WO2010009938A1

WO2010009938A1 - Polymers with polysaccharide grafts, cosmetic compositions and treatment method

Info

Publication number: WO2010009938A1
Application number: PCT/EP2009/057039
Authority: WO
Inventors: Xavier Schultze; Anne-Claude Dublanchet; Franck Hernandez
Original assignee: L'oreal
Priority date: 2008-07-24
Filing date: 2009-06-08
Publication date: 2010-01-28
Also published as: FR2934268A1; FR2934268B1

Abstract

The present invention relates to polymers which have a polymeric backbone bearing polysaccharide grafts. The invention also relates to the cosmetic compositions, in particular hair compositions, comprising said polymers, and also to a cosmetic treatment method using same.

Description

Polysaccharide graft polymers, cosmetic compositions and method of treatment

The present invention relates to novel polysaccharide graft polymers, the compositions comprising them being especially cosmetic and to their use in cosmetics, especially in the hair field.

In the field of so-called "rinsed" hair compositions, such as shampoos or hair conditioners, water-soluble, synthetic cationic polymers known to provide good hair cosmetics are used. Mention may in particular be made of the commercial products "Merquat 550" and "Merquat 100", as well as the poly (vinylpyrrolidone / dimethylaminoethyl methacrylate quaternized) or poly (vinylpyrrolidone / imidazolinium methochloride) copolymers. However, these polymers are generally not used in post-coloring conditioner or care compositions, for which disentangling of wet hair must be very easy. Indeed, these polymers do not provide enough cosmetic properties. In the field of hair care, in particular of sensitized hair, in particular having undergone coloring, it is sought to provide cosmetic properties on wet hair, in particular an improved feel, as well as shine, softness and disentangling. in dry environment (on dry hair). Indeed, it is known that hair sensitized, that is to say damaged and / or weakened, to varying degrees by the action of atmospheric agents, including light, as well as by repeated action different mechanical or chemical treatments, such as perms, straightening, coloring and discoloration, may exhibit an alteration of the hair fiber, in particular a reduction in their mechanical properties such as tensile strength, tensile strength and elasticity. The hair can be more hydrophilic, losing part of the scales, which results in great difficulty in disentangling and styling the hair, and a loss of softness. To remedy this, it is possible to use cetyltrimethylammonium cationic surfactants, in oil-in-water emulsion, in the presence of fatty alcohols. However, the cosmetic properties are not optimal and the formulation of these compositions is complicated: compromise between the stability of the emulsion and the non-greasy feel to be found, in particular.

It has also been proposed to use compositions comprising polysaccharides, especially cationic polysaccharides, to improve the properties of the fiber. There may be mentioned the application WO02 / 055034 which describes cosmetic compositions containing a fructan, a polysaccharide and a beneficial agent for improving the properties of the fiber; as well as the application WO06 / 017589 which describes the use of polycationic graft polysaccharides for conditioning the fiber. However, it has been found that, in certain cases, the cationic polymers may be deposited in excessive amounts on the hair, in particular on damaged hair, which can lead to charged touches. In addition, these cationically charged polymers may cause formulation problems (incompatibility, precipitation) in the presence of anionic component usually used in cosmetics, such as surfactant or anionic styling polymer.

There is therefore still a need for polymers that can improve the quality of the hair, particularly in terms of touch, softness, disentangling, and mechanical properties of the fiber, whether it is on wet hair (in a humid environment) or on dry hair (in dry conditions).

The object of the present invention is to provide polymers, and the cosmetic compositions comprising them, which provide conditioning properties, and in particular make it possible to protect and repair keratin materials, in particular damaged keratin materials; in the case of the hair, this results among other things by an improvement of the disentangling properties on dry and wet hair and an improvement of the touch, in particular of the softness.

An object of the present invention is therefore a polymer of structure (POL) - (L-PS) _x where

POL represents a polymeric backbone,

L represents a linker,

PS represents a (poly) saccharide grafted onto POL via the linker L, and

x represents a non-zero integer characteristic of the number of PS grafts.

Another subject of the invention is a cosmetic composition comprising, in a cosmetically acceptable medium, at least one such polymer.

