Process for preparing a crosslinked polyester of glycerol by means of a cyclic polycarboxylic anhydride in the presence of a catalyst

Abstract

The present invention relates to a process for preparing a crosslinked polyester of glycerol, comprising a step of crosslinking a glycerol polyester with a cyclic polycarboxylic anhydride A in the presence of a metal triflate (or trifluoromethylsulfonate) compound, wherein the cyclic polycarboxylic anhydride A comprises at least two cyclic carboxylic anhydride groups, the cyclic polycarboxylic anhydride A does not comprise linear carboxylic anhydride functions, and the metal of the metal triflate (or trifluoromethylsulfonate) compound is chosen from alkali metals and alkaline-earth metals. The present invention also relates to a crosslinking composition that can be used for implementing the process of the invention.

Description

[0001] Process for preparing a cross-linked glycerol polyester using a cyclic carboxylic polyanhydride in the presence of a catalyst

[0002] FIELD OF INVENTION

[0003] The present invention relates to glycerol-crosslinked polyesters. The present invention also relates to a method for their preparation and a crosslinking composition useful for preparing said crosslinked polyesters.

[0004] STATE OF THE ART

[0005] Biodegradable and / or bio-based polyesters, such as polylactic acid (PLA), polyglycolic acid (PGA), poly(glycerol sebacate) (PGS), and their copolymers, are now ubiquitous in the preparation of biomaterials useful both as medical biomaterials and for surface coating for various fields of application.

[0006] Conventionally, these polyesters are prepared by melt polycondensation of glycerol and a diacid at high temperature, with relatively long reaction times. These reaction times are further extended to modify the polyester's mechanical properties through crosslinking.

[0007] There is therefore a need for processes for preparing crosslinked polyesters, adapted to the preparation of biomaterials, with shorter crosslinking times and / or lower reaction temperatures - therefore compatible with a greater number of additives and in particular active ingredients to be encapsulated in said crosslinked polyesters.

[0008] DESCRIPTION OF THE INVENTION

[0009] The inventors demonstrated that the use of a cyclic carboxylic polyanhydride type crosslinking agent in the presence of a triflate (or trifluoromethylsulfonate) metal compound, the metal being of oxidation state (I) or (II) and chosen from the alkali and alkaline earth metals, made it possible to overcome the problems of the prior art.

[0010] Thus, the present invention relates to a process for preparing a crosslinked glycerol polyester, comprising a step of crosslinking a glycerol polyester with a cyclic carboxylic polyanhydride A in the presence of a metal triflate (or trifluoromethylsulfonate) compound, the cyclic carboxylic polyanhydride A comprising at least two cyclic carboxylic anhydride groups, the cyclic carboxylic polyanhydride A not comprising a linear carboxylic anhydride function, and the metal of the metal triflate (or trifluoromethylsulfonate) compound being chosen from the alkali and alkaline earth metals.

[0011] The process of the invention thus makes it possible to achieve shorter crosslinking times.

[0012] Advantageously, the glycerol polyester is a polyester of glycerol and a diacid monomer or a carboxylic diester monomer, the diacid monomer and the carboxylic diester monomer having the formula [R'OOC-(CH2) P -COOR'], in which R' is H or each of the R's represents, independently of the other, a linear or branched alkyl in C1-C10, preferably in C1-C6, preferably in C1-C4, p is a number from 1 to 30, preferably a number from 1 to 10, preferably p is 8.

[0013] Advantageously, the dicarboxylic acid monomer is sebacic acid.

[0014] Advantageously the carboxylic diester monomer is a sebacic acid diester, preferably dimethyl sebacate.

[0015] Advantageously, the polyester of glycerol has an average number molar mass Mn less than or equal to 10,000 g / mol.

[0016] Advantageously, the polyester of glycerol is a poly(glycerol-sebacate) having a number molar mass Mn less than or equal to 10,000 g / mol.

[0017] Advantageously, the cyclic carboxylic anhydride groups of the cyclic carboxylic polyanhydride A are independently chosen from ortho phthalic, succinic, maleic, homo phthalic groups.

[0018] Advantageously, the cyclic carboxylic anhydride groups of the cyclic polycarboxylic anhydride A are joined, linked together by at least one covalent bond or carried by a spacer group L,

[0019] The representative -O- ; -S- ; -S(O)- ; -S(O)2- ; -C(O)- ; -NR n R n - with R n and R n'independently chosen from H or an alkyl group in Ci-Ce, or a multivalent hydrocarbon group comprising 1 to 40 carbon atoms, cyclic or acyclic, saturated, unsaturated or aromatic, and which may contain one or more heteroatoms of O, S, Cl, Br, F, N, P or Si, L being devoid of linear anhydride groups.

[0020] Advantageously, the cyclic carboxylic polyanhydride A comprises or is a compound of formula (I) or (II): in which

[0021] • L1 represents a bond; -O- ; -S- ; -S(O)- ; -S(O)2- ; -NR n R n - with R n and R n 'independently chosen from H or an alkyl group in Ci-Ce; -C(O)-; or an aliphatic chain of 1 to 30 carbon atoms, in which 1 to 6 methylene unit(s) is / are optionally replaced by an arylene group, a heteroarylene group, -C(O)-, -O-, -S-, -S(O)-, -S(O)2-, -NR m - with R mchosen from H or an alkyl group in Ci-Ce, -P-, -P(O)-, -SiRaRb- with R a and Rb independently representing a -OH, alkyl in Ci-Ce or alkoxy in Ci-Ce group, said aliphatic chain being substituted or unsubstituted by one or more, in particular one or two, alkyl in Ci-Ce, alkoxy in Ci-Ce, hydroxyl, nitro, cyano, halogen atom, haloalkyl in Ci-Ce group(s),

[0022] • Zi is absent or represents a -CH2- (methylene) group

[0023] • Z2 is absent or represents a -CH2- (methylene) group

[0024] • X independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom,

[0025] • n represents an integer from 0 to 3, preferably from 0 to 2,

[0026] • Y independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom,

[0027] • m represents an integer from 0 to 3, preferably from 0 to 2,

[0028] • Ai represents: o a CC bond or a C=C bond linking the four carbon atoms of the two carboxylic anhydride functions, o a saturated, unsaturated or aromatic carbocycle, optionally bridged, said carbocycle comprising from 4 to 30 carbon atoms, and o a saturated, unsaturated or aromatic heterocycle, optionally bridged, said heterocycle comprising from 4 to 30 carbon atoms, and said carbocycle or heterocycle being substituted or unsubstituted by one or more substituents selected from a Ci-Ce alkyl, hydroxyl, Ci-Ce alkoxy, nitro, cyano, or halogen atom group.

[0029] Advantageously, the metal triflate compound is lithium triflate, sodium triflate, potassium triflate, magnesium triflate, calcium triflate, strontium triflate, barium triflate, or a mixture thereof.

[0030] Advantageously, the process comprises the following steps: a) contacting 100 parts by weight of at least one glycerol polyester with 0.1 to 200 parts by weight of at least one cyclic carboxylic polyanhydride in the presence of 0.0001 wt% (0.1 ppm) to 1 wt% (10,000 ppm) relative to the mass of glycerol polyester, of a triflate metal compound, the metal being selected from the alkali and alkaline earth metals; b) pressurizing the mixture obtained in step a) to a target temperature T c ranging from 60°C to 175°C, and maintenance at temperature T c and under pressure for a heating time t Ch sufficient to obtain a crosslinked polyester, c) cooling and recovery of the crosslinked polyester. Advantageously, step a) of this process comprises contacting 100 parts by weight of at least one polyester of glycerol, with 10 to 100 parts by weight of at least one cyclic carboxylic polyanhydride.

[0031] Advantageously, step a) of this process includes the use of 0.05 wt% (500ppm) to 1 wt% (10000ppm) relative to the polyester mass of glycerol, of the metal triflate (or trifluoromethylsulfonate) compound.

[0032] Another object of the invention relates to a crosslinking composition, comprising: o 100 parts by weight of at least one polyester of glycerol, o from 0.1 to 200 parts by weight of at least one cyclic carboxylic polyanhydride as defined above o from 0.0001% by mass (0.1 ppm) to 1% by mass (10000 ppm) relative to the mass of polyester of glycerol, of a triflate (or trifluoromethylsulfonate) compound of metal, the metal being selected from the alkali and alkaline earth metals.

