Process for the preparation of cross-linked polyesters of glycerol from cyclic polycarboxylic anhydrides and corresponding cross-linked polyesters

Abstract

This invention relates to a method for preparing a crosslinked polyester of glycerol and an aliphatic dicarboxylic acid or diester monomer, the method comprising the step of crosslinking the polyester of glycerol and the aliphatic dicarboxylic acid or diester monomer using a cyclic polycarboxylic anhydride A, said cyclic polycarboxylic anhydride A comprising at least two cyclic carboxylic anhydride groups and not containing linear carboxylic anhydride functional groups. The invention also relates to crosslinking compositions that can be used to carry out the method of the invention and crosslinked polyesters obtained in this manner.

Description

Technical Field

[0001] This invention relates to crosslinked glycerol polyesters. The invention also relates to methods for preparing them and crosslinking compositions for preparing said crosslinked polyesters. Background Technology

[0002] Biodegradable and / or bio-based polyesters (such as polylactic acid (PLA), polyglycolic acid (PGA) and their copolymers (such as poly(glycerol sebacate) (PGS))) are now ubiquitous in the preparation of biomaterials, both as medical biomaterials and as surface coatings for a wide range of applications.

[0003] Typically, these polyesters are prepared by melt polycondensation of glycerol and diacid at high temperatures, which involves a considerably long reaction time. These reaction times are further extended to alter the mechanical properties of the polyester through crosslinking.

[0004] Therefore, there is a need for a method for preparing crosslinked polyesters that has a shortened crosslinking time and / or a lower reaction temperature, thus being compatible with a larger amount of additives (especially the active ingredients to be encapsulated in the crosslinked polyester) while maintaining or even improving the mechanical properties suitable for the intended use. Summary of the Invention

[0005] The inventors have demonstrated that the use of cyclic polycarboxylic anhydride crosslinking agents can overcome the problems of the prior art.

[0006] Therefore, the present invention relates to a method for preparing a crosslinked polyester of glycerol with an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters, the method comprising the step of crosslinking the polyester of glycerol with an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters using a cyclic polycarboxylic anhydride A, wherein the cyclic polycarboxylic anhydride A comprises at least two cyclic carboxylic anhydride groups and does not contain any linear carboxylic anhydride functional groups.

[0007] Therefore, the method of the present invention can achieve significantly improved elastic properties and shortened crosslinking time.

[0008] Advantageously, the cyclic carboxylic anhydride group of the cyclic polycarboxylic anhydride A is independently selected from phthalic acid groups, succinic acid groups, maleic acid groups, o-carboxyphenylacetic acid groups and itoric acid groups, preferably selected from phthalic acid groups, succinic acid groups, maleic acid groups and o-carboxyphenylacetic acid groups.

[0009] Advantageously, the cyclic carboxylic anhydride groups of the cyclic polycarboxylic anhydride A are fused together, connected to each other by at least one covalent bond or carried by a spacer group L. L represents -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -NR n Rn’ -, where R n and R n’ The hydrocarbon group is independently selected from H or C1-C6 alkyl groups, or from a polyvalent cyclic or acyclic, saturated, unsaturated, or aromatic hydrocarbon group containing 1 to 40 carbon atoms, wherein the hydrocarbon group may contain one or more heteroatoms selected from O, S, Cl, Br, F, N, P, or Si. L does not contain straight-chain anhydride groups.

[0010] Advantageously, the cyclic polycarboxylic anhydride A comprises a compound of formula (I) or (II), or a compound of formula (I) or (II): (I) or (II) in L1 represents the bond, -O-, -S-, -S(O)-, -S(O)2-, -NR n R n’ -, where R n and R n’ Independently selected from H or C1-C6 alkyl, -C(O)- or aliphatic chains having 1 to 30 carbon atoms, wherein 1 to 6 methylene units are optionally replaced by arylene, heteroarylene, -C(O)-, -O-, -S-, -S(O-, -S(O)2-, -NR m - Replacement, where R m Selected from H or C1-C6 alkyl, -P-, -P(O)-, -SiR a R b -, where R a and R b Each can independently represent -OH, C1-C6 alkyl, or C1-C6 alkoxy. The aliphatic chain is substituted with one or more, particularly one or two C1-C6 alkyl, C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom, or C1-C6 haloalkyl, or is unsubstituted. • Z1 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z1 either does not exist or represents a -CH2- group. • Z2 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z2 either does not exist or represents a -CH2- group. • X independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·n represents an integer ranging from 0 to 3, preferably from 0 to 2. • Y independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·m represents an integer ranging from 0 to 3, preferably from 0 to 2. A1 indicates: ○ The C-C bond or C=C bond connecting the four carbon atoms of the two carboxylic anhydride functional groups. ○ A saturated, unsaturated, or aromatic optionally bridged carbon ring, said carbon ring comprising 4 to 30 carbon atoms, and ○ A saturated, unsaturated, or aromatic optionally bridged heterocycle, the heterocycle comprising 4 to 30 carbon atoms, and The carbocyclic or heterocyclic ring is substituted with one or more substituents, or is unsubstituted, wherein the substituents are selected from C1-C6 alkyl, hydroxy, C1-C6 alkoxy, nitro, cyano, or halogen atoms.

[0011] Preferably, Z1 either does not exist or represents a -CH2- group, and Z2 either does not exist or represents a -CH2- group.

[0012] Typically, the crosslinking step includes the following steps: a) Contacting 100 parts by weight of at least one glycerol with a polyester of an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters with 0.1 parts by weight to 200 parts by weight of at least one cyclic polycarboxylic anhydride as defined herein, thereby obtaining a mixture of crosslinking precursors. b) Pressurize the mixture obtained in the crosslinking precursor step of step a) to a target temperature T ranging from 100°C to 200°C. c And maintain the heating time t under pressure sufficient to obtain crosslinked polyester. ch , c) Cool and recycle the cross-linked polyester.

[0013] Advantageously, step a) comprises contacting 100 parts by weight of at least one glycerol with a polyester of an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters.

[0014] Another subject of the present invention relates to a crosslinking composition comprising: ○ 100 parts by weight of at least one glycerol and a polyester selected from dicarboxylic acids and dicarboxylic acid diesters. ○ 0.1 parts by weight to 200 parts by weight of at least one cyclic polycarboxylic anhydride as defined herein.

[0015] Advantageously, the dicarboxylic acid monomer or dicarboxylic acid ester monomer conforms to the general formula R'OOC-(CH2). p -COOR', where p represents an integer ranging from 1 to 30, preferably from 1 to 10, more preferably p=8, and R' represents H, or each R' independently represents a linear or branched C1-C 10 Preferably C1-C4 alkyl, more preferably methyl or ethyl.

[0016] Advantageously, the number-average molar mass Mn of the polyester of glycerol and aliphatic dicarboxylic acid or dicarboxylic acid ester monomer is less than or equal to 10,000 g / mol.

[0017] Advantageously, at least one cyclic polycarboxylic anhydride comprises a compound of formula (I) or (II): (I) or (II) in L1 represents the bond, -O-, -S-, -S(O)-, -S(O)2-, -NR n R n’ -, where R n and R n’ Independently selected from H or C1-C6 alkyl, -C(O)- or aliphatic chains having 1 to 30 carbon atoms, wherein 1 to 6 methylene units are optionally replaced by arylene, heteroarylene, -C(O)-, -O-, -S-, -S(O-, -S(O)2-, -NR m - Replacement, where R m Selected from H or C1-C6 alkyl, -P-, -P(O)-, -SiR a R b -, where R a and R b Each can independently represent -OH, C1-C6 alkyl, or C1-C6 alkoxy. The aliphatic chain is substituted with one or more, particularly one or two C1-C6 alkyl or C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom or C1-C6 haloalkyl, or is unsubstituted. • Z1 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z1 either does not exist or represents a -CH2- group. • Z2 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z2 either does not exist or represents a -CH2- group. • X independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·n represents an integer ranging from 0 to 3, preferably from 0 to 2. • Y independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·m represents an integer ranging from 0 to 3, preferably from 0 to 2.

[0018] A1 indicates: ○ The C-C bond or C=C bond connecting the four carbon atoms of the two carboxylic anhydride functional groups. ○ A saturated, unsaturated, or aromatic optionally bridged carbon ring, said carbon ring comprising 4 to 30 carbon atoms, and ○ A saturated, unsaturated, or aromatic optionally bridged heterocycle, the heterocycle comprising 4 to 30 carbon atoms, and The carbocyclic or heterocyclic ring is substituted with one or more substituents, or is unsubstituted, wherein the substituents are selected from C1-C6 alkyl, hydroxy, C1-C6 alkoxy, nitro, cyano, or halogen atoms.

[0019] Preferably, Z1 either does not exist or represents a -CH2- group, and Z2 either does not exist or represents a -CH2- group.

[0020] Advantageously, L1 represents a bond or an aliphatic chain having 1 to 6 carbon atoms, wherein one or two methylene units are optionally replaced by aryl, -C(O)-, -O-, -S-, -S(O)-, or -S(O)2-. The aliphatic chain is preferably substituted with a group selected from C1-C6 alkyl, C1-C6 alkoxy, or C1-C6 haloalkyl groups, or is unsubstituted.