The polymers according to the invention can be represented by the following structure: (POL) - (L-PS) _x where

POL represents the polymeric backbone,

L represents a linker (or linker),

PS represents a polysaccharide grafted onto POL via the linker L, and

x represents a non-zero integer characteristic of the number of PS grafts.

In the rest of the text, POL will be called the polymeric backbone on which the polysaccharide grafts are present. It can be of natural origin (extraction of certain plants, crustaceans or insects for example) or synthetic. This polymer can be obtained by radical polymerization, controlled radical polymerization, anionic polymerization, cationic polymerization, ring opening polymerization, metathesis, polycondensation, coordination or enzymatic polymerization. Said polymeric backbone can have a statistical structure, with a gradient, a block, star, branched, hyperbranched, grafted, reticulated. It may be a homopolymer or a copolymer resulting from the copolymerization of several monomers, preferably between 2 and 5 different monomers.

This polymer backbone may be derived from the polymerization of one or more ethylenic monomers chosen from those of formula: R ¹ R ² C = CR ³ R ⁴ wherein R ^1, R ^2, R ³ and R ⁴ are independently one of the other,

a linear or branched and / or cyclic, saturated or unsaturated, linear or branched C1-20 alkyl, which may be substituted with 1 or more halogen atoms and / or one or more groups; OH,

a C2-C10 linear or branched alkenyl or alkynyl group which may be substituted by one or more halogen atoms; a C3-8 cycloalkyl group which may be substituted with one or more halogen atoms,

- a cyano group,

an aryl group,

a 4- to 12-membered heterocyclic group comprising one or more N, O, S and P atoms,

a group -C (= Y) R ⁵ , -CH ₂ C (= Y) R ⁵ , -C (= Y) NR ⁶ R ⁷ , -YC (= Y) R ⁵ , -NR ⁶ C (= Y) ) R ⁵ , -OR ⁵ , -SO ₂ R ⁵ , -OSO ₂ R ⁵ , -NR ⁸ SO ₂ R ⁵ , -P (R ⁵ ) ₂ , -P (= Y) (R ⁵ ) ₂ , -YP (R ⁵ ) ₂ , -YP (= Y) (R ⁵ ) ₂ or -N (R ⁸ ) ₂ optionally quaternized with an additional R ⁸ , wherein:

Y is NR ^8, S or O, R ⁵ is alkyl, alkoxy or alkylthio, linear, branched or cyclic, saturated or unsaturated, optionally hydroxylated Ci _-2 O, mono- or poly (alkyleneoxy) optionally etherified, hydroxyl, -OM (with M = alkali metal), aryloxy or heterocyclyloxy, R ⁶ and R ⁷ represent, independently of one another, a hydrogen atom or a linear, branched or cyclic alkyl group, saturated or unsaturated, Ci _-2 O or form with the nitrogen atom to which they are attached a ring with 3 to 8 members, R ⁸ represents a hydrogen atom, a linear, branched or cyclic alkyl group, saturated or unsaturated , Ci _-2 O, or an aryl group,

- -C (= O) -XR ⁹ -Z or -Z -R ⁹ wherein R ⁹ represents a radical valent di- (hydro) carbonaceous Ci _-20 saturated or unsaturated, linear, branched or cyclic, optionally halogen and which may comprise one or more heteroatoms, X represents a NR ¹⁰ group or an oxygen atom, and Z represents a group - N (R ¹⁰ ) ₂ , -SR ¹⁰ or P (R ¹⁰ ) ₂ with R ¹⁰ representing independently of one another, a hydrogen atom or a saturated or unsaturated, linear, branched or cyclic, optionally halogenated C ₂ -C hydrocarbon group, optionally halogenated and possibly containing one or more heteroatoms, the nitrogen atom present in X and / or Z (when present) capable of being protonated or quaternized by C 1 -C ₂ alkyl radicals,

a group -R ⁹ -NR ¹⁰ -Acide or -C (= O) -XR ⁹ -NR ¹⁰ -Acide in which X, R ⁹ and R ¹⁰ are as defined above, and Acid represents a carboxylic, sulfonic or phosphonic acid function;

a radical comprising at least one silicon atom and in particular a radical-R-siloxane, -CONHR-siloxane, -COOR-siloxane, or OCO-R-siloxane, in which R is a linear alkyl, alkylthio or alkoxy radical, branched or cyclic, saturated or unsaturated, C 1 -C 20, aryloxy or heterocyclyloxy.

