High molecular weight polymer

Abstract

The present invention relates to obtaining high molecular weight polymers thanks to a combination of purification and of particular polymerization conditions.

Description

[0001] HIGH MOLECULAR WEIGHT POLYMER

[0002] Technical field of the invention

[0003] The present invention relates to a method for preparing high molecular weight polymers of itaconic acid and / or one of the derivatives thereof thanks to a combination of purification and particular polymerization conditions of itaconic acid and / or one of the derivatives thereof.

[0004] Prior art

[0005] In recent years, monomers derived from renewable resources have become increasingly important and have started to constitute an alternative to chemical products of fossil origin. This development is mainly due to the imminent scarcity of fossil resources, the replacement of which will be one of the main challenges in the coming decades and to the increased public awareness and, consequently, the increase in demand for biosourced and renewable products in order to reduce the impact of man on the planet.

[0006] Intense research has been carried out to produce environmentally-friendly biopolymers obtained from renewable raw materials in order to replace the compounds of fossil origin. This is an essential aspect of the implementation of the circular bioeconomy strategy, expressly declared by the European Commission in 2018 in terms of “repair, reuse and recycling”.

[0007] In this context, itaconic acid has aroused strong interest in recent years by its biosourced origin, its biocompatibility and its biodegradability in polymer form. Its trifunctional structure also makes it a promising precursor for obtaining numerous chemical compounds and, in particular, new biopolymers being able to replace those coming from compounds of fossil origin. The US Energy Agency classified it, in 2004, as one of the 12 basic chemical compounds for promoting biorefineries and reducing the environmental impact of industries.

[0008] The main problem encountered during the preparation of polymers of itaconic acid is the low integration of this monomer and therefore the impossibility of obtaining homopolymers of high molecular weight and polymers of high molecular weight with a high itaconic acid content. The use of these polymers is thus limited to dispersants, superabsorbents or as drug carriers. In view of the current climate challenges, it is more than urgent to find solutions which make it possible to obtain high molecular weight polymers which correctly integrate itaconic acid in order to replace the polymers coming from compounds of fossil origin. Balilvand et al. (Journal of the Mechanical Behavior of Biomedical Materials, 2022, 126, 105020) discloses the preparation of polymers of itaconic acid wherein the itaconic acid is purified by recrystallization in water / ethanol.

[0009] Katime (Polymer Bulletin, 2002, 49, 119-126) studies the influence of the pH on the yield of polymerization of unpurified itaconic acid.

[0010] CN 105439845 A and et Hogle et al. (Ind.Eng.Chem.Res ., 2002, 41, 2069-2073) describes purification methods of itaconic acid.

[0011] The Applicant has discovered that the purification of itaconic acid under particular conditions in combination with particular polymerization conditions leads to the obtention of high molecular weight polymers which correctly integrate itaconic acid and thus make it possible to use it in numerous fields of application. The aim of the invention is a better integration of itaconic acid in the synthesis of polymers, and corresponds to the second principle of green chemistry, the saving of atoms. The method according to the invention makes it possible to reduce the E-factor, which is the measurement of the total quantity of waste produced by a reaction with respect to the quantity of final product.

[0012] The method according to the invention falls under a principle of environmental awareness and of the impact of industries and of man on the planet. The method according to the invention makes it possible to reduce the E-factor and therefore to reduce the total quantity of waste produced during the preparation of itaconic acid-based polymers. Thanks to the polymers obtained according to the method of the invention, it is possible to replace polymers coming from compounds of fossil origin with a biosourced and biodegradable equivalent, thus reducing the environmental impact of the industries using them.

[0013] The present invention is advantageously made from materials of biological origin, such as biomass, or recycled materials. The synthesis of the monomer used in the invention is advantageously a biological synthesis, for example by enzymatic catalysis or extracted from a renewable raw material. The energy used to implement the method according to the invention advantageously comes from a heat pump or a pump of renewable origin, for example, a wind or photovoltaic pump.

[0014] Summary of the invention The present invention relates to a method for preparing a polymer having a molecular weight of between 300 000 g / mol and 30 million g / mol, comprising the polymerization of at least one compound of formula (I), the polymer comprising:

[0015] - at least 15 mol% of the compound of formula (I) and / or the salts thereof: with:

[0016] - Z and Y, identical or different, represent: -OH, -O X+, ORa, NH2, NHRa, NRaRb;

[0017] X+being a metal cation or organic cation and

[0018] Ra and Rb, identical or different, represent a saturated or unsaturated, linear, branched or cyclic hydrocarbon chain, having from 1 to 30 carbon atoms, advantageously from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, and optionally one or more heteroatoms selected from among N, O, P and S, the hydrocarbon chain being optionally substituted with one or more groups selected from among acid, aryl, ester, amine, amide, carbamate, hydroxyl, ether, advantageously in C2 and / or C3, nitrile, vinyl, allyl, thioether or halogen groups; the polymerization being a radical polymerization in a heterogeneous or an insoluble medium for the polymer; the compound of formula (I) being a purified itaconic acid and / or one of the derivatives thereof; the purified itaconic acid being obtained by a method of purification comprising at least the following steps: i) mixing of itaconic acid with an aqueous solution comprising at least 80% by weight of an aqueous solvent based on the total weight of the aqueous solution, in order to form a suspension SI; ii) heating of the suspension SI at a temperature T1 between 30°C and 90°C at a ramp of 5°C / hour to 55 °C / hour, in order to obtain a solution Sol; iii) cooling of the solution Sol at a temperature T2 between 10°C and 50°C at a ramp of 2 °C / hour to 20°C / hour, in order to obtain a suspension S2 comprising crystals of purified itaconic acid; iv) liquid / solid separation of the suspension S2 in order to isolate the crystals of purified itaconic acid; v) optionally washing of the crystals of purified itaconic acid; vi) optionally drying of the washed crystals of purified itaconic acid.

[0019] The present invention also relates to the use of said polymer in: hydrocarbon recovery (oil or gas); drilling wells; cementing wells; stimulation of hydrocarbon wells (oil or gas) other than hydraulic fracturing, for example conformance or diversion; open, closed or semi-closed circuit water treatment; treatment of fermentation broth; sludge treatment; construction; paper or cardboard manufacture; the field of batteries; wood treatment; treatment of hydraulic composition (concrete, cement, mortar and aggregates); in the mining industry; formulation of cosmetic products; formulation of detergents; textile manufacture; geothermal energy; manufacture of nappies; or agriculture.

[0020] The present invention also relates to the use of said polymer as a flocculant, binding agent, fixing agent, viscosity reducing agent, thickening agent, absorbent agent, friction reducing agent, draining agent, filler retention agent, dehydrating agent, conditioning agent, stabilising agent, film-forming agent, bonding agent, superplasticising agent, clay inhibitor.

[0021] Description of the invention

[0022] By “polymer”, this means a homopolymer prepared only from a compound of formula (I) and / or its salts; or a copolymer prepared from at least two different monomers, it can therefore be an itaconic acid copolymer and / or a compound of formula (I) and / or their salts, and / or at least a monomer selected from among anionic hydrophilic monomers, cationic hydrophilic monomers, non-ionic hydrophilic monomers, zwitterionic hydrophilic monomers, hydrophobic monomers and their mixtures.

[0023] By “hydrophilic monomer” is meant a monomer which has a log (octanol / water partition coefficient), log(Kow), of less than or equal to 1 determined at 25 °C in an octanol / water mixture having a volume ratio of 1 / 1, at a pH between 6 and 8. By “hydrophobic monomer” is meant a monomer which has a log (octanol / water partition coefficient), log(Kow), greater than or equal to 1 determined at 25 °C in an octanol / water mixture having a volume ratio of 1 / 1, at a pH between 6 and 8.

[0024] The octanol-water partition coefficient, Kow, represents the concentration ratio (g / L) of a monomer between the octanol phase and the aqueous phase. It is defined as follows:

[0025] \monomer~\octanol

[0026] Kow= ~ - n -

[0027] [monomer]water

[0028] By “water-soluble polymer”, is meant a polymer which gives an aqueous solution without insoluble particle, when it is dissolved under stirring at 25°C and with a concentration of 10 g.l'1in deionised water.

[0029] By “itaconic acid derivative”, is meant a compound of formula (I) in which Z and Y, identical or different, are not a hydroxyl function -OH.

[0030] By “purified itaconic acid”, is meant the itaconic acid obtained according to the method of purification described in the invention.

[0031] By “unpurified itaconic acid”, is meant any itaconic acid other than that obtained according to the method of purification described in the invention. In particular, it can come directly from a fermentation broth or be commercial itaconic acid.

[0032] By “having from n to p carbon atoms” is meant comprising n to p carbon atom wherein “n” and “p” are integers

[0033] By “X and / or Y”, is meant, according to the invention, “X”, or “Y”, or “X and Y”.

[0034] All possible combinations between the different embodiments disclosed also form part of the invention, whether they are preferred embodiments or given as an example. Furthermore, when ranges of values are indicated, the limit values form part of these ranges. The disclosure also includes all of the combinations between the limit values of these ranges of values. For example, the ranges of values “1-20, preferably 5-15” imply the disclosure of the ranges “1- 5”, “1-15”, “5-20” and “15-20” and the values 1, 5, 15 and 20.

[0035] Throughout the application, the molecular weight means the weight-average molecular weight. All of the particular and / or preferred embodiments described in the invention can be combined, on the condition that they are not incompatible.

[0036] Polymer obtained by the method of polymerization of the invention

[0037] Monomeric composition

[0038] The polymer according to the invention has a molecular weight of between 300 000 g / mol and 30 million g / mol, and comprises:

[0039] - at least 15 mol% of at least one compound of formula (I) and / or the salts thereof: with:

[0040] - Z and Y, identical or different, represent: -OH, -O X+, ORa, NH2, NHRa, NRaRb; X+being a metal cation or organic cation and

[0041] Ra and Rb, identical or different, represent a saturated or unsaturated, linear, branched or cyclic hydrocarbon chain having from 1 to 30 carbon atoms, advantageously from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, and optionally one or more heteroatoms selected from among N, O, P and S, the hydrocarbon chain being optionally substituted by one or more groups selected from among acid, aryl, ester, amine, amide, carbamate, hydroxyl, ether, advantageously in C2 and / or C3, nitrile, vinyl, allyl, thioether or halogen groups; the compound of formula (I) is a purified itaconic acid and / or one of the derivatives thereof.

[0042] The polymer is advantageously water-soluble.

[0043] By salts of the compound of formula (I), is meant the substitution of a proton of at least one of the acid functions of the monomer (R-C(=O)-OH) by a metal cation or organic cation to form a salt (R-C(=0)-0‘ X+(X+being a metal cation or an organic cation)). The salification of the acid functions can be partial or total.

[0044] The metal cation is advantageously an alkali metal (Li, Na, K, etc.) or an alkaline earth metal (Ca, Mg, etc.), and the organic cation is advantageously ammonium ion or a tertiary ammonium ion. The preferred salts are sodium salt.

[0045] The salification can be done, partially or totally, before, during or after polymerization.

[0046] The polymer advantageously has a molecular weight of at least 500 000 g / mol, preferably of at least 1 million g / mol, more preferably of at least 2 million g / mol, more preferably of at least 3 million g / mol, and more preferably of at least 5 million g / mol. Generally, the molecular weight of the polymer does not exceed 25 million g / mol, preferably not more than 20 million g / mol, more preferably not more than 15 million g / mol, more preferably not more than 10 million g / mol.

[0047] The molecular weight is understood as a weight average molecular weight.

[0048] The molecular weight is determined by the intrinsic viscosity of the polymer. The intrinsic viscosity can be measured by methods known to a person skilled in the art and can be calculated from the reduced viscosity values for different polymer concentrations by a graphical method consisting of plotting the reduced viscosity values (y-axis) against the concentration (x-axis) and extrapolating the curve to zero concentration. The intrinsic viscosity value is plotted on the y-axis or by using the least-squares method. The molecular weight can thus be determined using the Mark-Houwink equation:

[0049] [>1] = K M"

[0050] [q| represents the intrinsic viscosity of the polymer as determined by the solution viscosity measurement method

[0051] K represents an empirical constant

[0052] M represents the molecular weight of the polymer a represents the Mark-Houwink coefficient

[0053] K and a depend on the particular polymer-solvent system.