[0021] Advantageously, at least one cyclic polycarboxylic anhydride comprises a compound of formula (III) or (IV): (III) (IV) in Indicates a single or double C bond. L2 and L3, together with the carbon atoms to which they are bonded, represent a saturated, unsaturated, or aromatic carbocyclic or heterocyclic ring containing 4 to 30 carbon atoms, and the carbocyclic or heterocyclic ring is substituted by one or more substituents, or is unsubstituted, the substituents being selected from C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atoms.

[0022] Another subject of the invention relates to polyesters using at least one cyclic polycarboxylic anhydride-crosslinked glycerol as defined herein with an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters, wherein the elongation at break, as measured according to standard ASTM D 1708, ranges from 20% to 300%, and advantageously, the crosslinked polyester has a Shore A hardness, as measured according to standard ASTM D 2240, at ambient temperature, ranging from 10 to 90. The crosslinked polyester can be obtained by the method of the invention. Detailed Implementation

[0023] definition For the purposes of this invention, the terms "a", "an", or "a" mean "one or more" or "at least one".

[0024] For the purposes of this invention, the numerical range expressed as "between a and b" represents a numerical range strictly greater than a to strictly less than b (i.e., excluding the limits a and b), while any numerical range expressed as "a to b" represents a numerical range from a to b (i.e., including the strict limits a and b).

[0025] In this specification, the term “about” is understood to mean that the value under consideration may be 10% lower or higher than the value shown, particularly 5%, and more particularly 1%.

[0026] The compounds mentioned in the specification can be fossil-derived or bio-based compounds. In the case of bio-based compounds, they can be partially or entirely derived from biomass, or obtained from renewable starting materials derived from biomass. In the same manner, the mentioned compounds can also be derived from the recycling of materials that have already been used, meaning they can be partially or entirely derived from recycling processes, or obtained from starting materials that are themselves derived from recycling processes. This particularly includes monomers, namely, more specifically glycerol, dicarboxylic acid monomers, and cyclic polycarboxylic anhydrides.

[0027] Glycerol is a triol with the following formula: .

[0028] In this invention, "cyclic polycarboxylic anhydride" means an organic compound containing at least two cyclic carboxylic anhydride functional groups. Each functional group is selected from carboxylic anhydride functional groups or nitrogen-containing anhydride functional groups. A "cyclic (nitrogen- or nitrogen-free) carboxylic anhydride functional group" is attached to two carbons (adjacent or non-adjacent) of the remainder of the molecule, thereby forming a ring containing either a carboxylic anhydride functional group or a nitrogen-containing anhydride functional group. In contrast, a "linear (nitrogen- or nitrogen-free) anhydride functional group" means a divalent (nitrogen- or nitrogen-free) carboxylic anhydride functional group attached to two carbons of the remainder of the molecule, but not contained in a ring.

[0029] In this invention, the "carboxylic anhydride functional group" conforms to the formula -C(=O)-OC(=O)-. This functional group is divalent.

[0030] In this invention, the "nitrogen-containing carboxylic anhydride functional group" conforms to the formula -C(=O)-OC(=O)-NH. This functional group is divalent.

[0031] In this invention, "cyclic carboxylic anhydride group" is understood to mean a group that contains (nitrogen-containing or nitrogen-free) a carboxylic acid cyclic anhydride functional group and further contains 3 to 40 carbon atoms. The cyclic anhydride group can be polyvalent or monovalent. When the cyclic anhydride group is an itotonic acid group, the cyclic anhydride group contains a nitrogen-containing anhydride functional group.

[0032] When the group is further substituted, it contains 1 to 4, preferably 1 to 2, substituents. The substituents are preferably (independently) C1-C6 alkyl or C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom or C1-C6 haloalkyl.

[0033] For the purposes of this invention, "straight-chain anhydride group" is understood to mean a group containing a straight-chain (nitrogen- or nitrogen-free) carboxylic anhydride functional group. Unlike cyclic anhydride groups, in straight-chain carboxylic anhydride groups, the divalent (nitrogen- or nitrogen-free) carboxylic anhydride functional group is attached to two carbons of the remaining portion of the molecule, but is not contained in a ring.

[0034] In this invention, "monovalent hydrocarbon group" means a saturated (i.e., without any unsaturation or multiple bonds), unsaturated (i.e., containing at least one double or triple bond, but not aromatic), or aromatic, cyclic or acyclic (straight-chain or branched) monovalent hydrocarbon chain containing 1 to 40 carbon atoms. Monovalent hydrocarbon groups specifically encompass substituted or unsubstituted C1-C... 40 Alkyl, cycloalkyl, alkenyl, cycloalkenyl, ynyl, or cycloynyl. Preferably, the monovalent hydrocarbon group is a substituted or unsubstituted C1-C group. 40 Alkyl, cycloalkyl, alkenyl or cycloalkenyl.

[0035] As used herein, "divalent hydrocarbon group" refers to a saturated, unsaturated, or aromatic, cyclic or acyclic (straight-chain or branched) divalent hydrocarbon chain containing 1 to 40 carbon atoms. Divalent hydrocarbon groups specifically encompass straight-chain or branched, substituted or unsubstituted C1-C... 40 Alkyl, alkenyl, or ynyl. Divalent hydrocarbon groups also encompass substituted or unsubstituted C1-C groups. 40 Cycloalkyl, cycloalkenyl, or cycloynyl groups. The divalent hydrocarbon group also encompasses substituted or unsubstituted divalent aromatic groups. Preferably, the monovalent hydrocarbon group is a substituted or unsubstituted C1-C group. 40 Alkyl (straight-chain or branched), alkenyl (straight-chain or branched), cycloalkanediyl or cycloalkenyl.

[0036] In this invention, "polyvalent hydrocarbon group" means a hydrocarbon chain containing 1 to 40 carbon atoms in a saturated, unsaturated (i.e., containing at least one C-C double bond or optionally one C-C triple bond, but not aromatic) or aromatic, cyclic or acyclic (straight or branched) tetravalent or higher valence state.

[0037] "Aliphatic" is understood to refer to straight-chain, branched, and / or cyclic hydrocarbon groups that can be saturated or unsaturated but are not aromatic.

[0038] For the purposes of this invention, "alkyl" is understood to mean a saturated, straight-chain or branched monovalent hydrocarbon chain containing 1 to 40 carbon atoms, preferably 1 to 10 carbon atoms. Examples may include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, or hexyl.

[0039] For the purposes of this invention, "cycloalkyl" is understood to mean a cyclic monovalent saturated hydrocarbon chain comprising 3 to 40 cyclic carbon atoms. Cycloalkyl groups can be monocyclic, bicyclic, or polycyclic. Examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or cycloheptyl. An example of a polycyclic cycloalkyl group is adamantyl.

[0040] For the purposes of this invention, "alkenyl" is understood to mean a straight-chain or branched monovalent hydrocarbon chain containing at least one double bond and comprising 2 to 40 carbon atoms. As examples, vinyl, propenyl, allyl, butenyl, pentenyl, or hexenyl may be mentioned.

[0041] For the purposes of this invention, "cycloalkenyl" is understood to mean a cyclic monovalent hydrocarbon chain comprising 3 to 40 cyclic carbon atoms and at least one double bond. Cycloalkenyl groups can be monocyclic, bicyclic, or polycyclic. Examples include cyclobutenyl, cyclopentenyl, cyclohexenyl, or cycloheptenyl. An example of a polycyclic cycloalkenyl group is bicyclic [2.2.2]octyl-7-ene.

[0042] For the purposes of this invention, "alkynyl" is understood to mean a straight-chain or branched monovalent hydrocarbon chain containing at least one triple bond and comprising 2 to 40 carbon atoms. As examples, ethynyl, propynyl, butynyl, pentynyl, or hexynyl may be mentioned.

[0043] For the purposes of this invention, "cycloynyl" is understood to mean a cyclic monovalent hydrocarbon chain comprising 5 to 40 cyclic carbon atoms, preferably 7 to 40 such atoms, and at least one triple bond. Cycloynyl groups can be monocyclic, bicyclic, or polycyclic. As an example, cycloheptyynyl may be mentioned.

[0044] For the purposes of this invention, "aromatic group" is understood to mean an aromatic hydrocarbon group that preferably comprises 6 to 40 carbon atoms and includes one or more fused rings. Examples of monovalent aromatic groups may include phenyl, naphthyl, or pyrene, with phenyl being advantageous. Examples of divalent aromatic groups may include phenylene, naphthylene, or pyrene, with pyrene being advantageous.

[0045] For the purposes of this invention, "alkyldiyl" is understood to mean a straight-chain or branched acyclic divalent hydrocarbon chain containing 1 to 40 carbon atoms, such as methylene, ethanediyl, propanediyl, butanediyl, pentanediyl, or hexanediyl.

[0046] For the purposes of this invention, "cycloalkyldiyl" is understood to mean a cyclic divalent saturated hydrocarbon group containing 3 to 40 cyclic carbon atoms, such as cyclobutylene, cyclohexylene, or cyclopentylene.

[0047] For the purposes of this invention, "enediyl" is understood to mean a straight-chain or branched acyclic divalent hydrocarbon chain containing 2 to 40 carbon atoms and at least one double bond, such as ethylene (ethyleneide) or propyleneide.

[0048] For the purposes of this invention, "cycloenyl" is understood to mean a straight or branched cyclic divalent hydrocarbon chain containing 3 to 40 carbon atoms, preferably 4 to 40 or even 5 to 40 such atoms and at least one double bond, such as cyclopentenyl.