[0033] Advantageously, the glycerol polyester is a polyester of glycerol and a diacid monomer or a carboxylic diester monomer, the diacid monomer and the carboxylic diester monomer having the formula [R'OOC-(CH2) P-COOR'], in which R' is H or each of the R's represents, independently of the other, a linear or branched C1-C10 alkyl, preferably Ci-Ce, preferably C1-C4, p is a number from 1 to 30, preferably a number from 1 to 10, most preferably p=8.

[0034] Advantageously, the dicarboxylic acid monomer is sebacic acid.

[0035] Advantageously the carboxylic diester monomer is a sebacic acid diester, preferably dimethyl sebacate.

[0036] Advantageously, the polyester of glycerol has a molar mass in number M n less than or equal to 10,000 g / mol.

[0037] Advantageously, at least one cyclic carboxylic polyanhydride comprises a compound of formula (I) or (II): in which

[0038] • L1 represents a bond; -O- ; -S- ; -S(O)- ; -S(O)2- ; -NR n R n - with R n and R n'independently chosen from H or an alkyl group in Ci-Ce; -C(O)-; or an aliphatic chain of 1 to 30 carbon atoms, in which 1 to 6 methylene unit(s) is / are optionally replaced by an arylene group, a heteroarylene group, -C(O)-, -O-, -S-, -S(O)-, -S(O)2-, -NR m - with R m chosen from H or an alkyl group in Ci- Ce, ; -P-, -P(O)-, -SiRaRb- with R a and Rb independently representing a -OH, alkyl Ci-Ce or alkoxy Ci-Ce group, said aliphatic chain being substituted or unsubstituted by one or more, in particular one or two, alkyl Ci-Ce, alkoxy Ci-Ce, hydroxyl, nitro, cyano, halogen atom, haloalkyl Ci-Ce group(s),

[0039] • Zi is absent or represents a -CH2- (methylene) group

[0040] • Z2 is absent or represents a -CH2- (methylene) group

[0041] • X independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom,

[0042] • n represents an integer from 0 to 3, preferably from 0 to 2,

[0043] • Y independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom,

[0044] • m represents an integer from 0 to 3, preferably from 0 to 2.

[0045] • Ai represents:

[0046] -a C-C bond or a C=C bond linking the four carbon atoms of the two carboxylic anhydride functions,

[0047] -a saturated, unsaturated, or aromatic carbocycle, optionally bridged, said carbocycle comprising from 4 to 30 carbon atoms, and

[0048] -a saturated, unsaturated, or aromatic heterocycle, optionally bridged, said heterocycle comprising from 4 to 30 carbon atoms, and said carbocycle or heterocycle being substituted or unsubstituted by one or more substituents selected from a Ci-Ce alkyl, hydroxyl, Ci-Ce alkoxy, nitro, cyano, or halogen atom group.

[0049] Advantageously, L1 represents an aliphatic bond or chain of 1 to 6 carbon atoms, in which one or two methylene unit(s) is / are optionally replaced by an arylene, -C(O)-, -O-, -S-, -S(O)-, -S(O)2- group, said aliphatic chain being substituted or unsubstituted by a group preferably selected from a Ci-Ce alkyl, Ci-Ce alkoxy, or Ci-Ce haloalkyl.

[0050] Advantageously, the metal triflate (or trifluoromethylsulfonate) compound is selected from lithium triflate (Li), sodium triflate (Na), potassium triflate (K), magnesium triflate (Mg), calcium triflate (Ca), strontium triflate (Sr), barium triflate (Ba) and mixtures of at least two of these metal triflates.

[0051] Another object of the invention is a crosslinked product based on a crosslinkable composition as defined above. DETAILED DESCRIPTION OF THE INVENTION

[0052] DEFINITIONS

[0053] Unless otherwise indicated, the terms "a" or "an" as used in this description should be interpreted as including the plural, i.e. "one or more" or "at least one" or "one or more" or "at least one".

[0054] For the purposes of the present invention, a range of values ​​designated by the expression "between a and b" represents the range of values ​​from greater than strictly a, to less than strictly b (i.e. excluding the bounds a and b), while any range of values ​​designated by the expression "from a to b" represents the range of values ​​from a to b, i.e. including the strict bounds a and b.

[0055] In this description, "approximately" means that the value in question may be 10% lower or higher, in particular 5%, and especially 1% higher, than the stated value.

[0056] The term "ppm" commonly refers to "parts per million". In the context of this invention, ppm refers to the mass of polyester in glycerol.

[0057] The compounds mentioned in the description can be of fossil origin or bio-based. In the latter case, they may be partially or entirely derived from biomass or obtained from renewable raw materials derived from biomass. Similarly, the compounds mentioned may also come from the recycling of previously used materials; that is, they may be partially or entirely produced through a recycling process, or obtained from raw materials themselves derived from a recycling process. This includes, in particular, monomers, such as glycerol, diacid or carboxylic diester monomers, and cyclic carboxylic polyanhydride.

[0058] In the present invention, a "glycerol polyester" means a "glycerol and diacid or carboxylic diester polyester", that is, a glycerol and diacid carboxylic monomer polyester or a glycerol and diester monomer of a diacid

[0059] OH carboxylic acid. Glycerol is a triol with the following formula:

[0060] In the present invention, a "cyclic polycarboxylic anhydride" is understood to be an organic compound comprising at least two cyclic carboxylic anhydride functional groups. Each functional group is selected from either a carboxylic anhydride or a nitrogen anhydride functional group. A "carboxylic anhydride (nitrogen or cyclic) functional group" is linked to two carbons from the rest of the molecule, adjacent or not, so as to form a ring comprising a carboxylic anhydride or nitrogenous anhydride function. In contrast, a

[0061] "Linear anhydride (nitrogenous or non-nitrogenous) function" means a divalent carboxylic anhydride function (nitrogenous or non-nitrogenous) which is linked to two carbons of the rest of the molecule, but is not included in a ring.

[0062] In the present invention, a "carboxylic anhydride function" corresponds to the formula -C(=O)- OC(=O)-. This function is divalent.

[0063] In the present invention, a "nitrogenous carboxylic anhydride function" corresponds to the formula -C(=O)-OC(=O)-NH. This function is divalent.

[0064] In the present invention, a "cyclic carboxylic anhydride group" means a group comprising a cyclic carboxylic anhydride function (nitrogenous or non-nitrogenous) and further comprising from 3 to 40 carbon atoms. The cyclic anhydride group may be multivalent or monovalent.

[0065] When the group is further substituted, it comprises from 1 to 4, preferably from 1 to 2, substituents. The substituent(s) is / are, independently, preferably an alkyl group in Ci-Ce, an alkoxy group in Ci-Ce, a hydroxyl group, a nitro group, a cyano group, a halogen atom, or a haloalkyl group in Ci-Ce.

[0066] A "linear anhydride group" is understood, for the purposes of this invention, to be a group comprising a linear carboxylic anhydride function (nitrogenous or non-nitrogenous). Unlike a cyclic anhydride group, in a linear carboxylic anhydride group, the divalent carboxylic anhydride function (nitrogenous or non-nitrogenous) is bonded to two carbons of the rest of the molecule, but is not contained within a ring.

[0067] In the present invention, a "monovalent hydrocarbon group" means a monovalent hydrocarbon chain that is saturated (i.e., containing no unsaturation or multiple bonds), unsaturated (i.e., containing at least one double or triple bond, but not aromatic), or aromatic, cyclic or acyclic (linear or branched), comprising from 1 to 40 carbon atoms. A monovalent hydrocarbon group includes, in particular, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, or cycloalkynyl groups, substituted or unsubstituted, in the C1-C40 range. Preferably, a monovalent hydrocarbon group is an alkyl, cycloalkyl, alkenyl, or cycloalkenyl group, substituted or unsubstituted, in the C1-C40 range.

[0068] As used here, a "divalent hydrocarbon group" refers to a saturated, unsaturated, or aromatic divalent hydrocarbon chain, cyclic or acyclic (linear or branched), containing from 1 to 40 carbon atoms. A divalent hydrocarbon group includes, in particular, substituted or unsubstituted, linear or branched, C1-C40 alkanediyl, alkenediyl, or alkynediyl groups. A divalent hydrocarbon group also includes substituted or unsubstituted, C1-C40 cycloalkanediyl, cycloalkenediyl, or cycloalkynediyl groups. A divalent hydrocarbon group also includes a substituted or unsubstituted divalent aromatic group. Preferably, a monovalent hydrocarbon group is an alkanediyl (linear or branched), alkenediyl (linear or branched), cycloalkanediyl, cycloalkenediyl, substituted or unsubstituted, C1-C40 group.In the present invention, a "multivalent hydrocarbon group" means a hydrocarbon chain with a valence of four or more, saturated, unsaturated (i.e. comprising at least one double or possibly one triple C-C bond, but non-aromatic) or aromatic, cyclic or acyclic (linear or branched), comprising from 1 to 40 carbon atoms.

