At least one type of thermoplastic polyurethane, - At least one polyamide block-polyether block copolymer containing amine chain ends, detected by potentiometric assay in metacresol using a 0.02 N perchloric acid solution. This relates to polymer foams containing [specific material].

[0007] In a given embodiment, at least a portion of the total polyamide block-polyether block copolymer is covalently bonded to thermoplastic polyurethane molecules via urea functional groups.

[0008] In a given embodiment, the urea functional group concentration in DMSO-D6 is 13 Measurements by 13C NMR showed values ​​of 0.001 meq / g to 0.1 meq / g, more preferably 0.003 meq / g to 0.08 meq / g, and more preferably 0.005 meq / g to 0.05 meq / g.

[0009] In a given embodiment, the polyamide block-polyether block copolymer has an NH2 amine functional group concentration of 0.002 meq / g to 0.2 meq / g, preferably 0.005 to 0.1 meq / g, as measured by potentiometric assay in metacresol using a 0.02 N perchloric acid solution.

[0010] In a given embodiment, the amount of polyamide block is determined by proton NMR in a TFA / CDCl3(1 / 4v / v) mixture to be at least 15% by weight, preferably at least 25% by weight, relative to the total weight of the foam.

[0011] In a given embodiment, the polyamide block-polyether block copolymer contains at least 30% by weight, preferably at least 40% by weight, of the polyamide block relative to the total weight of the copolymer, as measured by proton NMR in a TFA / CDCl3(1 / 4v / v) mixture.

[0012] In a given embodiment, at least one thermoplastic polyurethane is a copolymer containing a hard block and a soft block, and the content of the hard block in the thermoplastic polyurethane is 90% by weight or less, more preferably 80% by weight or less, and even more preferably 30% to 60% by weight, as measured by proton NMR in DMSO-D6.

[0013] In a given embodiment, the foam, based on the total weight of the foam, - at least one thermoplastic polyurethane of 5% to 70% by weight, preferably 15% to 60% by weight, and even more preferably 20% to 45% by weight, and - at least one amine chain-end-containing polyamide block-polyether block copolymer of 30% to 95% by weight, preferably 40% to 85% by weight, and even more preferably 55% to 80% by weight is included.

[0014] In a given embodiment, at least one thermoplastic polyurethane is a copolymer containing a hard block and a soft block, where - the soft block is selected from a polyether block, a polyester block, a polycarbonate block, and combinations thereof; preferably, the soft block is selected from a polyether block, a polyester block, and combinations thereof, and even more preferably, it is a polytetrahydrofuran, polypropylene glycol, and / or polyethylene glycol block; and / or - the hard block contains units derived from 4,4'-diphenylmethane diisocyanate and / or 1,6-hexamethylene diisocyanate, and preferably contains units derived from at least one chain extender selected from 1,3-propanediol, 1,4-butanediol, and / or 1,6-hexanediol.

[0015] In certain embodiments, the polyamide block of the amine chain end-containing polyamide block-polyether block copolymer is a polyamide 11, polyamide 12, polyamide 10, polyamide 6, polyamide 6.10, polyamide 6.12, polyamide 6.13, polyamide 10.9, polyamide 10.10, polyamide 10.12 and / or polyamide 12.9 block, preferably a polyamide 11, polyamide 12, polyamide 6, polyamide 6.12, polyamide 6.13, polyamide 10.9 and / or polyamide 12.9 block; and / or the polyether block of the amine chain end-containing polyamide block-polyether block copolymer is a polyethylene glycol and / or polypropylene glycol and / or polytetrahydrofuran block.

[0016] In certain embodiments, the foam has a density of 800 kg / m 3 or less, preferably 400 kg / m 3 or less, more preferably 300 kg / m 3 or less, even more preferably 230 kg / m 3 or less, as measured at 23 °C in accordance with ISO 1183-1 standard.

[0017] In certain embodiments, the foam has an Asker C hardness of 20 to 90, preferably 25 to 70, as measured at 23 °C in accordance with ISO 7619-1 standard.

[0018] The present invention also relates to a method for producing the above-mentioned foam, comprising the following steps: - providing a polymer composition comprising at least one thermoplastic polyurethane and at least one amine chain end-containing polyamide block-polyether block copolymer; - mixing the polymer composition with a blowing agent; and [[ID=二十六]]- foaming the mixture of the polymer composition and the blowing agent

[0019] ​In a given embodiment, a foaming agent is mixed with a molten polymer composition, and the foaming of the mixture is preferentially carried out within the mold.

[0020] In a given embodiment, the blowing agent is a physical blowing agent, which is mixed with a polymer composition in the form of a solid preform, and the foaming of the mixture is preferably carried out in an autoclave.

[0021] The present invention also relates to articles which are formed from or include at least one element made of the aforementioned foam, preferably selected from sports shoe soles, balloons or balls, gloves, personal protective equipment, rail pads, automotive parts, construction parts, and electrical and electronic equipment components.

[0022] The present invention satisfies the above-mentioned needs. More specifically, it provides a regular, homogeneous, low-density polymer foam that has improved flexibility and good mechanical properties, particularly good tear resistance and good abrasion resistance, while simultaneously maintaining high rebound elasticity and relatively low compression set.

[0023] This is achieved by using a mixture of thermoplastic polyurethane (TPU) and a polyamide block-polyether block copolymer having amine (NH2) chain ends for foam formation.

[0024] In certain advantageous embodiments, a covalent bond is formed between at least a portion of the amine-terminal polyamide block-polyether block copolymer and at least a portion of the thermoplastic polyurethane, more specifically, between the amine functional groups of the polyamide block-polyether block copolymer and the urethane functional groups of the thermoplastic polyurethane, or between isocyanate functional groups present in the precursor of the thermoplastic polyurethane. This reaction between at least a portion of the amine-terminal polyamide block-polyether block copolymer and at least a portion of the thermoplastic polyurethane improves the compatibility between these polymers. This improves the foamability of the alloy thus obtained, and thus improves the structure (finer and more homogeneous cell structure, lower density) and properties (in particular, higher rebound elasticity, lower compression set, higher flexibility) of the foam obtained from these alloys. [Modes for carrying out the invention]

[0025] The present invention will be described in more detail and in a non-limiting manner in the following description. Unless otherwise specified, all percentages are mass percentages. In this specification, the quantities given for a given species may be applied to that species according to all of its definitions (as referred to herein), including more limited definitions.

[0026] The present invention first relates to a foam comprising at least one amine chain-terminus-containing polyamide block-polyether block copolymer and at least one thermoplastic polyurethane.

[0027] The presence of amine chain ends in polyamide block-polyether block copolymers can be detected by potentiometric assay according to the following method: The material sample is dissolved in metacresol at 80°C, and the NH2 functional groups of this sample are then measured by potentiometric assay using a 0.02 N perchloric acid solution.

[0028] [Amine chain terminal-containing polyamide block-polyether block copolymer (PEBA)] PEBA is obtained from the polycondensation of a polyamide block (hard block) having reactive ends and a polyether block (soft block) having reactive ends, particularly from the polycondensation of a polyamide block having dicarboxylic acid chain ends with a polyoxyalkylene block having diamine chain ends, which is obtained by cyanoethylation and hydrogenation of an α,ω-dihydroxylated aliphatic polyoxyalkylene block called a polyetherdiol.

[0029] Polyamide blocks having dicarboxylic acid chain ends can be obtained, for example, by condensation of polyamide precursors in the presence of chain-restricted dicarboxylic acids.

[0030] Three types of polyamide blocks can be used advantageously.

[0031] According to the first type, the polyamide block is obtained by condensation of a dicarboxylic acid, particularly one containing 4 to 36 carbon atoms, preferably one containing 4 to 20 carbon atoms, more preferably one containing 6 to 18 carbon atoms, with an aliphatic or aromatic diamine, particularly one containing 2 to 20 carbon atoms, preferably one containing 6 to 14 carbon atoms.

[0032] Examples of dicarboxylic acids include 1,4-cyclohexanedicarboxylic acid, butanediic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, terephthalic acid, and isophthalic acid, as well as dimerized fatty acids.

[0033] Examples of diamines include tetramethylenediamine, hexamethylenediamine, 1,10-decamethylenediamine, dodecamethylenediamine, trimethylhexamethylenediamine, isomers of bis(4-aminocyclohexyl)methane (BACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM), and 2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), para-aminodicyclohexylmethane (PACM), isophoronediamine (IPDA), 2,6-bis(aminomethyl)norbornane (BAMN), and piperazine (Pip).

[0034] Advantageously, polyamide blocks PA4.12, PA4.14, PA4.18, PA6.10, PA6.12, PA6.14, PA6.18, PA9.12, PA10.10, PA10.12, PA10.14 and / or PA10.18 are used. In the PA XY notation, as before, X represents the number of carbon atoms derived from the diamine residue, and Y represents the number of carbon atoms derived from the diacid residue.

