EP3105260A1

EP3105260A1 - Polyphosphorus polymer that is thiol-functionalised at the chain ends and production method thereof

Info

Publication number: EP3105260A1
Application number: EP15703585.8A
Authority: EP
Inventors: Charlotte Dire; Rachid Matmour; Issam BLIDI; Olivier COUTELIER; Mathias Destarac
Original assignee: Michelin Recherche et Technique SA Switzerland; Centre National de la Recherche Scientifique CNRS; Compagnie Generale des Etablissements Michelin SCA; Michelin Recherche et Technique SA France; Universite Toulouse III Paul Sabatier
Current assignee: Centre National de la Recherche Scientifique CNRS; Compagnie Generale des Etablissements Michelin SCA; Universite Toulouse III Paul Sabatier
Priority date: 2014-02-11
Filing date: 2015-02-10
Publication date: 2016-12-21
Also published as: US20170218099A1; WO2015121223A1; CN105960420A; FR3017387A1; FR3017387B1

Abstract

The invention relates to a novel polyphosphorus polymer that is thiol-functionalised at the chain ends, of which the polymer chain comprises units bearing at least one phosphonate pendant functional group and/or at least one phosphonic pendant functional group along the length of the chain. This novel polymer is particularly suitable for use in a thiol-ene coupling reaction. This provides the possibility of grafting the polyphosphorus polymers to diene polymers for example.

Description

Polyphosphoric polymer functionalized thiol end chain

and its method of obtaining.

The present invention relates to a process for synthesizing a polymer carrying phosphonate and / or phosphonic functions pendant along the chain, functionalized thiol end chain. The present invention also relates to such a poly (phosphorus) polymer terminated thiol.

In order to modify the properties of the synthetic elastomers contained in the tire rubber compositions, different strategies are possible. Among these, the introduction of new chemical functions at the end or along the polymer chain is one of the methods used.

The Applicants are particularly interested in the context of the invention in the functionalization along the diene polymer chain. Various types of reactions on unsaturations of diene polymers for functionalization are known in the literature. Diels-Alder reaction type [4 + 2] cycloaddition reactions can be mentioned between a dienophile (maleic anhydride, for example) and diene copolymers having conjugated dienes along the chain through the insertion of a conjugated triene comonomer (alloocimene) during the anionic copolymerization (EP 2423 239A1). We may also mention the hydrosilylation reactions of a hydrogenosilane carrying a function (epoxide, for example) on the pendant unsaturations of a diene polymer (FR 13/62946).

The 1,3-dipolar cycloaddition reactions in the presence of nitrile oxide or nitrone are also known for the functionalization (WO 2012007441 A1, WO 2006045088 A2) or the diene polymer crosslinking (FR 1583406, WO 2006081415 A2).

The radical grafting of functional or non-functional thiols via photochemical or chemical catalysts (with or without a radical initiator) is part of these functionalization reactions of diene polymers (natural and synthetic rubber) in the same way as the cycloaddition or hydrosilylation reactions mentioned. upper. The thiol-ene coupling (reaction of a thiol on a double bond) on polydienes offers some versatility for molecular design. Indeed, the good tolerance of the Thiol-ene chemistry with respect to many functional groups and the good availability of polydienes containing various microstructures made it possible to produce series of original materials by varying the nature of the grafted functionality.

The radical addition of thiols containing carboxyl, hydroxyl, epoxy and siloxy groups on polybutadienes has been widely studied since the end of the Second World War.

The Applicants are particularly interested within the scope of the invention in obtaining diene polymer carrying phosphorus functional groups along the chain.

Indeed, phosphorus polymers have recently gained increasing interest because of their utility in a wide range of applications such as for example fuel cells (J. Fuel Cells, 2005, 5, (3), 355), membranes electrolytes (cation exchange membranes) (J.App.Poly Sci, 1999, 74, 83), flame retardants (Macromolecules, 1998, 31, 1010, Rhodia Chimie WO 2003076531), dental cement additives (J. Dent Res, 1974, 53, (4), 867), biomaterials (orthopedic applications) (J. Mater Sci Lett, 1990, 9, 1058, Macromol Rapid Commun 2006,20, 1719-24), solubilization of drugs (hydrogels for drug release) (J. Appl.Polym Sci, 1998, 70, 1947), cell proliferation promoters (Fuji Photo Film Co. US 6,218,075, Biomaterials, 2005, 26, 3663). 3671) and corrosion inhibiting agents in cooling systems (Macromolecules, 1998, 31, 1010). One of the methods of synthesis of diene phosphorus polymers known to those skilled in the art is the chemical modification of diene polymer by radical grafting of phosphonate functional thiols. The group of Pr. Boutevin (Polym Bull, 1998, 41, 145-151) describes the radical grafting of a thiol, diethyl 3-mercaptopropyl phosphonate (HS- (CH ₂ ) ₃ -P (= O) ( OEt) ₂ ), on a hydroxy-telechelic polybutadiene (M _n = 1200 g / mol and 20% or 80% butadiene-1, 2) in THF with AIBN as a radical initiator at 70 ° C for 6 hours.

It appears that to have a real benefit in terms of properties for a phosphonate or phosphonic elastomer in various applications, particularly in the tire field, a large molar content of phosphorus units may be necessary. However, an increase in the molar ratio of phosphorus functional groups on the elastomer involves the use of significant amounts of phosphonate or phosphonic functional thiols. The use of thiol molecules carrying a phosphorus function in significant proportion has the disadvantage of a greater macrostructure evolution in the case of molar levels of high target grafts. This macrostructure evolution observed in the context of radical grafting is generally due to secondary reactions (radical-radical bimolecular coupling, transfer reaction, etc.); the proportion of these secondary reactions increasing with the target graft rate. This evolution of macrostructure is often responsible for a degradation of the elastomeric properties of the polymer, and therefore a drop in its performance in the intended application, such as in tires.

The technical problem that arises with respect to the state of the art is to have a simple and reproducible method for synthesizing a polymer having a high molar ratio of phosphorus functions along the chain while overcoming the drawbacks related to the use of high proportions of thiol molecules carrying a phosphorus function.