[0054] In the case where the compound of formula (I) is an itaconic acid derivative, the latter is obtained by chemical transformation of the purified itaconic acid and / or the salts thereof. The chemical reactions that transform purified itaconic acid and / or the salts thereof to an itaconic acid derivative are simple and conventional reactions known to a person skilled in the art and which form part of their general knowledge.

[0055] The polymer can further comprise at least one other monomer, other than purified itaconic acid and / or one of the derivatives thereof, selected from: anionic hydrophilic monomers, nonionic hydrophilic monomers, cationic hydrophilic monomers, zwitterionic hydrophilic monomers, hydrophobic monomers and their mixtures.

[0056] Advantageously, the other anionic hydrophilic monomer(s) that may be used in the scope of the invention are selected from monomers having a vinyl group contained in particular in acrylic acid, maleic acid, fumaric acid, malonic acid or allyl group. They can also contain a carboxylate, phosphonate, phosphate, sulfonate, sulfate group, or another anionic charged group. Preferably, the anionic hydrophilic monomer(s) used in the scope of the invention are selected from: acrylic acid; methacrylic acid; dimethylacrylic acid; acryloyl chloride; crotonic acid; maleic acid; fumaric acid; 3-acrylamido 3 -methylbutanoic acid; strong acid monomers having, for example, a sulfonic acid or phosphonic acid group, such as vinylsulfonic acid, vinylphosphonic acid, allylsulfonic acid, methallylsulfonic acid, 2-methylidenepropane-l,3- disulfonic acid, 2-sulfoethylmethacrylate, sulfopropylmethacrylate, sulfopropylacrylate, allylphosphonic acid, ethylene glycol methacrylate phosphate, sulfonic styrene acid, 2- acrylamido-2-methylpropane sulfonic acid (AMPS), 2-acrylamido-2 -methylpropane disulfonic acid, 3-allyloxy-2-hydroxypropane sulfonic acid, diethylallylphosphonate, carboxy ethyle acrylate; water-soluble salts of these monomers such as their alkali metal salts, alkaline earth metals salts, or ammonium salts; and their mixtures.

[0057] The polymer advantageously comprises between 0 and 80 mol% of anionic hydrophilic monomer(s) other than purified itaconic acid.

[0058] In a particular embodiment of the invention, the anionic hydrophilic monomer(s) can be partially or totally salified.

[0059] By “salified”, this means the substitution of a proton of at least one acid function such as Ra(=O)-OH type (with Rarepresenting P, S or C) of the anionic monomer by a metal cation or organic cation to form a salt of the -Ra(=O)-O'X+type (X+being a metal cation or an organic cation). In other words, the non-salified form corresponds to the acid form of the monomer, for example Rb-C(=O)-OH in the case of the carboxylic acid function, while the salified form of the monomer corresponds to the Rb-C(=0)-0‘ X+form, X+corresponding to a metal cation or an organic cation. The salification of the acid functions can be partial or total.

[0060] The metal cation is advantageously an alkali metal (Li, Na, K, etc.) or an alkaline earth metal (Ca, Mg, etc.), and the organic cation is advantageously ammonium ion or a tertiary ammonium ion. The preferred salts are sodium salts.

[0061] The salification can be done, partially or totally, before, during or after polymerization.

[0062] Advantageously, the non-ionic hydrophilic monomer(s) that may be used in the scope of the invention are selected from acrylamide, methacrylamide, N-alkylacrylamides, N- alkylmethacrylamides, N,N-dialkyl acrylamides (for example, N,N-dimethylacrylamide or N,N-diethylacrylamide), N,N-dialkylmethacrylamides, acrylic acid alkyl esters, methacrylic acid alkyl esters, N-vinylpyrrolidone, N-methylol(meth)acrylamide, N-vinyl caprolactame, N- vinylformamide (NVF), N-vinyl acetamide, N-vinyl imidazole, N-vinyl succinimide, acryloyl morpholine (ACMO), glycidyl methacrylate, vinyl acetate, glyceryl methacrylate, diacetone acrylamide, methacrylic anhydride, acrylonitrile, maleic anhydride, itaconic anhydride, hydroxyalkyl (meth)acrylate, thioalkyl (meth)acrylate, isoprenol and its alkoxy derivatives, hydroxyethyl(meth)acrylates and their alkoxy derivatives, hydroxypropyl(meth)acrylate and its alkoxy derivatives, and their mixtures. In these non-ionic monomers, the alkyl groups are advantageously in C1-C5, more advantageously in C1-C3.

[0063] The polymer advantageously comprises between 0 and 80 mol% of non-ionic hydrophilic monomer(s).

[0064] Advantageously, the cationic hydrophilic monomer(s) that may be used in the scope of the invention are selected from monomers having a vinyl group contained, in particular in acrylamide, acrylic acid, maleic acid or allyl derivatives having an amine function or ammonium, advantageously quaternary ammonium. Preferably, the cationic hydrophilic monomer(s) are selected from diallyldialkyl ammonium salts like dimethyldiallylammonium chloride (DADMAC); acidified or quatemised N,N-dialkyl- aminoalkyl(meth)acrylamide salts, like for example (3-methacrylamidopropyl)trimethylammonium chloride (MAPTAC), (3-acrylamidopropyl)trimethylammonium chloride (APTAC); acidified or quatemised N,N- dialkyl-aminoalkyl acrylate salts like quatemised or salified dimethylaminoethyl acrylate (DMAEA); acidified or quatemised N,N-dialkyl aminoalkyl methacrylate salts like quatemised or salified dimethylaminoethyl methacrylate (DMAEMA); acidified or quatemised N,N-dimethylallylamine salts; acidified or quaternised diallylmethylamine salts; acidified or quatemised diallylamine salts; vinylamine obtained by hydrolysis (basic or acid) of an amide group -N(R2)-CO-R1with R1and R2being, independently, a hydrogen atom or an alkyl chain of 1 to 6 carbons, for example vinylamine coming from the hydrolysis of vinylformamide; vinylamine obtained by Hofmann degradation; and their mixtures. Advantageously, the alkyl groups are in C1-C7, preferably in C1-C3 and can be linear, cyclic, saturated or unsaturated hydrocarbon chains.

[0065] The polymer advantageously comprises between 0 and 80 mol% of cationic hydrophilic monomer(s).

[0066] A person skilled in the art will know how to prepare the quatemised monomers, for example by means of an R-X quaternisation agent, R being an alkyl group and X+ being a halogen or a sulfate.

[0067] By “quaternisation agent”, is meant a molecule that can alkylate a tertiary amine.

[0068] The quaternisation agent can be selected from dialkyl sulfates having from 1 to 6 carbon atoms or alkyl halides having from 1 to 6 carbon atoms. Preferably, the quaternisation agent is selected from methyl chloride, benzyl chloride, dimethyl sulfate or diethyl sulfate.

[0069] Furthermore, the present invention also covers DADMAC, APTAC and MAPTAC monomers, the counter-ion of which is a sulfate, a fluoride, a bromide or an iodide instead of chloride.

[0070] Advantageously, the zwitterionic hydrophilic monomer(s) that may be used in the scope of the invention are selected, in particular, from monomers having a vinyl group (advantageously contained in acrylamide, acrylic acid, maleic acid derivatives or allyl- contained groups compounds). This monomer has a quaternary ammonium group and a carboxylic acid (or carboxylate), sulfonic acid (or sulfonate) or phosphoric acid (or phosphate) group.

[0071] Advantageously, the zwitterionic hydrophilic monomer(s) used in the scope of the invention are selected from: dimethylaminoethyl acrylate derivatives, such as 2-[[2-9(acryloyloxy)ethyl] dimethylammonio]ethane-l -sulfonate, 3-[[2-(acryloyloxy) ethyl]dimethylammonio] propane- 1-sulfonate, 4-[[2-(acryloyloxy) ethyl]dimethylammonio]butane-l-sulfonate, [2-(acryloyloxy) ethyl](dimethylammonio)acetate; derivatives of dimethylaminoethyl methacrylate such as 2- [[2-(methacryloyloxy) ethyl]dimethylammonio]ethane-l-sulfonate, 3-[[2-

[0072] (methacryloyloxy)ethyl]dimethylammonio]propane-l-sulfonate, 4-[[2-

[0073] (methacryloyloxy)ethyl]dimethylammonio]butane- 1 -sulfonate, [2-

[0074] (methacryloyloxy)ethyl](dimethylammonio)acetate; derivatives of epropyl acrylamide dimethylamino such as 2-[3-acrylamidopropyl)dimethylammonio]ethane-l-sulfonate, 3-[(3- acrylamidopropyl)dimethylammonio]propane-l -sulfonate, 4-[(3- acrylamidopropyl)dimethylammonio]butane-l -sulfonate, [3-

[0075] (acryloyloxy)propyl](dimethylammonio)acetate, N-[3-

[0076] (dimethylamino)propyl]methacrylamide; derivatives such as 2-[(3- methacrylamidopropyl)dimethylammonio]ethane-l -sulfonate, 3-(dimethylammonio)propane- 1 -sulfonate, 4-[(3 -(methacrylamido)propyl](dimethyl)ammoniobutane- 1 -sulfonate and propyl [3 -(methacryloyloxy)](dimethylammonio)acetate; and mixtures thereof.

[0077] Other zwitterionic hydrophilic monomers can be used, in particular those described by the Applicant in document WO2021 / 123599.

[0078] The quantity of zwitterionic hydrophilic monomer is advantageously of less than 30 mol% based on the total molar quantity of monomers, preferably less than 10 mol%.

[0079] In a preferred embodiment, the polymer is free of zwitterionic hydrophilic monomers.

[0080] Preferably, the hydrophobic monomer(s) is selected from the group consisting of:

[0081] - anionic, cationic or non-ionic (meth)acrylic acid ester comprising:

[0082] (i) a C4-C30 alkyl group, or a C5-C30 aryl group, or

[0083] (ii) an arylalkyl constituted of a C4-C30 alkyl group and a C5-C30 aryl group, or

[0084] (iii) a propoxylated chain, or

[0085] (iv) a propoxylated and ethoxylated chain comprising both ethoxylated units and propoxylated units;

[0086] - sulfonated monomer having an unsaturated double bond and comprising:

[0087] (i) a C4-C30 alkyl group, or a C5-C30 aryl group, or

[0088] (ii) an arylalkyl constituted of a C4-C30 alkyl group and a C5-C30 aryl group, or

[0089] (iii) a propoxylated chain, or

[0090] (iv) a propoxylated and ethoxylated chain comprising both ethoxylated units and propoxylated units; - anionic, cationic or non-ionic mono-substituted or di -substituted (meth)acrylamide comprising:

[0091] (i) a C4-C30 alkyl group, or a C5-C30 aryl group, or

[0092] (ii) an arylalkyl constituted of a C4-C30 alkyl group and a C5-C30 aryl group, or

[0093] (iii) a propoxylated chain, or

[0094] (iv) a propoxylated and ethoxylated chain comprising both ethoxylated units and propoxylated units; and

[0095] - mixtures thereof.

[0096] The hydrophobic monomers can comprise halogen atoms, for example chlorine.

[0097] In these hydrophobic monomers:

[0098] - alkyl groups are preferably in C4-C20, more preferably in C4-C8 groups. C6-C20 alkyls are preferably linear alkyls, while C4-C5 alkyls are preferably branched,

[0099] - the arylalkyl groups are preferably in C7-C25, more preferably in C7-C15,

[0100] - ethoxylated chains advantageously comprise between 1 and 200 -CH2-CH2-O- groups, preferably between 6 and 100, more preferably between 10 and 40,

[0101] - propoxylated chains advantageously comprise between 1 and 50 -CH2-CH2-CH2-O- groups, more preferably between 1 and 20.

[0102] The preferred hydrophobic monomers are:

[0103] - n-hexyl (meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl (meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate, myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl (meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl (meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl (meth)acrylamide, N-tert-Butyl(meth)acrylamide, vinylpyridine, 2-ethylhexyl acrylate, C4-C22 itaconic acid hemi-esters, acidified or quatemised C4-C22 (meth)arcrylate dialkyl aminoalkyl salts, acidified or quaternised C4-C22 dialkyl-aminoalkyl(meth)acrylamide salts, undecanoic acrylamido acid, and their mixtures,

[0104] - cationic allyl derivatives of formula (II) or (III): wherein

[0105] R is an alkyl chain having from 1 to 4 carbons;

[0106] Ri: is an alkyl or arylalkyl chain having from 8 to 30 carbons; X is a halide selected from the group composed of bromides, chlorides, iodides, fluorides and of any negatively charged counter-ion; and, preferably, hydrophobic cationic derivatives containing a (meth)acryloyl group and represented by formula (IV): wherein

[0107] - A represents O or N-R5 (preferably, A represents N-R5),

[0108] - R2, R3, R4, Rs, Re, R7 are independently, a hydrogen atom or an alkyl chain containing 1 to 4 carbons,

[0109] - Q is an hydrocarbon chain having from 1 to 20 carbons, - Rs is an alkyl or arylalkyl chain having from 8 to 30 carbons, - X is a halide selected from the group composed of bromides, chlorides, iodides, fluorides, and any negatively charged counter-ion.