[0049] For the purposes of this invention, "acetylenic dimethyl" is understood to mean a straight-chain or branched acyclic divalent hydrocarbon chain containing 2 to 40 carbon atoms and at least one triple bond.

[0050] For the purposes of this invention, "cycloalkynyl" is understood to mean a cyclic monovalent hydrocarbon chain containing 5 to 40 cyclic carbon atoms, preferably 7 to 40 or even 8 to 40 such atoms, and at least one cyclic triple bond. The cycloalkynyl group can be monocyclic, bicyclic, or polycyclic.

[0051] For the purposes of this invention, "C1-C6 alkoxy" is understood to mean a C1-C6 alkyl group as defined above, bonded to the remainder of the molecule by an oxygen atom. As examples, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, or n-hexoxy may be mentioned.

[0052] For the purposes of this invention, "halogen atom" or "halogen" is understood to mean fluorine atom, chlorine atom, bromine atom and iodine atom, preferably fluorine atom and chlorine atom.

[0053] For the purposes of this invention, "C1-C6 haloalkyl" is understood to mean a C1-C6 alkyl group as defined above in which one or more hydrogen atoms are replaced by a halogen atom, more particularly a chlorine atom, a bromine atom, an iodine atom, or a fluorine atom, preferably a fluorine atom. As an example, trifluoromethyl (-CF3) may be mentioned.

[0054] The hydroxyl group is an -OH group. The cyano group is a -CN group. The nitro group is a -NO2 group.

[0055] "Carbon ring containing 4 to 30 carbon atoms" means a (monovalent) cyclic hydrocarbon group containing 4 to 30 carbon atoms. The carbon ring can be monocyclic or polycyclic, optionally bridged (including bridged rings and / or fused rings). When the carbon ring is a polycyclic carbon ring, it contains at least two, advantageously two or three fused rings or bridged rings. The carbon ring can be saturated (i.e., not containing any unsaturation or multiple bonds), unsaturated (i.e., containing at least one double bond or optionally a triple bond, rather than an aromatic one), or aromatic. When the carbon ring is an aromatic carbon ring, the term "aryl" will be used.

[0056] For the purposes of this invention, "heterocycles comprising 4 to 30 carbon atoms" is understood to mean one or more, advantageously 1 to 4, or even more advantageously 1 or 2, of which are heteroatoms (e.g., sulfur, nitrogen, or oxygen atoms) and the other cyclic atoms are carbon atoms, of which are (monovalent) saturated, unsaturated, or aromatic monocyclic or polycyclic rings (optionally bridged, including bridged rings and / or fused rings). Examples of saturated or unsaturated heterocycles are: pyrrolidine, piperidine, piperazine, morpholine, pyrazolyl, imidazoline, aziridine, thiazoline, isothiazolidine, oxonitrile-nitrogenine, thioaziridine, benzimidazolone.

[0057] Aromatic heterocycles (also known as (monovalent) heteroaryl groups) contain 5 to 10 ring atoms, including one or more, preferably 1 to 4, or even more preferably 1 or 2 heteroatoms (e.g., sulfur, nitrogen, or oxygen atoms), with the other ring atoms being carbon atoms. Examples of heteroaryl groups are furan, thiophene, pyrrole, pyridine, imidazole, triazolyl, tetrazolium, oxazole, isoxazole, thiazole, isothiazole, pyrazole, oxadiazole, thiadiazole, pyridazine, pyrimidine, pyrazine, triazine, quinoline, isoquinoline, quinoxaline, or indole groups.

[0058] "Areneyl" refers to a divalent aromatic hydrocarbon group, such as phenyl or naphthyl, that preferably contains 6 to 10 carbon atoms and includes one or more fused rings. Advantageously, the group in question is phenylene.

[0059] "Hypoaryl" refers to a divalent aromatic heterocycle containing 5 to 10 ring atoms, comprising one or more, preferably 1 to 4, or even more preferably 1 or 2 heteroatoms (e.g., sulfur, nitrogen, or oxygen atoms), with the other ring atoms being carbon atoms. As an example, pyridylene may be mentioned.

[0060] According to the present invention, "phthalic acid group" means having the formula: Preferably, it has the following formula: The group, which is linked by a bond Connected to the rest of the polyacid anhydride molecule, or meaning having the formula: The divalent group, which on the one hand, is bonded by a bond On the other hand, through the key It is attached to the rest of the polyacid anhydride molecule. The phthalic acid group can be substituted or unsubstituted.

[0061] In this invention, "succinic acid group" refers to a group having the following formula: The monovalent group, which is bonded by a bond It is attached to the rest of the polyacid anhydride molecule and can be substituted or unsubstituted, or it means having the formula: The divalent group, which on the one hand, is bonded by a bond On the other hand, through the key It attaches to the rest of the polyacid anhydride molecule. Succinic acid groups differ from phthalic acid groups, therefore divalent succinic acid groups typically do not fuse with phenyl groups.

[0062] In this invention, "maleic acid group" refers to a group having the following formula: The monovalent group, which is bonded by a bond It is attached to the rest of the polyacid anhydride molecule and can be substituted or unsubstituted, or it means having the formula A divalent group, on the one hand, is linked by a bond. On the other hand, through the key It connects to the rest of the polyhydric anhydride molecule. Maleic acid groups differ from phthalic acid groups, therefore divalent maleic acid-type cyclic anhydride groups typically do not fuse with phenyl groups.

[0063] In this invention, "o-carboxyphenylacetic acid group" refers to a group having the following formula: Preferably, it has the following formula: The group, which is linked by a bond Connected to the rest of the polyacid anhydride molecule, or meaning having the formula: The divalent group, which on the one hand, is bonded by a bond On the other hand, through the key It is attached to the rest of the polyacid anhydride molecule. The o-carboxyphenylacetic acid group can be substituted or unsubstituted.

[0064] In this invention, "italic acid group" refers to a group having the formula: Preferably, it has the following formula: or The group, which is linked by a bond Connected to the rest of the polyacid anhydride molecule, or meaning having the formula: The divalent group, which on the one hand, is bonded by a bond On the other hand, through the key It is attached to the rest of the polyacid anhydride molecule. The itotonic acid group can be substituted or unsubstituted.

[0065] The term “ambient temperature” is understood here to mean a temperature that is generally in the range of 15°C to 40°C, preferably 20°C to 30°C, and especially about 25°C.

[0066] I. Methods for preparing crosslinked polyesters This invention relates to a method for preparing a crosslinked polyester of glycerol with an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters, the method comprising the step of crosslinking the polyester of glycerol with an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters using a cyclic polycarboxylic anhydride A, wherein the cyclic polycarboxylic anhydride A comprises at least two cyclic carboxylic anhydride groups and does not contain any straight-chain carboxylic anhydride functional groups.

[0067] Cyclic polycarboxylic anhydrides Preferably, the cyclic polycarboxylic anhydride comprises two cyclic carboxylic anhydride functional groups, meaning it is a cyclic carboxylic dianhydride. Advantageously, the functional groups involved are nitrogen-free cyclic carboxylic anhydride functional groups.

[0068] In this invention, the cyclic carboxylic anhydride group of the cyclic polycarboxylic anhydride A is preferably independently selected from phthalic acid groups, succinic acid groups, maleic acid groups, o-carboxyphenylacetic acid groups and itotonic acid groups, and more preferably selected from phthalic acid groups, succinic acid groups, maleic acid groups and o-carboxyphenylacetic acid groups.

[0069] Cyclic polycarboxylic anhydrides may contain the same or different cyclic carboxylic anhydride groups. Preferably, the cyclic carboxylic anhydride groups in the cyclic polycarboxylic anhydride are the same.

[0070] Advantageously, the cyclic carboxylic anhydride group is independently a phthalic acid group, a succinic acid group, or a maleic acid group.

[0071] Advantageously, the cyclic carboxylic anhydride groups of the cyclic polycarboxylic anhydride A are fused together, or linked to each other by at least one covalent bond or carried by a spacer group L. L represents -O-, -S-, -S(O)-, -S(O)2-, -NR n -, where R n The hydrocarbon group is selected from H or C1-C6 alkyl, -C(O)- or a polyvalent cyclic or acyclic, saturated, unsaturated or aromatic hydrocarbon group containing 1 to 40 carbon atoms, and the hydrocarbon group may contain one or more heteroatoms selected from O, S, Cl, Br, F, N, P or Si, and L does not contain straight-chain anhydride groups.

[0072] L is chemically stable. Therefore, an oxygen atom cannot bond to another oxygen atom, and a nitrogen atom cannot bond to another nitrogen atom. Therefore, L preferably does not contain peroxy (-OO-) or hydrazine (-NH-NH- or -NH-N(C1-C6 alkyl)- or -N(C1-C6 alkyl)-N(C1-C6 alkyl)). Similarly, the ester functional group (C(O)O) cannot bond to another ester functional group. Furthermore, L advantageously does not contain readily hydrolyzable groups. In particular, L does not contain straight-chain anhydride groups, more particularly (divalent) straight-chain carboxylic anhydride groups of the formula -OC(=O)-O-. Advantageously, L also does not contain ester functional groups (-OC(=O)-) or amide functional groups (-OC(=O)-NR-, where R represents H or a substituent (e.g., a hydrocarbon chain)).

[0073] The valence of group L is even (because L has a divalent cyclic carboxylic anhydride group), and is usually 4 or 6, preferably 4.