The inventors have now developed a novel phosphorous molecule which allows the preparation of diene polymers having a high molar ratio of phosphonate and / or phosphonic functions along the chain, while retaining the benefit of thiol-ene coupling while at the same time limiting significant evolution of polymer macrostructure related to grafting of high proportions of functions. In fact, the inventors have synthesized a poly (phosphorus) polymer carrying a thiol function at the end of the chain which can be grafted by thiol-ene coupling on a diene polymer. In this way, high molar levels of phosphonate and / or phosphonic functions on the polymer after grafting are obtained for a fraction of the double bonds consumed on the comparatively lower polymer backbone than with a thiol molecule carrying a single phosphorus function. As a result, the macrostructure of the polymer and therefore its intrinsic properties are further preserved after the grafting step. The subject of the invention is a poly (phosphorus) polymer carrying a thiol function at the chain end.

The invention also relates to a process for synthesizing such a polymer.

In the present description, the term "phosphorus", whether it is the function or the polymer, means that a group or a polymeric unit, as the case may be, comprises at least one phosphonate function. , a phosphonic hemiacide function or a phosphonic diacid function. The term "a phosphonic function" is used to refer to a phosphonic hemiacide function or a phosphonic diacid function. In the present description, the term "unit" of a polymer, any unit derived from a monomer of the backbone of the polymer in question.

In the present description, the term "terminated thiol" refers to the poly (phosphorus) polymer, the fact of carrying a thiol function at one end of the chain. In the present description, the number of moles of these units in the polymer relative to the total number of moles of the units present in said polymer is defined as the molar percentage or percentage of a unit in a polymer.

On the other hand, any range of values designated by the expression "between a and b" represents the range of values from more than a to less than b (i.e. terminals a and b excluded) while any range of values designated by the term "from a to b" means the range from a to b (i.e., including the strict limits a and b).

According to the invention, the polyphosphorus polymer carrying an end thiol function is a thiol derivative whose polymer chain comprises units carrying at least one phosphonate function and / or at least one phosphonic function pendant along the chain. The polymer chain may be any homopolymer obtained by polymerization of a monomer carrying at least one phosphorus functional group, or of any copolymer of one or more monomers bearing at least one phosphorus functional group with one another or with one or more comonomers.

According to the invention, the polyphosphorus polymer carrying a thiol function at the end of the chain may be represented by the formula RP-SH, R representing an alkyl, acyl, aryl, alkenyl or alkynyl group, a saturated or unsaturated carbon cycle, optionally aromatic, a heterocycle, saturated or unsaturated, optionally aromatic; or a polymer chain, and P representing the polyphosphorus chain.

According to a variant of the invention, the poly (phosphorus) terminated thiol polymer corresponds to the following general formula (I):

(I) with where m denotes an integer greater than or equal to 2 and n denotes an integer greater than or equal to 0, provided that when n is not equal to 0, n and m may be identical or different, preferably greater than 2 and preferably less than 500.

- R represents:

(i) an alkyl, acyl, aryl, alkenyl or alkynyl group,

(ii) a saturated or unsaturated carbon ring, optionally aromatic;

(iii) a heterocycle, saturated or unsaturated, optionally aromatic; or

these groups and rings (i), (ii) and (iii) may be substituted by substituted phenyl groups, substituted aromatic groups or groups: alkoxycarbonyl or aryloxycarbonyl (-COOR '), carboxy (-COOH), acyloxy (- 0 ₂ CR '), carbamoyl (-CONR' ₂ ), cyano (-CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino, guanidimo, hydroxy (-OH), amino (-NR ' ₂ ), halogen, allyl, epoxy, alkoxy (-OR '), S-alkyl, S-aryl, groups having a hydrophilic or ionic character such as the alkaline salts of carboxylic acids, the alkaline salts of sulfonic acid, the polyalkylene oxide chains (POE, POP), cationic substituents (quaternary ammonium salts), R 'representing an alkyl or aryl group,

(iv) a polymer chain,

X, X ', which may be identical or different, represent H, a halogen or a group R 1,

OR 1, OCOR 1, NHCOH, OH, NH ₂ , NHR _1; N {R _2, (R ^ N + O ^", NHCORi, ∞ _2H,

C0 ₂ R 1, CN, CONH ₂ , CONHR or CON (R 1) ₂ , in which R 1 is chosen from alkyl, aryl, aralkyl, alkylaryl, alkene or organosilyl groups, optionally perfluorinated and optionally substituted by one or more carboxyl groups, epoxy , hydroxyl, alkoxy, amino, halogen or sulfonic acid.

- Υ, Υ ', which are identical or different, are such that either Y, or Y', or both, contain at least one phosphorus functional group -P (O) (OR ₂ ) (OR ₃ ), R ₂ and R ₃ , identical or different, representing a hydrogen atom or an alkyl radical, optionally haloalkyl.

According to variants of the invention, the poly (phosphorus) terminated thiol polymer may consist of a type of monomer unit comprising Y and Y '. The poly (phosphorus) terminated thiol polymer is then a thiol derivative of a homopolymer of a monomer carrying at least one phosphorus functional group. According to variants of the invention, the poly (phosphorus) terminated thiol polymer may consist of several types of monomeric units comprising Y and Y ', Y and Y' then being different from one type of unit to another . The poly (phosphorus) terminated thiol polymer is then a thiol derivative of a copolymer of several monomers carrying at least one phosphorus function. The sequence of the different monomer units comprising Y and Y 'may be random or blocky.

According to variants of the invention, the poly (phosphorus) terminated thiol polymer may consist of one or more types of monomeric units comprising Y and Y ', and one or more types of monomeric units containing X and X ', Y and Y' on the one hand, and X and X 'on the other hand, then being different from one type of unit to another. The poly (phosphorus) terminated thiol polymer is then a thiol derivative of a copolymer of one or more monomers carrying at least one phosphorus functional group and one or more comonomers comprising X, X '. The sequence of the different monomeric units, comprising X, X 'on the one hand, and on the other hand Y and Y', can be statistical or block.

According to the invention, the term "alkyl" denotes a linear or branched hydrocarbon radical of 1 to 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, isobutyl, pentyl, hexyl, heptyl or octyl. , nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl or icosyl.