[0110] The polymer advantageously comprises less than 3 mol% hydrophobic monomers.

[0111] When the polymer is water-soluble and comprises hydrophobic monomers, they are present in a quantity such that the polymer remains soluble in water.

[0112] In a preferred embodiment, the polymer is free of hydrophobic monomers.

[0113] The quantities of the different monomers will be adjusted by a person skilled in the art in order not to exceed 100 mol% during the preparation of the polymer.

[0114] The polymer can be structured by a branching agent. By “structured”, this means a non-linear polymer which has side chains, it can have a branched shape, a star shape, a comb shape or a dendritic shape.

[0115] The branching agent is advantageously selected from:

[0116] - structuring agents, that can be selected from the group comprising unsaturated polyethylene compounds (having at least two unsaturated functions) different from the monomers described above, like for example, vinyl functions, in particular contained in allyl or acrylic groups, methylene bis acrylamide (MBA), triallyamine, or tetraallylammonium chloride or 1,2 dihydroxy ethylene bis-(N-acrylamide) can be cited as examples,

[0117] - compounds having at least two epoxy functions,

[0118] - compounds having at least one unsaturated function and one epoxy function,

[0119] - macroinitiators such as polyperoxides, polyazoics and transfer polyagents, such as polymercaptan polymers, and polyols,

[0120] - functionalised polysaccharides,

[0121] - water-soluble metal complexes composed:

[0122] * of a metal of a valence greater than 3 such as, as an example and in a non-limiting manner, aluminium, boron, zirconium, or also titanium, and

[0123] * of a ligand carrying a hydroxyl function.

[0124] When the polymer comprises a branching agent, the polymer remains soluble in water. A person skilled in the art knows how to adjust the quantity of branching agent and, optionally, the quantity of transfer agent in order to arrive at this result. In a particular embodiment, the polymer is free of branching agent.

[0125] In a particular embodiment, the polymer comprises a transfer agent.

[0126] The transfer agent is advantageously selected from methanol; isopropylic alcohol; sodium hypophosphite; calcium hypophosphite; magnesium hypophosphite; potassium hypophosphite; ammonium hypophosphite; formic acid; sodium formiate; calcium formiate; magnesium formiate; potassium formiate; ammonium formiate; 2-mercaptoethanol; 3- mercaptopropanol; glycol dithiopropylene; thioglycerol; thioglycolic acid; thiohydracrylic acid; thiolactic acid; thiomalic acid; cysteine; aminoethanethiol; thioglycolates; allyl phosphites; allyl mercaptans; like n-dodecyl mercaptan; sodium methallysulfonate; calcium methallysulfonate; magnesium methallysulfonate; potassium methallysulfonate; ammonium methallysulfonate; alkyl phosphites like tri alkyl (C12-C15) phosphites, di-ol eyl- hydrogenophosphites, dibutyl phosphite; dialkyldithiophosphates like dioctyl phosphonate; tertiary nonylmercaptan; 2-ethylhexyl thioglycolate; n-octyl mercaptan; n-dodecyl mercaptan; tertio-dodecyl mercaptan; iso-octylthioglycolate; 2-ethylhexyl thioglycolate; 2-ethylhexyl mercaptoacetate; polythiols; and their mixtures. Preferably, the transfer agent is sodium hypophosphite or sodium formiate.

[0127] In a particular embodiment, the polymer is free of transfer agent.

[0128] Method for preparing the polymer according to the invention

[0129] The method for preparing the polymer according to the invention, having a molecular weight of between 300 000 g / mol and 30 million g / mol, comprises the polymerization of at least one compound of formula (I) and / or the salts thereof: with:

[0130] - Z and Y, identical or different, represent: -OH, -O X+, ORa, NH2, NHRa, NRaRb; X+being a metal cation or organic cation and

[0131] Ra and Rb, identical or different, represent a saturated or unsaturated, linear, branched or cyclic hydrocarbon chain having from 1 to 30 carbon atoms, advantageously from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, and optionally one or more heteroatoms selected from among N, O, P and S, the hydrocarbon chain being optionally substituted by one or more groups selected from among acid, aryl, ester, amine, amide, carbamate, hydroxyl, ether, advantageously in C2 and / or C3, nitrile, vinyl, allyl, thioether or halogen groups.

[0132] The polymerization is a radical polymerization in a heterogeneous or an insoluble medium for the polymer.

[0133] In order to obtain a polymer having a molecular weight of between 300 000 g / mol and 30 million g / mol and comprising at least 15 mol% of the compound of formula (I), and / or the salts thereof, it is necessary to combine the method of purification of itaconic acid with particular polymerization conditions.

[0134] Thus, the polymerization temperature Tpis comprised between 15°C and 115°C, preferably between 20°C and 90°C.

[0135] The polymerization is carried out at a pHpof between 2 and 8, preferably between 2.5 and 4.5.

[0136] The polymerization advantageously lasts between 15 minutes and 1 440 minutes, preferably between 20 minutes and 600 minutes, more preferably between 30 minutes and 300 minutes.

[0137] In a preferred embodiment, the polymerization is carried out in the presence of 2- hydroxyethyl-trimethylazanium.

[0138] The quantity of 2-hydroxyethyl-trimethylazanium is advantageously between 0.1 and 50% by weight based on the weight of compound of formula (I) and / or the salts thereof.

[0139] In a particular embodiment, the polymerization is a reversible deactivation controlled radical polymerization (RDRP). RDRP groups together techniques such as iodine transfer polymerization (ITP), nitroxide mediated polymerization (NMP), atom transfer radical polymerization (ATRP), reversible addition fragmentation chain transfer polymerization (RAFT), which MADIX (Macromolecular Design by Interchange of Xanthates) technology forms part of, various variations of polymerizations with organometallic compounds (organometallic mediated radical polymerization (OMRP)), organoheteroatom-mediated radical polymerization (OHRP).

[0140] All of these techniques are based on a reversible balance between a dormant species and an active species. This activation-deactivation process enables the chains to grow at the same speed, and this, until the total consumption of the monomer, making controlling the molecular weights of the polymers and obtaining narrow distributions of the latter possible. The reversible deactivation of the growing chains lies at the origin of minimising irreversible end reactions. The large majority of polymer chains remains in dormant form, and can therefore be reactivated. It is thus possible to functionalise the chain ends in view of priming other polymerization modes or to make chain extensions. This is the key for accessing high molecular weights, controlled compositions and architectures.

[0141] Controlled radical polymerization can therefore have the following distinctive aspects:

[0142] 1. The number of polymeric chains is fixed during the entire duration of the reaction,

[0143] 2. Polymeric chains all grow at the same speed, which is conveyed through:

[0144] * A linear increase of the molecular weights,

[0145] * A constricted distribution of the molecular weights,

[0146] 3. The average molecular weight is controlled by the monomer / precursor molar ratio.

[0147] The controlled character is even more pronounced that the reactivation speed of the radical chains is very high in front of the growth speed of the chains. However, in certain cases, the reactivation speed of the radical chains is greater than or equal to the propagation speed. In these cases, conditions 1 and 2 are not observed and, consequently, controlling the molecular weights is not possible.

[0148] In a preferred embodiment, the polymer is obtained by reversible addition-fragmentation chain-transfer (RAFT) polymerization.

[0149] RAFT is based on a reversible chain-transfer mechanism which is composed of two additionfragmentation balances involving a control agent. The priming, as well as the ending between radicals are the same as in conventional radical polymerization. After breakdown of the initiator into radicals, the first radical species produced is added to the monomer to form a carbon radical which will then react rapidly with the control agent to form the corresponding radical entity. The latter will be fragmented into a initiator and into a new radical capable of re-priming a polymerization.

[0150] The reversible addition-fragmentation chain-transfer polymerization requires the presence of at least one control agent, advantageously of formula (V): wherein

[0151] - W= Ri, or Z-R3, with Z = an oxygen atom (O), a sulfur atom (S) or an amine (NR4);

[0152] - Ri and R2, R3 and R4, identical or different, represent:

[0153] * an optionally substituted alkyl, alcenyl or alcynyl group (i), or

[0154] * a carbon cycle (ii), saturated or not, optionally substituted or aromatic, or

[0155] * a heterocycle (iii), saturated or not, optionally substituted or aromatic, these groups and cycles (i), (ii) and (iii) may be substituted by substituted aromatic groups or by alkoxycarbonyl or aryloxycarbonyl (-COOR), carboxy (-COOH), acyloxy (-O2CR), carbamoyl (-C0N(R)2), cyano (-CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phtalimido, maleimido, succinimido, amidino, guanidimo, hydroxy (-OH), amino (-N(R)2), halogen, allyl, epoxy, alkoxy (-OR), S-alkyl, S-aryl groups, groups having a hydrophilic or ionic character, such as carboxylic acid alkaline salts, sulfonic acid alkaline salts, alkylene polyoxide chains (POE, POP), cationic substitutes (quaternary ammonium salts);

[0156] - R representing a C1-C20 alkyl or aryl group;

[0157] - R3 can further represent a hydrogen atom;

[0158] - Q is a linear or structured polymeric chain comprising n identical or different monomers comprising at least one ethylenic function;

[0159] - n is an integer of between 4 and 500, more advantageously between 4 and 100. The hydrophilic monomer(s) used to form Q are advantageously selected from the same hydrophilic monomers as those described to form the polymer.

[0160] In the N(R)2functions, the two R groups can be identical or different from one another.

[0161] In a preferred embodiment, the control agent is of formula V wherein Z represents O. In another preferred embodiment, the control agent is of formula V in which:

[0162] - Z represents O,

[0163] - Q is a linear or structured polymer chain obtained from 4 to 100 monomers comprising at least one non-ionic hydrophilic monomer and / or at least one anionic hydrophilic monomer and / or at least one cationic hydrophilic monomer described above. In another preferred embodiment, the control agent is of formula (VI): wherein Q is a linear or structured polymer chain obtained from 4 to 100 monomers selected from quaternised or salified acrylamide, acrylic acid or dimethylaminoethyl acrylate, preferably between 4 and 50 monomers. In another preferred embodiment, the control agent is of formula V wherein Z represents S.

[0164] In another preferred embodiment, the control agent is of formula (VII): wherein the R3 groups are identical or different, independently represent a hydrogen atom or a CH3 or a cation, the cation being advantageously selected from cations of alkali metals (Li, Na, K, etc.), alkaline earth metals (Ca, Mg, etc.) or ammonium (for example, ammonium ion or a tertiary ammonium ion), preferably sodium.

[0165] In another preferred embodiment, the control agent is of formula (VIII): wherein

[0166] - the R3 groups are identical or different, independently represent a hydrogen atom or a CH3 or a cation, the cation being advantageously selected from cations of alkali metals (Li, Na, K, etc.), alkaline earth metals (Ca, Mg, etc.) or ammonium (for example, ammonium ion or a tertiary ammonium ion), preferably sodium;

[0167] - Q is a linear or structured polymer chain obtained from 4 to 100 monomers selected from quatemised or salified acrylamide, acrylic acid or dimethylaminoethyl acrylate, preferably between 4 and 50 monomers.

[0168] In another preferred embodiment, the control agent is of formula (IX): wherein the R3 groups are identical or different, independently represent a hydrogen atom or a CH3 or a cation, the cation being advantageously selected from among cations of alkali metals (Li, Na, K, etc.), alkaline earth metals (Ca, Mg, etc.) or ammonium (for example, ammonium ion or a tertiary ammonium ion), preferably sodium. In another preferred embodiment, the control agent is of formula (X): wherein

[0169] - the R3 groups, identical or different, independently represent an H or a CH3 or a cation, the cation being advantageously selected from cations of alkali metals (Li, Na, K, etc.), alkaline earth metals (Ca, Mg, etc.) or ammonium (for example, ammonium ion or a tertiary ammonium ion), preferably sodium; and

[0170] - Q is a linear or structured polymer chain obtained from 4 to 100 monomers selected from quatemised or salified acrylamide, acrylic acid or dimethylaminoethyl acrylate, preferably between 4 and 50 monomers.