[0074] Advantageously, L represents a saturated, unsaturated, or aromatic cyclic or acyclic polyvalent hydrocarbon group containing 1 to 40 carbon atoms, the hydrocarbon group may contain one or more heteroatoms selected from O, S, Cl, Br, F, N, P or Si, which means that L represents a saturated, unsaturated, or aromatic cyclic or acyclic polyvalent hydrocarbon group containing 1 to 40 carbon atoms, wherein one or more carbon atoms may be replaced by one or more heteroatoms or -C(O)- groups selected from O, S, Cl, Br, F, N, P or Si.

[0075] Phosphorus (P) atoms, sulfur (S) atoms, nitrogen (N) atoms and silicon (Si) atoms can be in oxidized form (especially P(O), SO, SO2) and / or substituted (especially substituted by C1-C6 alkyl groups, depending on the valence of the atom).

[0076] In a particularly advantageous manner, L represents a saturated, unsaturated, or aromatic cyclic or acyclic polyvalent hydrocarbon group comprising 1 to 40 carbon atoms, wherein one or more carbon atoms may be replaced by one or more oxygen (O) atoms or -C(O)- or -S(O)2- groups, and optionally by one or more heteroatoms selected from Cl, Br, F, N, P or Si.

[0077] According to a specific implementation, L represents a saturated or unsaturated acyclic polyvalent hydrocarbon group containing 1 to 10 carbon atoms, wherein one or more carbon atoms may be replaced by one or more oxygen (O) atoms or -C(O)-, -S-, -S(O)- or -S(O)2- groups, and optionally by one or more heteroatoms selected from Cl, Br, F, N, P or Si.

[0078] According to other specific embodiments, L represents a saturated, unsaturated, or aromatic cyclic polyvalent hydrocarbon group comprising 3 to 40 carbon atoms, wherein one or more carbon atoms may be replaced by one or more oxygen (O) atoms or -C(O)- groups, and optionally by one or more heteroatoms selected from S, Cl, Br, F, N, P, or Si, preferably by heteroatoms selected from Cl, Br, or F. In these embodiments, the polyvalent group may be monocyclic, bicyclic, or polycyclic. When L is bicyclic or polycyclic, it advantageously comprises one or more fused rings.

[0079] In a particular embodiment, the cyclic polycarboxylic anhydride comprises a compound of formula (I) or preferably a compound of formula (Ia), or is composed of a compound of formula (I) or preferably a compound of formula (Ia): (I), (Ia) in L1 represents the bond, -O-, -S-, -S(O)-, -S(O)2-, -NR n R n’ -, where R n and R n’ Independently selected from H or C1-C6 alkyl, -C(O)- or aliphatic chains having 1 to 30 carbon atoms, wherein 1 to 6 (preferably non-adjacent) methylene units are optionally replaced by arylene, heteroarylene, -C(O)-, -O-, -S-, -S(O-, -S(O)2-, -NR m - Replacement, where R m Selected from H or C1-C6 alkyl, -P-, -P(O)-, -SiR a R b -, where R a and R b Each can independently represent -OH, C1-C6 alkyl, or C1-C6 alkoxy. The aliphatic chain is substituted with one or more, particularly one or two C1-C6 alkyl or C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom or C1-C6 haloalkyl, or is unsubstituted. • Z1 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z1 either does not exist or represents a -CH2- group. • Z2 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z2 either does not exist or represents a -CH2- group. • X independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·n represents an integer ranging from 0 to 3, preferably from 0 to 2. • Y independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·m represents an integer ranging from 0 to 3, preferably from 0 to 2.

[0080] Advantageously, Z1 either does not exist or represents a -CH2- group, and Z2 either does not exist or represents a -CH2- group. Preferably, Z1 and Z2 are the same. Advantageously, both Z1 and Z2 represent a bond (which is equivalent to both Z1 and Z2 not existing).

[0081] Preferably, L1 represents a bond, -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, or an aliphatic chain having 1 to 30 carbon atoms, wherein 1 to 6 (preferably non-adjacent) methylene units are optionally replaced by arylene, heteroarylene, -C(O)-, -O-, -S-, -S(O)-, -S(O)2-, -NR m - Replacement, where R m Selected from H or C1-C6 alkyl, the aliphatic chain is substituted by one or more, particularly one or two, C1-C6 alkyl or C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom, C1-C6 haloalkyl, or unsubstituted.

[0082] Preferably, L1 represents a bond, -O-, -S(O)2-, -C(O)-, or an aliphatic chain having 1 to 20 carbon atoms, wherein 1 to 4 (preferably 1 to 2) (preferably non-adjacent) methylene units are optionally replaced by aryl, -C(O)-, -O-, -S-, -S(O)-, or -S(O)2-. The aliphatic chain is substituted with one or more, particularly one or two, substituents, or is unsubstituted, wherein the substituents are preferably selected from C1-C6 alkyl, C1-C6 alkoxy, or C1-C6 haloalkyl groups. In particular, L1 may contain one or two divalent aromatic groups, such as phenylene.

[0083] More specifically, L1 represents the group G1-G2-G3, wherein G1 and G3 are independently selected from O, -S(O)2, -C(O)-, and G2 is a divalent hydrocarbon group having 4 to 15 carbon atoms, which may contain one or two divalent aromatic groups (e.g., phenylene) and may be substituted by one or more, particularly one or two groups, said groups preferably selected from C1-C6 alkyl, C1-C6 alkoxy or C1-C6 haloalkyl.

[0084] Advantageously, L1 represents a bond, -O-, -S(O)2-, -C(O) or an aliphatic chain having 1 to 10 carbon atoms, particularly 1 to 6 carbon atoms, wherein 1 to 2 (preferably non-adjacent) methylene units are optionally replaced by aryl, -C(O)-, -O-, -S-, -S(O)-, -S(O)2-. The aliphatic chain is substituted by one or more, particularly one or two, groups, or is unsubstituted, the groups preferably selected from C1-C6 alkyl, C1-C6 alkoxy, or C1-C6 haloalkyl.

[0085] Advantageously, L1 represents a bond, -O-, -S(O)2-, -C(O) or an aliphatic chain having 1 to 10 carbon atoms, particularly 1 to 6 carbon atoms, wherein 1 to 2 (preferably non-adjacent) methylene units are optionally replaced by aryl, -C(O)-, -O-, said aliphatic chain being substituted by one or more, particularly one or two C1-C6 alkyl or C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom, C1-C6 haloalkyl, or unsubstituted, usually substituted by C1-C6 alkyl or C1-C6 alkoxy, halogen atom, or C1-C6 haloalkyl, or unsubstituted.

[0086] More specifically, X can independently represent C1-C6 alkyl, hydroxyl, or halogen atoms.

[0087] Advantageously, n represents 0 or 1.

[0088] Preferably, Y can independently represent C1-C6 alkyl, hydroxyl, or halogen atoms.

[0089] Advantageously, m represents 0 or 1.

[0090] Depending on the specific variant, n and m represent 0 or 1 independently of each other, and X and Y represent C1-C6 alkyl, hydroxyl, or halogen atoms independently of each other.

[0091] In other specific embodiments, the cyclic polycarboxylic anhydride comprises a compound of formula (II) or preferably a compound of formula (IIa), or consists of a compound of formula (II) or preferably a compound of formula (IIa): (II) or (IIa) in Z1 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z1 either does not exist or represents a -CH2- group. Z2 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z2 either does not exist or represents a -CH2- group. A1 indicates: ○ The C-C bond or C=C bond connecting the four carbon atoms of the two carboxylic anhydride functional groups. ○ A saturated, unsaturated, or aromatic carbon ring, said carbon ring comprising 4 to 30 carbon atoms, and ○ Saturated, unsaturated, or aromatic heterocycles, said heterocycles comprising 4 to 30 carbon atoms, and The carbocyclic or heterocyclic ring is substituted by one or more substituents, particularly C1-C6 alkyl or C1-C6 haloalkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atoms, or is unsubstituted.

[0092] Preferably, in formula (II), Z1 does not exist or represents a -CH2- group, and Z2 does not exist or represents a -CH2- group.

[0093] According to certain variants, A1 represents a carbon ring or polycyclic heterocycle having 10 to 30 cyclic atoms. In these variants, the polycyclic ring may include a fused ring. Advantageously, A1 represents a carbon ring or polycyclic aromatic heterocycle (including two or more fused rings) having 10 to 30 cyclic atoms. In particular, it may be a naphthyl group.

[0094] Depending on some variants, A1 represents an aromatic carbon ring containing 6 to 10 carbon atoms, such as phenyl or naphthyl.

[0095] According to other variations, A1 represents a saturated carbon ring (monocyclic or bicyclic) containing 4 to 10, preferably 4 to 6, carbon atoms. Preferably, it is a saturated monocyclic carbon ring containing 4 to 6 carbon atoms.

[0096] According to some variants, at least one cyclic polycarboxylic anhydride comprises, or is composed of, a compound of formula (III): (III) in Indicates a single or double C bond. L2 and L3, together with the carbon atoms they are bonded to, represent saturated, unsaturated, or aromatic optionally bridged carbocyclic or heterocyclic rings, comprising 4 to 30 carbon atoms, and The carbocyclic or heterocyclic ring is substituted with one or more substituents, or is unsubstituted, wherein the substituents are selected from C1-C6 alkyl, hydroxy, C1-C6 alkoxy, nitro, cyano, or halogen atoms.