By "alkenyl" is meant a linear or branched hydrocarbon chain of 2 to 20 carbon atoms comprising one or more double bonds. Examples of particularly preferred alkenyl groups are alkenyl groups having a single double bond such as -CH ₂ -CH ₂ -Cl-l = C (CH ₃₎ _2, vinyl or allyl. By "alkynyl" is meant a linear or branched hydrocarbon chain of 2 to 20 carbon atoms comprising one or more triple bonds. Examples of particularly preferred alkynyl groups are alkynyl groups having one triple bond such as-CH ₂ -CH ₂ -C≡CH.

By "cycloalkyl" is meant saturated hydrocarbon groups which may be mono-or polycyclic and comprise from 3 to 12 carbon atoms, preferably from 3 to 8. Particularly preferred monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl and cyclododecyl. By "cycloalkenyl" is meant according to the invention a group derived from a cycloalkyl group as defined above, having one or more double bonds, preferably a double bond.

By "cycloalkynyl" is meant according to the invention a group derived from a cycloalkyl group as defined above, having one or more triple bonds, preferably a triple bond.

By "aryl" is meant an aromatic mono- or bicyclic hydrocarbon group comprising 6 to 10 carbon atoms, such as phenyl or naphthyl.

By "alkaryl" is meant an alkyl group as defined above, substituted with an aryl group.

By "aralkyl" is meant an alkyl group as defined above, substituted with an aryl group.

By "alkoxy" is meant an O-alkyl group generally having 1 to 20 carbon atoms, especially methoxy, ethoxy, propoxy and butoxy. The heterocyclic group (iii) denotes saturated or preferably unsaturated monocyclic or bicyclic carbon rings having 5 to 12 members and having 1, 2 or 3 endocyclic heteroatoms selected from O, N and S. These are generally derivatives of heteroaryl groups. Generally speaking, "heteroaryl" means 5- to 7-membered monocyclic aromatic groups or 6- to 12-membered bicycles comprising one, two or three endocyclic heteroatoms chosen from O, N and S. Examples are furyl groups, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, triazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrazinyl and triazinyl. Preferably, the heterocycle when unsaturated comprises a single double bond. Preferred examples of unsaturated heterocycles are dihydrofuryl, dihydrothienyl, dihydropyrrolyl, pyrrolinyl, oxazolinyl, thiazolinyl, imidazolinyl, pyrazolinyl, isoxazolinyl, isothiazolinyl, oxadiazolinyl, pyranyl and mono-unsaturated derivatives of piperidine, dioxane, piperazine, trithiane. , morpholine, dithiane, thiomorpholine, as well as tetrahydropyridazinyl, tetrahydropyrimidinyl, and tetrahydrotriazinyl. According to variants of the invention, R is as defined in WO 98/58974, WO 00/75207 and WO 01/42312 (definition of Ri), WO 98/01478 and WO 99/31 144 (definition of R ), or WO 02/26836 (definition of Ri).

Among these variants, R is more particularly a cyanomethyl group CNCH ₂ -, 1 -phenylethyl CH ₃ (C ₆ H ₅ ) CH- or methylpropionyl CH ₃ (CO ₂ CH ₃ ) CH-.

The mole fraction of monomer units with X and X 'may be zero, and is generally from 0 to 0.5, preferably from 0 to 0.25, more preferably from 0 to 0.1.

Among the monomers from which the units carrying phosphorus functional groups in Y and Y 'that are useful in the present invention are vinyl phosphonic acid, vinyl phosphonic acid dimethyl ester, bis (2-chloroethyl) ester, and the like; vinyl phosphonic acid, vinylidene diphosphonic acid, vinylidene diphosphonic acid tetraisopropyl ester, alpha-styrene phosphonic acid, dimethyl-p-vinylbenzylphosphonate, diethyl-p-vinylbenzylphosphonate, dimethyl (methacryloyloxy) ) methyl phosphonate, diethyl (methacryloyloxy) methyl phosphonate, diethyl-2- (acrylamido) ethylphosphonate, more generally any styrene unsaturated monomer, acrylate or methacrylate, acrylamido or methacrylamido, vinyl or allyl carrier of at least one dialkylphosphonate group; , phosphonic acid or hemiacide-P (OH) (OR), or a mixture of these monomers. Preferably, the dimethyl ester of vinylphosphonic acid and dimethyl-p-vinylbenzylphosphonate will be used.

Among the monomers from which the units substituted by X and X 'that are useful for the present invention are the hydrophilic (h) or hydrophobic (H) monomers chosen from the following monomers.

Among the hydrophilic monomers (h), mention may be made of:

vinyl alcohol resulting from the hydrolysis of vinyl acetate, for example.

neutral acrylamido monomers such as acrylamide, Ν, Ν-dimethylacrylamide and N-isopropylacrylamide.

the cyclic amides of vinylamine, such as N-vinylpyrrolidone and vinylcaprolactam.

ethylenically unsaturated mono- and di-carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, or fumaric acid.

the ethylenic monomers comprising a sulphonic acid group or an alkali or ammonium salt thereof, for example vinylsulphonic acid, vinylbenzene sulfonic acid, alpha-acrylamido-methylpropanesulfonic acid, or 2-sulfoethylene-methacrylate, or

monomers selected from aminoalkyl (meth) acrylates, aminoalkyl (meth) acrylamides; monomers comprising at least one secondary, tertiary or quaternary amine functional group, diallyldialkyl ammonium salts such as dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide, 2-vinylpyridine, 4-vinylpyridine, diallyldimethyl ammonium chloride.

Preferably, the hydrophilic monomeric units (h) are chosen from acrylic acid (AA), dimethylaminopropyl acrylamide, and N-vinylpyrrolidone.

Among the hydrophobic monomers (H), mention may be made of:

styrenic derived monomers such as styrene, alphamethylstyrene, paramethylstyrene or paratertiobutylstyrene, or

- esters of acrylic acid or methacrylic acid with alcohols -C _12, preferably -C _8, optionally fluorinated, such as, for example, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, t-butyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylate, n-butyl, isobutyl methacrylate,

vinyl nitriles containing from 3 to 12 carbon atoms, and in particular acrylonitrile or methacrylonitrile,

vinyl esters of carboxylic acids, such as vinyl acetate (VAc), vinyl versatate, or vinyl propionate,

vinyl or vinylidene halides, for example vinyl chloride, vinylidene chloride and vinylidene fluoride, and

diene monomers, for example butadiene or isoprene.