[0171] The quantity of control agent will be adjusted by a person skilled in the art according to the molecular weight they seek to achieve.

[0172] To obtain a high molecular weight polymer, it is necessary to use a polymerization technique in a heterogeneous or an insoluble medium for the polymer. This can be a polymerization in a lipophilic phase or in brine. The polymerization technique is therefore selected from inverse emulsion, suspension, water-in-water or precipitation polymerization techniques.

[0173] Inverse emulsion polymerization

[0174] The expression “inverse emulsion” means inverse emulsions and inverse microemulsions. These are water-in-oil emulsions wherein the aqueous phase is dispersed in the lipophilic phase in the form of drops or droplets.

[0175] An inverse emulsion consists of a two-phase medium. It may be unstable in the absence of surfactant (the surfactants group together the water-in-oil emulsifying agents and the oil-in- water emulsifying agents). Under stirring, hydrophilic phase particles are dispersed in a lipophilic phase, with a wide size distribution and an average of about one micrometer. During an inverse emulsion polymerization, the monomer is dispersed in large droplets of the emulsion (diameter: around 50 nm to 10 pm), and in small micelles of emulsifier (diameter: around 5 to 10 nm).

[0176] An inverse emulsion generally comprises at least:

[0177] - a hydrophilic phase comprising at least one hydrophilic monomer;

[0178] - a lipophilic phase;

[0179] - at least one water-in-oil emulsifying agent;

[0180] - optionally, an oil-in-water emulsifying agent.

[0181] By “water-in-oil emulsifying agent”, is meant a compound that can emulsify water in an oil and an “oil-in-water emulsifying agent” is a compound that can emulsify an oil in water. Generally, it is considered that a water-in-oil emulsifying agent is a surfactant having a HLB strictly less than 8, and that an oil-in-water emulsifying agent is a surfactant having a HLB greater than or equal to 10. A surfactant having a HLB of between 8 and 10 is considered as a wetting agent. A person skilled in the art can refer to the document, “ Handbook of Applied Surface and Colloid Chemistry' by K.Holmberg, Chapter 11, if needed.

[0182] The hydrophilic-lipophilic balance (HLB) of a chemical compound is a measurement of its hydrophilic and / or lipophilic properties, determined by calculating the values for the different regions of the molecule, such as described by Griffin in 1949.

[0183] In the present invention, the Griffin method was used, based on the calculation of a value based on the chemical groups of the molecule. Griffin attributed a dimensionless number between 0 and 20 to give information on the solubility of water and oil.

[0184] The HLB value of a substance having a total molar mass M and a hydrophilic part of a molar mass Mh is given by:

[0185] HLB = 20 (Mh / M).

[0186] The hydrophilic phase can be any solvent capable of solubilising the hydrophilic monomers. Advantageously the hydrophilic phase is water.

[0187] The lipophilic phase can be a mineral oil, a vegetable oil, a synthetic oil, or a mixture of several of these oils. Preferably, the lipophilic phase is vegetable oil. Examples of mineral oils are mineral oils containing saturated or unsaturated hydrocarbons such as aliphatic-, naphtenic-, paraffin-, isoparaffin-, cycloparaffin- or naphtyl-based oils.

[0188] Examples of vegetable oils are squalene, an ester- or triglyceride-type oil, like coco caprylate / caprate, octyldodecyl myristate, ethoxylated vegetable oils, jojoba oil, macadamia oil.

[0189] Examples of synthetic oil are hydrogenated polydecene or hydrogenated polyisobutene, esters such as octyl stearate or butyl oleate. Exxsol® products from ExxonMobil are fully suitable.

[0190] The water-in-oil emulsifying agent is advantageously selected from the following list: polyesters having a molecular weight of between 1000 and 3 000 g / mol, condensation products between a succinic poly(isobutenyl) acid or its anhydride and a glycol polyethylene, sequenced block polymers having a molecular weight of between 2500 and 3 500 g / mol, like for example those sold under Hypermer® names, sorbitan extracts, such as monooleate or sorbitan polyoleates, sorbitan isostearate or sorbitan sesquioleate, polyethoxylated sorbitan esters, or also diethyoxyl oleocetylic alcohol or tetraethoxyl lauryl acrylate, fatty alcohol condensation products greater than ethylene, like oleic alcohol reaction product with 2 ethylene oxide units; alkylphenol and ethylene oxide condensation products, such as the nonyl phenol reaction product with 4 ethylene oxide units. Ethoxyl fatty amines such as Witcamide® 511, alkyl phosphate esters, betaine-based products and ethoxyl amine are also good candidates as water-in-oil emulsifying agents.

[0191] The quantity of water-in-oil emulsifying agent in the inverse emulsion is advantageously of between 1 and 10% by weight based on the total weight of the inverse emulsion, preferably between 2 and 6% by weight.

[0192] The method of the invention can comprise the addition of at least one oil-in-water emulsifying agent.

[0193] The oil-in-water emulsifying agent(s) are advantageously selected from ethoxylated nonylphenol, preferably having 4 to 10 ethoxylations (i.e. preferably having a degree of ethoxylation going from 4 to 10); ethoxylated / propoxylated alcohols preferably having an ethoxylation / propoxylation comprising 12 to 25 carbon atoms; ethoxylated tridecyl alcohols; ethoxylated / propoxylated fatty alcohols; ethoxylated sorbitan esters (advantageously having 20 molar equivalents of ethylene oxide); polyethoxylated sorbitan laurate (advantageously having 20 molar equivalents of ethylene oxide); polyethoxylated castor oil (advantageously having 40 molar equivalents of ethylene oxide); decaethoxylated oleodecyl alcohol; heptaoxy ethylated lauric alcohol; polyethoxylated sorbitan monostearate (advantageously having 20 molar equivalents of ethylene oxide); polyethoxylated phenol alkyls (advantageously having 10 molar equivalents of ethylene oxide) cetyl ether; polyethylene alkyl aryl ether; N-cetyl-N-ethyl morpholinium ethosulfate; sodium lauryl sulfate; condensation products of fatty alcohols with ethylene oxide (advantageously having 10 molar equivalents molar ethylene oxide); condensation products of alkylphenols and ethylene oxide (advantageously having 12 molar equivalents of ethylene oxide); condensation products of fatty amines with 5 or more molar equivalents of ethylene oxide (advantageously 5 to 50 equivalents); ethoxylated tristyryl phenols; condensates of ethylene oxide with partially esterified polyhydric alcohols with fatty chains as well as their anhydrous forms; amine oxides advantageously having alkyl polyglucosides; glucamide; phosphate esters; alkylbenzene sulfonic acids and their salts; and surfactant block polymers and their mixtures. The alkyl groups of these oil-in-water-type emulsifying agents mean linear or branched groups and advantageously having 1 to 20 carbon atoms, more advantageously 3 to 15 carbon atoms. Furthermore, the aryls of these oil-in-water-type emulsifying agents, advantageously comprising 6 to 20 carbon atoms, more advantageously 6 to 12 carbon atoms.

[0194] Generally, the inverse emulsion comprises between 0.01 and 10% by weight of oil-in-water emulsifying agent based on the total weight of the inverse emulsion.

[0195] The oil-in-water emulsifying agent(s) can be added before, during or after polymerization. Preferably the oil-in-water emulsifying agent(s) are added after polymerization.

[0196] The weight ratio between the hydrophilic phase and the lipophilic phase in the inverse emulsion is advantageously comprised between 50 / 50 and 90 / 10, preferably between 60 / 40 and 85 / 15, more preferably between 70 / 30 and 80 / 20.

[0197] The inverse emulsion advantageously comprises between 5 and 60% by weight of polymer based on the total weight of the inverse emulsion, preferably between 10 and 50 % by weight, more preferably between 15 and 35 % by weight.

[0198] The polymerization initiators advantageously used can be selected from compounds which dissociate in radicals in polymerization conditions, for example: organic peroxides, hydroperoxides, hydrogen peroxide, persulfates, azoic compounds and redox salts. The use of initiators that are soluble in water is preferred. In certain cases, it is advantageous to use mixtures of various polymerization initiators, for example, mixtures of redox salts and of azoic compounds.

[0199] Advantageously, the quantity of initiator is comprised between 5 and 1 000 ppm based on the total quantity of polymerized monomer, preferably between 10 and 500 ppm, more preferably between 20 and 100 ppm.

[0200] The inverse emulsion polymerization can be carried out in batch, in semi-batch or continuously. Advantageously the polymerization is carried out in batch.

[0201] In a particular embodiment, at the end of the polymerization, the inverse emulsion can be concentrated, advantageously by distillation, to form a concentrated inverse emulsion. This concentration step consists of removing at least some of the hydrophilic phase and / or the lipophilic phase of the inverse emulsion.

[0202] The polymer concentration in the concentrated inverse emulsion is advantageously comprised between 30 and 80% by weight based on the total weight of the concentrated inverse emulsion, preferably between 35 and 70% by weight, more preferably between 40 and 60% by weight.

[0203] In a particular embodiment, at the end of the polymerization, the inverse emulsion can be dried to obtain a powder. The drying can be done by spraying (or “spray drying”), by spray granulation, on a drum, by electromagnetic radiation (microwave, high frequency) or also in a fluidised bed.

[0204] Suspension polymerization

[0205] Suspension polymerization, also called bead polymerization, is a heterogeneous polymerization technique in which, the monomers and the polymer resulting from the polymerization of said monomers are insoluble in the polymerization solvent. The polymer forms in monomer droplets in the form of spherical particles having the appearance of beads.

[0206] The monomers present in the droplets polymerise using a initiator to obtain “gelled” droplets composed mainly of polymer. One or more liquid / solid separation steps are then necessary, in order to isolate the polymer in the form of beads. The liquid / solid separation can be done by any means known to a person skilled in the art, this can be filtration, distillation or drying. The liquid / solid separation is preferably carried out in two stages, a first filtration or distillation step followed by a drying step.

[0207] Suspension polymerization differs the from inverse emulsion polymerization by the size of the polymer particles obtained. While the suspension makes it possible to obtain particle sizes of 20 micrometres and more, the inverse emulsion only makes it possible to obtain particle sizes of around 10 micrometresmaximum. The size of the polymer particles depends of the size of the droplets formed in the suspension or in the emulsion.

[0208] A suspension polymerization generally comprises at least the following steps: i) preparation of a suspension by mixing a hydrophilic phase comprising at least one hydrophilic monomer and a lipophilic phase comprising at least one water-in-oil emulsifying agent; ii) polymerising the at least one hydrophilic monomer using a polymerization initiator in order to form a polymer; iii) liquid / solid separation of the bead polymer from the hydrophilic phase and the lipophilic phase.

[0209] The hydrophilic phase can be any solvent capable of solubilising the hydrophilic monomers, advantageously this is water.

[0210] The lipophilic phase can be a mineral oil, a vegetable oil, a synthetic oil, or a mixture of several of these oils. The oils of the lipophilic phase of the suspension are the same as those described above.

[0211] The polymerization initiators and the quantity thereof is as described for the inverse emulsion polymerization.

[0212] The suspension polymerization can be done in batch, in semi -batch or continuously, advantageously it is carried out in batch.

[0213] The suspension polymerization requires the presence of at least one water-in-oil emulsifying agent, in order to stabilize the formation of monomer droplets.

[0214] The water-in-oil emulsifying agent(s) can be selected from sodium dodecyl ether sulfate, chlorinated trimethyl stearyl ammonium, carboxymethylketyl ammonium, sucrose, fatty acid esters such as sucrose monostearate, sucrose dilaurate, sorbitan esters such as sorbitan monostearate. These compounds include methyl cellulose ethers, hydroxypropyl methyl cellulose ethers, ethyl cellulose ethers, ethyl hydroxyethyl cellulose, methyl hydroxymethyl cellulose, starches, partially saponified polyvinyl acetates, saponified ethylene / vinyl acetate copolymers, alkali metal salts of poly(meth)acrylic acid, copolymers of styrene and vinyl acetate, copolymers of (meth)acrylate with (meth)acrylic acids or their salts, polyethylene imines, polyvinyl alcohols, polyalkyl (meth)acrylates, for which the alkyl group is a linear hydrocarbon chain of 12-18 carbon atoms, with (meth)acrylic acids or their salts, and their mixtures.