[0069] By "aliphatic" we mean a linear, branched and / or cyclic hydrocarbon group, whether saturated or unsaturated but non-aromatic.

[0070] For the purposes of this invention, the term "alkyl group" refers to a monovalent, saturated, linear or branched hydrocarbon chain comprising from 1 to 40 carbon atoms, preferably from 1 to 10 carbon atoms. Examples include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and hexyl groups.

[0071] For the purposes of this invention, a "cycloalkyl" group is defined as a monovalent cyclic saturated hydrocarbon chain comprising 3 to 40 cyclic carbon atoms. A cycloalkyl may be monocyclic, bicyclic, or polycyclic. Examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl groups. Adamantyl is an example of a polycyclic cycloalkyl.

[0072] For the purposes of this invention, an "alkenyl" group is defined as a monovalent, linear or branched hydrocarbon chain comprising at least one double bond and from 2 to 40 carbon atoms. Examples include ethenyl, propenyl, allyl, butenyl, pentenyl, and hexenyl groups.

[0073] For the purposes of this invention, a "cycloalkenyl" group is defined as a monovalent cyclic hydrocarbon chain comprising 3 to 40 cyclic carbon atoms and at least one cyclic double bond. A cycloalkenyl may be monocyclic, bicyclic, or polycyclic. Examples include cyclobutenyl, cyclopentenyl, cyclohexenyl, and cycloheptenyl. Bicyclo[2.2.2]oct-7-ene is an example of a polycyclic cycloalkenyl.

[0074] For the purposes of this invention, an "alkynyl" group is defined as a monovalent, linear or branched hydrocarbon chain comprising at least one triple bond and from 2 to 40 carbon atoms. Examples include ethynyl, propynyl, butynyl, pentynyl, and hexynyl groups.

[0075] For the purposes of this invention, a "cycloalkynyl group" is defined as a monovalent cyclic hydrocarbon chain comprising 5 to 40, preferably 7 to 40, cyclic carbon atoms and at least one triple cyclic bond. A cycloalkynyl group may be monocyclic, bicyclic, or polycyclic. The cycloheptynyl group is an example. For the purposes of this invention, an "aromatic group" is defined as an aromatic hydrocarbon group comprising preferably 6 to 40 carbon atoms and one or more fused rings. Examples of monovalent aromatic groups include phenyl, naphthyl, or pyrene, advantageously phenyl. Examples of divalent aromatic groups include phenylene, naphthylene, or pyrenylene, advantageously pyrenylene.

[0076] For the purposes of this invention, an "alkanediyl" group is defined as a linear or branched acyclic divalent hydrocarbon chain comprising 1 to 40 carbon atoms, such as, for example, a methylene, ethanediyl, propanediyl, butanediyl, pentanediyl, or hexanediyl group.

[0077] For the purposes of this invention, the term "cycloalkanediyl group" means a saturated divalent cyclic hydrocarbon group comprising 3 to 40 cyclic carbon atoms, such as, for example, a cyclobutylene, cyclohexylene or cyclopentylene group.

[0078] For the purposes of this invention, an "alkeniyl" group is defined as a linear or branched acyclic divalent hydrocarbon chain comprising 2 to 40 carbon atoms and at least one double bond, such as, for example, a vinylene (ethenylene) or propenylene group.

[0079] For the purposes of this invention, a "cycloalkeniyl" group is defined as a linear or branched cyclic divalent hydrocarbon chain comprising 3 to 40, preferably 4 to 40 or even 5 to 40 carbon atoms and at least one double bond, such as, for example, a cyclopentenylene group.

[0080] For the purposes of this invention, an "alkynediyl" group is defined as a divalent, linear or branched, acyclic hydrocarbon chain comprising 2 to 40 carbon atoms and at least one triple bond.

[0081] For the purposes of this invention, a "cycloalkyndiyl" group is defined as a monovalent cyclic hydrocarbon chain comprising 5 to 40, preferably 7 to 40 or even 8 to 40, cyclic carbon atoms and at least one cyclic triple bond. A cycloalkyndiyl group may be monocyclic, bicyclic, or polycyclic.

[0082] For the purposes of this invention, an "alkoxy Ci-Ce group" is defined as an alkyl Ci-Ce group, as defined above, linked to the rest of the molecule via an oxygen atom. Examples include methoxy, ethoxy, n-propoxy, / so-propoxy, n-butoxy, sec-butoxy, t-butoxy, n-pentoxy, and n-hexoxy.

[0083] For the purposes of this invention, "halogen atom" or "halogen" means fluorine, chlorine, bromine and iodine atoms, preferably fluorine and chlorine atoms.

[0084] For the purposes of this invention, a "Ci-Ce haloalkyl group" is defined as a Ci-Ce alkyl group, as defined above, in which one or more hydrogen atoms are replaced by a halogen atom, in particular a chlorine, bromine, iodine, or fluorine atom, preferably a fluorine atom. The trifluoromethyl (-CF3) group is an example.

[0085] The hydroxy group is the -OH group. The cyano group is the -CN group. The nitro group is the -NO2 group.

[0086] A "carbocycle comprising 4 to 30 carbon atoms" is understood to be a cyclic (monovalent) hydrocarbon group comprising 4 to 30 carbon atoms. A carbocycle can be monocyclic or polycyclic, optionally bridged (including bridged and / or fused rings). When the carbocycle is polycyclic, it comprises at least 2, advantageously 2 or 3, fused or bridged rings. The carbocycle can be saturated (i.e., containing no unsaturation or multiple bonds), unsaturated (i.e., containing at least one double bond or possibly one triple bond, without being aromatic), or aromatic. When the carbocycle is aromatic, it is referred to as an "aryl" group.

[0087] For the purposes of this invention, a "heterocycle comprising 4 to 30 carbon atoms" means a (monovalent) ring of 4 to 30 carbon atoms, saturated, unsaturated, or aromatic, monocyclic or polycyclic, optionally bridged (including bridged and / or bonded rings), of which one or more, advantageously 1 to 4, and more advantageously 1 or 2, atoms of the ring are heteroatoms, such as, for example, sulfur, nitrogen, or oxygen atoms, the other cyclic atoms being carbon atoms. Examples of saturated or unsaturated heterocycles include: pyrrolidine, piperidine, piperazine, morpholine, pyrazolidinyl, imidazolidine, azepane, thiazolidine, isothiazolidine, oxazocane, thiazepane, and benzimidazolone.

[0088] An "aromatic heterocycle," also called a heteroaryl (monovalent) group, comprises 5 to 10 ring atoms, one or more of which are heteroatoms, advantageously 1 to 4 and even more advantageously 1 or 2, such as sulfur, nitrogen, or oxygen atoms, the other ring atoms being carbon atoms. Examples of heteroaryl groups are furan, thiophene, pyrrole, pyridine, imidazole, triazolyl, tetrazole, oxazole, isoxazole, thiazole, isothiazole, pyrazole, oxadiazole, thiadiazole, pyridazine, pyrimidine, pyrazine, triazine, quinole, isoquinole, quinoxal, and indole.

[0089] An "arylene group" is understood to be a divalent aromatic hydrocarbon group, preferably comprising 6 to 10 carbon atoms, and including one or more attached rings, such as a phenyl or naphthyl group. Advantageously, this refers to phenylene.

[0090] A "heteroarylene group" is understood to be a divalent aromatic heterocycle comprising 5 to 10 ring atoms, one or more of which are heteroatoms, advantageously 1 to 4 and even more advantageously 1 or 2, such as, for example, sulfur, nitrogen, or oxygen atoms, the other ring atoms being carbon atoms. Pyridinylene is an example. According to the invention, an "orthophthalic group" is understood to be a group with the formula: preferably formula group being linked to the rest of the polyanhydride molecule by the i bond or a divalent group of formula: This group is linked to the rest of the polyanhydride molecule by the i bond on one side, and by the l bond on the other. The orthophthalic group can be substituted or unsubstituted.

[0091] In the present invention, a "succinic group" is understood to be a monovalent group of formula a group being linked to the rest of the polyanhydride molecule by the i bond and which may be substituted or unsubstituted, or a divalent group of formula:

[0092] O

[0093] ° , this group being linked to the rest of the polyanhydride molecule by the i bond

[0094] _ J on the one hand, and by the l bond on the other hand. A succinic group is distinct from an orthophthalic group, so that in general, a divalent succinic group is not attached to a phenyl group.