[0035] According to the second type, polyamide blocks are obtained from the condensation of one or more α,ω-aminocarboxylic acids and / or one or more lactams containing 6 to 12 carbon atoms in the presence of a dicarboxylic acid or diamine containing 4 to 18 carbon atoms. Examples of lactams include caprolactam, enantractam, and lauryllactam. Examples of α,ω-aminocarboxylic acids include aminocaproic acid, 7-aminoheptanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

[0036] Advantageously, the second type of polyamide block is the PA10 (polydecaneamide), PA11 (polyundecaneamide), PA12 (polydodecaneamide), or PA6 (polycaprolactam) block. In the PA X notation, X represents the number of carbon atoms derived from amino acid residues or lactam residues.

[0037] According to the third type, the polyamide block is obtained by the condensation of at least one α,ω-aminocarboxylic acid (or lactam), at least one diamine, and at least one dicarboxylic acid.

[0038] In this case, the polyamide PA block is - A linear aliphatic or aromatic diamine containing X carbon atoms; - Dicarboxylic acid containing Y carbon atoms; and - Comonomer {Z} selected from lactams containing Z carbon atoms and α,ω-aminocarboxylic acids and equimolar mixtures of at least one diamine containing X1 carbon atoms and at least one dicarboxylic acid containing Y1 carbon atoms (where (X1,Y1) is different from (X,Y)). It is a polycondensation of, - The comonomer {Z} is introduced in a weight proportion of up to 50%, preferably up to 20%, and more preferably up to 10%, relative to the total amount of the polyamide precursor monomer; - In the presence of a chain limiting agent selected from dicarboxylic acids It is prepared by polycondensation.

[0039] Advantageously, a dicarboxylic acid containing Y carbon atoms is used as a chain limiting agent, which is introduced in excess of the diamine's stoichiometry.

[0040] According to one variation of this third type, the polyamide block is obtained from the condensation of at least two α,ω-aminocarboxylic acids, or at least two lactams containing 6 to 12 carbon atoms, or one lactam having a different number of carbon atoms and one aminocarboxylic acid, in the presence of an optional chain limiter. Examples of aliphatic α,ω-aminocarboxylic acids include aminocaproic acid, 7-aminoheptanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples of lactams include caprolactam, enantractam, and lauryllactam. Examples of aliphatic diamines include hexamethylenediamine, dodecamethylenediamine, and trimethylhexamethylenediamine. An example of an alicyclic diacid is 1,4-cyclohexanedicarboxylic acid. Examples of aliphatic diacids include butanediic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, α,ω-diacid polyoxyalkylenes, and dimerized fatty acids. These dimerized fatty acids correspond to the dimerization reaction products of fatty acids (generally containing 18 carbon atoms, often mixtures of oleic acid and / or linoleic acid); they preferably have a dimer content of at least 98%; they are preferably hydrogenated; they are preferably mixtures containing 0% to 15% by weight of C18 monoacid, 60% to 99% by weight of C36 diacid, and 0.2% to 35% by weight of C54 or higher triacid or polyacid; these are products sold, for example, by Croda under the brand name Pripol, by BASF under the brand name Empol, or by Oleon under the brand name Radiacid. Examples of aromatic diacids include terephthalic acid (T) and isophthalic acid (I). Examples of alicyclic diamines include isomers of bis(4-aminocyclohexyl)methane (BACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM), and 2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), as well as para-aminodicyclohexylmethane (PACM).Other commonly used diamines may include isophoronediamine (IPDA), 2,6-bis(aminomethyl)norbornane (BAMN), and piperazine.

[0041] Examples of a third type of polyamide block include the following: - PA6.6 / 6 (where 6.6 represents the hexamethylenediamine unit condensed with adipic acid, and 6 represents the unit produced by the condensation of caprolactam); - PA6.6 / 6.10 / 11 / 12 (where 6.6 represents hexamethylenediamine condensed with adipic acid, 6.10 represents hexamethylenediamine condensed with sebaciic acid, 11 represents a unit produced by the condensation of aminoundecanoic acid, and 12 represents a unit produced by the condensation of lauryl lactam).

[0042] The notations PA X / Y, PA X / Y / Z, etc., relate to copolyamides, where X, Y, Z, etc., represent the homopolyamide units mentioned above.

[0043] Advantageously, the polyamide blocks of copolymers used in this invention are polyamide blocks PA6, PA10, PA11, PA12, PA5.4, PA5.9, PA5.10, PA5.12, PA5.13, PA5.14, PA5.16, PA5.18, PA5.36, PA6.4, PA6.6, PA6.9, PA6.10, PA6.12, PA6.13, PA6.14 , PA6.16, PA6.18, PA6.36, PA10.4, PA10.9, PA10.10, PA10.12, PA10.13, PA10.14, PA10.16, PA10.1 8, PA10.36, PA10.T, PA12.4, PA12.9, PA12.10, PA12.12, PA12.13, PA12.14, PA12.16, PA12.18, PA12 It comprises (or consists of) .36, PA12.T, or mixtures or copolymers thereof; preferably, polyamide blocks PA6, PA10, PA11, PA12, PA6.10, PA6.12, PA6.13, PA10.9, PA10.10, PA10.12, PA12.9, or mixtures or copolymers thereof, more preferably, polyamide blocks PA6, PA10, PA11, PA12, PA6.10, PA6.12, PA6.13, PA10.9, PA12.9, or mixtures or copolymers thereof, more preferably, polyamide blocks PA6, PA11, PA12, PA6.12, PA6.13, PA10.9, PA12.9, or mixtures or copolymers thereof.

[0044] Polyether blocks are formed from alkylene oxide units. Polyether blocks may be, in particular, PEG (polyethylene glycol) blocks, i.e., blocks formed from ethylene oxide units, and / or PPG (polypropylene glycol) blocks, i.e., blocks formed from propylene oxide units, and / or PO3G (polytrimethylene glycol) blocks, i.e., blocks formed from polytrimethylene glycol ether units, and / or PTMG blocks, i.e., blocks formed from tetramethylene glycol units, also known as polytetrahydrofuran. Preferably, PEBA polyether blocks are polyethylene glycol and / or polypropylene glycol and / or polytetrahydrofuran blocks. PEBA copolymers may contain several types of polyethers in their chains, and the copolyethers may be in block or statistical form.

[0045] Blocks obtained by oxyethylation of bisphenols, such as bisphenol A, can also be used. The latter products are described in particular in EP613919.

[0046] Polyether blocks can also consist of ethoxylated primary amines. Examples of ethoxylated primary amines include the products of the following formulas: [ka] (In the above formula, m and n are integers between 1 and 20, and x is an integer between 8 and 18). These products are marketed, for example, under the brand name Noramox® by CECA and under the brand name Genamin® by Clariant.

[0047] The polyether soft blocks of PEBA include polyoxyalkylene blocks having NH2 chain termini, and such blocks can be obtained by cyanoacetylation of α,ω-dihydroxylated aliphatic polyoxyalkylene blocks called polyetherdiols. More specifically, commercially available products such as Jeffamine or Elastamine can be used (e.g., Huntsman's commercially available products Jeffamine® D400, D2000, ED2003 or XTJ542, as described in references JP2004346274, JP2004352794 and EP1482011).

[0048] The polyetherdiol block is thus aminated to a polyetherdiamine and condensed with a polyamide block having a carboxyl terminus. A general method for preparing PEBA copolymers having an amide bond between the PA block and the PE block is known, for example, described in reference EP1482011. The polyether block can also be mixed with a polyamide precursor and a chain-limiting diacitor to prepare a polymer containing polyether and polyamide blocks with randomly distributed units (one-step process). Polyetherdiols having OH chain terminus may coexist with aminated polyetherdiols during their condensation with the polyamide block. These OH chain-terminated polyetherdiols can be condensed with polyamide blocks having a carboxyl terminus, forming an ester bond between the PA block and the PE block (the resulting product is a polyether esteramide).

[0049] Preferably, in the preparation of PEBA, a polyetherdiol block is copolymerized with a carboxyl-terminated polyamide block.

[0050] A general method for preparing PEBA copolymers containing an ester bond between a PA block and a PE block in two steps is known, for example, described in FR2846332. A general method for preparing PEBA copolymers having an amide bond between a PA block and a PE block is known, for example, described in EP1482011. A polyether block can also be mixed with a polyamide precursor and a chain-limiting diacitor to prepare polymers containing polyamide and polyether blocks with randomly distributed units (one-step process).

[0051] Needless to say, the name PEBA in this specification of the present invention refers not only to the Pebax® products sold by Arkema, the Vestamid® products sold by Evonik, and the Grilamid® products sold by EMS, but also to the Pelestat® PEBA-type products sold by Sanyo, or any other PEBA from other suppliers.

[0052] The PEBAs that can be used in the present invention include not only copolymers comprising a single polyamide block and a single polyether block, but also copolymers comprising three, four (or more) different blocks selected from those described herein, as long as these blocks comprise at least one polyamide block and one polyether block. In addition, the PEBAs that can be used in the present invention also include copolymers comprising, in addition to polyamide and polyether blocks, one or more blocks of different properties, selected from the group consisting of polyester blocks, polysiloxane blocks, e.g., polydimethylsiloxane (or PDMS) blocks, polyolefin blocks, polycarbonate blocks, and mixtures thereof, and preferably selected from the group consisting of polyester blocks, polysiloxane blocks, and mixtures thereof.