[0215] Advantageously, the quantity of water-in-oil emulsifying agent is comprised between 0.2 and 20% by weight based on the total weight of the suspension, preferably between 1 and 10% by weight.

[0216] Generally, the size of the polymer beads is comprised between 20 pm and 1 000 pm, more advantageously between 50 pm and 1 000 pm, and more preferably between 100 pm and 700 pm.

[0217] By “particle size”, is meant the number-average size of the polymer particles. It corresponds to the most important dimension, for example the diameter for spherical particles, measured preferably with a laser measuring apparatus using the conventional techniques which form part of the knowledge of a person skilled in the art. A Mastersizer apparatus of the company Malvern, for example, the MS2000, can be used for this purpose. This type of apparatus can be used to measure, by laser diffraction, the particle-size distribution of particles in a liquid medium or in solid form, preferably in a multiphase suspension.

[0218] The suspension advantageously comprises between 5 and 40% by weight of polymer based on the total weight of the suspension before the liquid / solid separation step, preferably between 10 and 30% by weight.

[0219] In a particular embodiment, the suspension polymerization is carried out in the presence of salts.

[0220] Water-in-water polymerization

[0221] Water-in-water polymerization consists of polymerising in an aqueous phase saturated with salts or with charged species, at least one hydrophilic monomer. As the forming polymer

[0222] T1 chain extends, the polymer precipitates in the form of droplets. Thus, a dispersion of polymer in the form of dispersed droplets is obtained (discontinuous phase) in an aqueous phase saturated with salts (continuous phase). In this system, the two phases are thermodynamically balanced due to the immiscibility of the polymer in the aqueous phase saturated with salts or with charged species.

[0223] Water-in-water polymerization is based on the stabilisation of the reaction medium by forcing the forming polymer to precipitate. This polymerization is advantageously achieved according to one of the three following methods: i) adding additives to the water, making it possible to prevent the polymer particles being formed and being hydrated in contact with the continuous phase. These are mainly salts or ionic species which prevent the solubilisation of the compounds by shielding the surface charges and by the ionic force in solution that they generate. ii) adding additives to the water, making it possible to limit the deployment of polymers resulting from the polymerization by a steric bulk mechanism. This is mainly stabilising polymer; iii) a combination of the two preceding methods.

[0224] All of these additives make it possible to maintain the compounds present in the discontinuous phase in a good state of dispersion and therefore to avoid the phenomena of settling, creaming or coacervate formation, by acting on the variables of Stokes’ law (density, viscosity of the continuous phase).

[0225] The salts are not limited by their nature. These can be alkali metal (Li, Na, K, etc.), alkaline earth metal (Ca, Mg, etc.), organic cation like ammoniums, advantageously ammonium ion or a tertiary ammonium ion and their mixtures.

[0226] In a preferred embodiment, at least one combination between at least one sulfate salt and at least one phosphate salt is used for the water-in-water polymerization, advantageously with a mass ratio of between 25:75 and 75:25, preferably with a ratio of between 65:35 and 35:65.

[0227] The sulfate salt can be selected from alkali metal sulfates, alkali metal hydrogen sulfates, ammonium sulfate, ammonium hydrogen sulfate, magnesium sulfate, calcium sulfate, and aluminium sulfate or any other sulfuric acid salt. The preferred sulfate salt is ammonium sulfate. The phosphate salt can be selected from alkali metal phosphates, alkali metal hydrogen phosphates, alkali metal dihydrogen phosphates, ammonium phosphate, diammonium phosphate (ammonium hydrogen phosphate), ammonium dihydrogen phosphate, alkaline- earth metal phosphates, alkaline-earth metal hydrogen phosphates, alkaline-earth metal dihydrogen phosphates and aluminium phosphate or any other phosphoric acid salt. The preferred phosphate salt is diammonium phosphate.

[0228] The quantity of salts is generally comprised between 5% by weight and saturation based on the weight of the water, preferably between 10% by weight and saturation, more preferably between 15 and 25% by weight.

[0229] In case ii), the monomers are polymerised in the presence of a stabilising polymer. The stabilising polymer can be anionic or cationic according to the nature of the polymer, while remaining of an opposite charge to the latter. In the case of amphoteric polymers, it has an overall charge opposite to the majority charge of the polymer.

[0230] The stabilising polymer advantageously has a molecular weight of between 50 000 and 30 000 000 g / mol, preferably between 100 000 and 10 000 000 g / mol, more preferably between 200 000 and 5 000 000 g / mol.

[0231] Advantageously, the quantity of stabilising polymer in the dispersion is comprised between 5 and 45% by weight based on the total weight of the dispersion, preferably between 10 and 40% by weight, more preferably between 15 and 35% by weight.

[0232] The reaction medium advantageously comprises between 5 and 45% by weight of polymer based on the total weight of the dispersion, preferably between 10 and 40% by weight.

[0233] During water-in-water polymerization, the dispersion can further comprise fluidifying additives, like polyfunctional alcohols, for example glycerol, polyethyleneglycol and polypropyleneglycol; glycol polyalkylenes.

[0234] The water-in-water polymerization is advantageously initiated using an azoic initiator or redox salts.

[0235] The quantity of initiator is advantageously comprised between 1 and 5 000 ppm based on the total quantity of polymerised monomer, preferably between 10 and 2 000 ppm, more preferably between 50 and 1 000 ppm. The water-in-water polymerization can be carried out in batch, in semi-batch or continuously, advantageously it is carried out in batch.

[0236] A person skilled in the art will know how to choose and adapt the operating conditions to optimise the water-in-water polymerization according to the polymer that they seek to obtain.

[0237] Precipitation polymerization

[0238] Precipitation polymerization consists of polymerization of monomers soluble in a solvent, while the polymer obtained is insoluble and precipitates. Once polymerization is complete, the polymer appears in the reaction medium in the form of a precipitate. This is usually a white precipitate and forms a dispersion. It can be isolated easily by using the usual separation, evaporation and drying methods. The solvent can be removed by filtration and / or distillation.

[0239] Advantageously, the solvent used for precipitation polymerization is selected from water, alcohols comprising between 1 and 4 carbon atoms, ketones comprising between 3 and 5 carbon atoms, ethers comprising between 4 and 5 carbon atoms, and their mixtures. Preferably, it is selected from among water, methanol, ethanol, 1 -propanol, 2-propanol, 2- methyl-1 -propanol, isopropanol, tert-butanol, 1-butanol, 2-butanol, dimethylketone, di ethylketone, pentan-2-one, butanone, tetrahydropyran, tetrahydrofuran, 2- methyltetrahydrofuran, 1,3-dioxane, 1,4-dioxane, and their mixtures. When the solvent is water, this can be deionised water, fresh water, a brine saturated or unsaturated with salts, for example an ammonium sulfate brine. The solvent is preferably tert-butanol.

[0240] In a preferred embodiment, the solvent used for precipitation polymerization is a mixture of polar solvents, advantageously a mixture of water and a solvent selected from at least one alcohol comprising between 1 and 4 carbon atoms, at least one ketone comprising between 3 and 5 carbon atoms, at least one ether comprising between 4 and 5 carbon atoms, and their mixtures. It is preferably a mixture of water and solvent selected from methanol, ethanol, 1- propanol, 2-propanol, 2-methyl-2-propanol, isopropanol, tert-butanol, 1-butanol, 2-butanol, dimethylketone, diethylketone, pentan-2-one, butanone, tetrahydropyran, tetrahydrofuran, 2- methyltetrahydrofuran, 1,3-dioxane, 1,4-dioxane and mixtures thereof. More preferably, the solvent used for precipitation polymerization is a mixture of protic solvents, and even more preferably, a mixture of polar and protic solvents, advantageously a mixture of water and tertbutanol.

[0241] In a preferred embodiment, the solvent used for precipitation polymerization can comprise up to 10% by weight of water based on the total weight of the solvent, preferably up to 5% by weight of water.

[0242] In this case, the solvent used for precipitation polymerization advantageously consists:

[0243] (i) of 90% to 100% by weight a) of at least one alcohol comprising between 1 and 4 carbon atoms and / or b) of at least one ketone comprising between 3 and 5 carbon atoms, and

[0244] (ii) of 0% to 10% by weight of water, the % being based on the total weight of the polymerization solvent.

[0245] In a particular embodiment, the monomers are polymerised in the presence of a dispersant or at least one water-in-oil emulsifying agent in order to stabilise the formation of monomer droplets, in order to increase the concentration of the polymer of the reaction medium.

[0246] The water-in-oil emulsifying agents are as defined for the suspension polymerization.

[0247] Generally, the size of the solid polymer particles is comprised between 5 nm and 5 mm, more advantageously between 50 nm and 5 mm, preferably between 100 nm and 2 mm, even more preferably between 200 pm and 1 mm. It can, in particular, be between 50 nm and 1 mm, or between 500 pm and 5 mm, or between 5 pm and 1 mm, or also between 100 pm and 1 mm.

[0248] By “particle size”, is meant the number-average size of the polymer particles. It corresponds to the most important dimension, for example the diameter for spherical particles, measured preferably with a laser measuring apparatus using the conventional techniques which form part of the knowledge of a person skilled in the art. A Mastersizer-type apparatus of the company Malvern, for example, the MS2000, can be used for this purpose. This type of apparatus makes it possible to measure, by laser diffraction, the particle-size distribution of particles in a liquid medium or in solid form, preferably in a multiphase suspension.

[0249] The dispersion advantageously comprises between 5 and 40% by weight of polymer based on the total weight of the dispersion, preferably between 7.5 and 25% by weight.

[0250] Precipitation polymerization is advantageously initiated using an azoic initiator or redox salts. The quantity of initiator is advantageously between 100 and 50 000 ppm based on the total quantity of polymerised monomer, preferably between 200 and 30 000 ppm, more preferably between 500 and 20 000 ppm.

[0251] Precipitation polymerization can be carried out in batch, in semi-batch or continuously, advantageously it is carried out in batch.

[0252] In a particular embodiment, the polymerization is carried out in the presence of templates.

[0253] In template polymerization, the formation of the polymer occurs in the presence of another low molecular weight polymer (template). Before starting polymerization and during it, some of the monomers are spatially distributed around these templates by electrostatic interactions, van der Waals forces or hydrogen bonds, enabling, once the polymerization is initiated, the formation of blocks having a well-defined structure in terms of size, polarity and functionality. By simultaneous or delayed addition of a comonomer, a polymer is obtained, having block inclusions, the properties of which are different from a polymer obtained by conventional polymerization. The interactions with the template are reversible, enabling their recycling once polymerization has ended.

[0254] A person skilled in the art can refer to the document, “ Template polymerization and copolymerization”, Stefan Polowinski, Prog. Polym. Sci. 27 (2002) 537-577, or also to the document, “Monitoring Polymerization Reactions: From Fundamentals to Applications”, Wayne F.Reed and Alina M.Alb, John Wiley & Sons. 2014.

[0255] The template is advantageously prepared from cationic monomers, the following can be cited, in particular and in a non-limiting manner: quaternised dimethylaminoethyl acrylate (DMAEA), quaternized dimethylaminoethyl methacrylate (DMAEMA), dimethyldiallylammonium chloride (DADMAC), acrylamido propyltrimethyl ammonium chloride (APTAC), and methacrylamido propyltrimethyl ammonium chloride (MAPTAC), the vinylamine obtained from the hydrolysis of vinylformamide or from the Hofmann degradation and their mixtures. Preferably, this is quaternised dimethylaminoethyl acrylate or dimethyl di ally 1 ammonium chi ori de .

[0256] The molecular weight of the template is advantageously comprised between 1 000 and 10 000 000 g / mol, preferably between 5 000 and 1 000 000 g / mol, even more preferably between 10 000 and 500 000 g / mol, and even more preferably, between 20 000 and 200 000 g / mol. Purification of itaconic acid

[0257] The polymer of the invention comprises at least one compound of formula (I) and / or one of the salts thereof. This compound of formula (I) is purified itaconic acid or a derivative of this acid obtained by chemical transformation of the purified itaconic acid.

[0258] The combination of the polymerization conditions and the purification method of itaconic acid makes it possible to obtain a high molecular weight polymer.