The unsaturated monomers are chosen from acrylates, methacrylates, acrylamides, methacrylamides, vinyls, allylic and styrenics, and mixtures thereof. It can act even more preferably, (meth) acrylates, (meth) acrylamides and / or styrenics.

We can especially mention, alone or in mixture:

acrylic acid, methacrylic acid, straight-chain, branched or cyclic C 1-20 alkyl (meth) acrylates, such as methyl methacrylate, ethyl methacrylate, methacrylate of pro pyl, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate and cyclohexyl methacrylate; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate and tert-butyl acrylate,

C 6-20 aryl (meth) acrylates,

- C1-4 hydroxyalkyl (meth) acrylates, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,

vinyl esters and especially vinyl acetate, vinyl propionate, vinyl benzoate and vinyl tert-butylbenzoate,

vinyl ethers, such as vinylisobutyl ether,

heterocyclic monomers such as N-vinylpyrrolidone, vinylcaprolactam, vinyl-N- (C 1-6 alkyl) -pyrroles, vinyloxazoles, vinylthiazoles, vinylpyrimidines, vinylimidazoles, (meth) acrylamide,

aliphatic, cycloaliphatic or aromatic (meth) acrylamides, such as tert-butylacrylamide, undecylacrylamide or N-octylacrylamide; and di (C 1-4 alkyl) (meth) acrylamides,

styrene and its derivatives, (meth) acrylic, (meth) acrylamide or vinyl monomers containing a fluorinated or perfluorinated group, in particular (meth) acrylic esters with a perfluoroalkyl chain, such as perfluorooctylethyl (meth) acrylate,

- (meth) acrylic, (meth) acrylamides or vinylic silicone monomers such as (meth) acryloxypropylths (thmethylsiloxy) silane, - (meth) acrylic or vinyl monomers comprising an optionally neutralized or quaternized amine function, such as (meth) acrylate ) dimethylaminoethyl acrylate, dimethylaminoethylmethacrylamide, vinylamine, vinylpyridine, diallyldimethylammonium chloride, dimethylaminopropyl methacrylamide, 3-aminopropyl methacrylamide, 2-aminoethyl methacrylate;

the ethylenic carboxybetaines or sulfobetaines obtained, for example, by quaternization of ethylenically unsaturated monomers containing an amine function by sodium salts of a mobile halogen carboxylic acid (for example sodium chloroacetate) or by cyclic sulphones (p. eg propanesultone).

Most preferably, alone or as a mixture,

linear, branched or cyclic C 1 -C ₂ alkyl (meth) acrylates, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylate, isobutyl, tert-butyl methacrylate and cyclohexyl methacrylate; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate and tert-butyl acrylate,

the (meth) acrylic or vinyl monomers comprising an optionally neutralized or quaternized amine functional group, such as dimethylaminoethyl (meth) acrylate, dimethylaminoethyl methacrylamide, dimethylaminopropyl methacrylamide, 3-aminopropyl methacrylamide, 2-aminoethyl methacrylate; styrene and its derivatives.

The polymeric backbone POL may also be a polyester, polycarbonate, polyamide, polyimide, polyurethane, polyurea, polysaccharide, polysiloxane, polyphenol, polyether, polypeptide. Preferably, said backbone is chosen from (co) polymers derived from the polymerization of (meth) acrylates, (meth) acrylamides, styrenics or represents a polyurethane, a polypeptide, a polysaccharide or a polyether. More preferably still, said backbone is chosen from (co) polymers resulting from the polymerization of (meth) acrylates, (meth) acrylamides and / or styrene.

Preferably, the polymeric backbone has a number-average molecular weight (Mn) of between 1,000 and 5,000,000, especially between 2,000 and 1,000,000 and more preferably between 2,000 and 100,000 g / mol.