[0097] Preferably, L2 and L3, together with the carbon atoms they are bonded to, represent a saturated, unsaturated, or aromatic optionally bridged carbon ring. The carbon ring contains 4 to 10 carbon atoms, and The carbon ring is substituted by one or more (especially one or two) substituents, or is unsubstituted, the substituents being selected from C1-C6 alkyl or halogen atoms.

[0098] Preferably, L2 and L3 are represented together with the carbon atoms to which they are bonded: • A saturated or unsaturated, optionally bridged carbon ring comprising 4 to 8 carbon atoms, said carbon ring being substituted with one or more (particularly one or two) substituents, or unsubstituted, said substituents being selected from C1-C6 alkyl groups, halogen atoms, or... • An aromatic carbon ring having 6 to 10 carbon atoms, wherein the aromatic carbon ring is substituted by one or more (especially one or two) substituents, or is unsubstituted, wherein the substituents are selected from C1-C6 alkyl groups and halogen atoms.

[0099] In particular, L2 and L3 can together with the carbon atom to which they are bonded to represent cyclobutyl, cyclopentyl, cyclohexyl, bicyclo[2.2.2]oct-2-enyl or phenyl.

[0100] According to some variants, cyclic polycarboxylic anhydrides include, or consist of, compounds of formula (IV): (IV) in Indicates a single or double C bond. According to a preferred embodiment, the cyclic polycarboxylic anhydride of formula (I) is selected from: [Table 1] and its mixtures.

[0101] Preferably, the cyclic polycarboxylic anhydride is BTDA, BPADA, BPDA and ODPA or a mixture thereof.

[0102] Cyclic polycarboxylic anhydrides (particularly the cyclic carboxylic dianhydrides of this invention) are well known to those skilled in the art (see in particular US 7425650). They can be obtained by the condensation of the corresponding tetracarboxylic acids, and some are commercially available. More specifically, the synthesis of cyclic polycarboxylic anhydrides includes: o-Carboxyphenylacetic acid groups: can be used or adapted to the synthesis described in US 6797838; Itoric acid groups: can be synthesized using or adapted from “Sonochimie ultrasonique”, Vol. 14, No. 5, July 2007, pp. 497-501.

[0103] Starting glycerol polyester (i.e., before crosslinking) The starting glycerol polyester can be a polyester of glycerol and dicarboxylic acid monomers, or a polyester of glycerol and dicarboxylic acid diester monomers.

[0104] The dicarboxylic acid monomer or dicarboxylic acid diester monomer is aliphatic. The aliphatic dicarboxylic acid monomer or dicarboxylic acid diester monomer preferably contains 3 to 36 carbon atoms, more preferably 4 to 36 carbon atoms.

[0105] According to a preferred variant of the invention, the dicarboxylic acid monomer is saturated, more particularly linear or branched, preferably (C3-C4) 20 Alkyl dicarboxylic acid, more preferably (C8-C 15 )Alkyldicarboxylic acid. (C x -C y Alkyl groups are saturated, straight-chain or branched divalent hydrocarbon groups containing x to y carbon atoms.

[0106] According to a preferred variant of the invention, the dicarboxylic acid monomer or dicarboxylic acid ester monomer conforms to the general formula R'OOC-(CH2). p -COOR', where p represents an integer ranging from 1 to 30, preferably from 1 to 10, and R' represents H (hydrogen atom), or each R' independently represents a straight-chain or branched C1-C. 10 Preferably C1-C4 alkyl, more preferably methyl or ethyl.

[0107] Dicarboxylic acid monomers advantageously include those of the general formula [HOOC-(CH2)]. p A diacid of the formula [-COOH], or derived from the general formula [HOOC-(CH2] p The diacid composition of [-COOH], wherein p is a number ranging from 1 to 30, preferably ranging from 5 to 10.

[0108] In particular, according to these variants, the dicarboxylic acid monomer can be selected from malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, dodecanoic acid, hexadecanoic acid, octadecanoic acid, and mixtures of two or more of these dicarboxylic acids.

[0109] Preferably, the dicarboxylic acid monomer may be selected from malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, and mixtures of two or more of these dicarboxylic acids.

[0110] According to a variant of the invention, the dicarboxylic acid monomer can be a mixture of at least two dicarboxylic acids. Preferably, in this case, the dicarboxylic acid monomer includes sebacic acid.

[0111] The dicarboxylic acid monomer preferably includes sebacic acid, or is composed of sebacic acid.

[0112] According to a preferred variant of the invention, the dicarboxylic acid monomer and glycerol are the only monomers in the polycondensation. Very preferably, the sebacic acid monomer and glycerol are the only constituent monomers in the polyester of glycerol and dicarboxylic acid monomer.

[0113] According to other variants, the monomer conforms to the general formula R''OOC-(CH2). n -COOR'' dicarboxylic acid diesters, where n represents an integer ranging from 1 to 30, preferably from 1 to 10, and each R'' independently represents a straight-chain or branched C1-C 10 Preferably C1-C4 alkyl, more preferably methyl and ethyl.

[0114] In particular, according to these variants of the invention, the monomer (which is a dialkyl ester of a dicarboxylic acid) may be selected from dialkyl esters corresponding to malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, or mixtures of two or more of these dicarboxylic acid diesters. More preferably, the dicarboxylic acid diester is selected from dimethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, dimethyl pimelic acid, dimethyl octanoate, dimethyl azelaic acid, dimethyl sebacic acid, and mixtures thereof. According to some variants of the invention, the dicarboxylic acid diester monomer may be a mixture of at least two different dicarboxylic acid diesters. Preferably, in this case, the dicarboxylic acid diester monomer includes dimethyl sebacic acid.

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

[0116] According to a preferred variant of the invention, the dicarboxylic acid diester monomer and glycerol are the only monomers. Very preferably, in this case, the dimethyl sebacate monomer and glycerol are the only monomers.

[0117] The molar ratio of glycerol to dicarboxylic acid or diester monomers is advantageously in the range of 1 / 2 to 10 / 1, particularly 1 / 1 to 5 / 1, and preferably 1 / 1 to 2 / 1.

[0118] Polyesters of glycerol and aliphatic dicarboxylic acids or diester monomers (hereinafter referred to as uncrosslinked polyesters) advantageously exhibit one or more of the following characteristics: - Number-average molar mass (Mn) of uncrosslinked polyester greater than or equal to 1500 g / mol, preferably greater than or equal to 2000 g / mol. - Number-average molar mass (Mn) of uncrosslinked 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. - The polydispersity Ip (Mw / Mn) of the uncrosslinked polyester is less than 10, preferably less than or equal to 8. - Residual monomer content less than or equal to 5% by weight of the uncrosslinked polyester; - The content of 1,2,3-triacylglycerol units less than or equal to 20 mol% relative to all units of the uncrosslinked polyester, and particularly less than or equal to 15 mol%. - The molar ratio of 1,3-diacylglycerol units to 1,2-diacylglycerol units in an uncrosslinked polyester greater than 1.

[0119] Polyesters of glycerol and aliphatic dicarboxylic acid monomers can be obtained, in particular, by practicing the methods described in EP3149067 and EP1448656. Polyesters of glycerol and aliphatic dicarboxylic acid ester monomers can be obtained, in particular, by practicing the methods described in FR2315383.

[0120] Number-average molar mass (Mn), weight-average molar mass (Mw), and dispersibility (also known as polydispersity and expressed as...) The Mw / Mn ratio can be measured in a known manner by size exclusion chromatography (SEC), particularly as described below.

[0121] The content of residual monomers and the content of 1,2,3-triacylglycerol units are determined in a known manner by... 1 H NMR measurements, combined with 2D HSQC / HMBC and, where appropriate, 13 C NMR experiment.

[0122] Crosslinking Advantageously, the crosslinking step includes the following steps: a) Contacting 100 parts by weight of at least one glycerol with a polyester of an aliphatic dicarboxylic acid or diester monomer with 0.1 parts by weight to 200 parts by weight of at least one cyclic polycarboxylic anhydride as defined herein, thereby obtaining a crosslinking precursor mixture. b) Pressurize the mixture obtained in the crosslinking precursor step of step a) to a target temperature T ranging from 100°C to 200°C. c and maintained under pressure (at temperature T) c (Under pressure) sufficient heating time t to obtain cross-linked polyester ch , c) Cool and recycle the cross-linked polyester.

[0123] Typically, step a) involves contacting 100 parts by weight of at least one glycerol with a polyester of an aliphatic dicarboxylic acid or diester monomer with 10 to 100 parts by weight, particularly 15 to 90 parts by weight of at least one cyclic polycarboxylic anhydride.

[0124] Contact step a) is preferably carried out in the absence of solvents, diluents or other additives.

[0125] Step a) comprises mixing at least one glycerol with a polyester of aliphatic dicarboxylic acid or diester monomers and at least one cyclic polycarboxylic anhydride, preferably at a temperature T capable of melting the glycerol and the polyester of aliphatic dicarboxylic acid or diester monomers, and preferably capable of uniformly dispersing the cyclic polycarboxylic anhydride. a Below. Therefore, T a The temperature range is typically 20°C to 100°C, especially 30°C to 80°C.

[0126] To promote homogenization, stirring can be set up in a known manner. Therefore, step a) is usually carried out under stirring.

[0127] According to a particular embodiment of the invention, contact is carried out by introducing a cyclic polycarboxylic anhydride in solid form.