[0259] The method for purifying itaconic acid comprises at least the following steps: i) mixing itaconic acid with an aqueous solution comprising at least 80% by weight of an aqueous solvent based on the total weight of the aqueous solution, in order to form a suspension SI; ii) heating the suspension SI at a temperature T1 between 30 and 90°C at a ramp of 5°C / hour to 55 °C / hour, in order to obtain a solution Sol; iii) cooling the solution Sol at a temperature T2 between 10 and 50°C at a ramp of 2°C / hour to 20°C / hour, in order to obtain a suspension S2 comprising crystals of purified itaconic acid; iv) liquid / solid separation of the suspension S2 in order to isolate the crystals of purified itaconic acid; v) optionally washing of the crystals of purified itaconic acid; vi) optionally drying of the washed crystals of purified itaconic acid.

[0260] Step i)

[0261] The preparation of the suspension SI is carried out by mixing between an aqueous solution, comprising at least 80% by weight of an aqueous solvent based on the total weight of the aqueous solution, and the unpurified itaconic acid.

[0262] The mixing time between the aqueous solution and the unpurified itaconic acid is advantageously of at least 1 minute, preferably between 1 minute and 600 minutes, more preferably between 5 minutes and 400 minutes, and even more preferably between 10 minutes and 240 minutes.

[0263] The mixing of the compounds of step 1) can be done using various technologies. Examples include, but are not limited to, reactors with stirrers, loop reactors, static mixers, microreactors, piston reactors, agitated filter dryers, for example, Nutsche, paddle mixers, twin-cone mixers, ploughshare mixers and disc mixers. The aqueous solution comprises at least 80% by weight of an aqueous solvent based on the total weight of the aqueous solution, preferably at least 90% by weight, more preferably at least 95% by weight, and more preferably 100% of the aqueous solution is an aqueous solvent.

[0264] The aqueous solvent can be water or brine. The brine is optionally saturated with salts.

[0265] The brine may be an aqueous solution of one salt or of a mixture of salts. Preferably the brine is an aqueous solution of one salt.

[0266] The salt(s) that can be used to form the brine, is selected from alkali metal salts, preferably selected from sodium, potassium and lithium, more preferably, this salt is sodium.

[0267] Advantageously, the salt concentration in brine is comprised between 1% by weight and saturation, preferably between 10% by weight and saturation, more preferably between 20% by weight and saturation, more preferably between 30% by weight and saturation, more preferably between 40% by weight and saturation, and even more preferably between 50% by weight and saturation, by weight based on the weight of aqueous solution.

[0268] The brine concentration and / or the quantity of unpurified itaconic acid added in step (i) is controlled in order to obtain a salification rate of the itaconic acid of between 1 and 100 mol%, preferably between 50 and 100 mol%.

[0269] In a particular embodiment, the aqueous solvent is water and a bubbling of gaseous ammonia is performed prior to adding unpurified itaconic acid and / or during step i) and / or during ii) and / or during iii). The bubbling of ammonia is controlled in order to obtain a salification rate of itaconic acid of between 1 and 100 mol%, preferably between 50 and 100 mol%.

[0270] In a particular embodiment, the aqueous solvent is a mixture of water and ethylene diamine. The quantity of ethylene diamine is advantageously of between 1% by weight and saturation, preferably between 10% by weight and saturation, more preferably between 20% by weight and saturation, more preferably between 30% by weight and saturation, more preferably between 40% by weight and saturation, and even more preferably between 50% by weight and saturation, by weight based on the weight of aqueous solvent.

[0271] The aqueous solution can comprise one or more other solvents, in particular, organic solvents So. The proportion of these other solvents do not exceed 20% by weight. The organic solvent(s) So are advantageously selected from the following compounds:

[0272] - organic acids, advantageously carboxylic acids having from 1 to 8 carbons;

[0273] - amides advantageously having from 1 to 8 carbon atoms;

[0274] - alcohols advantageously having from 1 to 8 carbon atoms;

[0275] - ketones advantageously having from 3 to 8 carbon atoms;

[0276] - ethers advantageously having from 2 to 8 carbon atoms;

[0277] - esters advantageously having from 2 to 8 carbon atoms;

[0278] - alkanes advantageously having from 4 to 8 carbon atoms;

[0279] - halogenated hydrocarbon compounds advantageously having from 2 to 8 carbon atoms;

[0280] - nitriles advantageously having from 1 to 8 carbon atoms; or

[0281] - their mixtures.

[0282] When an organic solvent So is used in the scope of the invention, the temperature can be adjusted in order for the mixture organic solvent So + aqueous solvent to remain in liquid form.

[0283] These compounds can be linear or branched. They can be saturated or comprise unsaturated bonds, an unsaturated bond corresponds to a carbon-carbon double or a triple bond (for example, C=C or C=C).

[0284] The organic solvent So is generally in liquid form at the temperature at which the different steps i) to iv) are carried out. Furthermore, it is advantageously partially miscible in water, preferably completely miscible in water.

[0285] The organic solvent So can, if necessary, make it possible to solubilise possible impurities or by-products present with the itaconic acid used to form the aqueous suspension SI. However, the itaconic acid to be purified is not necessarily soluble in the organic solvent So.

[0286] In a preferred embodiment, the aqueous solution does not comprise organic solvent So.

[0287] Step i) is carried out at a temperature of between 10°C and 30°C, preferably between 15°C and 25°C.

[0288] The concentration of the unpurified itaconic acid in the suspension SI is advantageously comprised between 8 and 65% by weight based on the total weight of the suspension SI, preferably between 15 and 60% by weight, more preferably between 20 and 55% by weight. Step ii)

[0289] Heating of the suspension SI is carried out at a temperature T1 between 30°C and 90°C, preferably of between 40°C and 80°C at a ramp going from 5°C / hour to 55°C / hour, preferably of between 7°C / hour and 30°C / hour.

[0290] In a preferred embodiment, the heating of the suspension SI is constant throughout the temperature rise to reach Tl. In other words, the temperature of the ramp, during step ii), is constant for the duration of the heating.

[0291] Then a solution Sol is obtained when all the unpurified itaconic acid crystals are dissolved.

[0292] Advantageously, the solution Sol is left between 1 minute and 180 minutes at the temperature Tl, preferably between 5 minutes and 120 minutes, more preferably between 10 minutes and 60 minutes.

[0293] Step Hi)

[0294] The cooling of the solution Sol is carried out at a temperature T2 between 10°C and 50°C, preferably of between 15 °C and 40°C at a ramp going from 2°C / hour to 20°C / hour, preferably from 2°C / hour to 15°C / hour, more preferably from 2°C / hour to 10°C / hour.

[0295] In a preferred embodiment, the cooling of the solution Sol is constant throughout the temperature drop to reach T2. In other words, the temperature of the ramp, during step iii), is constant for the duration of the cooling.

[0296] At the end of step iii), a suspension S2 comprising crystals of purified itaconic acid is obtained.

[0297] Step iv)

[0298] In step iv), the suspension S2 undergoes a liquid / solid separation step in order to isolate the crystals of purified itaconic acid.

[0299] The liquid / solid separation step can be carried out using various technologies. Examples include, but are not limited to, the use of a centrifuge, a decanter, a filter press, an agitated filter, a belt filter, a disc filter or a rotary drum filter. Preferably, the liquid / solid separation is preferably carried out using a centrifuge. The liquid / solid separation can also be carried out by gravitational settling.

[0300] Step iv) is advantageously performed at a temperature of between -20°C and 40°C, and preferably between -5°C and 30°C.

[0301] In a particular embodiment, the liquid phase obtained after the liquid / solid separation of step iv) is reused, with or without a prior treatment step, totally or partially to form the suspension SI of step i) or as a washing solution of step v).

[0302] Step v)

[0303] In an optional step v), the isolated itaconic acid crystals obtained in step iv) are washed using a washing solution.

[0304] The washing solution can be water, the solution recovered in step iv), or any other solvent or combination of solvents used to form the suspension SI.

[0305] In a particular embodiment, the washing of the crystals of purified itaconic acid obtained in step iv) is carried out by spraying the washing solution over the crystals of purified itaconic acid.

[0306] In a particular embodiment, the washing of the crystals of purified itaconic acid obtained in step iv) is carried out by putting the crystals of purified itaconic acid in the washing solution.

[0307] The weight ratio between the aqueous washing solution and the crystals of purified itaconic acid obtained in step iv) is advantageously between 0.05: 1 and 10: 1 and more preferably, between 0.1 :1 and 5: 1.

[0308] This washing step is advantageously carried out at a temperature of between -5°C and 40°C, preferably between 0°C and 30°C. A person skilled in the art will know how to adjust the temperature so the crystals of purified itaconic acid crystals are no solubilised in the washing step.

[0309] The crystals of itaconic acid obtained in step v) can be isolated from the washing solution by a liquid / solid separation step. The liquid / solid separation step can be carried out using various technologies. Examples include, but are not limited to, the use of a vertical or horizontal centrifuge, a decanter, a filter press, a belt filter, a disc filter, a push filter or a rotary drum filter. The liquid / solid separation can also be done by gravitational settling.

[0310] In a particular embodiment, the washing solution is recovered to be used, totally or partially, as a solvent to form the suspension SI in step i), with or without a prior treatment step.

[0311] Step vi)

[0312] In an optional step vi), the isolated crystals of itaconic acid in step iv) or obtained in step v) are dried.

[0313] The drying step can be carried out using various technologies. Examples include, but are not limited to, the use of all convection, conduction or radiation drying technologies (fluidised bed dryer, through-bed dryer, drying by conveyor belt, microwave, heated agitated filter, high-frequency radiation, infrared radiation, spraying).

[0314] The drying operation can be carried out at atmospheric pressure or under vacuum.

[0315] In a particular embodiment, step vi) is carried out at a pressure less than atmospheric pressure.

[0316] In this particular embodiment, the pressure is advantageously between 1 and less than lOOOmbar absolute (1 mbar = 100 Pa). It is preferably less than 900mbar absolute, more preferably less than 800 mbar absolute, more preferably less than 700 mbar absolute, more preferably less than 600 mbar absolute, more preferably less than 500 mbar absolute, more preferably less than 400 mbar absolute, more preferably less than 300 mbar absolute, more preferably less than 200 mbar absolute, more preferably less than 100 mbar absolute and even more preferably less than 50 mbar absolute, and advantageously greater than 1 mbar absolute. The absolute pressure corresponds to the pressure based on zero pressure (vacuum).

[0317] The drying step can be carried out discontinuously (batch) or continuously.

[0318] The purified itaconic acid can then be reacted to prepare an itaconic acid derivative of formula (I), wherein Z and Y, identical or different, are not a - hydroxyl function -OH .

[0319] The chemical transformation of the purified itaconic acid is done by simple and conventional reactions known to a person skilled in the art as forming part of their general knowledge. In a preferred embodiment, the different monomers, branching agents and transfer agents used in the scope of the invention are of renewable and non-fossil origin.

[0320] In the scope of the invention, the terms “of renewable and non-fossil origin” mean the origin of a chemical compound coming from biomass or syngas, i.e. being the result of one or more chemical transformations done on one or more raw materials having a natural and non-fossil origin. The terms “biosourced” or “bioresourced” can also be used to characterise the renewable and non-fossil origin of a chemical compound. The renewable and non-fossil origin of a compound includes renewable and non-fossil raw materials from the circular economy, and which have been previously recycled, one or more times, during a process of recycling material coming from biomass, like for example, materials coming from polymer depolymerization or pyrolysis oil transformation.

[0321] According to the invention, the quality of “at least partially of renewable and non-fossil origin” of a compound means a biosourced carbon content preferably of between 5% by weight and 100% by weight based on the total weight of carbon of said compound.

[0322] In the scope of the invention, the standard ASTM D6866-21, method B is used to characterize the biosourced nature of a chemical compound, and to determine the biosourced carbon content of said compound. The value is expressed as a percentage by weight of biosourced carbon based on the total weight of carbon in said compound.

[0323] The standard ASTM D6866-21 is a test method which teaches how to experimentally measure the biosourced carbon content of solids, liquids, and gaseous samples by radiocarbon analysis.

[0324] In a preferred embodiment, the polymer has a carbon content of renewable and non-fossil origin of between 5% by weight and 100% by weight, based on the total weight of carbon of the polymer, preferably between 30% by weight and 100% by weight, more preferably between 50% by weight and 100% by weight, more preferably between 70% by weight and 100% by weight, more preferably between 90% by weight and 100% by weight.