The polymers according to the invention preferably have a degree of grafting of between 1 and 100%, especially between 20 and 100%, and even more preferentially between 40 and 100%. In the present description by grafting rate is meant the ratio (x 100) between the number of repeating units of the polymeric backbone POL grafted by polysaccharide grafts (x), and the total number of repeating units of the polymeric backbone (or degree of polymerization). The polysaccharide grafts can be distributed on the polymeric backbone of statistically, alternately (1 graft every 2, 3 or n repetitive units of the polymer skeleton), or even in blocks (no grafts on a part of the skeleton, then all the repetitive units of a part of the grafted skeleton). Preferably, they are distributed statistically.

PS represents a polysaccharide graft or a saccharide (consisting of one or two sugar units).

The polysaccharides of the present invention are preferably selected from those described in "Encyclopedia of Chemical Technology, Kirk-Othmer, ^3rd editions tion, 1982, Volume 3, pp. 896-900, and Volume 15, pp 439-458" , in "Polymers in Nature by MacGREGOR and GREENWOOD, John Wiley & Sons edition, Chapter 6, pp 240-328, 1980" and in "Industrial Gums-Polysaccharides and their Derivatives, edited by Roy L. WHISTLER, 2 ^nd edition , Academy Press Publishing Inc. ", the contents of these three books are included in this application for reference.

The polysaccharides may be of natural origin or obtained enzymatically or chemically. In a nonlimiting manner, the polysaccharides of the present invention may be chosen from, alone or as a mixture:

fructans including inulin; glucans;

modified or unmodified starches, such as those derived, for example, from cereals such as wheat, corn or rice, from vegetables such as sweet pea, from tubers such as potatoes or cassava;

amylose, amylopectin, glycogen; dextrans and their derivatives, such as dextran sulfate, dextran diethylaminoethyl and carboxymethyl dextran;

celluloses and their derivatives such as methylcelluloses, hydroxyalkylcelluloses, ethylhydroxyethylcelluloses and carboxymethylcelluloses;

mannans, xylans, lignins, arabans, galactans, galacturonans, chitin, chitosans, glucoronoxylans, arabinoxylans, xyloglucans, glucomannans, pectic acids and pectins; - ginic and alginates, arabinogalactans, carrageenans, agars,

glycosaminoglucans such as hyaluronic acid, chondroitins and chondroitin sulphates; - Arabic gums, Tragacanth gums, Ghatti gums, Karaya gums, locust bean gums, gellan gums, curdlan gums, xanthan gums;

galactomannans such as guar gums and their derivatives, in particular hydroxypropylguar).

These saccharides or polysaccharides may optionally be modified chemically or enzymatically to introduce hydroxyethyl, hydroxypropyl, oligo (oxyethyl), oligo (oxypropyl), carboxylic and derivatives, sulphates groups. and derivatives, phosphates and derivatives, amino and derivatives (including nitro), esters, ether, amides. These groups can also be naturally present in the polysaccharides considered or present in protected form (N-acetyl in the case of chitin).

These (poly) saccharides PS consist of a combination of furanosic and pyranosic units, and can therefore be defined by the sequence of units (I) and / or (II) of formula:

(I) (") in which Ra to Re represent, independently of one another,

-OH,

-O- (repeating unit of the polysaccharide)

-CH ₃

-NHCOCH ₃ -NH2

-OCH ₂ COOH

COOH

-OSO ₃ H

-OPO ₃ H provided that at least one of Ra to Re is -O- (repeating unit of the polysaccharide) or OH, and one of Ra to Re is a covalent bond with the One- ker L; preferably only one of Ra to Re across the (poly) saccharide is a covalent bond.