[0095] In the present invention, a "maleic group" is understood to be a monovalent group of O formula: ° , this group being linked to the rest of the polyanhydride molecule by the bond 1 and which can be substituted or unsubstituted, or of a divalent group of formula:

[0096] O

[0097] ° l, this group being then linked to the rest of the polyanhydride molecule by the -J-I bond on one side, and by the l bond on the other. A maleic group is distinct from an orthophthalic group, so that in general, a divalent maleic cyclic anhydride group is not attached to a phenyl group.

[0098] In the present invention, a "homo-phthalic group" is understood to mean a group of formula: remainder of the polyanhydride molecule by the i bond or of a divalent group of formula: The group is linked to the rest of the polyanhydride molecule by the i bond on one side, and by the l bond on the other. The homophthalic group can be substituted or unsubstituted.

[0099] The alkali metals and alkaline earth metals here refer to the metals in the first two columns of the Periodic Table of Elements.

[0100] By "room temperature" we mean here a temperature generally within a range of 15°C to 40°C, preferably from 20°C to 30°C, in particular around 25°C.

[0101] / . Process for preparing a crosslinked polyester

[0102] The invention relates to a process for preparing a crosslinked glycerol polyester, comprising a step of crosslinking a glycerol polyester with a cyclic carboxylic polyanhydride A in the presence of a metal triflate (or trifluoromethylsulfonate) compound, the cyclic carboxylic polyanhydride A comprising at least two cyclic carboxylic anhydride groups, the cyclic carboxylic polyanhydride A not comprising linear carboxylic anhydride functions, and the metal of the metal triflate (or trifluoromethylsulfonate) compound being selected from the alkali and alkaline earth metals.

[0103] Polyester of the starting glycerol (i.e., before crosslinking)

[0104] The starting glycerol polyester can be a polyester of glycerol and a dicarboxylic acid monomer or a polyester of glycerol and a diester monomer of a dicarboxylic acid.

[0105] The dicarboxylic acid monomer or the diester monomer of a dicarboxylic acid is aliphatic.

[0106] The carboxylic diacid or diester preferably comprises from 3 to 36 carbon atoms.

[0107] According to preferred embodiments of the invention, the diacid monomer or the carboxylic diester monomer is aliphatic, in particular saturated, especially linear or branched, and comprises from 3 to 36 carbon atoms. Preferably, it is a (C3-C3o)alkanediyldiacid carboxylic acid, more preferably a (C8-Cis)alkanediyldiacid carboxylic acid, or one of its diesters. A (C) group x -C y )alkanediyl is a divalent, saturated, linear or branched hydrocarbon group, comprising x to y carbon atoms.

[0108] Advantageously, the dicarboxylic acid monomer or the carboxylic diester monomer corresponds to the general formula R'OOC-(CH2) P -COOR', in which p represents an integer from 1 to 30, preferably a number from 1 to 10, and R' represents H (hydrogen atom) or each R' represents, independently of each other, a linear or branched alkyl, in C1-C10, preferably in C1-C4, preferably also methyl or ethyl.

[0109] Depending on the variant, the monomer is a dicarboxylic acid corresponding to the general formula [HOOC-(CH2) P -COOH] in which p is a number from 1 to 30, preferably a number from 1 to 10.

[0110] In particular, according to these variants, the dicarboxylic acid monomer can be chosen from malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, hexadecanedioic acid, octadecanedioic acid and a mixture of two or more of these dicarboxylic acids.

[0111] Preferably, the dicarboxylic acid monomer can be selected from malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and a mixture of two or more of these dicarboxylic acids. According to embodiments of the invention, the dicarboxylic acid monomer can be a mixture of at least two dicarboxylic acids. Preferably, the dicarboxylic acid monomer comprises sebacic acid.

[0112] Preferably, the dicarboxylic acid monomer comprises or consists of sebacic acid. According to preferred embodiments of the invention, the dicarboxylic acid monomer and glycerol are the only monomers during polycondensation.

[0113] According to other variants, the monomer is a diester of a dicarboxylic acid corresponding to the general formula R"OOC-(CH2)n-COOR", in which n represents an integer from 1 to 30, preferably a number from 1 to 10, and each R" represents, independently of each other, a linear or branched alkyl, in C1-C10, preferably in C1-C4, preferably also methyl or ethyl.

[0114] In particular, according to these variants of the invention, the alkyl diester monomer of dicarboxylic acid can be chosen from the alkyl diesters corresponding to malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid or a mixture of two or more of these dicarboxylic acid diesters, more preferably the dicarboxylic acid diester is chosen from the group consisting of dimethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, dimethyl pimelate, dimethyl suberate, dimethyl azelate, dimethyl sebacate, and mixtures thereof. According to variations of the invention, the dicarboxylic acid diester monomer may be a mixture of at least two different dicarboxylic acid diesters. Preferably, the dicarboxylic acid diester monomer comprises dimethyl sebacate.

[0115] According to preferred embodiments of the invention, the dicarboxylic acid diester monomer is dimethyl sebacate.

[0116] According to preferred embodiments of the invention, the dicarboxylic acid diester monomer and glycerol are the only monomers. Most preferably, the dimethyl sebacate monomer and glycerol are the only monomers.

[0117] Advantageously, the molar ratio of glycerol / diacid or carboxylic diester monomer varies from 1 / 2 to 10 / 1, notably from 1 / 1 to 5 / 1, preferably from 1 / 1 to 2 / 1.

[0118] Glycerol polyester and a diacid or carboxylic diester monomer (hereinafter referred to as non-crosslinked polyester) advantageously exhibits one or more of the following characteristics:

[0119] - an average number molar mass (Mn) of the non-crosslinked polyester greater than or equal to 1500 g / mol, preferably greater than or equal to 2000 g / mol;

[0120] - an average number molar mass (Mn) of the non-crosslinked polyester less than or equal to 10,000 g / mol, preferably less than or equal to 7,000 g / mol, preferably less than or equal to 5,000 g / mol;

[0121] - a polydispersity Ip (Mw / Mn) of the non-crosslinked polyester of less than 10, preferably less than or equal to 8.

[0122] The polyester of glycerol and a dicarboxylic acid monomer can be obtained, in particular, by implementing the processes described in EP3149067 and EP1448656. The polyester of glycerol and a carboxylic diester monomer can be obtained, in particular, by implementing the processes described in FR2315383.

[0123] The number-average molar mass (Mn), the mass-average molar mass (Mw), and the dispersity (also called polydispersity and denoted D, which is the Mw / Mn ratio) can be measured in a known manner by size-exclusion chromatography (SEC) analysis, notably as described later in the examples. Cyclic polycarboxylic anhydride

[0124] Preferably, the cyclic carboxylic polyanhydride comprises two cyclic carboxylic anhydride functions, that is to say, it is a cyclic bis-carboxylic anhydride.

[0125] In the present invention, the cyclic carboxylic anhydride groups of the cyclic carboxylic polyanhydride A are preferably independently selected from orthophthalic, succinic, maleic and homophthalic groups.

[0126] The cyclic carboxylic polyanhydride may comprise identical or different cyclic carboxylic anhydride groups. Preferably, the cyclic carboxylic anhydride groups of the cyclic carboxylic polyanhydride are identical.

[0127] Advantageously, the cyclic carboxylic anhydride groups are independent of the orthophthalic, succinic, or maleic groups.

[0128] Advantageously, the cyclic carboxylic anhydride groups of the cyclic polycarboxylic anhydride A are joined or linked to each other by at least one covalent bond or carried by a spacer group L,

[0129] The representative -O- ; -S- ; -S(O)- ; -S(O)2- ; -NR n - with R nchosen from H or an alkyl group in Ci-Ce; -C(O)-; or a multivalent hydrocarbon group comprising 1 to 40 carbon atoms, cyclic or acyclic, saturated, unsaturated or aromatic, and which may contain one or more heteroatoms of O, S, Cl, Br, F, N, P or Si, and

[0130] L being devoid of linear anhydride groups.

[0131] L is chemically stable. Thus, an oxygen atom cannot be bonded to another oxygen atom and a nitrogen atom cannot be bonded to another nitrogen atom. Therefore, L is preferably devoid of peroxide (-OO-) or hydrazine (-NH-NH- or -NH-N(alkyl Ci-Ce)- or -N(alkyl Ci-Ce)-N(alkyl Ci-Ce) groups). Similarly, an ester (C(O)O) function cannot be bonded to another ester function. Furthermore, L is advantageously devoid of readily hydrolyzable groups. In particular, L is devoid of linear anhydride groups, especially linear (divalent) carboxylic anhydride groups of formula -OC(=O)-O-. Advantageously, L is also devoid of ester (-OC(=O)-) or amide (-OC(=O)-NR-) functions, with R representing H or a substituent such as a hydrocarbon chain.