[0053] For example, the copolymer may be a segmented block copolymer (or "triblock" copolymer) containing three different types of blocks, which is obtained by the condensation of several of the blocks described above. The triblock may be, for example, a copolymer containing a polyamide block, a polyester block and a polyether block, or a copolymer containing a polyamide block and two different polyether blocks, such as a PEG block and a PTMG block.

[0054] Particularly preferred PEBA copolymers in the context of the present invention are copolymers comprising, in particular, the following blocks: PA10 and PEG; PA10 and PTMG; PA11 and PEG; PA11 and PTMG; PA12 and PEG; PA12 and PTMG; PA6.10 and PEG; PA6.10 and PTMG; PA6 and PEG; PA6 and PTMG; PA6.12 and PEG; PA6.12 and PTMG.

[0055] The number-average molar mass of polyamide blocks in the PEBA copolymer is preferably 400 to 20000 g / mol, more preferably 500 to 10000 g / mol. In a given embodiment, the number-average molar mass of polyamide blocks in the PEBA copolymer is 400 to 500 g / mol, or 500 to 600 g / mol, or 600 to 1000 g / mol, or 1000 to 1500 g / mol, or 1500 to 2000 g / mol, or 2000 to 2500 g / mol, or 2500 to 3000 g / mol, or 3000 to 3500 g / mol, or 3500 to 4000 g / mol, or 4000 to 5000 g / mol, or 5000 to 6000 g / mol, or 6000 to 7000 g / mol, or 70 The ranges are 0-8000 g / mol, or 8000-9000 g / mol, or 9000-10000 g / mol, or 10000-11000 g / mol, or 11000-12000 g / mol, or 12000-13000 g / mol, or 13000-14000 g / mol, or 14000-15000 g / mol, or 15000-16000 g / mol, or 16000-17000 g / mol, or 17000-18000 g / mol, or 18000-19000 g / mol, or 19000-20000 g / mol.

[0056] The number-average molar mass of the polyether block is preferably 100 to 6000 g / mol, more preferably 200 to 3000 g / mol. In a given embodiment, the number-average molar mass of the polyether block is 100 to 200 g / mol, or 200 to 500 g / mol, or 500 to 800 g / mol, or 800 to 1000 g / mol, or 1000 to 1500 g / mol, or 1500 to 2000 g / mol, or 2000 to 2500 g / mol, or 2500 to 3000 g / mol, or 3000 to 3500 g / mol, or 3500 to 4000 g / mol, or 4000 to 4500 g / mol, or 4500 to 5000 g / mol, or 5000 to 5500 g / mol, or 5500 to 6000 g / mol.

[0057] The number-average molar mass is determined by the amount of chain limiting agent. This is given by: M n =n モノマー ×MW 反復単位 / n 連鎖制限剤 +MW 連鎖制限剤 can be calculated according to the following. In this formula, n モノマー represents the number of moles of the monomer, and n 連鎖制限剤 represents the excess number of moles of the diacid limiting agent, and MW 反復単位 represents the molar mass of the repeating unit, and MW 連鎖制限剤 represents the excess molar mass of the diacid.

[0058] The number average molar mass of the polyamide block and the polyether block can be measured by gel permeation chromatography (GPC) before the copolymerization of the blocks.

[0059] Advantageously, the amount of polyamide blocks in PEBA is at least 10% by weight, preferably at least 20% by weight (relative to the total weight of PEBA). More advantageously, the amount of polyamide blocks in PEBA is at least 30% by weight, more preferably at least 40% by weight, and even more preferably at least 50% by weight. The amount of polyamide blocks in PEBA can be 10% to 95% by weight (the amount of polyether blocks is preferably 5% to 90%), preferably 30% to 90% by weight (the amount of polyether blocks is preferably 10% to 70%), and more preferably 40% to 85% by weight (the amount of polyether blocks is preferably 15% to 60%). More specifically, the amount of polyamide block in PEBA may be 10% to 30% by weight (preferably 70% to 90% by weight of polyether block), or 30% to 40% by weight (preferably 60% to 70% by weight of polyether block), or 40% to 50% by weight (preferably 50% to 60% by weight of polyether block), or 50% to 60% by weight (preferably 40% to 50% by weight of polyether block), or 60% to 70% by weight (preferably 30% to 40% by weight of polyether block), or 70% to 80% by weight (preferably 20% to 30% by weight of polyether block), or 80% to 95% by weight (preferably 5% to 20% by weight of polyether block). The amount of polyamide blocks in PEBA can be quantified by proton (1H) NMR in a TFA / CDCl3 (1 / 4v / v) mixture, preferably using a Brueker AM500 spectrometer, following the protocol described in the paper “Synthesis and characterization of poly(copolyethers-block-polyamides)-II. Characterization and properties of the multiblock copolymers”, Marechal et al., Polymer, Volume 41, 2000, 3561-3580 (signal assignment is performed using Figure 5 of the said paper).These quantities result in a foam with low density, high flexibility, and good rebound elasticity.

[0060] Advantageously, PEBA has an NH2 functional group concentration of 0.01 meq / g to 1 meq / g, preferably 0.02 meq / g to 0.4 meq / g. PEBA has concentrations of 0.01 to 0.015 meq / g, or 0.015 to 0.02 meq / g, or 0.02 to 0.025 meq / g, or 0.025 to 0.03 meq / g, or 0.03 to 0.035 meq / g, or 0.035 to 0.04 meq / g, or 0.04 to 0.045 meq / g, or 0.045 to 0.05 meq / g, or 0.05 to 0.06 meq / g, or 0.06 to 0.07 meq / g, or 0.07 The NH2 functional group concentration may be 0.08 meq / g, or 0.08-0.09 meq / g, or 0.09-0.1 meq / g, or 0.1-0.2 meq / g, or 0.2-0.3 meq / g, or 0.3-0.4 meq / g, or 0.4-0.5 meq / g, or 0.5-0.6 meq / g, or 0.6-0.7 meq / g, or 0.7-0.8 meq / g, or 0.8-0.9 meq / g, or 0.9-1 meq / g. The NH2 functional concentration can be measured by potentiometric assay according to the following method: the foam sample is dissolved in metacresol at 80°C, and then the NH2 functional groups of this sample are analyzed by potentiometric assay using a 0.02 N perchloric acid solution.

[0061] PEBA may have a COOH functional group concentration of 0.002 meq / g to 0.2 meq / g, preferably 0.005 meq / g to 0.1 meq / g, and more preferably 0.01 meq / g to 0.08 meq / g. In particular, PEBA may have COOH functional group concentrations of 0.002-0.005 meq / g, or 0.005-0.01 meq / g, or 0.01-0.02 meq / g, or 0.02-0.03 meq / g, or 0.03-0.04 meq / g, or 0.04-0.05 meq / g, or 0.05-0.06 meq / g, or 0.06-0.07 meq / g, or 0.07-0.08 meq / g, or 0.08-0.09 meq / g, or 0.09-0.1 meq / g, or 0.1-0.15 meq / g, or 0.15-0.2 meq / g. The COOH functional group concentration can be quantified by potentiometric assay according to the following method: the material sample is dissolved in benzyl alcohol, and then the COOH functional groups of this sample are analyzed by potentiometric assay using a 0.02 N tetrabutylammonium hydroxide solution.

[0062] PEBA may also contain hydroxyl (OH) chain ends (e.g., derived from the condensation of a polyetherdiol having an OH chain end and a polyamide block having a carboxyl end). In particular, PEBA may have an OH functional group concentration (i.e., hydroxyl chain end concentration) of 0.002 to 0.2 meq / g, preferably 0.005 to 0.05 meq / g. The OH functional group concentration can be quantified by proton (1H) NMR in a TFA / CDCl3 (1 / 4 v / v) mixture, preferably using a Brueker AM500 spectrometer, according to the protocol described in the paper “Synthesis and characterization of poly(copolyethers-block-polyamides)-II. Characterization and properties of the multiblock copolymers”, Marechal et al., Polymer, Volume 41, 2000, 3561-3580 (signal assignment is performed using Figure 5 of the said paper).

[0063] Advantageously, the polyamide block-polyether block copolymer has a Shore D hardness of 30 or higher. Preferably, the copolymer used in the present invention has an instantaneous hardness of 65 Shore A to 80 Shore D, more preferably 75 Shore A to 65 Shore D, and more preferably 80 Shore A to 55 Shore D. Hardness measurement may be performed in accordance with ISO 7619-1.

[0064] [Thermoplastic Polyurethane (TPU)] Thermoplastic polyurethane is a copolymer containing rigid and flexible blocks.

[0065] In general, in this specification, the term "hard block" refers to a block having a melting point above 50°C. The presence of a melting point can be quantified by differential scanning calorimetry in accordance with ISO 11357-3 (Plastics - Differential Scanning Calorimetry (DSC) Part 3). The term "soft block" refers to a block having a glass transition temperature (Tg) of 0°C or lower. The glass transition temperature can be quantified by differential scanning calorimetry in accordance with ISO 11357-2 (Plastics - Differential Scanning Calorimetry (DSC) Part 2).