Preferably, the hydrophobic monomer units (H) of the copolymers of the invention are butadiene, isoprene, butyl acrylate and styrene.

The poly (phosphorus) functional thiol polymer as defined above has an average number of units of at least 2 and at most equal to 1000.

The poly (phosphorus) functional thiol polymer at the end of the chain may be obtained by any method allowing the functionalization at the chain end by a thiol function of any poly (phosphorus) polymer obtained by homopolymerization of a monomer carrying at least one functional group. phosphorus, or by copolymerization of one or more monomers carrying at least one phosphorus functional group with one another or with one or more comonomers. Depending on the processes, the functionalization may be concomitant with the polymerization or may be posterior thereto.

Many techniques are known for the synthesis of functionalized thiol polymers at their ends. For example, the chemical modification of a polymer terminated with mercaptoacetic acid (Du et al., J. Appl., Polym., Sci., 2003, 90, 2494-607) or the hydrolysis of a thiocarbonylthio terminus. a polymer synthesized by RAFT (RAFT for Reversible Addition Fragmentation Chain Transfer Polymerization, Moad et al., Aust.J.Chem., 2012, 65, 985-1076) (Bae et al., Reactive and Functional Polymers, 201 1, 71, 2.187 -194). In particular, using specific thiocarbonylthio compounds, these same RAFT polymers are transformed into macrothiols by simple thermal elimination (WO 2002090424 A1, Rhodia Chimie and Destarac et al., ACS Symp Ser 944, American Chemical Society, 2006. Matyjaszewski, K., Ed. "Controlled / Living Radical Polymerization: From Synthesis to Materials", 564). According to an advantageous variant of the invention, the poly (phosphorus) functional thiol polymer at the end of the chain is obtained by controlled RAFT or MADIX controlled radical (co) polymerization of at least one monomer carrying at least one phosphorus functional group in the presence of a source of free radicals and a thiocarbonylthio chain transfer agent of general formula II

R-S (C = S) -Z (II) in which,

- R represents:

(i) an alkyl, acyl, aryl, alkenyl or alkynyl group,

(ii) a carbon cycle, saturated or unsaturated, optionally aromatic;

(iii) a heterocycle, saturated or unsaturated, optionally aromatic; or

these groups and rings (i), (ii) and (iii) may be substituted by substituted phenyl groups, substituted aromatic groups or groups: alkoxycarbonyl or aryloxycarbonyl (-COOR '), carboxy (-COOH), acyloxy (- 0 ₂ CR '), carbamoyl (-CONR' ₂ ), cyano (-CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino, guanidimo, hydroxy (-OH), amino (-NR ' ₂ ), halogen, allyl, epoxy, alkoxy (-OR '), S-alkyl, S-aryl, groups having a hydrophilic or ionic nature such as the alkali metal salts of carboxylic acids, the alkali metal salts of sulfonic acid, the polyalkyleneoxide chains (POE, POP), the cationic substituents (quaternary ammonium salts), R 'representing an alkyl or aryl group,

(iv) a polymer chain,

Z is an oxygen atom, a carbon atom, a sulfur atom, a nitrogen atom or a phosphorus atom, these atoms being substituted with one, two or three hydrocarbon radicals R ", so as to have a suitable valency, which may comprise at least one heteroatom, such that R "represents a group as defined above for R. According to variants of the invention, R and R" are as defined in the documents WO 98/58974. , WO 00/75207 and WO 01/42312 (definition of respectively R ₂ ), WO 98/01478 and WO 99/31144 (definition of R respectively of Z and Ei), or WO 02/26836 (definition of R ¹ respectively nitrogen group).

According to variants of the invention, in the general formula RS (C = S) -Z, R is more particularly a cyanomethyl group CNCH ₂ -, 1 -phenylethyl CH ₃ (C ₆ H ₅ ) CH- or methylpropionyl CH ₃ ( C0 ₂ CH ₃ ) CH-.

According to variants of the invention, in the general formula RS (C = S) -Z, Z denotes a group OR 'with R' denoting a C ₁ -C ₅ alkyl radical, preferentially

Thus, according to variants of the invention, the poly (phosphorus) polymers of formula I can be obtained by controlled radical polymerization RAFT or MADIX monomers comprising Y and Y 'and, where appropriate, the monomers comprising X and X', listed above.

The preferred and variant aspects above are combinable with each other. The synthesis of a thiocarbonylthio transfer agent having the general formula R-S- (C = S) -Z can be carried out in a manner known to those skilled in the art.

The initiator of polymerization RAFT OR MADIX may be chosen from the initiators conventionally used in radical polymerization.

Thus, transfer agents or processes that are useful for carrying out the synthesis of the polyphosphorous polymer carrying a thiol function are described in particular in the following documents: the methods and agents of applications WO 98/58974, WO 00/75207 and WO 01/42312 which implement a controlled radical polymerization by xanthate control agents (group -S- (C = S) -O-) , the process and the radical polymerization agents controlled by dithioester type control agents (-S- (C = S) -S-carbon group) or trithiocarbonates (-S- (C = S) -S-) group of WO 98/01478, the method and the radical polymerization agents controlled by dithiocarbamate type control agents (group -S- (C = S) -Azote) of the application WO 99/31144, - the method and the radical polymerization agents controlled by dithiocarbazate type control agents (group -S- (C = S) -Azote) of the application WO 02/26836, the agents of xanthates, dithiocarbonates and / or trithiocarbonates type described in the documents WO02070571; WO2001060792; WO2004037780; WO2004083169; WO2003066685; WO2005068419; WO2003062280; WO2003055919; WO2006023790, and methods using them.

One of the advantages of the RAFT or MADIX polymerization process is the ability to control the length of the poly (phosphorus) polymer by adjusting the molar ratio of the monomer and the transfer agent. The molar ratio of the monomer to the transfer agent is generally at least 2. According to variants of the invention related to the choice of the phosphorus monomer, this ratio is at most 1000.

At the end of the polymerization, the product is predominantly of the general formula R-P-S- (C = S) -Z, where P denotes the poly (phosphorus) polymer chain.