[0132] The valence of the L group is even (since L carries cyclic carboxylic anhydride groups, which are divalent), and generally of 4 or 6, preferably of 4.

[0133] Advantageously, L represents a multivalent hydrocarbon group comprising 1 to 40 carbon atoms, cyclic or acyclic, saturated, unsaturated or aromatic, and capable of containing one or more heteroatoms of O, S, Cl, Br, F, N, P or Si, which means that L then represents a cyclic or acyclic, saturated, unsaturated or aromatic multivalent hydrocarbon group, comprising 1 to 40 carbon atoms, in which one or more carbon atoms can be replaced by one or more heteroatoms of O, S, Cl, Br, F, N, P or Si or by a -C(O)- group.

[0134] Phosphorus (P), sulfur (S), nitrogen (N) and silicon (Si) atoms can be in oxidized form (notably P(O), SO, SO2), and / or substituted - notably by one or alkyl group in C1-C6 - depending on the valence of the atom.

[0135] Most advantageously, L represents a cyclic or acyclic, saturated, unsaturated or aromatic multivalent hydrocarbon group, comprising 1 to 40 carbon atoms, in which one or more carbon atoms can be replaced by one or more oxygen (O) atoms or a -C(O)- or -S(O)2- group, and optionally by one or more heteroatoms of Cl, Br, F, N, P or Si.

[0136] According to particular embodiments, L represents a multivalent acyclic hydrocarbon group, saturated or unsaturated, comprising 1 to 10 carbon atoms, in which one or more carbon atoms can be replaced by one or more oxygen (O) atoms or a -C(O)-, -S-, -S(O)-, -S(O)2- group, and optionally by one or more heteroatoms of Cl, Br, F, N, P or Si.

[0137] In other specific embodiments, L represents a saturated, unsaturated, or aromatic cyclic multivalent hydrocarbon group comprising 3 to 40 carbon atoms, wherein one or more carbon atoms may be replaced by one or more oxygen atoms (O) or a -C(O)- group, and optionally by one or more heteroatoms of S, Cl, Br, F, N, P, or Si, preferably a heteroatom of Cl, Br, or F. In these embodiments, the multivalent group may be monocyclic, bicyclic, or polycyclic. When L is bicyclic or polycyclic, it advantageously comprises one or more fused rings.

[0138] In particular embodiments, the cyclic carboxylic polyanhydride comprises or is made up of a compound of formula (I) or preferably of formula (la): in which

[0139] • L1 represents a bond; -O- ; -S- ; -S(O)- ; -S(O)2- ; -NR n R n - with Rn and R n 'independently chosen from H or an alkyl group in Ci-Ce; -C(O)-; or an aliphatic chain of 1 to 30 carbon atoms, in which 1 to 6 methylene unit(s) (preferably non-adjacent) is / are optionally replaced by an arylene group; a heteroarylene group; -C(O)-; -O-; -S-; -S(O)-; -S(O)2-; -NR m - with R m chosen from H or an alkyl group in Ci-Ce; -P-; -P(O)-; -SiR a Rb- with R a and Rb independently representing a -OH, Ci-Ce alkyl or Ci-Ce alkoxy group, said aliphatic chain being substituted or unsubstituted by one or more, in particular one or two, Ci-Ce alkyl, Ci-Ce alkoxy, hydroxyl, nitro, cyano, halogen atom, Ci-Ce haloalkyl group,

[0140] • Zi is absent or represents a -CH2- (methylene) group

[0141] • Z2 is absent or represents a -CH2- (methylene) group

[0142] • X independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom,

[0143] • n represents an integer from 0 to 3, preferably from 0 to 2,

[0144] • Y independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom,

[0145] • m represents an integer between 0 and 3, preferably between 0 and 2.

[0146] Preferably, Z1 and Z2 are identical. Advantageously, Z1 and Z2 both represent a link.

[0147] Preferably, L1 represents a bond of -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, or an aliphatic chain of 1 to 30 carbon atoms, in which 1 to 6 methylene unit(s) (preferably non-adjacent) is / are optionally replaced by an arylene group, a heteroarylene group, -C(O)-, -O-, -S-, -S(O)-, -S(O)2-, or -NR m - with R m chosen from H or a Ci-Ce alkyl group, said aliphatic chain being substituted or unsubstituted by one or more, in particular one or two, Ci-Ce alkyl, Ci-Ce alkoxy, hydroxyl, nitro, cyano, halogen atom, or Ci-Ce haloalkyl group.

[0148] Preferably, L1 represents a bond of -O-, -S(O)2-, -C(O)-, or an aliphatic chain of 1 to 20 carbon atoms, wherein 1 to 4 (preferably 1 to 2) methylene unit(s) (preferably non-adjacent) is / are optionally replaced by an arylene, -C(O)-, -O-, -S-, -S(O)-, or -S(O)2- group, said aliphatic chain being substituted or unsubstituted by one or more, in particular one or two, substituents preferably selected from a Ci-Ce alkyl, Ci-Ce alkoxy, or Ci-Ce haloalkyl group. In particular, L1 may comprise one or two divalent aromatic groups, such as phenylenes.

[0149] In particular, L1 represents a G1-G2-G3 radical where G1 and G3 are independently chosen from O, -S(O)2, -C(O)-; G2 is a divalent hydrocarbon group of 4 to 15 carbon atoms that may include one or two divalent aromatic groups, such as phenylenes, and may be substituted by one or more, in particular one or two, preferably chosen from a Ci-Ce alkyl, Ci-Ce alkoxy, or Ci-Ce haloalkyl group. Advantageously, Li represents a -O-, -S(O)2-, or -C(O)- bond. or an aliphatic chain of 1 to 10 carbon atoms, in particular of 1 to 6 carbon atoms, wherein 1 to 2 methylene unit(s) (preferably non-adjacent) is / are optionally replaced by an arylene, -C(O)-, -O-, -S-, -S(O)-, -S(O)2- group, said aliphatic chain being substituted or unsubstituted by one or more, in particular one or two group(s) preferably selected from a Ci-Ce alkyl, Ci-Ce alkoxy, or Ci-Ce haloalkyl.

[0150] Advantageously, Li represents a bond ; -O- ; -S(O)2- ; -C(O) ; or an aliphatic chain of 1 to 10 carbon atoms, in particular of 1 to 6 carbon atoms, in which 1 to 2 methylene unit(s) (preferably non-adjacent) is / are optionally replaced by an arylene, -C(O)-, -O- group, said aliphatic chain being substituted or unsubstituted by one or more, in particular one or two, Ci-Ce alkyl, Ci-Ce alkoxy, hydroxyl, nitro, cyano, halogen atom, Ci-Ce haloalkyl group, typically substituted or unsubstituted by a Ci-Ce alkyl, Ci-Ce alkoxy, halogen atom, or Ci-Ce haloalkyl group.

[0151] In particular, X can independently represent an alkyl group in Ci-Ce, hydroxyl, or a halogen atom.

[0152] Advantageously, n represents 0 or 1.

[0153] Preferably, Y can independently represent an alkyl group in Ci-Ce, hydroxyl, or a halogen atom. Advantageously, m represents 0 or 1.

[0154] According to particular variants, n and m independently represent 0 or 1, and X and Y independently represent a Ci-Ce alkyl group, hydroxyl, or a halogen atom.

[0155] In other particular embodiments, the cyclic carboxylic polyanhydride comprises or is made up of a compound of formula (II) or preferably of formula (Ha): in which

[0156] Zi is absent or represents a -CH2- (methylene) group

[0157] Z2 is absent or represents a -CH2- (methylene) group

[0158] Ai represents: o a CC bond or a C=C bond linking the four carbon atoms of the two carboxylic anhydride functions, o a saturated, unsaturated or aromatic carbocycle, said carbocycle comprising from 4 to 30 carbon atoms, and o a saturated, unsaturated or aromatic heterocycle, said heterocycle comprising from 4 to 30 carbon atoms, and said carbocycle or heterocycle being substituted or unsubstituted by one or more substituents, including a Ci-Ce alkyl group, a Ci-Ce haloalkyl group, a hydroxyl group, a Ci-Ce alkoxy group, a nitro group, a cyano group, or a halogen atom.