[0066] Thermoplastic polyurethanes are obtained by the reaction of at least one polyisocyanate, at least one isocyanate-reactive compound, more preferably a polyol, containing two isocyanate-reactive functional groups, and a chain extender, optionally in the presence of a catalyst. Rigid blocks of TPU consist of units derived from polyisocyanates and chain extenders, while soft blocks mainly consist of units derived from isocyanate-reactive compounds, preferably polyols, having a molar mass between 0.5 kg / mol and 100 kg / mol.

[0067] Polyisocyanates can be aliphatic, alicyclic, aromatic aliphatic, and / or aromatic. Preferably, the polyisocyanate is aliphatic or aromatic. More advantageously, the polyisocyanate is aliphatic. Preferably, the polyisocyanate is a diisocyanate.

[0068] Advantageously, polyisocyanates include tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanates, 2-methylpentamethylene 1,5-diisocyanate, 2-ethylbutylene 1,4-diisocyanate, 1,5-pentamethylene diisocyanate, 1,4-butylene diisocyanate, and 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclo Xane(isophorone diisocyanate, IPDI), 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), 2,4-paraphenylenediisocyanate (PPDI), 2,4-tetramethylenexylenediisocyanate (TMXDI), 4,4'-, 2,4'- and / or 2,2'-dicyclohexylmethane diisocyanate (H12 Selected from the group consisting of MDI), 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and / or 1-methyl-2,6-cyclohexane diisocyanate, 2,2'-, 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 2,4- and / or 2,6-toluene diisocyanate (TDI), diphenylmethane diisocyanate, 3,3'-dimethyldiphenyl diisocyanate, 1,2-diphenylethane diisocyanate, phenylene diisocyanate, methylenebis(4-cyclohexyl isocyanate) (HMDI), and mixtures thereof.

[0069] More preferably, the polyisocyanate is selected from the group consisting of diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), methylenebis(4-cyclohexyl isocyanate) (HMDI), and mixtures thereof.

[0070] More preferably, the polyisocyanate is 4,4'-MDI (4,4'-diphenylmethane diisocyanate), 1,6-HDI (1,6-hexamethylene diisocyanate), or a mixture thereof. Even more favorably, the polyisocyanate is 1,6-HDI.

[0071] The isocyanate-reactive compound preferably has an average functional value between 1.8 and 3, more preferably between 1.8 and 2.6, and more preferably between 1.8 and 2.2. The average functional value of the isocyanate-reactive compound corresponds to the number of isocyanate-reactive functional groups of a molecule theoretically calculated per molecule from a given amount of the compound. Preferably, the isocyanate-reactive compound has a number of Zerewitinoff active hydrogens within the above range, according to a statistical mean.

[0072] Preferably, the isocyanate-reactive compound (preferably a polyol) has a number-average molar mass of 500 to 100,000 g / mol. The isocyanate-reactive compound may have a number-average molar mass in the range of 500 to 8,000 g / mol, preferably 700 to 6,000 g / mol, and more specifically 800 to 4,000 g / mol. In a given embodiment, the isocyanate-reactive compound is present in concentrations of 500-600 g / mol, or 600-700 g / mol, or 700-800 g / mol, or 800-1000 g / mol, or 1000-1500 g / mol, or 1500-2000 g / mol, or 2000-2500 g / mol, or 2500-3000 g / mol, or 3000-3500 g / mol, or 3500-4000 g / mol, or 4000-5000 g / mol, or 5000-6000 g / mol, or 6000-70 The number-average molar mass is in the range of 00 g / mol, or 7000-8000 g / mol, or 8000-10000 g / mol, or 10000-15000 g / mol, or 15000-20000 g / mol, or 20000-30000 g / mol, or 30000-40000 g / mol, or 40000-50000 g / mol, or 50000-60000 g / mol, or 60000-70000 g / mol, or 70000-80000 g / mol, or 80000-100000 g / mol. The number-average molar mass can preferably be quantified by GPC in accordance with the ISO 16014-1:2012 standard.

[0073] Advantageously, the isocyanate-reactive compound has at least one reactive group selected from a hydroxyl group, an amine group, a thiol group, and a carboxylic acid group. Preferably, the isocyanate-reactive compound has at least one hydroxyl-reactive group, more preferably several hydroxyl groups. And, in a particularly advantageous form, the isocyanate-reactive compound contains or consists of a polyol.

[0074] Preferably, the polyol is selected from the group consisting of polyester polyols, polyether polyols, polycarbonate diols, polysiloxane diols, polyalkylenediols, and mixtures thereof. More preferably, the polyol is a polyether polyol, a polyester polyol, and / or a polycarbonate diol, resulting in the flexible blocks of thermoplastic polyurethane being a polyether block, a polyester block, and / or a polycarbonate block, respectively. Also preferably, the flexible blocks of thermoplastic polyurethane are a polyether block and / or a polyester block (the polyol is a polyether polyol and / or a polyester polyol).

[0075] Examples of polyester polyols include polycaprolactone polyols and / or copolyesters based on one or more carboxylic acids selected from adipic acid, succinic acid, pentanediol, and / or sebacic acid, and one or more alcohols selected from 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and / or polytetrahydrofuran. More specifically, the copolyester may be based on adipic acid and a mixture of 1,2-ethanediol and 1,4-butanediol, or the copolyester may be based on adipic acid, succinic acid, pentanediol, sebacic acid, or a mixture thereof, and polytetrahydrofuran (tetramethylene glycol), or the copolyester may be a mixture of these copolyesters.

[0076] As the polyether polyol, polyetherdiol (i.e., aliphatic α,ω-dihydroxylated polyoxyalkylene block) is preferably used. Preferably, the polyether polyol is a polyetherdiol based on ethylene oxide, propylene oxide and / or butylene oxide, a block copolymer based on ethylene oxide and propylene oxide, polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetrahydrofuran, polybutanediol, or a mixture thereof. The polyether polyol is preferably polytetrahydrofuran (the flexible block of thermoplastic polyurethane is therefore a polytetrahydrofuran block) and / or polypropylene glycol (the flexible block of thermoplastic polyurethane is therefore a polypropylene glycol block) and / or polyethylene glycol (the flexible block of thermoplastic polyurethane is therefore a polyethylene glycol block), preferably polytetrahydrofuran having a number average molar mass of 500 to 15000 g / mol, preferably 1000 to 3000 g / mol. Polyether polyols can be polyether diols which are reaction products of ethylene oxide and propylene oxide; the molar ratio of ethylene oxide to propylene oxide is preferably 0.01 to 100, more preferably 0.1 to 9, more preferably 0.25 to 4, more preferably 0.4 to 2.5, more preferably 0.6 to 1.5, and more preferably 1.

[0077] The polysiloxane diols that can be used in the present invention preferably have a number-average molar mass of 500 to 15000 g / mol, and more preferably 1000 to 3000 g / mol. The number-average molar mass can preferably be quantified by GPC in accordance with ISO 16014-1:2012. Advantageously, the polysiloxane diol is of formula (I): [ka] (In the above formula, R is preferably a C2-C4 alkylene, R' is preferably a C1-C4 alkyl, and each of n, m, and p independently represents an integer preferably between 0 and 50, with m being more preferably in the range of 1 to 50, and even more preferably in the range of 2 to 50) the polysiloxane is of the following formula (II): [ka] (In the above formula, Me is a methyl group.) Or the following equation (III): [ka] It has.

[0078] The polyalkylenediol that can be used in the present invention is preferably butadiene-based.

[0079] The polycarbonate diols that can be used in the present invention are preferably aliphatic polycarbonate diols. The polycarbonate diols are preferably alkanediol-based. Preferably, they are strictly bifunctional. Preferred polycarbonate diols are based on butanediol, pentanediol and / or hexanediol, particularly 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentane-(1,5)-diol, or mixtures thereof, more preferably 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, or mixtures thereof. In particular, the polycarbonate diol may be based on butanediol and hexanediol, or based on pentanediol and hexanediol, or based on hexanediol, or may be a mixture of two or more of these polycarbonate diols. Polycarbonate diols have a number-average molar mass in the range of 500 to 4000 g / mol, preferably 650 to 3500 g / mol, and more preferably 800 to 3000 g / mol. The number-average molar mass can be quantified by GPC, preferably in accordance with the ISO 16014-1:2012 standard.

[0080] One or more types of polyols can be used as isocyanate-reactive compounds.

[0081] In a particularly preferred form, the flexible block of the TPU is a block of polytetrahydrofuran, polypropylene glycol, and / or polyethylene glycol.

[0082] In addition to isocyanates and isocyanate-reactive compounds, chain extenders are used in the preparation of thermoplastic polyurethanes.

[0083] The chain extender may be aliphatic, aromaticaliphatic, aromatic, and / or alicyclic. Advantageously, it has a number-average molar mass of 50 to 499 g / mol. The number-average molar mass can be quantified by GPC, preferably in accordance with the ISO 16014-1:2012 standard. The chain extender preferably has two isocyanate reactive groups (also known as "functional groups"). A single chain extender or a mixture of at least two chain extenders may be used.