[0325] In a particularly preferred embodiment, 100% by weight of the carbon of the polymer comes from a raw material comprising recycled materials or materials of biological origin, the content of carbon of biological origin being measured according to the standard ASTM D6866-21, method B.

[0326] Hybrid and biodegradable polymer In a preferred embodiment, the compound of formula (I), and / or one of the salts thereof, are used to form hybrid polymers.

[0327] By “hybrid polymer”, is meant a polymer obtained by reaction between at least one synthetic monomer and / or synthetic polymer and a biopolymer.

[0328] By “synthetic monomer”, is meant a monomer which has been synthesized by man.

[0329] By “synthetic polymer”, is meant a polymer which has been synthesized by man.

[0330] By “biopolymer”, is meant a polymer coming from natural resources i.e. that has not been synthesized by man. In other words it comes from living organisms, that are preferably polysaccharides and / or proteins.

[0331] By “polysaccharides”, is meant native or natural polysaccharides, polysaccharides obtained synthetically from natural compounds, polysaccharide derivatives and modified polysaccharides.

[0332] By “modified polysaccharides”, is meant a polysaccharide which has undergone one or more treatments that can be of physical and / or chemical and / or enzymatic nature.

[0333] By “protein”, is meant both native (or chemically unmodified) proteins and modified proteins.

[0334] By “modified proteins”, is meant a protein which has undergone one or more pre-treatments. These pre-treatments can be of a physical nature by shearing, chemical by acid or alkaline hydrolysis and / or enzymatic by a protease.

[0335] There are three conventional hybrid polymer synthesis methods.

[0336] The first method, called “ grafting through", consists of polymerizing a synthetic monomer and a biopolymer comprising a terminal group which enables it to behave like a monomer and to be incorporated into a polymer chain, such that each biopolymer only contributes one single monomer unit in the new polymer formed. This method makes it possible to add branches or side chains, heterogeneously or homogeneously depending on the reactivity ratio between the terminal group of the biopolymer and the monomers.

[0337] In the second method, called “ grafting from", the biopolymer backbone naturally comprises, or is chemically modified to comprise, sites capable of priming the growth of polymer chains. The number of chains grafted can be controlled by the number of initiating sites. The third method, called “ grafting to” , consists of directly grafting polymers onto biopolymers. This method involves a covalent chemical bond between pre-existing polymers and biopolymers.

[0338] Polysaccharides can be extracted from plants, animal extracts or produced by microorganisms such as bacteria, fungi, prokaryotes, eukaryotes. For example, xanthan gum can be produced by Xanthomonas campeslris, gellan by Sphingomonas paucimobllis, xyloglucan can be extracted from tamarind seeds.

[0339] Preferably, the polysaccharide is selected from the group consisting of: starch, starch derivatives, maltodextrin, tamarind gum (preferably consisting of xyloglucan), guar gum, locust bean gum (preferably consisting of galactomannan), tara gum, , chia gums, flax seed mucilages, psyllium gums, quince seed mucilages, xanthan gum, gellan gum, welan gum, rhamsan gum, dextran, curdlan, pullulan, scleroglucan, schizophyllan, chitin, hydroxyalkylcellulose, arabinans (preferably obtained from sugar beets), arabinoxylan, galactans (preferably obtained from lupin and / or potatoes), pectic galactans (preferably obtained from potatoes), galactomannan (preferably obtained from locust beans or fenugreek), glucomannan, lichenan (preferably obtained from Icelandic moss), mannan (preferably obtained from ivory nuts), pachyman, rhamnogal acturonan, acacia gum, agar, alginates, carrageenan, chitosan, clavan, hyaluronic acid, heparin, inulin, cellodextrins, cellulose, cellulose derivatives, and mixtures thereof.

[0340] According to a preferred embodiment, the biopolymer is a polysaccharide, preferably selected from: starch, starch derivatives such as carboxymethyl starch; cellulose, cellulose derivatives such as carboxymethyl cellulose, hemicellulose; polysaccharides extracted from algae such as agarose, carrageenans, alginates; pectins; inulin; guars gums; konjac gums; dextran; pullulan; gellan gum; curdlan and mixture thereof.

[0341] The protein(s) according to the invention can be of animal, plant or bacterial origin, or come from fungi, algae or yeasts.

[0342] As proteins of animal origin, milk proteins such as P-lactoglobulin, casein and whey; serum proteins such as horse serum; fibrous dermal proteins such as collagen, elastin, silk proteins can be cited.

[0343] As proteins of plant origin, proteins extracted from maize, wheat, barley, oats, soybean or peas such as glutelin, prolamin, zein and gluten can be cited. Advantageously, the plant proteins are selected from among soybean, wheat, oat or pea proteins. Proteins can also be obtained from seeds, for example soybean, cotton, peanuts, sunflower, rapeseed, coconut, flax, sesame, safflower, peas, beans or lentils.

[0344] As examples of bacterial proteins, Pseudomonas, Lactobacillus or E. coli can be cited. As fungi proteins, Penicillium can be cited, for algae: blue algae, green algae such as Chlorella or Spirulina can be cited.

[0345] In a preferred embodiment, the protein is selected from casein, serum proteins or wheat proteins.

[0346] In a particular embodiment, the compound of formula (I), and / or the salts thereof, is polymerised with at least one monomer selected from: cyclic ketene acetals, thionolactones, monomers having a heterocycle incorporating a disulfide group in its structure, and their mixtures.

[0347] The cyclic ketene acetal is advantageously selected from: 2-methylene-l,3-dioxepane (MDO), 5,6-benzo-2-methylene-l,3-dioxepane (BMDO), 2-methylene-4-phenyl- 1,3 -di oxolane (MPDL), 2-methylene-l,3,6-trioxocane (MTC), and their mixtures. Preferably, this is 2- methylene-l,3-dioxepane (MDO).

[0348] Advantageously, the quantity of cyclic ketene acetal in the polymer is between 5 and 30 mol%, based on the total quantity of monomers in the polymer, preferably between 5 and 20 mol%.

[0349] The thionolactone is advantageously selected from: dibenzo[c,e]oxepine(7H)-5-thione (DOT), s-thionocaprolactone, 3,3-dimethyl-2,3-dihydro-5H-benzo[e][l,4]dioxepine-5-thione (DBT) and their mixtures. Preferably, this is 3,3-dimethyl-2,3-dihydro-5H-benzo[e][l,4]dioxepine-5- thione.

[0350] Advantageously, the quantity of thionolactones in the polymer is of between 5 and 20 mol%, based on the total quantity of monomer in the polymer, preferably between 5 and 15 mol%.

[0351] As monomers having a heterocycle incorporating a disulfide group in its structure, in particular lipoloic acid or asparagusic acid can be cited.

[0352] Advantageously, the quantity of monomers having a heterocycle incorporating a disulfide group in its structure is of between 5 and 20 mol%, based on the total quantity of monomer in the polymer, preferably between 5 and 15 mol%. In a preferred embodiment according to the invention, the polymer is obtained by polymerization of the compound of formula (I) and / or the salts thereof and at least one cyclic ketene acetal and one thionolactone.

[0353] In a preferred embodiment, the oil(s) and the emulsifier(s) used during polymerization are biosourced.

[0354] In a preferred embodiment, the compound of formula (I) and / or the salts thereof are polymerised with at least one monomer selected from: cyclic ketene acetals, thionolactones, monomers having a heterocycle incorporating a disulfide group in its structure and their mixtures; the oil(s) and the emulsifier(s) used during polymerization are biosourced.

[0355] Use

[0356] The present invention also relates to the use of said polymer in: hydrocarbon recovery (oil or gas); drilling wells; cementing wells; stimulation of hydrocarbon wells (oil or gas) other than hydraulic fracturing, for example conformance or diversion; open, closed or semi-closed circuit water treatment; treatment of fermentation broth; sludge treatment; construction; paper or cardboard manufacture; batteries; wood treatment; treatment of hydraulic composition (concrete, cement, mortar and aggregates); in the mining industry; formulation of cosmetic products; formulation of detergents; textile manufacture; geothermal energy; manufacture of nappies; or agriculture.

[0357] The present invention also relates to the use of said polymer as a flocculant, coagulant, binding agent, fixing agent, viscosity reducing agent, thickening agent, absorbent agent, friction reducing agent, draining agent, filler retention agent, dehydrating agent, conditioning agent, stabilising agent, film-forming agent, bonding agent, superplasticizing agent, clay inhibitor.

[0358] Example

[0359] Characterisation of weight average molecular weight (Mw)

[0360] The polymers have been analysed by steric exclusion chromatography (SEC) in order to determine the average molecular weight (Mw). The analytical conditions are as follows:

[0361] - 1 Shodex pre-column referenced SB807-G;

[0362] - 2 OHpak Shodex columns mounted in series, referenced SB-807 HQ / SB-805 HQ; - The columns are coupled with a refraction index detector referenced Optilab T-rEX and Dawn Heleos II 18 angles commercialised by the company Wyatt Technology.

[0363] Characterisation of the final monomers compositions

[0364] The NMR (Nuclear Magnetic Resonance) analyses aimed at characterising the monomers incorporation rates as well as the final monomers compositions of the polymers have been carried out on an apparatus of the Briiker 400 MHz ASCEND ™ Avance III HD type equipped with a 10 mm BBO 400 MHz Z-Gradient probe.

[0365] Example 1: Purification of itaconic acid

[0366] The purification of commercial itaconic acid (IA) is performed according to the following protocol (assay 1): i) mixing 55 kg of itaconic acid with 45 L of deionised water for 15 minutes at ambient temperature to form the suspension SI; ii) heating the suspension SI at a temperature T1 of 50°C at a ramp of 10°C / hour in order to form the solution Sol; iii) cooling the solution Sol at a temperature of 25°C at a ramp of 5°C / hour in order to obtain the suspension S2 comprising crystals of purified itaconic acid.

[0367] The suspension S2 is then passed through a centrifuge in order to recover the crystals of purified itaconic acid which are then dried for 24 hours at 60°C in an oven.

[0368] The purification protocol is reproduced by changing different parameters which are detailed in table 1 (assays 2 to 10). example The itaconic acids of assays 1 to 2, 5 to 6 and 10 have been purified according to the method of purification of the invention while the itaconic acids of assays 3 to 4 and 7 to 9 have not been purified according to the method of purification of the invention (Tl, T2 or the ramps of step ii) or iii) are outside the invention).

[0369] Example 2: Polymerization in solution (comparative example)

[0370] In a synthesis reactor equipped with a stirring and heating system, the following are introduced at ambient temperature:

[0371] - 645 g of deionised water;

[0372] - 428.7 g of acrylamide (50% by weight in water);

[0373] - 84.1 g of purified itaconic acid from assay 1;

[0374] - 51.8 g of acrylic acid (90% by weight in water);

[0375] - 103.5 g of NaOH (50% by weight in water);

[0376] - 0.003 g of copper sulfate.

[0377] The reaction medium is degassed under nitrogen for 30 minutes.

[0378] The following are then added to the medium:

[0379] - 1.7 g of sodium hypophosphite;

[0380] - 0.86 g of sodium persulfate;

[0381] - 0.9 g of sodium metabisulfite.

[0382] The reaction medium is then heated at 90°C for 60 minutes and the pH is controlled between 4 and 6.5.

[0383] At the end of the reaction, 2.2 g of a bisulfite solution (40% by weight in water) are added to the medium. The medium is then left for 60 minutes at 90°C. At the end of the reaction, the polymer Pl-1 is obtained.

[0384] The molecular weight of the polymer Pl-1 is 507 000 g / mol with an itaconic acid conversion rate of 46% based on the initial quantity.

[0385] Example 3: Inverse emulsion polymerization

[0386] Preparation of the aqueous phase

[0387] In a reactor equipped with a stirring system, the following are introduced at ambient temperature:

[0388] - 220 g of deionised water;

[0389] - 330.3 g of acrylamide (50% in water); - 64.8 g of itaconic acid from assay 1;

[0390] - 39.9 g of acrylic acid (90% in water);

[0391] - 75.8 g of NaOH (50% by weight in water);

[0392] - 0.4 g of pentasodium diethylenetriaminepentaacetate;

[0393] - 450 ppm of sodium hypophosphite based on the total weight of monomers.

[0394] Preparation of the organic phase

[0395] 25 g of sorbitan monooleate are mixed in 215 g of Exxsol DI 00 oil.