[0159] In some variations, Ai represents a polycyclic carbocycle or heterocycle of 10 to 30 members. In these variations, the polycyclic group may include fused rings. Advantageously, Ai represents a polycyclic aromatic carbocycle or heterocycle of 10 to 30 members, comprising two or more fused rings. It may, in particular, be a naphthalene group.

[0160] Depending on the variant, Ai represents an aromatic carbocycle comprising 6 to 10 carbon atoms, such as a phenyl or a naphthalene.

[0161] According to other variants, Ai represents a saturated carbocycle (monocyclic or bicyclic) comprising from 4 to 10, preferably from 4 to 6, carbon atoms. Preferably, it is a saturated monocyclic carbocycle comprising from 4 to 6 carbon atoms.

[0162] Depending on variants, at least one of at least one cyclic carboxylic polyanhydride comprises or is made up of a compound of formula (III): in which it represents a simple or double DC connection,

[0163] L2 and L3 taken together with the carbon atoms to which they are bonded represent a saturated, unsaturated or aromatic carbocycle or heterocycle, optionally bridged, said carbocycle or heterocycle comprising from 4 to 30 carbon atoms, and said carbocycle or heterocycle being substituted or unsubstituted by one or more substituents selected from a Ci-Ce alkyl, hydroxyl, Ci-Ce alkoxy, nitro, cyano, or halogen atom group.

[0164] Preferably, L2 and L3 taken together with the carbon atoms to which they are bonded represent a saturated, unsaturated or aromatic carbocycle, optionally bridged, said carbocycle comprising from 4 to 10 carbon atoms, and said carbocycle being substituted or unsubstituted by one or more (in particular 1 or 2) substituents selected from a Ci-Ce alkyl group or a halogen atom.

[0165] Advantageously, l_2 and L3 taken together with the carbon atoms to which they are bonded represent:

[0166] • a saturated or unsaturated carbocycle, optionally bridged, comprising 4 to 8 carbon atoms, substituted or unsubstituted by one or more (in particular 1 or 2) substituents selected from a Ci-Ce alkyl group, halogen atom, or

[0167] • an aromatic carbocycle of 6 to 10 carbon atoms, substituted or unsubstituted by one or more (in particular 1 or 2) substituents chosen from an alkyl group in Ci-Ce, halogen atom.

[0168] In particular, L2 and L3 taken together with the carbon atoms to which they are bonded can represent a cyclobutyl, cyclopentyl, cyclohexyl, bicyclo[2.2.2]oct-2-enyl, or phenyl.

[0169] Depending on the variant, the cyclic carboxylic polyanhydride comprises or is made up of a compound of formula (IV):

[0170] ;i in which •' represents a single or double DC connection.

[0171] In preferred embodiments, the cyclic carboxylic polyanhydride is chosen from the group consisting of:

[0172] Table 1 and a mixture of these.

[0173] Preferably, the cyclic carboxylic polyanhydride is BDTA, BPADA, BPDA and ODPA, or a mixture of these.

[0174] Cyclic carboxylic polyanhydrides, particularly the cyclic bis-carboxylic anhydrides of the invention, are well known to those skilled in the art (see, in particular, US 7,425,650). They can be obtained by condensation of the corresponding tetracarboxylic acids, and some are commercially available. More specifically, for the synthesis of cyclic carboxylic polyanhydrides comprising the following groups:

[0175] Homophthalic: the syntheses described in US 6,797,838 may be used or adapted;

[0176] Metal triflate or trifluoromethylsulfonate

[0177] The metal triflate or trifluoromethylsulfonate is chosen from triflates with the generic formula: [CF3-S(=O)2-O1n, [M n+ ]

[0178] Or :

[0179] [M n+ ] corresponds to the cation of a metal raised to oxidation state I or II and chosen from among the alkali metals (M + ) and the alkaline earth metals (M 2+ Among the alkali metals, lithium (Li), sodium (Na), and potassium (K) are preferred. Among the alkaline earth metals, magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba) are preferred.

[0180] CF3S(=O)2-O" is the triflate anion or trifluoromethylsulfonate.

[0181] According to the invention, the metal triflate (or trifluoromethylsulfonate) compound can be a mixture of at least two metal triflate (or trifluoromethylsulfonate) compounds, the metal being chosen from the alkali and alkaline earth metals.

[0182] According to particular embodiments of the invention, the metal triflate or trifluoromethylsulfonate is lithium triflate, sodium triflate, potassium triflate, magnesium triflate, calcium triflate, strontium triflate, barium triflate, or a mixture of at least two of these metal triflates. Crosslinking

[0183] Advantageously, the crosslinking step comprises the following steps: a) contacting 100 parts by weight of at least one glycerol polyester with 0.1 to 200 parts by weight of at least one cyclic carboxylic polyanhydride as defined herein, to obtain a crosslinking precursor mixture, in the presence of 0.0001 wt% (0.1 ppm) to 1 wt% (10000 ppm) of a metal triflate (or trifluoromethylsulfonate) relative to the mass of glycerol polyester; b) pressurizing the mixture obtained in step a) to a target temperature T c between 60°C and 175°C, and maintenance (at temperature T c and under pressure) for a heating time under pressure sufficient to obtain a crosslinked polyester, c) cooling and recovery of the crosslinked polyester.

[0184] At least one glycerol polyester, at least one cyclic carboxylic polyanhydride and the metal triflate are as defined above.

[0185] Typically, step a) includes contacting 100 parts by weight of at least one polyester of glycerol, with 10 to 100, in particular 15 to 90, parts by weight of at least one cyclic carboxylic polyanhydride.

[0186] Typically, the amount of metal triflate (or trifluoromethylsulfonate) compound used in step a) varies in a range from 0.05 wt% (500 ppm) to 1 wt% (10000 ppm) relative to the mass of polyester glycerol.

[0187] Typically, step a) includes contacting 100 parts by weight of at least one polyester of glycerol, with 10 to 100, in particular 15 to 90, parts by weight of at least one cyclic carboxylic polyanhydride in the presence of 0.1 wt% (1000ppm) to 0.9 wt% (9000ppm) of a metal triflate (or trifluoromethylsulfonate) compound relative to the mass of polyester of glycerol.

[0188] Preferably, step a) of contacting is carried out in the absence of solvent or diluent.

[0189] According to one embodiment of the invention, step a) of contacting is carried out in the absence of any other additive.

[0190] According to another embodiment of the invention, at least one molecule or compound of interest can be added at this stage of the process during step a).

[0191] Step a) comprises a mixture of at least one glycerol polyester and at least one cyclic carboxylic polyanhydride, preferably at a temperature T a allowing the fusion of the glycerol polyester, and preferably a homogeneous dispersion of the cyclic carboxylic polyanhydride. Thus, T ais typically between 20°C and 100°C, particularly between 30°C and 80°C. Step a) involves the use of a metal triflate or trifluoromethylsulfonate as a catalyst. This can be introduced directly into the mixture in solid form. To promote homogenization, stirring can be carried out in a known manner. Thus, step a) is typically performed with stirring.

[0192] According to particular variants of the invention, the contact is made by introducing the cyclic carboxylic polyanhydride in solid form and the metal triflate or trifluoromethylsulfonate in solid form.

[0193] Advantageously, in step b), a platen press will be used, the plates of which have been preheated to temperature T c .

[0194] In step b), the temperature T cis typically between 60°C and 175°C, preferably between 80°C and 175°C, preferably still between 100°C and 160°C.

[0195] Advantageously, the overpressure applied by the press (relative to atmospheric pressure) in the heating step b) varies from 50 to 600 kPa (equivalent to 0.5 to 6 bar), in particular from 1 to 4 bar.

[0196] The heating time is determined by the duration between the moment the press is closed and the moment it is opened.

[0197] Generally, the heating time t C h is between 10 and 2000 min.

[0198] During step c), the crosslinked polyester is typically cooled and recovered at room temperature and atmospheric pressure.

[0199] II. Crosslinking Composition

[0200] The present invention also relates to a crosslinking composition, comprising: o 100 parts by weight of at least one polyester of glycerol, o from 0.1 to 200 parts by weight of at least one cyclic carboxylic polyanhydride as defined above, o from 0.0001 wt% (0.1 ppm) to 1 wt% (1000 ppm) relative to the mass of polyester of glycerol, of a metal triflate or trifluoromethylsulfonate.

[0201] Preferably, the composition comprises from 10 to 100, in particular from 15 to 90, parts by weight of at least one cyclic carboxylic polyanhydride.