[0084] The chain extender is preferably bifunctional. Examples of chain extenders are diamines and alkanediols containing 2 to 10 carbon atoms. In particular, the chain extender may be selected from the group consisting of 1,2-ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-dimethanolcyclohexane, neopentyl glycol, hydroquinone bis(beta-hydroxyethyl) ether (HQEE), di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona- and / or deca-alkylene glycols, their respective oligomers, polypropylene glycol, and mixtures thereof. More preferably, the chain extender is selected from the group consisting of 1,2-ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and mixtures thereof, more preferably selected from 1,3-propanediol, 1,4-butanediol, and / or 1,6-hexanediol. Even more preferably, the chain extender is a mixture of 1,4-butanediol and 1,6-hexanediol, and more preferably, the molar ratio is 6:1 to 10:1.

[0085] Advantageously, a catalyst is used to synthesize thermoplastic polyurethanes. The catalyst plays a role in facilitating the chain-extending reaction between the NCO group of the polyisocyanate and the isocyanate-reactive compound (preferably the hydroxyl group of the isocyanate-reactive compound).

[0086] The catalyst is preferably a tertiary amine, more preferably selected from triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N,N'-dimethylpiperazine, 2-(dimethylaminoethoxy)ethanol and / or diazabicyclo(2,2,2)octane. Alternatively or additionally, the catalyst is an organometallic compound, such as a titanate ester, an iron compound, preferably iron(III) acetylacetonate, a tin compound, preferably a carboxylic acid, more preferably tin diacetate, tin dioctanoate, tin dilaurate, or a dialkyltin salt, preferably dibutyltin diacetate and / or dibutyltin dilaurate, a bismuth carboxylate, preferably bismuth decanoate, or a mixture thereof.

[0087] More preferably, the catalyst is selected from the group consisting of tin dioctanoate, bismuth decanoate, titanate esters, and mixtures thereof. More preferably, the catalyst is tin dioctanoate.

[0088] When preparing thermoplastic polyurethanes, the hardness and melt flow index of the TPU can be adjusted by changing the molar ratio of the isocyanate-reactive compound to the chain extender. Specifically, as the proportion of the chain extender increases, the hardness and melt viscosity of the TPU increase, while the melt flow index of the TPU decreases. In the production of soft TPUs, preferably with a Shore A hardness of less than 95, more preferably 75 to 95, the isocyanate-reactive compound and chain extender can be used in a molar ratio of 1:1 to 1:5, preferably 1:1.5 to 1:4.5, and preferably the mixture of the isocyanate-reactive compound and chain extender has a hydroxyl equivalent weight greater than 200, more specifically 230 to 650, and even more preferably 230 to 500. When producing a harder TPU, preferably with a Shore A hardness greater than 98 and a Shore D hardness of 55-75, the isocyanate reactive compound and the chain extender may be used in a molar ratio of 1:5.5-1:15, preferably 1:6-1:12, and the mixture of the isocyanate reactive compound and the chain extender has a hydroxyl equivalent weight of 110-200, more preferably 120-180.

[0089] Advantageously, to prepare TPU, a polyisocyanate, an isocyanate-reactive compound, and a chain extender are reacted, preferably in the presence of a catalyst, in amounts such that the ratio of the NCO group equivalents of the polyisocyanate to the total hydroxyl groups of the isocyanate-reactive compound and chain extender is 0.95:1 to 1.10:1, preferably 0.98:1 to 1.08:1, and more preferably 1:1 to 1.05:1. The catalyst is preferably present in an amount of 0.0001 to 0.1 parts by weight per 100 parts by weight of the TPU synthesis reagent.

[0090] The TPU preferably has a weight-average molar mass of 10,000 g / mol or more, preferably 40,000 g / mol or more, and more preferably 60,000 g / mol or more. Preferably, the weight-average molar mass of the TPU is 80,000 g / mol or less. In a given embodiment, the weight-average molar mass of the TPU is 10,000 to 25,000 g / mol, or 25,000 to 40,000 g / mol, or 40,000 to 50,000 g / mol, or 50,000 to 60,000 g / mol, or 60,000 to 70,000 g / mol, or 70,000 to 80,000 g / mol. The weight-average molar mass can be quantified by gel permeation chromatography (GPC).

[0091] The hard block content in the TPU is preferably 90% by weight or less, more preferably 80% by weight or less (relative to the total weight of the TPU). More advantageously, the hard block content in the TPU is 30% to 60% by weight (the soft block content is 40% to 70% by weight). More specifically, the hard block content in the TPU can be 10% to 20% by weight (the amount of soft blocks is 80% to 90% by weight), or 20% to 30% by weight (the amount of soft blocks is 70% to 80% by weight), or 30% to 40% by weight (the amount of soft blocks is 60% to 70% by weight), or 40% to 50% by weight (the amount of soft blocks is 50% to 60% by weight), or 50% to 60% by weight (the amount of soft blocks is 40% to 50% by weight), or 60% to 70% by weight (the amount of soft blocks is 30% to 40% by weight), or 70% to 80% by weight (the amount of soft blocks is 20% to 30% by weight), or 80% to 90% by weight (the amount of soft blocks is 10% to 20% by weight). These quantities result in a foam with low density, high flexibility, and good rebound elasticity. The hard block content is expressed as a percentage and is defined as follows: [(Mass fraction of polyisocyanate + Mass fraction of chain extender) / (Mass fraction of polyisocyanate + Mass fraction of chain extender + Mass fraction of isocyanate-reactive compound)] × 100 This can be measured by proton NMR in DMSO-D6 according to the protocol described in the paper “Reactivity of isocyanates with urethanes: Conditions for allophanate formation”, Lapprand et al., Polymer Degradation and Stability, Volume 90, No. 2, 2005, 363-373.

[0092] Advantageously, TPU is semi-crystalline. Its melting point Tf is preferably between 100°C and 230°C, more preferably between 120°C and 200°C. The melting point can be measured in accordance with ISO 11357-3 standard (plastics - differential scanning calorimetry (DSC) Part III).

[0093] Advantageously, the TPU can be recycled TPU and / or partially or completely bio-based TPU.

[0094] Advantageously, TPUs have a melt flow index (MFI) of 10–100 g / 10 min, preferably 25–80 g / 10 min, and more preferably 35–65 g / 10 min. In particular, the melt flow index of TPUs can be 10–25 g / 10 min, or 25–35 g / 10 min, or 35–45 g / 10 min, or 45–55 g / 10 min, or 55–65 g / 10 min, or 65–80 g / 10 min, or 80–100 g / 10 min. The melt flow index is measured in accordance with ASTM D1238 standard at 200°C under a 10 kg load.

[0095] Preferably, the TPU has a Shore D hardness of 75 or less, more preferably 65 or less. In particular, the TPU used in the present invention may have a hardness of 65 Shore A to 70 Shore D, preferably 75 Shore A to 60 Shore D. Hardness measurement may be performed in accordance with the ISO 7619-1 standard.

[0096] Advantageously, the TPU according to the present invention has an OH functional group concentration of 0.002 meq / g to 0.6 meq / g, preferably 0.01 meq / g to 0.4 meq / g, and more preferably 0.03 meq / g to 0.2 meq / g. In a given embodiment, the TPU has an OH functional group concentration of 0.002 to 0.005 meq / g, or 0.005 to 0.01 meq / g, or 0.01 to 0.02 meq / g, or 0.02 to 0.04 meq / g, or 0.04 to 0.06 meq / g, or 0.06 to 0.08 meq / g, or 0.08 to 0.1 meq / g, or 0.1 to 0.2 meq / g, or 0.2 to 0.3 meq / g, or 0.3 to 0.4 meq / g, or 0.4 to 0.5 meq / g, or 0.5 to 0.6 meq / g. The OH functional group concentration can be quantified by proton NMR in DMSO-D6 according to the protocol described in the following document: “Reactivity of isocyanates with urethanes: Conditions for allophanate formation”, Lapbrand et al., Polymer Degradation and Stability, Volume 90, No. 2, 2005, 363-373.

[0097] A significant advantage is that the TPU is not cross-linked.

[0098] [TPU and PEBA foam] Advantageously, the amount of polyamide blocks in the foam is at least 15% by weight, preferably at least 20% by weight, more preferably at least 25% by weight, more preferably at least 30% by weight, and more preferably at least 35% by weight (relative to the total weight of the foam). The amount of polyamide blocks in the foam can be quantified by proton NMR in a TFA / CDCl3(1 / 4v / v) mixture, preferably using a Brueker AM500 spectrometer, according to the protocol described in the paper “Synthesis and characterization of poly(copolyethers-block-polyamides)-II. Characterization and properties of the multiblock copolymers”, Marechal et al., Polymer, Volume 41, 2000, 3561-3580 (signal assignment is performed using Figure 5 of the said paper).

[0099] The amount of rigid blocks of thermoplastic polyurethane in the foam is preferably 50% by weight or less, more preferably 35% by weight or less, more preferably 25% by weight or less, and more preferably 15% by weight or less, relative to the total weight of the foam. The amount of rigid blocks of thermoplastic polyurethane in the foam can be quantified by proton NMR in DMSO-D6 according to the protocol described in the literature “Reactivity of isocyanates with urethanes: Conditions for allophanate formation”, Lapprand et al., Polymer Degradation and Stability, Volume 90, No. 2, 2005, 363-373.