[0128] Advantageously, in step b), a flatbed press will be used, the press plates of which have been preheated to temperature T. c .

[0129] In step b), the temperature Tc typically ranges from 110°C to 175°C, and preferably from 120°C to 160°C.

[0130] Advantageously, the overpressure (relative to atmospheric pressure) applied by the press in heating step b) varies from 50 kPa to 500 kPa (equivalent to 0.5 bar to 5 bar), and particularly from 1 bar to 4 bar.

[0131] The heating time is determined by the duration between the moment the press is turned off and the moment the press is turned on.

[0132] Typically, heating time t ch The range is from 10 min to 2000 min.

[0133] In step c), the crosslinked polyester is typically cooled and recycled at ambient temperature and atmospheric pressure.

[0134] Polyacid anhydrides, as crosslinking agents, have the following advantages: Polyacid anhydrides can form elastic networks with crosslinking points containing hydrolyzable ester groups. The resulting material is also biodegradable because it fully retains the degradation properties of polyesters, especially polyesters of glycerol and sebacic acid (poly(glycerol sebacic acid)).

[0135] Unlike polyacyl chlorides that produce hydrogen chloride or polyacids that produce water during the reaction, the reaction does not cause the formation of byproducts that can lead to the hydrolysis of polyester chains.

[0136] Finally, compared to diisocyanates (whose use is described as a crosslinking agent to form non-hydrolyzable or less hydrolyzable polyurethane bonds), polyanhydrides represent a more favorable alternative because they reduce toxicological risks.

[0137] II. Crosslinking Composition The present invention also relates to a crosslinking composition comprising: ○ 100 parts by weight of a polyester of at least one glycerol and an aliphatic dicarboxylic acid or diester monomer, ○ 0.1 parts by weight to 200 parts by weight of at least one cyclic polycarboxylic anhydride as defined above.

[0138] Preferably, the composition comprises 10 to 100 parts by weight, particularly 15 to 90 parts by weight, of at least one cyclic polycarboxylic anhydride.

[0139] The polyesters of glycerol and aliphatic dicarboxylic acids or diester monomers and cyclic polycarboxylic anhydrides may be as defined in Part 1 above.

[0140] Advantageously, the cross-linking product of glycerol with aliphatic dicarboxylic acid or diester monomers and cyclic polycarboxylic anhydride A contains only ester functional groups.

[0141] III. Crosslinked Polyester The present invention also relates to polyesters using at least one cyclic polycarboxylic anhydride crosslinked with glycerol and an aliphatic dicarboxylic acid or diester monomer as defined herein, having an elongation at break ranging from 20% to 300% as measured according to standard ASTM D 1708.

[0142] Crosslinked polyesters can be obtained by the method of the present invention.

[0143] Advantageously, the cross-linked polyester has a Shore A hardness range of 10 to 90 at ambient temperature, as measured according to standard ASTM D 2240.

[0144] Example The following examples are given by way of illustration, but should not be regarded as limiting the invention.

[0145] 1. Materials and Methods 1.1 Characteristics of the starting products [Table 2] Steps for synthesizing starting polyesters for glycerol and sebacic acid: In a 10-liter jacketed stainless steel reactor, glycerol (1.94 kg, 1 molar equivalent) and water (0.56 kg) were mixed at 40°C under a nitrogen flow (0.5 L / min). An instrumented distillation column configured for total reflux and a condenser connected to a distillate recovery vessel were mounted above the jacketed stainless steel reactor. Gentle stirring (20 rpm) was applied for 5 minutes. After the glycerol dissolved, sebacic acid (4.25 kg, 1 molar equivalent) was added to the aqueous mixture in the reactor. Finally, the remaining water (0.56 kg) was added to the medium. The reactor vessel was then gradually heated (following a gradual temperature gradient with an intermediate plateau) until a jacket temperature of 172°C was reached after 5 hours (corresponding to a medium temperature of 170°C as measured using an immersion probe). When the medium temperature exceeded 90°C, stirring was increased to 80 rpm. At the start of the test, the medium was in reflux. When the steam temperature at the top of the distillation column reaches 98°C, and after a 15-minute equilibration time, the column configuration is switched to full recovery to selectively recover the water generated during the reaction.

[0146] Esterification of the medium was carried out over a total duration of 8 hours and 30 minutes (starting from the moment distillation began, approximately 30 minutes after the introduction of the reactants). The water distilled during the test was recovered in a dedicated insulated recovery vessel.

[0147] Subsequently, a vacuum device was connected to the distillation condenser, and a pressure below atmospheric pressure was applied to the contents of the reactor. The pressure was slowly reduced to the target value of less than 30 mbar over approximately 30 minutes, through plateaus (approximately 10% to 15% per plateau).

[0148] After the pressure in the reaction vessel stabilized at 28 mbar, the medium was allowed to react for an additional 4 h at 170 °C. During this polycondensation step, the stirring speed was maintained at 80 rpm.

[0149] The generated PGS was transferred from the reactor vessel to a collection vessel and cooled to ambient temperature. The product was then transferred to a freezer for storage, remaining frozen for at least approximately 24 hours prior to analysis.

[0150] [Table 3] 1.2. Measurement Method Measurement of crosslinking kinetics: Crosslinking kinetics were measured using an Anton Paar MCR. Measurements included monitoring changes in the elastic modulus of the compositions at 1% deformation and a frequency of 1 Hz at 140°C. The time required to crosslink various compositions was measured to achieve an elastic modulus of 1 MPa.

[0151] Measurement of Shore A hardness: Shore A hardness was measured using a portable Shore hardness tester at ambient temperature (23℃±2℃) according to standard ASTM D2240.

[0152] Samples were prepared according to the protocol described in Section 2.2 below. The applied time t was determined according to the method used to measure crosslinking kinetics. ch The time required for the elastic modulus to reach a value of 1 MPa.

[0153] Measurement of elongation at break (EB, expressed as a percentage): Mechanical tensile testing was performed on an Instron elongator equipped with a 1 kN load sensor at an ambient temperature (23°C ± 2°C) using dumbbell specimens (thickness = 2 ± 0.5 mm) at a rate of 50 mm / min, according to standard ASTM D1708.

[0154] Macroeconomic structural analysis: SEC RI Size exclusion chromatography (SEC) technology separates macromolecules in solution based on their size by using a column packed with porous gel. Macromolecules are separated according to their hydrodynamic volume, with the largest macromolecules being eluted first.

[0155] SEC enables the understanding of the molar mass distribution of polymers, but it is not an absolute method. From commercial standard products, individual number-average molar masses (Mn) and weight-average molar masses (Mw) can be determined, and the polydispersity index (Ip = Mw / Mn) (also known as "dispersion") can be calculated.

[0156] The “macrostructure” of uncrosslinked polyesters was analyzed by size exclusion chromatography (SEC RI) with a differential refractive index detector, using low molecular weight polystyrene (PS) calibrated with intermediate molecular weight standards. The sample was dissolved in butylated hydroxytoluene (BHT)-free THF at a concentration of approximately 1 g / L and stirred for two hours prior to injection. The analysis was performed at 35 °C with a mobile phase flow rate of 1 mL / min using an Agilent 2 Mixed E+2 Mixed 2 column.

[0157] 2. Results 2.1. The tested formula The compositions studied are presented below. Content is expressed as mass % or phr (parts per hundred parts of rubber (i.e., polyester of glycerol and aliphatic dicarboxylic acid)).

[0158] The “reference” mixture used for each comparison was a high molecular weight poly(glycerol sebacate) polymer used alone (i.e., crosslinked without a crosslinking agent, particularly a cyclic carboxylic anhydride type). The preparation method used was the same as that described in Section 2.2, but without cyclic polycarboxylic anhydrides. It was then heat-treated at 140°C for 2880 min in a flatbed press.

[0159] ·Benzophenone-3,3',4,4'-tetracarboxylic dianhydride [Table 4] ·4,4'-(4,4'-isopropylidenediphenoxy)bis(phthalic anhydride) [Table 5] ·4,4'-O-diphthalic anhydride [Table 6] ·3,3',4,4'-Biphenyltetracarboxylic dianhydride [Table 7] 2.2. Preparation scheme for cross-linked polyester Step a) Place a 100 ml beaker on a heating plate equipped with a PT100 probe to control the temperature.

[0160] Poly(glycerol sebacate) is introduced.

[0161] Heat the polymer to 50°C while mixing it with a spatula.

[0162] In another preparation method, dianhydrides are added in various proportions.

[0163] Use a spatula to mix until a homogeneous mixture is obtained.

[0164] Cool to ambient temperature.

[0165] Step b): Crosslinking Place the mixture in the middle of a 2 mm mold between two silicone sheets: 15 g of the desired formulation.

[0166] Placed in a flatbed press at 140℃ (without humidity control).

[0167] The desired time t is predetermined according to the method for measuring crosslinking kinetics described in Part 1. ch During this time, the material undergoes crosslinking. The applied time t is determined according to the method used to measure crosslinking kinetics. chThe time required for the elastic modulus to reach a value of 1 MPa.

[0168] Cool to ambient temperature.