The thiol derivative RP-SH is obtained by chemical modification of this finished thiocarbonylthio product in a conventional manner and known to those skilled in the art. Among the methods envisaged, it is advantageous to mention the aminolysis reaction generally carried out with primary or secondary amine compounds. Even more advantageously, the poly (phosphorus) terminated thiol polymer RP-SH is formed directly by thermolysis of particular thiocarbonylthio groups, for example xanthates derived from secondary alcohol. The polyphosphor thiol-terminated polymer of the invention is particularly suitable for participating in a thiol-ene coupling reaction. The carbon-carbon double bonds are advantageously unsaturations of a diene polymer, allowing thus grafting the polyphosphorus polymers of the invention on diene polymers. It is thus possible to prepare polymers with a high phosphonate or phosphonic function content by significantly reducing the macrostructure evolutions of the polymers and the secondary reactions occurring during grafting of monophosphorus thiol molecules in order to achieve the same level of functions in the polymer. polymer.

The aforementioned features of the present invention, as well as others, will be better understood on reading the following description of several embodiments of the invention, given by way of illustration and not limitation.

EXAMPLE OF CARRYING OUT THE INVENTION

Measures used

The elastomers are characterized, before cooking, as indicated below. Excludable sterilization chemistry The number-average molar masses M n of the polymers and their dispersions were obtained by steric exclusion chromatography (SEC) with tetrahydrofuran (THF) as eluent at 1 ml. / min. Calibration is carried out with polystyrene (PS) standards having molar masses of between 1200 and 512800 g mol-1. The CES chain is equipped with a Waters 2414 RI detector and a set of 2 columns (Shodex KF-802.5 and KF-804) thermostatically controlled at 35 ° C.

Tem perter of tran siti on vitreu

The glass transition temperature determination analyzes were carried out with a Netzsch DSC (Phoenix) apparatus. An aluminum crucible comprising 5 to 10 mg of sample is deposited on a platinum boat. The rate of temperature rise used for all the samples is 10 ° C.min-1. The analyzes were conducted under nitrogen.

¹ H NMR, ³¹ P NMR, and ¹³ C NMR spectroscopy were recorded on a 300 MHz Bruker spectrometer at room temperature and using CDCl ³ as a solvent. The Chemical shifts are shown in ppm. The conversions to monomers are determined by ¹ H NMR and ³¹ P NMR.

Examples of realizati on of i nventi on

Example 1 Synthesis of a C4 Cyanomethyl Functionant Xanthate

- Reaction scheme

Scheme 1. Synthesis of xanthate with cyanomethyl function C4

In a 500 ml flask, 6 g (6.81 · 10 ^-2 mol) of 3-methylbutanol are solubilized in 45 ml of THF, a solution of BuLi (1.6 M in hexane) (46.5 ml, 7 mmol). 44.10 ^"2 mol) is added dropwise at 0 ° C. to the reaction mixture. The reaction is stirred for 30 minutes. The carbon disulphide (30 ml, 4.96 × 10 ^-1 mol) is added dropwise at 0 ° C. to the reaction medium, the reaction mixture is then kept under magnetic stirring for 30 minutes at 0 ° C. (1.1 g, 6 g). 13.62.10 ^"2 mol) of bromoacetonitrile is added dropwise to the reaction mixture and then the solution is stirred for 15h. After evaporation of THF, the residue is purified by CH ₂ Cl ₂ / water (1: 1) extraction. The CH ₂ Cl _{2 solution} is evaporated under vacuum. After purification on a chromatographic column (eluent: petroleum ether / ethyl acetate, 95/5) and evaporation, the product is obtained in the form of a yellowish oil with a final yield of 86%.

¹ H NMR (300 MHz, CDCl ₃ , δ = ppm): 5.58 (1H, m, 0-CHCH ₃ ), 3.85 (2H, s, NC-CH ₂ -SC = S), 2, 02 (1H, m, (-CH (CH ₃ ) ₂ ), 1, 33 (3H, d, O-CHCH ₃ ), 0.96 (6H, d, (-CH (CH ₃ ) ₂ ).

¹³ C NMR (300 MHz, CDCl ₃ , δ = ppm): 208.6 (S = CSCH-), 1 15.5 (NC-CH ₂ -SC = S),

87.8 (O-CHCH ₃ ), 32.7 ((-CH (CH ₃ ) ₂ ), 21, 1 (NC-CH ₂ -SC = S), 18.1 (-CH (CH ₃ ) ₂ ) 17.9 (O-CHCH ₃ ), 15.8 (O-CHCH ₃ ).

Example 2 Synthesis of DMVP-C4 Dimethyl Vinylphosphonate Monoadduct

- Reaction scheme

Scheme 2. Synthesis of the DMVP-C4 monoadduct

C4 xanthate (2.76 g, 13.59 × 10 ^-2 mol), dimethyl vinylphosphonate (1 g, 7.35 × 10 ^-3 mol) and solvent 1 are introduced into a 25 ml flask surmounted by a coolant. 2- dichloroethane (6 ml). The mixture is degassed with argon for 15 minutes. The reaction mixture is then maintained at reflux of the solvent (95 ° C.) and with magnetic stirring for 7 hours. 5 mol% of dilauroyl peroxide are added every 60 minutes to 25 mol%. After purification on a chromatographic column (eluent ethyl acetate) and evaporation, the final yield of the synthesis is 65%.

¹ H NMR (300 MHz, CDCl ₃ , δ = ppm): 5.58 (1H, m, 0-CHCH ₃ ), 4.35 (1H, m, NC-CH ₂ -CH ₂ -CH SC = S), 3.82 (3H, s, P = (OCH ₃ ) ₂ ), 2.62 (2H, m, NC-CH ₂ -CH ₂ -CHR S-C = S), 2.45-2.21 (2H, m, NC-CH ₂ -CH ₂ -CH SC = S), 2.03 (-CH (CH ₃ ) ₂ ), 1.35 (3H, d, O -CHCH ₃ ), 0.95 ( 6H, d, (-CH (CH ₃ ) ₂ ).

³¹ P NMR (300 MHz, CDCl ₃ , δ = ppm): 24.6 (1 P, d, P = (OCH ₃ ) ₂ ).