[0100] The above quantities result in a foam with low density, high flexibility, and good rebound elasticity.

[0101] The foam according to the present invention preferably comprises 40% to 95% by weight of PEBA and 5% to 60% by weight of TPU, more preferably 50% to 90% by weight of PEBA and 10% to 50% by weight of TPU, based on the total weight of the foam. More advantageously, the foam according to the present invention comprises 55% to 80% by weight of PEBA and 20% to 45% by weight of TPU, more preferably 60% to 75% by weight of PEBA and 25% to 40% by weight of TPU, based on the total weight of the foam. In a predetermined embodiment, the foam is composed of 40% to 45% by weight of PEBA and 55% to 60% by weight of TPU relative to the total weight of the foam, or 45% to 50% by weight of PEBA and 55% to 50% by weight of TPU, or 50% to 55% by weight of PEBA and 45% to 50% by weight of TPU, or 55% to 60% by weight of PEBA and 40% to 45% by weight of TPU, or 60% to 65% by weight of PEBA and 35% to 40% by weight of TPU, or 65% by weight It includes 70% by weight of PEBA and 30% by weight of TPU, or 70% by weight of PEBA and 25% by weight of TPU, or 75% by weight of PEBA and 25% by weight of TPU, or 80% by weight of PEBA and 20% by weight of TPU, or 80% by weight of PEBA and 15% by weight of TPU, or 85% by weight of PEBA and 10% by weight of TPU, or 90% by weight of PEBA and 5% by weight of TPU.

[0102] Advantageously, the foam contains a total soft block content of PEBA and TPU between 30% and 80% by weight, preferably between 40% and 75% by weight, relative to the total weight of the foam. The total soft block content can be quantified by nuclear magnetic resonance (NMR), as described above. In particular, these soft blocks include polyether blocks of PEBA and soft blocks of TPU.

[0103] The molar ratio of urethane functional groups to NH2 amine functional groups in the foam according to the present invention, in an assembly comprising at least one amine chain end-containing polyamide block-polyether block copolymer and at least one thermoplastic polyurethane, may be 15 to 350, preferably 25 to 250, and more preferably 40 to 200. The amine functional group concentration and the urethane functional group concentration are as described in the following paper, “Reactivity of isocyanates with urethanes: Conditions for allophanate formation”, Lapbrand et al., Polymer Degradation and Stability, Volume 90, No. 2, 2005, 363-373, in DMSO-D6 13 It can be quantified by 13C NMR.

[0104] Advantageously, the TPU and PEBA foams according to the present invention include at least a portion of a total polyamide block-polyether block copolymer covalently bonded to a thermoplastic polyurethane via urea functional groups.

[0105] Preferably, the foam according to the present invention has a urea functional group concentration of 0.001 meq / g to 0.1 meq / g, preferably 0.003 meq / g to 0.08 meq / g, and more preferably 0.005 meq / g to 0.05 meq / g. The urea functional group concentration in the foam may be 0.001 to 0.005 meq / g, or 0.005 to 0.01 meq / g, or 0.01 to 0.02 meq / g, or 0.02 to 0.03 meq / g, or 0.03 to 0.04 meq / g, or 0.04 to 0.05 meq / g, or 0.05 to 0.08 meq / g, or 0.08 to 0.1 meq / g. The urea functional group concentration is as described in the paper “Reactivity of isocyanates with urethanes: Conditions for allophanate formation”, Lapprand et al., Polymer Degradation and Stability, Volume 90, No. 2, 2005, 363-373, in DMSO-D6. 13It can be measured by 13C NMR. The urea functional group content is quantified by integrating the signals corresponding to the carbonyl groups of the urethane and urea functional groups, and the signal assignment is performed using Figure 6 of the aforementioned paper.

[0106] Advantageously, the foam according to the present invention has an NH2 functional group concentration of 0.01 meq / g to 1 meq / g, preferably 0.02 meq / g to 0.4 meq / g.

[0107] The foam is 0.01-0.015 meq / g, or 0.015-0.02 meq / g, or 0.02-0.025 meq / g, or 0.025-0.03 meq / g, or 0.03-0.035 meq / g, or 0.035-0.04 meq / g, or 0.04-0.045 meq / g, or 0.045-0.05 meq / g, or 0.05-0.06 meq / g, or 0.06-0.07 meq / g, or 0.07-0 The NH2 functional group concentration may be 0.08 meq / g, or 0.08-0.09 meq / g, or 0.09-0.1 meq / g, or 0.1-0.2 meq / g, or 0.2-0.3 meq / g, or 0.3-0.4 meq / g, or 0.4-0.5 meq / g, or 0.5-0.6 meq / g, or 0.6-0.7 meq / g, or 0.7-0.8 meq / g, or 0.8-0.9 meq / g, or 0.9-1 meq / g. The NH2 functional group concentration can be measured by potentiometric assay. This assay can be carried out, for example, in the following manner: First, PEBA is dissolved in m-cresol at 80°C, and then the terminal NH2 functional groups are analyzed using a perchloric acid solution.

[0108] In one embodiment, the foam according to the present invention contains urea functional groups and NH2 functional groups. Preferably, the foam according to the present invention contains more urea functional groups than NH2 functional groups.

[0109] Preferably, the portion of the polyamide block-polyether block copolymer covalently bonded to the thermoplastic polyurethane via urea functional groups accounts for 10% by weight or less, more preferably 5% by weight or less, more preferably 3% by weight or less, and more preferably 2% by weight or less of the total amount of the polyamide block-polyether block copolymer.

[0110] The foam according to the present invention, particularly in the case of closed-cell foams, may essentially consist of, or be composed of, at least one polyamide block-polyether block copolymer, at least one thermoplastic polyurethane, and optionally a blowing agent in the foam matrix and / or foam pores. The foam matrix may essentially consist of, or be composed of, at least one TPU and at least one PEBA. In particular, when a chemical blowing agent is used to form the foam, the foam may also contain decomposition products of the blowing agent (particularly in its matrix).

[0111] Alternatively, the foam may contain one or more additives, such as ethylene-vinyl acetate copolymer, i.e., EVA (e.g., sold by SK Chemical Co., Ltd. under the name Evatane®), or ethylene-acrylate copolymer, or ethylene-alkyl (meth)acrylate copolymer, e.g., sold by SK Chemical Co., Ltd. under the name Lotryl®. These additives may have the function of adjusting the hardness, appearance, and comfort of the foam component. Other additives suitable for the present invention include pigments (such as TiO2 and other compatible coloring pigments), adhesion promoters (to improve the adhesion between the foam and other materials), fillers (e.g., calcium carbonate, barium sulfate and / or silicon dioxide), nucleating agents (especially in pure or concentrated form, e.g., CaCO3, ZnO, SiO2, or combinations of two or more thereof), rubber (to improve rubber elasticity, e.g., natural rubber, SBR, polybutadiene and / or ethylene propylene polymer), stabilizers (e.g., antioxidants, UV absorbers and / or flame retardants), processing aids (e.g., stearic acid), antioxidants, especially phenolic antioxidants such as Irganox from Ciba Geigy. Additives may be present in an amount of 0 to 30% by weight, preferably 0.1% to 20% by weight, and more preferably 0.2% to 10% by weight, relative to the total weight of the foam.

[0112] According to one embodiment, the foam does not contain any crosslinking agent. Advantageously, the foam is a non-crosslinked foam.

[0113] The foam according to the present invention preferably has a density of 800 kg / m³. 3 More preferably 600 kg / m 3 Below, 400 kg / m² is given higher priority. 3 Below, with even higher priority, is 300 kg / m 3 The following is particularly preferred: 230 kg / m 3 The foam has the following densities: for example, 25-600 kg / m³ 3 , more preferably 50-300 kg / m 3 It can have a density of 25-100 kg / m³. 3, or 100-200 kg / m 3 , or 200-250 kg / m 3 , or 250-300 kg / m 3 , or 300-400 kg / m 3 , or 400-500 kg / m 3 , or 500-600 kg / m 3 , or 600-800 kg / m 3 It is possible. Density can be controlled by adjusting the parameters of the manufacturing process. Density can be measured at 23°C in accordance with the ISO 1183-1 standard.

[0114] Preferably, the foam according to the present invention has an Asker C hardness of 20 to 90, preferably 25 to 70. In particular, the Asker C hardness of the foam may be 20 to 25, or 25 to 30, or 30 to 40, or 40 to 50, or 50 to 60, or 60 to 70, or 70 to 80, or 80 to 90. The Asker C hardness can be quantified after 15 seconds at 23°C in accordance with ISO 7619-1 standard.

[0115] Preferably, the foam has a rebound elasticity of 50% or more, preferably 55% or more. The rebound elasticity is measured in accordance with the ISO 8307:2007 standard, but using an 18.8g ball.

[0116] Preferably, the foam has a compression set of 65% or less, preferably 50% or less, for example, 45% or less, or 40% or less, or 35% or less, in accordance with ISO 7214 standards. The residual strain is measured by applying 25% compression at 23°C for 70 hours, followed by relaxation for 30 minutes.