[0202] Preferably the composition comprises 0.05 wt% (500 ppm) to 1 wt% (10000 ppm) of metal triflate or trifluoromethylsulfonate, preferably also 0.1 wt% (1000 ppm) to 0.9 wt% (9000 ppm).

[0203] Glycerol polyester, as well as cyclic carboxylic polyanhydride and metal triflate or trifluoromethylsulfonate, may be as defined above.

[0204] III. Crosslinked product

[0205] The invention also relates to the crosslinked product based on a composition such as that described above, obtained after the crosslinking described above. EXAMPLES

[0206] The following examples are given for illustrative purposes only, but should in no way be considered as limiting the present invention.

[0207] 1. Materials and methods

[0208] 1.1. Characteristics of the starting products

[0209] Glycerol and sebaceous acid polyester

[0210] Table 2

[0211] Procedure for the synthesis of the starting glycerol and sebacic acid polyester: In a 10 L double-walled stainless steel reactor fitted with an instrumented distillation column configured for total reflux and a condenser connected to a distillate recovery vessel, glycerol (2.8 kg, 1 molar equivalent) is mixed with water (0.81 kg) at 40 °C under a nitrogen flow (0.5 L / min). Gentle stirring is applied (20 rpm) for 5 min. After the glycerol has dissolved, sebacic acid (6.15 kg, 1 molar equivalent) is added to the aqueous mixture in the reactor. Finally, the remaining water (0.81 kg) is added. The reactor vessel is then gradually heated, following a progressive temperature ramp with intermediate stages, until reaching a shell temperature of 170 °C after 5 hours, corresponding to an ambient temperature of 162 °C, measured using a immersion probe.Stirring is increased to 80 rpm when the temperature of the medium exceeds 90°C. The medium is left under reflux at the beginning of the test. When the vapor temperature at the top of the distillation column reaches 98°C, and after an equilibration time of 15 min, the column configuration is switched to total draw-off to selectively recover the water produced during the reaction.

[0212] The esterification of the medium is carried out over a total period of 21 hours, starting from the moment the distillation begins, approximately 30 minutes after the introduction of the reagents. The water distilled during the test is collected in a dedicated insulated recovery container.

[0213] Next, a vacuum system is connected to the distillation condenser, and a pressure lower than atmospheric pressure is applied to the reactor contents. The pressure is reduced slowly and in steps (approximately 10 to 15% per step) over about 30 minutes until a target value of less than 30 mbar is reached. The temperature setpoint is 130 °C.

[0214] Once the pressure in the reaction vessel stabilizes at 28 mbar, the medium is allowed to react for 2 hours, then the temperature setpoint is increased to 140 °C for an additional 7 hours. During this polycondensation step, the stirring speed is maintained at 80 rpm.

[0215] The PGS produced is transferred from the reactor vessel to a container and allowed to cool to room temperature. The product is then transferred to a freezer for storage, where it is frozen for at least approximately 24 hours before analysis.

[0216] cyclic carboxylic polyanhydride

[0217] Table 3

[0218] 1.2. Measurement Methods

[0219] Measurement of crosslinking kinetics:

[0220] The crosslinking kinetics were conducted using an MGR rheometer from ANTON PAAR. The measurements consisted of monitoring the evolution of the elastic modulus of the compositions at 140°C or 120°C, depending on the composition, with 1% strain and a frequency of 1 Hz. The crosslinking times of the different compositions were measured until the elastic modulus reached a value of 1 MPa.

[0221] Macrostructure analysis of PGS polymers: SEC RI

[0222] The SEC (Size Exclusion Chromatography) technique separates macromolecules in solution according to their size using columns filled with a porous gel. Macromolecules are separated according to their hydrodynamic volume, with the largest being eluted first.

[0223] While not an absolute method, SEC allows us to understand the molar mass distribution of a polymer. From commercial standard products, the various number-average molar masses (Mn) and weight-average molar masses (Mw) can be determined, and the polydispersity index (Ip = Mw / Mn), also called "dispersity," can be calculated.

[0224] Size exclusion chromatography analyses were performed using a Viscotek instrument (Malvern Instruments) equipped with 4 columns, a guard column, and 3 detectors (differential refractometer and viscometer, and light scattering). The samples were dissolved at a concentration of 1 mg / L. 1 in unstabilized THF, then shaken for 2 hours before being injected. Tl

[0225] 1 mL of a sample solution was filtered through a 0.45 µm PTFE membrane. 100 µL of this solution was eluted in THF using a flow rate of 1 mL / min. 1 at a temperature of 35 °C. OmniSEC software was used for data acquisition and analysis.

[0226] The technique used is size exclusion chromatography (SEC) with a column set optimized for the separation of low-mass species.

[0227] The analytical conditions used in the study are described in the following table:

[0228] THF eluent without antioxidant

[0229] Injection volume 100 pL

[0230] Temperature 35 °C

[0231] Waters RI Detector

[0232] Mobile phase flow rate 1 mL / min

[0233] Columns 2 Mixed D + 2 Mixed E

[0234] The calibration used for Moore's calculation is a PS calibration, covering a range from 2,520,000 to 162 g.mol' 1 .

[0235] The calibration used is a mixed low and medium weight PSS calibration from PSS Standards. The mass range extends from 162 to 66,000 g / mol. -1 Calibration allows the determination of Mn values ​​(g.mol). -1 ), Mw (g. mol' 1 ), D (Mw / Mn) in PS equivalent.

[0236] 2. Results

[0237] 2.1. Tested Formulations

[0238] The compositions studied are presented below. The contents are expressed as % mass for poly (glycerol sebacate) and bis-anhydride compound and in ppm (parts per million) relative to the mass of polyester of glycerol for the triflate (or trifluoromethylsulfonate) metal compound.

[0239] The reference mixtures T1 and T2 for each comparison are those comprising a high molecular weight poly(glycerol sebacate) polymer and a cyclic carboxylic polyanhydride (i.e., crosslinked in the absence of metal triflate or trifluoromethylsulfonate). The preparation protocol used is the same as that described in section 2.2, but in the absence of metal triflate or trifluoromethylsulfonate. • Sodium, potassium, calcium, and barium triflates with BTDA

[0240] Table 4

[0241] • Sodium, Potassium, Calcium, Barium Triflate with BPADA Table 5

[0242] 2.2. Protocol for the preparation of crosslinked polyesters

[0243] The mixtures are made by putting the poly (glycerol sebacate) in contact with the other ingredients in a plastic pot and mechanically agitating it in a planetary mixer (rotation of the basket plus counter-rotation of the pot).

[0244] Step a) Preparation of compositions

[0245] • Place a 100mL beaker on a hot plate equipped with a PT100 probe to control the temperature.

[0246] • Introduce the poly (glycerol sebacate) • Heat the polymer to 50°C while mixing it with a spatula.

[0247] • Add the required amount of bis-anhydride in the specified proportions to a 75ml container specifically designed for the Speed ​​Mixer (Hauschild SpeedMixer SMART DAC). • Add the required amount of metal triflate in the specified proportions to the container holding the bis-anhydride.

[0248] • Add the preheated polymer quantity to the pot containing the bis-anhydride and catalyst.

[0249] • Place the pot in the planetary mixer and run the program which sets the device in motion at 2500 rpm for at least 2 minutes.

[0250] • Cool to room temperature.

[0251] Step b): Crosslinking step

[0252] Crosslinking is carried out at 140°C or 120°C depending on the composition, in the MCR rheometer during the measurement of the crosslinking kinetics according to the method described above in point

[0253] 1.2. Crosslinking within the framework of this test protocol corresponds to obtaining a crosslinked polyester with an elastic modulus of 1MPa.

[0254] 2.3. Characterization of crosslinking kinetics

[0255] • Properties with Sodium, Potassium, Calcium, Barium Triflate with BTDA at 140°C

[0256] Table 6

[0257] • Properties with Sodium, Potassium, Calcium, and Barium Triflate with BPADA at 140°C Table 7

[0258] • Properties with Barium Triflate with BTDA at 120°C

[0259] Table 8 3. Discussion

[0260] Unexpectedly, a systematic and highly significant reduction in crosslinking time was observed for all compositions comprising the polyanhydride compound with metal triflate in various proportions. Among the triflate catalysts, the most effective, namely barium triflate, reduced the crosslinking time by more than 40% in the BTDA system and by more than 25% in the BPADA system at 140°C. It was also observed that with this catalyst, the invention is effective at 140°C but remains operational at lower temperatures such as 120°C.