¹³ C NMR (300 MHz, CDCl ₃ , δ = ppm): 210.7 (S = CSCH-), 1 19.1 (NC-CH ₂ -CH ₂ -CH SC = S), 88.0 (0- CHCH ₃ ), 54.2 (P = (OCH ₃ ) ₂ ), 44.4 and 42.6 (NC-CH ₂ -CH ₂ -CH SC = S), 32.7 ((-CH (CH ₃ ) ₂ ) , 26.6 (NC-CH ₂ -CH ₂ -CH SC = S), 19.1 (-CH (CH ₃ ) ₂ ), 16.4 (O -CHCH ₃ ), 15.1 (NC-CH ₂ -CH ₂ -CH ₂ -SC = S).

Example 3 Aminolysis of the DMVP-C4 Monoadduct

- Reaction scheme

Figure 3. Aminolysis of DMVP-C4 monoadduct

In a 25 ml flask, 200 mg (2.94 × 10 ^-4 mol) of DMVP-C4 monoadduct are solubilized in 6 ml of dichloromethane, the flask is placed in an ice bath, degassed with argon for 15 minutes and then kept at room temperature. shielded from light under inert atmosphere until complete solubilization of the monoadduct A second solution containing 1 ml of propylamine in 40 ml of dichloromethane is prepared and then degassed with argon for 15 minutes. From this stock solution, 1 ml (2.94 × 10 ^-4 mol) is added dropwise at 0 ° C. to the reaction mixture containing the monoadduct. The reaction is stirred for 60 minutes. After purification on a chromatographic column (eluent ethyl acetate) and evaporation, the final yield of aminolysis is 35%.

³¹ P NMR (300 MHz, CDCl ₃ , δ = ppm): 26.3 (1 P, s, P = (OCH ₃ ) ₂ ).

Example 4: Thermolysis of the DMVP-C4 monoadduct

- Reaction scheme

Figure 4. Thermolysis of the DMVP-C4 monoadduct

The DMVP-C4 monoadduct (250 mg, 7.37 × 10 ^-4 mol) and the 1,2-dichlorobenzene solvent (3 ml) are introduced into a 25 ml flask surmounted by a refrigerant. The reaction mixture is degassed with argon for 15 minutes and then kept at reflux of the solvent (200 ° C) in the absence of light and for 5 minutes. The yield of the thermolysis is 70%. ³¹ P NMR (300 MHz, CDCl ₃ , δ = ppm): 26.3 (1 P, s, P = (OCH ₃ ) ₂ ).

Example 5 Synthesis of the oligomers of PDMVP - Reaction Scheme

Scheme 5. Synthesis of the PDMVP-C4 Oligomer The polymerization is carried out according to the following protocol: Xanthate C4 (470 mg, 2.31 .10 ^-3 mol), vinyl dimethyl phosphonate (3 g, 2.2 × 10 ^-2 mol), AIBN (72 mg, 4.38-10 ^"4 mol) and 4.6 g of 1,4-dioxane are placed in a Schlenk tube, the solution is degassed with argon for 15 minutes and then placed in a bath preheated to 70 ° C. The reaction is stirred for 24 hours The reaction mixture is purified by drying under reduced pressure at 80 ° C. and washing with dichloromethane to remove residual monomer and dioxane. obtained is 50% and the molar mass, determined by ³¹ P NMR, is 720 g / mol (M _n _theo = 750 g / mol).

Example 6: Thermolysis of PDMVP-C4 Oligomers

- Reaction scheme

Figure 6. Thermolysis of PDMVP-C4 oligomers

The PDMVP-C4 (250 mg, 3.47 × 10 ^-4 mol) and the 1,2-dichlorobenzene solvent (3 ml) are introduced into a 25 ml flask surmounted by a condenser The reaction mixture is degassed with argon for 15 minutes and then kept at reflux of the solvent (200 ° C.) in the dark and for 15 minutes The yield of the thermolysis is 72% (determined by ³¹ P NMR).

Example 7: Thermolysis of the DMVP-C4 monoadduct followed by grafting on SBR

Reaction scheme

The DMVP-C4 monoadduct (250 mg, 7.37 × 10 ^-4 mol) and the 1,2-dichlorobenzene solvent (3 ml) are introduced into a 50 ml flask surmounted by a refrigerant. The mixture is degassed with argon for 15 minutes and then kept at reflux of the solvent (200 ° C) in the absence of light and for 5 minutes. 500 mg of SBR (M _n = 235,900 g / mol, dispersity D (Mw / Mn) = 1, 24, 75% of PB) are dissolved in 15 ml of methylhexane. The latter SBR is already antioxidized with A02246 (2,2'-methylenebis (4-methyl-6-tert-butylphenol) This second solution is added to the monoadduct and the reaction medium is degassed with argon for 15 minutes. The solution is then heated to 75 ° C. A solution of 10 mg of DLP in 20 ml of methyl ethylhexane is prepared and then degassed with argon for 15 minutes, from which stock solution (1 ml, 1.25 × 10 ⁶ mol) is added via a syringe in the reaction medium. After 3 hours of reaction, the mixture is cooled and then precipitated in methanol. The polymer is solubilized in dichloromethane and then antioxidized with 1 ml of a solution of A02246 at 10 g / l. The polymer is then dried under vacuum at 60 ° C. The grafting yield is 37.5% (determined by ¹ H NMR). Table 1 below summarizes the characteristics of polymers synthesized by grafting DMVP.

Table 1: Synthesis of SBR-g-DMVP by thiol-ene grafting. [SBR] ₀ = 1, 3.10 ⁴ moles [DLP] ₀ = 0.2% / [DMVP] ₀ , T

a determination by ¹ H-NMR, ^b determined by SEC-IR in THF with PS standards.