[0169] 2.3. Characterization of cross-linked polyesters Properties of benzophenone-3,3',4,4'-tetracarboxylic dianhydride [Table 8] Properties of 4,4'-(4,4'-isopropylidene diphenoxy)bis(phthalic anhydride) [Table 9] Properties of 4,4'-Oxyphthalic anhydride [Table 10] Properties of 3,3',4,4'-biphenyltetracarboxylic dianhydride [Table 11] 3. Discussion For all compositions containing polyanhydride compounds, a systematic reduction in crosslinking time was observed, and this reduction was more significant at higher concentrations of polyanhydride compounds.

[0170] The greater the amount of polyanhydride introduced, the greater the Shore A hardness. This clearly demonstrates that the degree of crosslinking is indeed related to the concentration of polyanhydride, and therefore, polyanhydride is indeed the root cause of crosslinking. The obtained Shore A values ​​are very close to or near those of the control PGS without polyanhydride.

[0171] Furthermore, compared with the control PGS alone which does not contain polyanhydrides, the elongation at break (EB (%)) of the composition according to the invention was increased by 10 to 20 times, which is a very significant improvement. Claims (as amended under Article 19 of the Treaty) 1. A method for preparing a crosslinked polyester of glycerol with an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters, the method comprising the step of crosslinking the polyester of glycerol with an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters using a cyclic polycarboxylic anhydride A, said cyclic polycarboxylic anhydride A comprising at least two cyclic carboxylic anhydride groups and said cyclic polycarboxylic anhydride A not containing any straight-chain carboxylic anhydride functional groups. 2. The method according to claim 1, wherein the cyclic carboxylic anhydride group of the cyclic polycarboxylic anhydride A is independently selected from phthalic acid groups, succinic acid groups, maleic acid groups, o-carboxyphenylacetic acid groups and itoric acid groups, preferably selected from phthalic acid groups, succinic acid groups, maleic acid groups and o-carboxyphenylacetic acid groups. 3. The method according to any one of the preceding claims, wherein the cyclic carboxylic anhydride groups of the cyclic polycarboxylic anhydride A are fused together, connected to each other by at least one covalent bond or carried by a spacer group L. L represents -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -NR n R n’ -, where R n and R n’ The hydrocarbon group is independently selected from H or C1-C6 alkyl groups, or from a polyvalent cyclic or acyclic, saturated, unsaturated, or aromatic hydrocarbon group containing 1 to 40 carbon atoms, wherein the hydrocarbon group may contain one or more heteroatoms selected from O, S, Cl, Br, F, N, P, or Si. L does not contain straight-chain anhydride groups. 4. The method according to any one of the preceding claims, wherein the cyclic polycarboxylic anhydride A comprises a compound of formula (I) or (II), or a compound of formula (I) or (II): (I) or (II) in L1 represents the bond, -O-, -S-, -S(O)-, -S(O)2-, -NR n R n’ -, where R n and R n’ Independently selected from H or C1-C6 alkyl, -C(O)- or aliphatic chains having 1 to 30 carbon atoms, wherein 1 to 6 methylene units are optionally replaced by arylene, heteroarylene, -C(O)-, -O-, -S-, -S(O-, -S(O)2-, -NR m - Replacement, where R m Selected from H or C1-C6 alkyl, -P-, -P(O)-, -SiR a R b -, where R a and R b Each can independently represent -OH, C1-C6 alkyl, or C1-C6 alkoxy. The aliphatic chain is substituted with one or more, particularly one or two C1-C6 alkyl or C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom or C1-C6 haloalkyl, or is unsubstituted. • Z1 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z1 either does not exist or represents a -CH2- group. • Z2 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z2 either does not exist or represents a -CH2- group. • X independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·n represents an integer ranging from 0 to 3, preferably from 0 to 2. • Y independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·m represents an integer ranging from 0 to 3, preferably from 0 to 2. A1 indicates: ○ The C-C bond or C=C bond connecting the four carbon atoms of the two carboxylic anhydride functional groups. ○ A saturated, unsaturated, or aromatic optionally bridged carbon ring, said carbon ring comprising 4 to 30 carbon atoms, and ○ A saturated, unsaturated, or aromatic optionally bridged heterocycle, the heterocycle comprising 4 to 30 carbon atoms, and The carbocyclic or heterocyclic ring is substituted with one or more substituents, or is unsubstituted, wherein the substituents are selected from C1-C6 alkyl, hydroxy, C1-C6 alkoxy, nitro, cyano, or halogen atoms. 5. The method 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 with a polyester of an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters with 0.1 parts by weight to 200 parts by weight of at least one cyclic polycarboxylic anhydride as defined in any one of claims 1 to 4, thereby obtaining a mixture of crosslinking precursors. b) Pressurize the mixture obtained in the crosslinking precursor step of step a) to a target temperature T ranging from 100°C to 200°C. c and at temperature T c The heating time t under pressure is sufficient to obtain cross-linked polyester. ch , c) Cool and recycle the cross-linked polyester. 6. The method of claim 5, wherein step a) comprises contacting 100 parts by weight of at least one glycerol with a polyester of an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters with 10 to 100 parts by weight of at least one cyclic polycarboxylic anhydride. 7. The method according to any one of claims 5 to 6, wherein the temperature T c The temperature range is 110°C to 175°C, preferably 120°C to 160°C. 8. The method according to any one of claims 5 to 7, wherein the overpressure applied by the press in heating step b) ranges from 50 kPa to 500 kPa. 9. The method according to any one of claims 5 to 8, wherein the heating time tch The range is from 10 min to 2000 min. 10. A crosslinking composition, said crosslinking composition comprising: ○ 100 parts by weight of at least one glycerol and a polyester selected from aliphatic monomers of dicarboxylic acids and dicarboxylic acid diesters, ○ 0.1 parts by weight to 200 parts by weight of at least one cyclic polycarboxylic anhydride as defined in any one of claims 1 to 4. 11. The composition according to claim 10, wherein the dicarboxylic acid monomer or dicarboxylic acid ester monomer conforms to the general formula R'OOC-(CH2). p -COOR', where p represents an integer ranging from 1 to 30, preferably from 1 to 10, more preferably p=8, and R' represents H, or each R' independently represents a linear or branched C1-C 10 Preferably C1-C4 alkyl, more preferably methyl or ethyl. 12. The composition according to claim 10 or 11, wherein the number-average molar mass M of glycerol and the polyester selected from aliphatic monomers of dicarboxylic acids and dicarboxylic acid diesters is... n Less than or equal to 10,000 g / mol, the number-average molar mass was determined by size exclusion chromatography (SEC). 13. The composition according to any one of claims 10 to 12, wherein the cyclic polycarboxylic anhydride comprises a compound of formula (I) or (II): (I) or (II) in L1 represents the bond, -O-, -S-, -S(O)-, -S(O)2-, -NR n R n’ -, where R n and R n’ Independently selected from H or C1-C6 alkyl, -C(O)- or aliphatic chains having 1 to 30 carbon atoms, wherein 1 to 6 methylene units are optionally replaced by arylene, heteroarylene, -C(O)-, -O-, -S-, -S(O-, -S(O)2-, -NR m - Replacement, where R m Selected from H or C1-C6 alkyl, -P-, -P(O)-, -SiR a R b -, where R a and R b Each can independently represent -OH, C1-C6 alkyl, or C1-C6 alkoxy. The aliphatic chain is substituted with one or more, particularly one or two C1-C6 alkyl or C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom or C1-C6 haloalkyl, or is unsubstituted. • Z1 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z1 either does not exist or represents a -CH2- group. • Z2 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z2 either does not exist or represents a -CH2- group. • X independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·n represents an integer ranging from 0 to 3, preferably from 0 to 2. • Y independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·m represents an integer ranging from 0 to 3, preferably from 0 to 2. A1 indicates: ○ The C-C bond or C=C bond connecting the four carbon atoms of the two carboxylic anhydride functional groups. ○ A saturated, unsaturated, or aromatic optionally bridged carbon ring, said carbon ring comprising 4 to 30 carbon atoms, and ○ A saturated, unsaturated, or aromatic optionally bridged heterocycle, the heterocycle comprising 4 to 30 carbon atoms, and The carbocyclic or heterocyclic ring is substituted with one or more substituents, or is unsubstituted, wherein the substituents are selected from C1-C6 alkyl, hydroxy, C1-C6 alkoxy, nitro, cyano, or halogen atoms. 14. The composition according to any one of claims 10 to 13, wherein at least one cyclic polycarboxylic anhydride comprises a compound of formula (III) or (IV): (III) (IV) in Indicates a single or double C bond. L2 and L3, together with the carbon atoms to which they are bonded, represent a saturated, unsaturated, or aromatic carbocyclic or heterocyclic ring containing 4 to 30 carbon atoms, and the carbocyclic or heterocyclic ring is substituted by one or more substituents, or is unsubstituted, the substituents being selected from C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atoms. 15. The composition according to claim 13, wherein L1 represents a bond or an aliphatic chain having 1 to 6 carbon atoms, and one or both methylene units are optionally replaced by aryl, -C(O)-, -O-, -S-, -S(O)-, -S(O)2-. The aliphatic chain is preferably substituted with a group selected from C1-C6 alkyl, C1-C6 alkoxy, or C1-C6 haloalkyl groups, or is unsubstituted. 16. A polyester using at least one cyclic polycarboxylic anhydride-crosslinked glycerol as defined in claims 1 to 4 or 10 to 15 and an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters, said polyester having an elongation at break ranging from 20% to 300% as measured according to standard ASTM D 1708. 17. The crosslinked polyester according to claim 16, wherein the crosslinked polyester can be obtained by the method according to any one of claims 1 to 9. 18. The polyester according to any one of claims 16 and 17, characterized in that the crosslinked polyester has a Shore A hardness ranging from 10 to 90 as measured at room temperature according to standard ASTM D 2240.