[0117] Preferably, this foam also has excellent properties in terms of fatigue strength and damping capacity.

[0118] Preferably, the foam also has good resistance to tearing and crack propagation.

[0119] The foam according to the present invention can be used in the manufacture of sports equipment, such as functional sole components in the form of inserts into various parts of the sole (e.g., heel or arch), or upper components of shoes in the form of reinforcing materials or inserts to the upper structure of shoes, or protective materials.

[0120] The foam can also be used in the manufacture of balls, sports gloves (e.g., soccer gloves), golf ball components, rackets, and protective gear (jackets, helmet linings, shells, etc.).

[0121] The foam according to the present invention possesses advantageous impact resistance, vibration resistance, and noise resistance, combined with tactile properties suitable for capital goods. Therefore, the foam can be used in the rail base of railway tracks, or in the manufacture of various components in the automotive industry, transportation, electrical and electronic equipment, construction, or manufacturing industries.

[0122] According to an advantageous embodiment, the foam according to the present invention can be easily recycled by melting it (after optionally shredding it) in an extruder equipped with a vent.

[0123] [Preparation of foam] The foam according to the present invention can be prepared by mixing a polymer composition containing at least one type of TPU and at least one type of amine chain-terminus-containing PEBA with a foaming agent (and optionally one or more types of additives), followed by a foaming step.

[0124] The blowing agent may be a chemical or physical blowing agent, or it may consist of any kind of hollow body or any kind of expandable microsphere. Preferably, the blowing agent is a physical blowing agent, such as dinitrogen or carbon dioxide, or hydrocarbons, chlorofluorocarbons, hydrochlorocarbons, hydrofluorocarbons (saturated or unsaturated), or mixtures thereof. For example, butane or pentane may be used. Also preferably, the blowing agent may be a chemical blowing agent, such as azodicarbonamide, or a mixture based on citric acid and sodium bicarbonate (NaHCO3) (for example, Clariant's Hydrocerol® product series).

[0125] In a given embodiment, a physical blowing agent is used and mixed with a molten polymer composition. The physical blowing agent may be in liquid or supercritical form and is then converted to a gas phase during the foaming process. Foaming can be brought about, for example, by a pressure drop occurring at the outlet of an extruder.

[0126] Advantageously, a mixture of polymer composition and foaming agent is injected into a mold, and foaming is carried out within the mold. Foaming can be induced by opening the mold, under-injecting, applying gas back pressure, using a permeable mold, or a mold equipped with a Variotherm® system. This technology makes it possible to directly manufacture three-dimensional foams of complex shapes. Furthermore, these are relatively easy to implement compared to certain processes that melt foam particles, in particular: specifically, the complex operation of filling a mold with foam polymer granules and then melting the particles to ensure the mechanical strength of the part without destroying the structure of the foam.

[0127] In alternative embodiments, the polymer composition is used to produce a preform. This preform can be prepared by compression molding, extrusion molding, injection molding, lamination molding, or 3D printing processes. Preferably, the preform is produced by extrusion molding or injection molding. The preform is brought into contact with a physical blowing agent in a solid state, either in gaseous or supercritical form. The physical blowing agent is impregnated into the solid preform, preferably by applying positive pressure. Preferably, foaming is carried out in an autoclave, preferably at a temperature slightly below the melting point of the polymer composition. Preferably, during foaming, the pressure in the autoclave is maintained between 0.20 MPa and 50 MPa. Advantageously, the foaming of the preform is carried out in a mold.

[0128] Other foaming techniques that may be used include, in particular, batch foaming, extrusion foaming, such as uniscrew or twinscrew extrusion foaming, and microwave foaming.

[0129] In a particularly preferred form, a polymer composition containing TPU and PEBA is prepared before being mixed with a foaming agent. Preferably, the polymer composition is an alloy of TPU and PEBA. The term "alloy" means a homogeneous mixture (macroscopically, i.e., visible to the naked eye).

[0130] According to a first advantageous modification, the polymer composition can be prepared by a method comprising the step of mixing a molten amine-chain-terminated polyamide block-polyether block copolymer with a thermoplastic polyurethane. Such a preparation method allows a reaction to occur between some of the amine functional groups of the polyamide block-polyether block copolymer and the urethane functional groups of the TPU under predetermined mixing time and temperature conditions, thereby improving the compatibility between the polyamide block-polyether block copolymer and the thermoplastic polyurethane.

[0131] The mixing of TPU and PEBA can be carried out in any apparatus known to those skilled in the art for mixing, kneading or extruding molten plastics, such as an internal mixer, open mill, extruder, e.g., a single-screw extruder or a twin-screw extruder that rotates in opposite directions or in conjunction with rotation, a cone kneader, e.g., a continuous cone kneader, or a stirring reactor. Preferably, the mixing is carried out in an extruder or cone kneader, more preferably in an extruder, and even more preferably in a twin-screw extruder.

[0132] Preferably, the mixing is carried out at a temperature of 160°C or higher, preferably 160-300°C, and more preferably 180-260°C. These temperature ranges allow for optimal reaction between the amine-chain-terminated polyamide block-polyether block copolymer and the thermoplastic polyurethane, thereby enabling better compatibility between the two polymers.

[0133] Advantageously, the mixing is carried out for 30 seconds to 15 minutes, preferably 40 seconds to 10 minutes. Preferably, the mixing is carried out with stirring. These mixing conditions enable the optimal reaction between the amine chain-terminated polyamide block-polyether block copolymer and the thermoplastic polyurethane, and consequently, better compatibility between the two polymers.

[0134] The step of mixing TPU with PEBA may include mixing a molten amine-chain-terminated polyamide block-polyether block copolymer with thermoplastic polyurethane together with additives.

[0135] According to another advantageous modification, the polymer composition may be prepared by introducing an amine-chain-terminated polyamide block-polyether block copolymer during the synthesis of a thermoplastic polyurethane. In such a preparation method, the amine-chain-terminated polyamide block-polyether block copolymer is optionally used as an isocyanate-reactive compound (as described in the "Thermoplastic Polyurethane (TPU)" section above), in addition to another isocyanate-reactive compound, preferably the polyol described above.

[0136] Therefore, the preparation method is - A step of introducing a thermoplastic polyurethane precursor (i.e., at least one polyisocyanate, at least one chain extender, and optionally at least one isocyanate-reactive compound) into the reactor; - A step of introducing an amine chain-terminated polyamide block-polyether block copolymer into the reactor; and - A step to synthesize a thermoplastic polyurethane in a reactor in the presence of an amine chain-terminated polyamide block-polyether block copolymer to obtain a polymer composition. It may include.

[0137] Through such a preparation method, during the synthesis of the thermoplastic polyurethane, some of the NH2 amine functional groups of the polyamide block-polyether block copolymer react with some of the isocyanate functional groups of the polyisocyanate, forming a covalent bond between the polyamide block-polyether block copolymer and the thermoplastic polyurethane, thereby improving the compatibility between the polyamide block-polyether block copolymer and the thermoplastic polyurethane.

[0138] The steps of adding the thermoplastic polyurethane precursor and the amine chain-terminus-containing polyamide block-polyether block copolymer may be carried out simultaneously or in any order. In particular, catalysts such as those described above may be added to the reactor again.

[0139] The reactor may be a batch reactor, a stirred reactor, a static mixer, an internal mixer, an open mill, an extruder, such as a single-screw extruder or a twin-screw extruder that rotates in opposite directions or in conjunction with another, a continuous kneader, or a combination thereof. Preferably, the reactor is an extruder, more preferably a twin-screw extruder.

[0140] Preferably, the step of synthesizing the thermoplastic polyurethane (in the presence of the amine chain end-containing polyamide block-polyether block copolymer) is carried out at a temperature of 160°C or higher, preferably 160 to 300°C, and more preferably 180 to 270°C. This temperature range allows for an optimal reaction between the amine chain end-containing polyamide block-polyether block copolymer and the thermoplastic polyurethane, resulting in good compatibility between the two polymers.

[0141] One or more additives can be added to the reactor (at any point during the process) and mixed with the thermoplastic polyurethane and the polyamide block-polyether block copolymer within the reactor.

[0142] In any of the modifications used, the preparation method may include a step of forming the mixture of TPU and PEBA into granules or powder. When forming the mixture into a powder, it is preferable to first form it into granules and then grind the granules into a powder. Any type of mill can be used, such as a hammer mill, pin mill, attrition disc mill, or impact classifier.

[0143] In the methods for preparing the above polymer compositions, all the characteristics described above in relation to polyamide block-polyether block copolymers and thermoplastic polyurethanes (in particular, their properties, quantities, concentrations of OH groups, COOH and / or amine functional groups, etc.) can also be applied to the polyamide block-polyether block copolymers and thermoplastic polyurethanes used in these methods. [Examples]

[0144] The following embodiments illustrate the present invention without limiting it.