Example 8: Thermolysis of PDMVP-C4 followed by grafting on SBR

- Reaction scheme

The PDMVP-C4 oligomer (250 mg, 3.47 × 10 ^-4 mol) and the 1,2-dichlorobenzene solvent (3 ml) are introduced into a 50 ml flask surmounted by a condenser. argon for 15 minutes and then kept at reflux of the solvent (200 ° C.) in the absence of light and for 5 minutes 500 mg of SBR (M _n = 235,900 g / mol, D = 1, 24, 75% by weight) are dissolved in 15 ml of methylcyclohexane.The latter SBR is already antioxidized with A02246 (2,2'-methylenebis (4-methyl-6-tert-butylphenol) This second solution is added to the solution of PDMVP then the medium The solution is then degassed with argon for 15 minutes The solution is then heated to 75 ° C. A solution of 10 mg of DLP in 20 ml of methylcyclohexane is prepared and then degassed with argon for 15 minutes. 1 mL, 1.25 × 10 ⁶ mol) is added via a syringe to the reaction medium.On the reaction for 3 hours, the mixture is cooled and then precipitated in the reaction medium. methanol The polymer is solubilized in dichloromethane and then antioxidized with 1 ml of a solution of A02246 at 10 g / l. The polymer is then dried under vacuum at 60 ° C. The graft yield is 48.5% (determined by ¹ H NMR).

Table 1 below summarizes the characteristics of polymers synthesized by grafting DMVP.

Table 2: Synthesis of SBR-g-PDMVP by thiol-ene grafting. [SBR] ₀ = 1 .3.10 ^"4 mol L ¹ , [PDMVP-C4] ₀ = 29.2.10 ^-3 mol L ^{" 1} , [DLP] ₀ = 0.2% / [PDMVP] ₀ , T = 75 ° C, t = 3h.

Determination by ¹ H NMR, ^b = CES-RI determination in THF with PS standards.

Results

Compared with the use of a thiol-terminated monophosphonate (Example 7), the grafting of thiol-terminated poly (phosphonates) (Example 8) makes it possible to obtain phosphonate-modified diene polymer having high phosphonate function levels without having to aim for high grafting rates.

The use of phosphonate functional thiol small molecules such as those described in Example 7 has the drawback of an evolution of the macrostructure in the case of high grafting rates.

In the case where a low grafting rate of the unsaturations of the diene elastomer is aimed at, we observe a conservation of the macrostructure of the final polymer (entry 2, table 1 of example 7). However, in this case the molar fraction of phosphonate functions in the final polymer is low (3.6%).

In order to obtain a diene polymer having high levels of phosphonate functions, we have aimed at a high degree of grafting of the unsaturations of the diene elastomer. The final polymer thus has a large molar fraction of phosphonate functions (18.2%). However, in this case the grafting reaction is accompanied by an evolution of the macrostructure which is due to the secondary reactions (bimolecular coupling, transfer reaction, ...) and whose proportion increases with the rate of grafts targeted. This is illustrated by the excessive evolution of the Mn (400600 g mol ^-1 ), the dispersity (D = 1.44) and the consumption of the double bonds of the diene elastomer (Table 1 entry 3 of the Example 7).

Advantageously, the use of a poly (phosphorus) polymer, in this case poly (phosphonate) bearing a thiol function at the end of the chain makes it possible to overcome the drawbacks associated with the use of thiol-functionalized small phosphonate molecules. In fact, the use of poly (phosphonate) polymers makes it possible to obtain a modified diene polymer having a high molar content of phosphonate functions along the chain, aiming for low grafting levels and without modifying the final polymer macrostructure.

This is illustrated in Table 2, entry 2 of Example 8. In fact, we succeed in grafting high molar levels of phosphonate functions (12.2%) without having to target a high level of unsaturations of the diene elastomer. . In this case, the grafting makes it possible to preserve the final polymer macrostructure (Mn = 239800 g mol ^-1 = 0.25). We can also increase the molar fraction of the phosphonate functions in the final diene polymer to reach a very high level of 55.8% (Table 2, entry 3 of Example 8) without observing a change in the macrostructure of the final polymer (Mn = 243000 g mol ^-1 , D = 1, 26) which was not the case with the monophosphonate carrying the thiol function of Example 7.

Claims

Polyphosphoric polymer bearing a thiol end-chain function whose polymer chain comprises units carrying at least one phosphonate function and / or at least one phosphonic function.

Polyphosphorus polymer carrying a thiol end-chain function according to Claim 1, characterized in that it corresponds to the formula RP-SH, R representing an alkyl, acyl, aryl, alkenyl or alkynyl group, a saturated carbon ring or not, optionally aromatic, a heterocycle, saturated or unsaturated, optionally aromatic; or a polymer chain, P representing the polyphosphorus chain comprising units bearing at least one phosphonate function and / or at least one phosphonic function, S representing a sulfur atom and H representing a hydrogen atom.

Polyphosphorus polymer carrying a thiol end-chain function according to Claim 2, characterized in that it corresponds to the following general formula (I):

(I) where m is an integer greater than or equal to 2 and n is an integer greater than or equal to 0, provided that when n is not 0, n and m may be the same or different, preferably each greater than 2 and preferably each less than 500.

R represents:

(i) an alkyl, acyl, aryl, alkenyl or alkynyl group,

(ii) a carbon cycle, saturated or unsaturated, optionally aromatic;

(iii) a heterocycle, saturated or unsaturated, optionally aromatic; or wherein said groups and rings (i), (ii) and (iii) may be substituted with substituted phenyl groups, substituted aromatic groups or: alkoxycarbonyl or aryloxycarbonyl (-COOR '), carboxy (-COOH), acyloxy ( -O ₂ CR '), carbamoyl (-CONR' ₂ ), cyano (-CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino, guanidimo, hydroxy (-OH), amino (-NR ' ₂ ), halogen, allyl, epoxy, alkoxy (-OR'), S-alkyl, S-aryl, groups having a hydrophilic character or ionic such as alkali metal salts of carboxylic acids, alkali metal salts of sulfonic acid, polyalkylene oxide chains (POE, POP), cationic substituents (quaternary ammonium salts), R 'representing an alkyl or aryl group (iv) a polymer chain,

X, X ', which may be identical or different, represent H, a halogen or a group R 1, OR 1, OCOR 1, NHCOH, OH, NH ₂ , NHR _1; N (R) _2, (R ^ N + O ^"

NHCOR _Ï, C0 ₂ H, C0 ₂ R _1; CN, CONH ₂ , CONH R or CONIR, wherein R 1 is selected from alkyl, aryl, aralkyl, alkylaryl, alkene or organosilyl groups, optionally perfluorinated and optionally substituted by one or more carboxyl, epoxy, hydroxyl, alkoxy, amino groups; , halogen or sulfonic.