Preferably, the polysaccharides according to the invention are constituted by the sequence of units (Ia) and / or (Ma) of formula, alone or as a mixture:

in which Rb to Rd represent, independently of each other, -OH, -CH ₃ , NHCOCH ₃ , NH ₂ , OCH ₂ COOH, COOH, OSO ₃ H, OPO ₃ H, and preferably Rb = Rc = Rd = OH ; By way of illustration, the following repetitive units may be mentioned in particular:

The acid groups (-OCH ₂ COOH, -COOH, -OSO ₃ H, -OPO ₃ H), whether they are present in the polysaccharide, the linker or the polymer backbone, may be neutralized with a mineral base, such as LiOH NaOH, KOH, Ca (OH) ₂ , Ba (OH) ₂ , NH ₄ OH or Zn (OH) ₂ ; or with an organic base such as a primary, secondary or tertiary alkylamine, especially triethylamine, isopropylamine or butylamine. This primary, secondary or tertiary alkylamine may comprise one or more nitrogen and / or oxygen atoms and may therefore comprise, for example, one or more alcohol functions; mention may especially be made of 2-amino-methyl-2-propanol, triethanolamine and dimethylamino-2-propanol. Mention may also be made of lysine or 3- (dimethylamino) propylamine.

The -NH ₂ groups can be neutralized with salts of mineral acids, such as sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid and boric acid. Mention may also be made of organic acid salts, which may comprise one or more carboxylic acid, sulfonic or phosphonic acid groups. It may be linear, branched or cyclic aliphatic acids or aromatic acids. These acids may furthermore comprise one or more heteroatoms chosen from O and N, for example in the form of hydroxyl groups. These include propionic acid, acetic acid, terephthalic acid, citric acid, tartaric acid, lactic acid, succinic acid, benzenesulphonic acid, para-toluene sulfonic acid, formic acid and methanesulfonic acid. Amino groups may be quaternized with mobile halogen compounds, including:

- halides such as alkyl chlorides or alkyl bromides Ci-Ci _2, for example methyl bromide, methyl iodide or ethyl chloride,

- Mobile halogen compounds containing carboxylic or sulfonic acid functions (optionally salified). Thus amphoteric hydrophilic monomers (also called betaines) are obtained. Quaternizing agents include, for example, sodium chloroacetate, dimethyl sulphate, diethyl sulphate or cyclic sulphones, for example propanesulphone.

Preferably, the polysaccharide grafts are chosen from dextrans and their derivatives (dextran sulfate, dextran diethylaminoethyl, carboxymethyl dextran), glycosaminoglucans and their derivatives (hyaluronic acid, chondroitins and chondroitin sulphates), celluloses and their derivatives (methylcelluloses, hydroxyalkylcelluloses, ethylhydroxyethylcelluloses, carboxymethyl- celluloses), amylose and its derivatives, chitins and their derivatives, carrageenans and their derivatives, oligomaltoses and their derivatives; and their mixtures.

The polysaccharide grafts may be of the same nature or of different natures.

Each (poly) saccharide graft PS preferably has a number-average molecular weight (Mn) of between 100 and 100,000 g / mol, in particular between 150 and 50,000 g / mol and preferably between 200 and 20,000 g / mol.

The nature of the linker L is conditioned by the chemical reaction involved in grafting the (poly) saccharides onto the repeating unit of the polymeric backbone. All chemical reactions known to those skilled in the art can be implemented. Different types of chemical reactions can be used to graft the (poly) saccharides onto the polymeric backbone.

Among the reactions that may be employed, between a reactive function of the polymer backbone and a reactive functional group of the (poly) saccharide PS, mention may be made without limitation of: the formation of ester or amide bonds by reaction between a hydroxyl function or a primary or secondary amine, and an acid derivative, an acid halide, an ester, an activated ester (N-hydroxysuccinimide ester, p-nitrophenyl ester, imidazole, etc.), a lactone, an anhydride, a mono , di or tri chlorotriazine, a thiolactone for example; the formation of a carbamate bond between an alcohol and an isocyanate or a urea bond between an amine and an isocyanate;

the formation of ether by reaction between 2 alcohols in the presence of a phosphine (Mitsunobu reaction), by addition of an alcohol to an alkyl halide;

a Michael addition between a thiol, an amine or an alcohol and an acrylate, a maleimide or any other compound carrying an unsaturation;

a Diels-Alder reaction between a diene (cyclopentadiene, furan derivatives, anthracene derivatives, etc.) and a dienophile (maleimide, acrylate, etc.).