[0145] The following polymers were used: - PEBA1: A PEBA copolymer containing PA11 blocks with a number-average molar mass of 1000 g / mol and PTMG blocks with a number-average molar mass of 1000 g / mol, with a hardness of 40 Shore D. This PEBA copolymer does not contain any NH2 functional groups. - PEBA2: A PEBA copolymer containing PA11 blocks with a number-average molar mass of 1000 g / mol and PTMG blocks with a number-average molar mass of 1000 g / mol, with a hardness of 40 Shore D. This PEBA copolymer has an NH2 functional group content of 0.032 meq / g. - TPU: TPU with a hard block and a soft polyether block (PTMG) based on 4,4'-MDI and 1,4-BDO (1,4-butanediol), hardness 85 Shore A.

[0146] Polymer composition 1 was prepared by mixing 65 wt% PEBA1 and 35 wt% TPU using an 18 mm ZSK twin-screw extruder (Coperion). The barrel temperature was set to 210°C, the screw speed to 280 rpm, and the flow rate to 8 kg / h. The composition was then dried under reduced pressure at 80°C to achieve a moisture content of less than 0.04%.

[0147] Polymer composition 2 was prepared by mixing 65 wt% PEBA2 and 35 wt% TPU using an 18 mm ZSK twin-screw extruder (Coperion). The barrel temperature was set to 210°C, the screw speed to 280 rpm, and the flow rate to 8 kg / h. The composition was then dried under reduced pressure at 80°C to achieve a moisture content of less than 0.04%.

[0148] [Evaluation of foam] Next, the foam was prepared: - Foam 1 (Comparative Example): Produced from polymer composition 1. - Foam 2 (Example of the present invention): Produced from polymer composition 2.

[0149] A 15mm thick foam was prepared using an Arburg Allrounder 520A 150T injection molding machine with a Trexel Series II physical foaming agent injection system. This machine utilizes Mucell® technology with partial mold release (core-back process). The operating parameters were as follows: - Barrel temperature: 250℃ - Mold geometry (mm): 200 x 100 x 1.6 mm - Injection speed: 120cm 3 / sec - Holding time before mold release: 1 second - Holding pressure: 25.0 MPa - Cooling time: 240 seconds - Mold temperature: 15℃ - Mold opening length: 15mm The foaming agent used was dinitrogen (N2), added at a concentration of 0.7% by weight.

[0150] The following foam properties were evaluated: - Density: In accordance with ISO 1183-1 standard, the test was conducted at 23°C using the underwater vertical thrust method; five repeated tests were performed. - ΔDensity: Characterizes the homogeneity of the foam and corresponds to the density difference of the foam between the point closest to the injection point and the point furthest from the injection point; the lower this value, the higher the homogeneity of the foam. - Rebound elasticity: In accordance with ISO 8307 standard, however, an 18.8g ball was used (when a steel ball weighing 18.8g and with a diameter of 16mm is dropped from a height of 500mm onto a foam sample, the rebound elasticity corresponds to the proportion of energy returned to the ball or the proportion of the initial height reached when the ball bounced back); the test was repeated 5 times. - Asker C hardness (15 seconds): Measured using a Hildebrand Asker C hardness tester in accordance with ISO 7619-1 standard. - Compression Test: Measurements were taken using a Zwick compression tester in accordance with ISO 3386-1 standard. A 50×50×15mm foam sample was subjected to four compression cycles up to 70% strain at a temperature of 23°C and a displacement rate of 100mm / min. The measurement taken in the fourth compression cycle represents the intrinsic behavior of the foam, and stresses corresponding to 25%, 40%, and 50% strain were recorded. - The NH2 functional group concentration can be measured by potentiometric assay. This assay is performed as follows: First, PEBA is dissolved in m-cresol at 80°C, and then the terminal NH2 functional groups are analyzed using a perchloric acid solution.

[0151] The results are shown in the following table. [Table 1]

[0152] The foam according to the present invention has a lower density and is more homogeneous than the comparative foam prepared from composition 1, which does not contain any amine chain ends. In addition, the foam according to the present invention is more flexible and has lower compressive stress than the comparative foam, as indicated by the Asker C hardness, but simultaneously possesses similar rebound elasticity.

Claims

1. - At least one type of thermoplastic polyurethane, - At least one polyamide block-polyether block copolymer containing amine chain ends, detected by potentiometric assay in metacresol using a 0.02 N perchloric acid solution. A polymer foam containing the following:

2. The foam according to claim 1, wherein at least a portion of the total polyamide block-polyether block copolymer is covalently bonded to thermoplastic polyurethane molecules via urea functional groups.

3. The urea functional group concentration is DMSO-D ６ inside １３ The foam according to claim 2, wherein the concentration measured by 13C NMR is 0.001 meq / g to 0.1 meq / g, more preferably 0.003 meq / g to 0.08 meq / g, and more preferably 0.005 meq / g to 0.05 meq / g.

4. The polyamide block-polyether block copolymer was measured by potentiometric assay in metacresol using a 0.02 N perchloric acid solution, and showed a NH content of 0.002 meq / g to 0.2 meq / g, preferably 0.005 to 0.1 meq / g. ２ A foam according to any one of claims 1 to 3, having an amine functional group concentration.

5. TFA / CDCl ３ The foam according to any one of claims 1 to 4, wherein the amount of polyamide blocks measured by proton NMR in a (1 / 4 v / v) mixture is at least 15% by weight, preferably at least 25% by weight, relative to the total weight of the foam.

6. Polyamide block-polyether block copolymer, TFA / CDCl ３ The foam according to any one of claims 1 to 5, comprising at least 30% by weight, preferably at least 40% by weight, of polyamide blocks relative to the total weight of the copolymer, as measured by proton NMR in a (1 / 4 v / v) mixture.

7. At least one thermoplastic polyurethane is a copolymer containing a hard block and a soft block, wherein the content of the hard block in the thermoplastic polyurethane is DMSO-D ６ The foam according to any one of claims 1 to 6, wherein, as measured by proton NMR in the foam, the content is 90% by weight or less, more preferably 80% by weight or less, and more preferably 30% by weight to 60% by weight.

8. In relation to the total weight of the foam, - At least one thermoplastic polyurethane in an amount of 5% to 70% by weight, preferably 15% to 60% by weight, and more preferably 20% to 45% by weight, - 30% to 95% by weight, preferably 40% to 85% by weight, and more preferably 55% to 80% by weight of at least one amine chain end-containing polyamide block-polyether block copolymer A foam according to any one of claims 1 to 7, including the following:

9. At least one type of thermoplastic polyurethane is a copolymer comprising a rigid block and a flexible block. - The flexible block is selected from polyether blocks, polyester blocks, polycarbonate blocks, and combinations thereof; preferably, the flexible block is selected from polyether blocks, polyester blocks, and combinations thereof, more preferably polytetrahydrofuran, polypropylene glycol, and / or polyethylene glycol blocks; and / or - The hard block contains units derived from 4,4'-diphenylmethane diisocyanate and / or 1,6-hexamethylene diisocyanate, preferably units derived from at least one chain extender selected from 1,3-propanediol, 1,4-butanediol, and / or 1,6-hexanediol. The foam according to any one of claims 1 to 8.

10. The foam according to any one of claims 1 to 9, wherein the polyamide block of the amine chain end-containing polyamide block-polyether block copolymer is polyamide 11, polyamide 12, polyamide 10, polyamide 6, polyamide 6.10, polyamide 6.12, polyamide 6.13, polyamide 10.9, polyamide 10.10, polyamide 10.12 and / or polyamide 12.9 block, preferably polyamide 11, polyamide 12, polyamide 6, polyamide 6.12, polyamide 6.13, polyamide 10.9 and / or polyamide 12.9 block; and / or the polyether block of the amine chain end-containing polyamide block-polyether block copolymer is polyethylene glycol and / or polypropylene glycol and / or polytetrahydrofuran block.

11. Measured at 23°C in accordance with ISO 1183-1 standard, 800 kg / m ３ Hereinafter, preferably 400 kg / m ３ Hereinafter, more preferably 300 kg / m ３ Hereinafter, even more preferably 230 kg / m ３ The foam according to any one of claims 1 to 10, having the following density.

12. A foam according to any one of claims 1 to 11, having an Asker C hardness of 20 to 90, preferably 25 to 70, as measured at 23°C in accordance with ISO 7619-1 standard.

13. A method for producing a foam according to any one of claims 1 to 12, - A step of providing a polymer composition comprising at least one thermoplastic polyurethane and at least one amine chain end-containing polyamide block-polyether block copolymer; - A step of mixing the polymer composition with a foaming agent; and - A process of foaming a mixture of polymer composition and foaming agent. Methods that include...

14. The method according to claim 13, wherein a foaming agent is mixed with a molten polymer composition, and the foaming of the mixture is preferentially carried out in a mold.

15. The method according to claim 13, wherein the blowing agent is a physical blowing agent, which is mixed with a polymer composition in the form of a solid preform, and the foaming of the mixture is preferably carried out in an autoclave.

16. Preferably, an article formed from or comprising at least one element made of the foam described in any one of claims 1 to 12, selected from sports shoe soles, balloons or balls, gloves, personal protective equipment, rail pads, automotive parts, construction parts, and electrical and electronic equipment components.

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