Claims

1. A method for preparing a crosslinked polyester of glycerol with an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters, the method comprising the step of crosslinking the polyester of glycerol with an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters using a cyclic polycarboxylic anhydride A, said cyclic polycarboxylic anhydride A comprising at least two cyclic carboxylic anhydride groups and said cyclic polycarboxylic anhydride A not containing any straight-chain carboxylic anhydride functional groups.

2. The method according to claim 1, wherein, The cyclic carboxylic anhydride group of the cyclic polycarboxylic anhydride A is independently selected from phthalic acid groups, succinic acid groups, maleic acid groups, o-carboxyphenylacetic acid groups, and itoric acid groups, preferably selected from phthalic acid groups, succinic acid groups, maleic acid groups, and o-carboxyphenylacetic acid groups.

3. The method according to any one of the preceding claims, wherein, The cyclic carboxylic anhydride groups of the cyclic polycarboxylic anhydride A are fused together, connected to each other by at least one covalent bond or carried by a spacer group L. L represents -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -NR n R n’ -, where R n and R n’ The hydrocarbon group is independently selected from H or C1-C6 alkyl groups, or from a polyvalent cyclic or acyclic, saturated, unsaturated, or aromatic hydrocarbon group containing 1 to 40 carbon atoms, wherein the hydrocarbon group may contain one or more heteroatoms selected from O, S, Cl, Br, F, N, P, or Si. L does not contain straight-chain anhydride groups.

4. The method according to any one of the preceding claims, wherein, The cyclic polycarboxylic anhydride A comprises a compound of formula (I) or (II), or a compound of formula (I) or (II): (I)or (II) in L1 represents the bond, -O-, -S-, -S(O)-, -S(O)2-, -NR n R n’ -, where R n and R n’ Independently selected from H or C1-C6 alkyl, -C(O)- or aliphatic chains having 1 to 30 carbon atoms, wherein 1 to 6 methylene units are optionally replaced by arylene, heteroarylene, -C(O)-, -O-, -S-, -S(O-, -S(O)2-, -NR m - Replacement, where R m Selected from H or C1-C6 alkyl, -P-, -P(O)-, -SiR a R b -, where R a and R b Each can independently represent -OH, C1-C6 alkyl, or C1-C6 alkoxy. The aliphatic chain is substituted with one or more, particularly one or two C1-C6 alkyl or C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom or C1-C6 haloalkyl, or is unsubstituted. • Z1 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z1 either does not exist or represents a -CH2- group. • Z2 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z2 either does not exist or represents a -CH2- group. • X independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·n represents an integer ranging from 0 to 3, preferably from 0 to 2. • Y independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·m represents an integer ranging from 0 to 3, preferably from 0 to 2. A1 indicates: ○ The C-C bond or C=C bond connecting the four carbon atoms of the two carboxylic anhydride functional groups. ○ A saturated, unsaturated, or aromatic optionally bridged carbon ring, said carbon ring comprising 4 to 30 carbon atoms, and ○ A saturated, unsaturated, or aromatic optionally bridged heterocycle, the heterocycle comprising 4 to 30 carbon atoms, and The carbocyclic or heterocyclic ring is substituted with one or more substituents, or is unsubstituted, wherein the substituents are selected from C1-C6 alkyl, hydroxy, C1-C6 alkoxy, nitro, cyano, or halogen atoms.

5. The method according to any one of the preceding claims, wherein, The crosslinking process includes the following steps: a) Contacting 100 parts by weight of at least one glycerol with a polyester of an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters with 0.1 parts by weight to 200 parts by weight of at least one cyclic polycarboxylic anhydride as defined in any one of claims 1 to 4, thereby obtaining a mixture of crosslinking precursors. b) Pressurize the mixture obtained in the crosslinking precursor step of step a) to a target temperature T ranging from 100°C to 200°C. c and at temperature T c The heating time t under pressure is sufficient to obtain cross-linked polyester. ch , c) Cool and recycle the cross-linked polyester.

6. The method according to claim 5, wherein, Step a) comprises contacting 100 parts by weight of at least one glycerol with a polyester of an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters with 10 to 100 parts by weight of at least one cyclic polycarboxylic anhydride.

7. The method according to any one of claims 5 to 6, wherein, Temperature T c The temperature range is 110°C to 175°C, preferably 120°C to 160°C.

8. The method according to any one of claims 5 to 7, wherein, The overpressure applied by the press in heating step b) ranges from 50 kPa to 500 kPa.

9. The method according to any one of claims 5 to 8, wherein, Heating time t ch The range is from 10 min to 2000 min.

10. A crosslinking composition, said crosslinking composition comprising: ○ 100 parts by weight of at least one glycerol and a polyester selected from aliphatic monomers of dicarboxylic acids and dicarboxylic acid diesters, ○ 0.1 parts by weight to 200 parts by weight of at least one cyclic polycarboxylic anhydride as defined in any one of claims 1 to 4.

11. The composition according to claim 10, wherein, Dicarboxylic acid monomers or dicarboxylic acid ester monomers conform to the general formula R'OOC-(CH2). p -COOR', where p represents an integer ranging from 1 to 30, preferably from 1 to 10, more preferably p=8, and R' represents H, or each R' independently represents a linear or branched C1-C 10 Preferably C1-C4 alkyl, more preferably methyl or ethyl.

12. The composition according to claim 10 or 11, wherein, The number-average molar mass M of glycerol and polyesters selected from aliphatic monomers of dicarboxylic acids and dicarboxylic acid diesters n Less than or equal to 10000 g / mol.

13. The composition according to any one of claims 10 to 12, wherein, The cyclic polycarboxylic anhydrides include compounds of formula (I) or (II): (I)or (II) in L1 represents the bond, -O-, -S-, -S(O)-, -S(O)2-, -NR n R n’ -, where R n and R n’ Independently selected from H or C1-C6 alkyl, -C(O)- or aliphatic chains having 1 to 30 carbon atoms, wherein 1 to 6 methylene units are optionally replaced by arylene, heteroarylene, -C(O)-, -O-, -S-, -S(O-, -S(O)2-, -NR m - Replacement, where R m Selected from H or C1-C6 alkyl, -P-, -P(O)-, -SiR a R b -, where R a and R b Each can independently represent -OH, C1-C6 alkyl, or C1-C6 alkoxy. The aliphatic chain is substituted with one or more, particularly one or two C1-C6 alkyl or C1-C6 alkoxy, hydroxyl, nitro, cyano, halogen atom or C1-C6 haloalkyl, or is unsubstituted. • Z1 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z1 either does not exist or represents a -CH2- group. • Z2 either does not exist or represents a -CH2- (methylene) or -NH- group; preferably, Z2 either does not exist or represents a -CH2- group. • X independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·n represents an integer ranging from 0 to 3, preferably from 0 to 2. • Y independently represents a C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atom. ·m represents an integer ranging from 0 to 3, preferably from 0 to 2. A1 indicates: ○ The C-C bond or C=C bond connecting the four carbon atoms of the two carboxylic anhydride functional groups. ○ A saturated, unsaturated, or aromatic optionally bridged carbon ring, said carbon ring comprising 4 to 30 carbon atoms, and ○ A saturated, unsaturated, or aromatic optionally bridged heterocycle, the heterocycle comprising 4 to 30 carbon atoms, and The carbocyclic or heterocyclic ring is substituted with one or more substituents, or is unsubstituted, wherein the substituents are selected from C1-C6 alkyl, hydroxy, C1-C6 alkoxy, nitro, cyano, or halogen atoms.

14. The composition according to any one of claims 10 to 13, wherein, At least one cyclic polycarboxylic anhydride includes a compound of formula (III) or (IV): (III) (IV) in Indicates a single or double C bond. L2 and L3, together with the carbon atoms to which they are bonded, represent a saturated, unsaturated, or aromatic carbocyclic or heterocyclic ring containing 4 to 30 carbon atoms, and the carbocyclic or heterocyclic ring is substituted by one or more substituents, or is unsubstituted, the substituents being selected from C1-C6 alkyl, hydroxyl, C1-C6 alkoxy, nitro, cyano, or halogen atoms.

15. The composition according to claim 13, wherein, L1 represents a bond or an aliphatic chain with 1 to 6 carbon atoms, wherein one or two methylene units are optionally replaced by aryl, -C(O)-, -O-, -S-, -S(O)-, or -S(O)2-. The aliphatic chain is preferably substituted with a group selected from C1-C6 alkyl, C1-C6 alkoxy, or C1-C6 haloalkyl groups, or is unsubstituted.

16. A polyester using at least one cyclic polycarboxylic anhydride-crosslinked glycerol as defined in claims 1 to 4 or 10 to 15 and an aliphatic monomer selected from dicarboxylic acids and dicarboxylic acid diesters, said polyester having an elongation at break ranging from 20% to 300% as measured according to standard ASTM D.

17. The crosslinked polyester according to claim 16, wherein the crosslinked polyester can be obtained by the method according to any one of claims 1 to 9.

18. The polyester according to any one of claims 16 and 17, characterized in that, The Shore A hardness of cross-linked polyester, measured at room temperature according to standard ASTM D 2240, ranges from 10 to 90.

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