Claims

DEMANDS 1. A process for preparing a crosslinked glycerol polyester comprising a step of crosslinking a glycerol polyester with a cyclic carboxylic polyanhydride A in the presence of a metal triflate compound, the cyclic carboxylic polyanhydride A comprising at least two cyclic carboxylic anhydride groups, the cyclic carboxylic polyanhydride A not comprising a linear carboxylic anhydride function, and the metal of the metal triflate compound being selected from the alkali and alkaline earth metals.

2. A process according to claim 1, wherein the glycerol polyester is a polyester of glycerol and a diacid monomer or a carboxylic diester monomer, the diacid monomer and the carboxylic diester monomer having the formula [R'OOC-(CH2) P-COOR'], in which p is a number from 1 to 30, preferably a number from 1 to 10, preferably p is 8, and R' represents H or each R' represents independently of each other, an alkyl, linear or branched, in C1-C10, preferably in Ci-Ce, preferably in C1-C4.

3. A method according to claim 1 or 2, wherein the cyclic carboxylic anhydride groups of the cyclic carboxylic polyanhydride A are independently selected from ortho phthalic, succinic, maleic and homo phthalic groups.

4. A method according to any one of the preceding claims, wherein the cyclic carboxylic anhydride groups of the cyclic polycarboxylic anhydride A are joined, linked together by at least one covalent bond, or carried by a spacer group L, The representative -O- ; -S- ; -S(O)- ; -S(O)2- ; -C(O)- ; -NR n R n - with R n and R n'independently chosen from H or an alkyl group in Ci-Ce, or a multivalent hydrocarbon group comprising 1 to 40 carbon atoms, cyclic or acyclic, saturated, unsaturated or aromatic, and which may contain one or more heteroatoms of O, S, Cl, Br, F, N, P or Si, L being devoid of linear anhydride groups.

5. A process according to any one of the preceding claims, wherein the cyclic carboxylic polyanhydride A comprises or is a compound of formula (I) or (II): in which • Li represents a bond; -O- ; -S- ; -S(O)- ; -S(O)2- ; -NR n R n - with R n and R n 'independently chosen from H or an alkyl group in Ci-Ce; -C(O)-; or an aliphatic chain of 1 to 30 carbon atoms, in which 1 to 6 methylene unit(s) is / are optionally replaced by an arylene group, a heteroarylene group, -C(O)-, -O-, -S-, -S(O)-, -S(O)2-, -NRm - with R m chosen from H or an alkyl group in Ci-Ce, -P-, -P(O)-, -SiRaRb- with R a and Rb independently representing a -OH, alkyl in Ci-Ce or alkoxy in Ci-Ce group, said aliphatic chain being substituted or unsubstituted by one or more, in particular one or two, alkyl in Ci-Ce, alkoxy in Ci-Ce, hydroxyl, nitro, cyano, halogen atom, haloalkyl in Ci-Ce group(s), • Zi is absent or represents a -CH2- (methylene) group • Z2 is absent or represents a -CH2- (methylene) group • X independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom, • n represents an integer from 0 to 3, preferably from 0 to 2, • Y independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom, • m represents an integer from 0 to 3, preferably from 0 to 2, • Ai represents: -a C-C bond or a C=C bond linking the four carbon atoms of the two carboxylic anhydride functions, -a saturated, unsaturated or aromatic carbocycle, optionally bridged, said carbocycle comprising from 4 to 30 carbon atoms, and -a saturated, unsaturated or aromatic heterocycle, optionally bridged, said heterocycle comprising from 4 to 30 carbon atoms, and said carbocycle or heterocycle being substituted or unsubstituted by one or more substituents selected from a Ci-Ce alkyl, hydroxyl, Ci-Ce alkoxy, nitro, cyano, or halogen atom group.

6. A method according to any one of the preceding claims, wherein the metal triflate compound is lithium triflate, sodium triflate, potassium triflate, magnesium triflate, calcium triflate, strontium triflate, barium triflate or a mixture of at least two of these metallic tritiates.

7. A process according to any one of the preceding claims, wherein the crosslinking step comprises the following steps: a) contacting 100 parts by weight of at least one glycerol polyester with 0.1 to 200 parts by weight of at least one cyclic carboxylic polyanhydride in the presence of 0.0001 wt% (0.1 ppm) to 1 wt% (10,000 ppm) relative to the mass of glycerol polyester, of a triflate metal compound, the metal being selected from alkali and alkaline earth metals; b) pressurizing the mixture obtained in step a) to a target temperature T c between 80°C and 175°C, and maintenance at temperature T cand under pressure for a heating time sufficient to obtain a crosslinked polyester, c) cooling and recovery of the crosslinked polyester, glycerol polyester, cyclic carboxylic polyanhydride and metal triflate are as defined in any one of claims 1 to 6.

8. A method according to claim 7, wherein step a) comprises contacting 100 parts by weight of at least one polyester of glycerol, with 10 to 100 parts by weight of at least one cyclic carboxylic polyanhydride.

9. A process according to claim 7 or 8, wherein step a) comprises the use of 0.05 wt% (500ppm) to 1 wt% (10000ppm) relative to the polyester mass of glycerol, of the metal triflate compound.

10. Crosslinking composition, comprising: o 100 parts by weight of at least one polyester of glycerol, o from 0.1 to 200 parts by weight of at least one cyclic carboxylic polyanhydride as defined in any one of claims 1 to 5, o 0.0001 wt% (0.1 ppm) to 1 wt% (1000 ppm) relative to the mass of polyester of glycerol, of a triflate metal compound, the metal being selected from the alkali and alkaline earth metals.

11. Composition according to claim 10, wherein the crosslinked glycerol polyester is a glycerol polyester and a crosslinked diacid monomer or carboxylic diester monomer, the diacid and carboxylic diester monomer having the formula [R'OOC-(CH2) P - COOR'], in which p is a number from 1 to 30, preferably a number from from 1 to 10, preferably p is 8, and R' represents H or each R' represents independently of each other, an alkyl, linear or branched, in C1-C10, preferably in Ci-Ce, preferably in C1-C4.

12. Composition according to claim 10 or 11, wherein the glycerol polyester has a molar mass in number M n less than or equal to 10,000 g / mol.

13. Composition according to any one of claims 10 to 12, wherein the cyclic carboxylic polyanhydride comprises a compound of formula (I) or (II): in which • L1 represents a bond; -O- ; -S- ; -S(O)- ; -S(O)2- ; -NR n R n - with R n and R n'independently chosen from H or an alkyl group in Ci-Ce; -C(O)-; or an aliphatic chain of 1 to 30 carbon atoms, in which 1 to 6 methylene unit(s) is / are optionally replaced by an arylene group, a heteroarylene group, -C(O)-, -O-, -S-, -S(O)-, -S(O)2-, -NR m - with R m chosen from H or an alkyl group in C1- Ce, ; -P-, -P(O)-, -SiRaRb- with R a and Rb independently representing a -OH, alkyl Ci-Ce or alkoxy Ci-Ce group, said aliphatic chain being substituted or unsubstituted by one or more, in particular one or two, alkyl Ci-Ce, alkoxy Ci-Ce, hydroxyl, nitro, cyano, halogen atom, haloalkyl Ci-Ce group(s), • Z1 is absent or represents a -CH2- (methylene) group • Z2 is absent or represents a -CH2- (methylene) group • X independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom, • n represents an integer from 0 to 3, preferably from 0 to 2, • Y independently represents an alkyl group in Ci-Ce, hydroxyl, alkoxy group in Ci-Ce, nitro, cyano, or a halogen atom, • m represents an integer from 0 to 3, preferably from 0 to 2. • Ai represents: -a C-C bond or a C=C bond linking the four carbon atoms of the two carboxylic anhydride functions, -a saturated, unsaturated or aromatic carbocycle, optionally bridged, said carbocycle comprising from 4 to 30 carbon atoms, and -a saturated, unsaturated or aromatic heterocycle, optionally bridged, said heterocycle comprising from 4 to 30 carbon atoms, and said carbocycle or heterocycle being substituted or unsubstituted by one or more substituents selected from a Ci-Ce alkyl, hydroxyl, Ci-Ce alkoxy, nitro, cyano, or halogen atom group.

14. Composition according to any one of claims 10 to 13, wherein the metal triflate compound is selected from lithium triflate, sodium triflate, potassium triflate, magnesium triflate, calcium triflate, strontium triflate, barium triflate and mixtures of at least two of these triflates.

15. Crosslinked product based on a crosslinking composition according to any one of claims 10 to 14 or obtained by a process according to any one of claims 1 to 9.

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