[0396] The aqueous phase is then mixed and emulsified in the oil phase.

[0397] The emulsion is then degassed for 30 minutes before the polymerization is initiated with a redox system:

[0398] - 100 ppm, based on the total weight of monomers, of tert-butyl hydroperoxide;

[0399] - 8 mL of a sodium metabisulfite solution (1 g / L).

[0400] The polymerization lasts for 60 minutes and the pH is controlled between 5 and 7. At the end of the reaction, the polymer P2-1 is obtained.

[0401] The molecular weight of the polymer P2-1 is 552 000 g / mol with an itaconic acid conversion rate of 100% based on the initial quantity.

[0402] Other examples have been carried out by changing the source of itaconic acid and are detailed in table 2.

[0403] Example 4: Precipitation polymerization

[0404] In a synthesis reactor equipped with a stirring and heating system the following are introduced at ambient temperature:

[0405] - 854 g of tert-butanol;

[0406] - 16.1 g of solid acrylic acid;

[0407] - 29.0 g of itaconic acid from assay 1;

[0408] - 23.6 g of sodium carbonate.

[0409] The temperature of the reaction medium during neutralisation is controlled, so as not to exceed 40°C.

[0410] At the end of neutralisation, 73.9 g of solid acrylamide is added and the reaction medium is heated at 50°C, then degassed with nitrogen for 30 minutes.

[0411] The polymerization is initiated by adding:

[0412] - 0.64 g of 2,2'-Azobis(2-methylpropionitrile);

[0413] - 0.24 g of dimethyl 2,2'-azobis(2-methylpropionate). The polymerization lasts 2 hours 30 minutes at 85°C, the solution obtained is then evaporated under vacuum. The powder is finally dried. At the end of the reaction, the polymer P3-1 is obtained.

[0414] The molecular weight of the polymer P3-1 is 591 000 g / mol with an itaconic acid conversion rate of 100% based on the initial quantity.

[0415] Other examples have been carried out by changing the source of itaconic acid and are detailed in table 2.

[0416] Example 5: Water-in-water polymerization

[0417] In a synthesis reactor equipped with a stirring and heating system, the following are introduced at ambient temperature:

[0418] - 926 g of deionised water;

[0419] - 200 g of ammonium sulfate;

[0420] - 200 g of diammonium phosphate;

[0421] - 270 g of a potassium polyacrylate;

[0422] - 280 g of acrylamide (50% in water);

[0423] - 33.8 g of acrylic acid (50% in water);

[0424] - 54.9 g of itaconic acid from assay 1;

[0425] - 67.6 g of NaOH (50% by weight in water);

[0426] - 0.3 g of pentasodium diethylenetriaminepentaacetate;

[0427] - 0.8 g of sodium hypophosphite.

[0428] The reaction medium is degassed with nitrogen for 30 minutes and heated under stirring at 30°C.

[0429] The polymerization is then initiated with 0.04 g of 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride.

[0430] 30 and 60 minutes after the start of polymerization, 0.04 g of 2,2'-azobis[2-(2-imidazolin-2- yl)propane] dihydrochloride is added.

[0431] The pH during polymerization is controlled between 6 and 8, the polymerization temperature progressively rises to 60°C.

[0432] Once this temperature has been reached, 0.2 g of 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride is added.

[0433] The polymerization continues for 1 hour. At the end of the reaction, the polymer P4-1 is obtained. The molecular weight of the polymer P4-1 is 539 000 g / mol with an itaconic acid conversion rate of 100% based on the initial quantity.

[0434] Other examples have been carried out by changing the source of itaconic acid and are detailed in table 2.

[0435] Example 6: Gel polymerization (comparative example)

[0436] In a synthesis adiabatic reactor, the following are introduced at ambient temperature:

[0437] - 806.7 g of deionised water;

[0438] - 440.2 g of acrylamide (50% in water);

[0439] - 53.1 g of acrylic acid (50% in water);

[0440] - 86.4 g of itaconic acid from assay 1;

[0441] - 106.2 g of NaOH (50% by weight in water);

[0442] - 1 g of a pentasodium di ethylenetriaminepentaacetate solution (15 g / L);

[0443] - 7.5 g of a 2,2'-Azobis(2-methylpropionamidine)dihydrochloride solution (200 g / L);

[0444] - 7.5 g of a sodium hypophosphite solution (50 g / L).

[0445] The reaction medium is then cooled to 2°C and degassed for 30 minutes with nitrogen bubbling.

[0446] The polymerization lasts for 60 minutes with a pH control between 5.5 and 7.5, and is initiated by adding:

[0447] - 10 g of a tert-butyl hydroperoxide solution (1.5g / L);

[0448] - 7.5 g of a Mohr's salt solution (3 g / L).

[0449] At the end of polymerization, the gel is cut, dried and ground to a particle size < 1mm, the polymer P5-1 is obtained.

[0450] The molecular weight of the polymer P5-1 is 592 000 g / mol with an itaconic acid conversion rate of 53% based on the initial quantity.

[0451] Example 7: Bead polymerization (suspension polymerization)

[0452] In a synthesis reactor equipped with a stirring and heating system, the following are introduced at ambient temperature:

[0453] - 612 g of isoparaphinic oil;

[0454] - 14.7 g of poly(methacrylic ester-co-methacrylic acid).

[0455] The reaction medium is degassed with nitrogen for 30 minutes, then the headspace of the reactor is flushed with nitrogen. 1 g of sulfur dioxide is added to the medium as well as 0.04 g of tertio butyl hydroperoxide.

[0456] In a beaker, the following are mixed under stirring at ambient temperature:

[0457] - 59.9 g of deionised water;

[0458] - 0.002 g of phenothiazine;

[0459] - 165.4 g of acrylamide (50% by weight in water);

[0460] - 75.8 g of a 50% neutralised sodium mono-itaconate solution (50% by weight in water);

[0461] - 46.9 g of a 100% neutralised sodium acrylate solution (50% by weight in water).

[0462] This mixture is introduced into an isobaric dropping funnel which surmounts the reactor, under nitrogen flushing, then the following are added to the funnel:

[0463] - 0.058 g of 2,2'-Azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride;

[0464] - 0.058 g of 2,2'-Azobis(2-methylpropionamidine)dihydrochloride;

[0465] - 0.19 g of di ethylenetriaminepentaacetic acid tetrasodium salt;

[0466] - 0.02 g of mercapto ethanol;

[0467] - 0.11 g of sodium sulfite.

[0468] The pH of this solution is controlled to be between 4.5 and 6 before being added to the reactor.

[0469] The polymerization is initiated at 20°C and lasts for 90 minutes. The reaction medium is not cooled during polymerization. At the end of the reaction, the polymer P6-1 is obtained.

[0470] The molecular weight of the polymer P6-1 is 577 000 g / mol with an itaconic acid conversion rate of 100% based on the initial quantity.

[0471] Other examples have been carried out by changing the source of itaconic acid and are detailed in table 2.

[0472]

[0473] Table 2: Comparison of the compositions and properties of the itaconic acid polymers prepared by the method of the invention in comparison with polymers outside the scope of the invention. Inv = invention; CE = comparative example Example 8: Preparation of inverse emulsion polymers comprising an itaconic acid derivative of formula (I)

[0474] Polymers of itaconic acid derivatives were prepared by inverse emulsion according to the protocol and the conditions of example 3 described above. The itaconic acid derivatives were prepared from purified itaconic acid (assay 1).

[0475] The nature of the itaconic acid derivatives as well as the composition and features of the polymers obtained are detailed in table 3 below.

[0476] Table 3 : Compositions and properties of polymers comprising an itaconic acid derivative of formula (I) according to the invention

Claims

CLAIMS1. Method for preparing a polymer having a molecular weight of between 300 000 g / mol and 30 million g / mol, comprising the polymerization of at least one compound of formula (I), the polymer comprising:- at least 15 mol% of the compound of formula (I) and / or the salts thereof:with:- Z and Y, identical or different, represent: -OH, -O X+, ORa, NH2, NHRb, NRaRb;X+being a metal cation or organic cation andRa and Rb, identical or different, represent a saturated or unsaturated, linear, branched or cyclic hydrocarbon chain, having from 1 to 30 carbon atoms, advantageously from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, and optionally one or more heteroatoms selected from among N, O, P and S, the hydrocarbon chain being optionally substituted with one or more groups selected from acid, aryl, ester, amine, amide, carbamate, hydroxyl, ether, advantageously in C2 and / or C3, nitrile, vinyl, allyl, thioether or halogen groups; the polymerization being a radical polymerization in a heterogeneous or an insoluble medium for the polymer; the compound of formula (I) being a purified itaconic acid or one of the derivatives thereof; the purified itaconic acid being obtained by a method of purification comprising at least the following steps: i) mixing of itaconic acid with an aqueous solution comprising at least 80% by weight of an aqueous solvent based on the total weight of the aqueous solution, in order to form a suspension SI; ii) heating of the suspension SI at a temperature T1 between 30°C and 90°C at a ramp of 5°C / hour to 5 °C / hour, in order to obtain a solution Sol;iii) cooling of the solution Sol at a temperature T2 between 10°C and 50°C at a ramp of 2 °C / hour to 20°C / hour, in order to obtain a suspension S2 comprising crystals of purified itaconic acid; iv) liquid / solid separation of the S2 suspension in order to isolate the crystals of purified itaconic acid; v) optionally washing of the crystals of purified itaconic acid; vi) optionally drying of the washed crystals of purified itaconic acid.

2. Method according to claim 1, characterised in that the polymer is water-soluble.

3. Method according to claim 1 or claim 2, characterised in that the polymerization is carried out in the presence of 2-hydroxyethyl-trimethylazanium.

4. Method according to claim 3, characterised in that the quantity of 2-hydroxyethyl- trimethylazanium is of between 0.1 and 50% by weight based on the weight of of compound of formula (I), and / or the salts thereof.

5. Method according to any one of the preceding claims, characterised in that the radical polymerization in a heterogeneous or an insoluble medium for the polymer is selected from inverse emulsion, suspension, water-in-water or precipitation polymerization techniques.

6. Method according to any one of the preceding claims, characterised in that, in step i), the aqueous solvent is water or brine, said brine being optionally saturated with salts.

7. Method according to any one of the preceding claims, characterised in that in step i), the brine concentration and / or the quantity of itaconic acid added is controlled in order to obtain a salification rate of the itaconic acid of between 50 and 100 mol%.

8. Method according to any one of the preceding claims, characterised in that, in step iii), the cooling of solution Sol is carried out at a ramp of between 2°C / hour and 15°C / hour.

9. Method according to any one of the preceding claims, characterised in that the ramp has a constant temperature for the duration of cooling of step iii).

10. Method according to any one of the preceding claims, characterised in that the polymer further comprises at least one monomer selected from: cyclic ketene acetals,thionolactones, monomers having a heterocycle incorporating a disulfide group in its structure and their mixtures.

11. Method according to claim 10, characterised in that the quantity of monomer selected from among: cyclic ketene acetals, thionolactones, monomers having a heterocycle incorporating a disulfide group in its structure and their mixtures in the polymer is of between 2 and 20 mol%.

12. Method according to any one of the preceding claims, characterised in that the compound of formula (I) has a biosourced carbon content of between 5% by weight and 100% by weight based on the total weight of carbon in the compound of formula (I), the biosourced carbon content being measured according to the standard ASTM D6866-21, method B.

13. Use of the polymer obtained according to the method of any one of the preceding claims, in: hydrocarbon recovery (oil or gas); drilling wells; cementing wells; stimulation of hydrocarbon wells (oil or gas) other than hydraulic fracturing, for example conformance or diversion; open, closed or semi-closed circuit water treatment; treatment of fermentation broth; sludge treatment; construction; paper or cardboard manufacture; batteries; wood treatment; treatment of hydraulic composition (concrete, cement, mortar and aggregates); in the mining industry; formulation of cosmetic products; formulation of detergents; textile manufacture; geothermal energy; manufacture of nappies; or agriculture.

14. Use of the polymer obtained according to the method of any one of claims 1 to 12, as a flocculant, coagulant, binding agent, fixing agent, viscosity reducing agent, thickening agent, absorbent agent, friction reducing agent, draining agent, filler retention agent, dehydrating agent, conditioning agent, stabilising agent, film-forming agent, bonding agent, superplasticising agent, clay inhibitor.

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