Y, Y ', which are identical or different, are such that either Y, Y' or both contain at least one phosphorus functional group -P (O) (OR ₂ ) (OR ₃ ), R ₂ and R ₃ , identical or different, representing a hydrogen atom or an alkyl radical, optionally haloalkyl.

4. Polyphosphorus polymer carrying a thiol end-chain function according to claim 3, characterized in that in formula I, R is a cyanomethyl group of formula CNCH ₂ -, 1 -phenylethyl of formula ΟΗ ₃ (0 ₆ Η ₅ ) ΟΙ-Ι- or methylpropionyl of formula CH ₃ (CO ₂ CH ₃ ) CI-1-.

5. Polyphosphorus polymer carrying a thiol end-chain function according to any one of claims 3 to 4, characterized in that the molar fraction of monomer units of the poly (phosphorus) polymer comprising X and X 'varies from 0 at 0.5, preferably from 0 to 0.25, more preferably from 0 to 0.1.

6. polyphosphoric polymer carrying a chain end thiol function according to any one of the preceding claims, characterized in that the poly (phosphorus) polymer carrying a chain end thiol function has a number of units at least equal to at 2 and at most equal to 1000

7. Polyphosphoric polymer carrying a thiol end-chain function according to any one of the preceding claims, characterized in that the polymer chain is a random copolymer of one or more carrier monomers at least one phosphonate and / or phosphonic function between them or with one or more comonomers.

8. polyphosphoric polymer carrying a thiol end chain function according to any one of claims 1 to 7, characterized in that the polymer chain is a block copolymer of one or more monomers carrying at least one function phosphonate and / or phosphonic acid with each other or with one or more comonomers.

9. Process for the synthesis of a polyphosphorated polymer carrying a thiol function at the end of the chain, characterized in that it comprises, on the one hand, the homopolymerization of a monomer carrying at least one phosphonate function and / or phosphonic acid, or the copolymerization of one or more monomers carrying at least one phosphonate and / or phosphonic function between them or with one or more comonomers, and, on the other hand, concomitantly or successively, the functionalization at the end of the d-chain. such a polymer by a thiol function.

10. Method according to claim 9, characterized in that it comprises the controlled radical polymerization of at least one monomer carrying at least one phosphonate and / or phosphonic function in the presence of a source of free radicals and a thiocarbonylthio chain transfer agent of general formula (II)

R-S (C = S) -Z (II) in which,

R represents:

(i) an alkyl, acyl, aryl, alkenyl or alkynyl group,

(ii) a carbon cycle, saturated or unsaturated, optionally aromatic;

(iii) a heterocycle, saturated or unsaturated, optionally aromatic; or

these groups and rings (i), (ii) and (iii) may be substituted by substituted phenyl groups, substituted aromatic groups or groups: alkoxycarbonyl or aryloxycarbonyl (-COOR '), carboxy (-COOH), acyloxy (- 0 ₂ CR '), carbamoyl (-CONR' ₂ ), cyano (-CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino, guanidimo, hydroxy (-OH), amino (-NR ' ₂ ), halogen, allyl, epoxy, alkoxy (-OR '), S-alkyl, S-aryl, groups having a hydrophilic or ionic character such as the alkaline salts of carboxylic acids, the alkaline salts of sulfonic acid, the polyalkylene oxide chains (POE, POP), cationic substituents (quaternary ammonium salts), R 'representing an alkyl or aryl group, (iv) a polymer chain,

Z is an oxygen atom, a carbon atom, a sulfur atom, a nitrogen atom or a phosphorus atom, these atoms being substituted with one, two or three hydrocarbon radicals R ", so as to have a valence suitable, which may comprise at least one heteroatom, such that R "represents a group as defined above for R; and, after polymerization, chemical modification of thiol thiocarbonyl thio terminated polymer.

1 1. Process according to Claim 10, characterized in that the chemical modification is carried out by aminolysis reaction or by thermolysis reaction of the thiocarbonylthio groups.

12. Process according to any one of claims 9 to 11, characterized in that the monomer carrying at least one phosphonate and / or phosphonic function is vinylphosphonic acid, the dimethyl ester of vinylphosphonic acid, vinylphosphonic acid bis (2-chlorohexyl) ester, vinylidene diphosphonic acid, vinylidene diphosphonic acid tetraisopropyl ester, alpha-styrene phosphonic acid, dimethyl-p-vinylbenzylphosphonate, diethyl-p- vinylbenzylphosphonate, dimethyl (methacryloyloxy) methylphosphonate, diethyl (methacryloyloxy) methylphosphonate, diethyl-2- (acrylamido) ethylphosphonate, any styrene unsaturated monomer, acrylate or methacrylate, acrylamido or methacrylamido, vinyl or allylic carrier from minus a dialkylphosphonate, phosphonic acid diacid or hemiacide -P (OH) (OR) group, or a mixture of these monomers.

13. Process according to any one of claims 9 to 12, characterized in that the comonomer is a hydrophilic monomer (h) or a hydrophobic monomer (H),

The hydrophilic monomer (h) being

the vinyl alcohol resulting from the hydrolysis of vinyl acetate,

a neutral acrylamido monomer,

a cyclic amide of vinylamine,

an ethylenically unsaturated mono- and dicarboxylic acid,

an ethylenic monomer comprising a sulphonic acid group or one of its alkaline or ammonium salts, or

a monomer chosen from aminoalkyl (meth) acrylates and aminoalkyl (meth) acrylamides; monomers comprising at least one secondary amine, tertiary or quaternary amine, diallyl dialkyl ammonium salts such as dimethyl amino ethyl (meth) acrylate, dimethyl amino propyl (meth) acrylate, dimethyl amino propyl (meth) acrylamide, 2-vinylpyridine, 4 -vinylpyridine, diallyldimethyl ammonium chloride. The hydrophobic monomer (H) being

a styrene monomer,

- an ester of acrylic acid or methacrylic acid with alcohols -C _12, preferably -C _8, optionally fluorinated,

a vinyl nitrile containing from 3 to 12 carbon atoms,

a vinyl ester of a carboxylic acid,

a vinyl or vinylidene halide, or

a diene monomer.