However, in a preferred embodiment, the polymers according to the invention are prepared by Chemo-Selective Ligation reaction between aldehyde or ketone functions carried especially by the (poly) saccharide or the polymer backbone and at least one of the compounds following: H ₂ N-LI-R, HR 1 N-L 1 -R, H ₂ N-O-L 1 -R, H ₂ NO- (O) C-LI-R, H ₂ NO- (O) C-NH -LI-R, H ₂ NO- (S) C-NH-LI-R, HR 1 N-O-L 1 -R, HR 1 NO- (O) C-LI-R, HR 1 NO- (O) C-NH 1H-R, HR 1 NO- (S) C-NH-Li-R, H ₂ N-NH-LI-R, H ₂ N-NH- (O) C-LI-R, H ₂ N-NH- (O) CO-LI-R, H ₂ N-NH- (O) C-NH-Li-R, H ₂ N-NH- (S) C-Li-R, H ₂ N-NH- (S) CO-LI-R, H ₂ N-NH- (S) C-NH-LI-R, H ₂ N-CHR-CH (LI-R) -SH, H ₂ N-CH (LI-IR) -CHR -SH, H ₂ N-NH-SO ₂ -LI-R, X-CH ₂ -X'-L 1 -R where

X and X 'are electron-withdrawing groups (esters, ketones, acids, nitro, halogens in particular);

- L1 is a covalent bond or a group selected from (i) linear, branched or cyclic C1 to C30 alkyl, preferably linear or branched C1 to C10; (ii) linear, branched or cyclic C2-C30 alkenyl, preferably linear or branched C1-C10, (iii) linear, branched or cyclic C2-C30 alkynyl; preferably linear or branched C1-C10; this group may comprise one or more heteroatoms chosen from O, N, S, Cl, Br, I, F, P and / or one or more substituents chosen from CO ₂ H, SO ₃ H, PO ₃ H, NH ₂ , OH , SH;

- R or R1 represent, independently of one another, the polymeric backbone POL or a (poly) saccharide graft PS or a hydrogen atom or a group chosen from (i) linear, branched or cyclic C1-C alkyl C30, preferably linear or branched C1-C10; (ii) linear, branched or cyclic C2-C30 alkenyl, preferably linear or branched C1-C10, (iii) linear, branched or cyclic C2-C30 alkynyl; preferably linear or branched C1-C10; this group may comprise one or more heteroatoms chosen from O, N, S, Cl, Br, I, F, P and / or one or more substituents chosen from CO ₂ H, SO ₃ H, PO ₃ H, NH ₂ , OH, SH; it being understood that only one of the groups R or R1 represents a (poly) saccharide PS or a polymeric backbone POL.

Preferably, the polymers according to the invention are prepared by Chemo-Selective Ligation reaction between aldehyde functions or ketones carried by the (poly) saccharide and at least one of the following compounds:

hydroxylamine derivatives H ₂ NO-LI -R, H ₂ NO- (O) C-LI-R, H ₂ NO- (O) C -NH-L 1 -R, H ₂ NO- (S) C -NH-LI-R, HR1 NO-L1-R, HR1 NO- (O) C-LI-R, HRI NO- (O) C-NH-L1-R, HR1 NO- (S) C-NH- LI -R,

derivatives of β-aminothiols H ₂ N -CHRI-CH (LI-R) -SH, H ₂ N-CH (LI-IR) -CHR-SH.

the following compounds: H ₂ N -NH- (O) C-LI-R and H ₂ N -NH- (S) C-NH-LI-R. in which L1 is preferably a single covalent bond (CC), R is the polymeric backbone, and R1 is H or an alkyl group as defined above

In these Chemo-Selective Ligation reactions, the reducing end of the (poly) saccharides may act as an aldehyde and, preferably, the role of aldehyde is played by the reducing end of the (poly) saccharide PS.

In the case of reactions between the reducing end of the polysaccharides and preferred compounds, in particular derivatives of hydroxylamines or β-aminothiols above, the linker can be schematised by the following general formulas:

in which :

Ra to Re represent, independently of each other, -OH, -CH ₃ , NHCOCH ₃ , NH ₂ , OCH ₂ COOH, COOH, OSO ₃ H, OPO ₃ H, or -O-linked to the polysaccharide graft; at least one of Ra to Re representing -O-linked to the polysaccharide graft;

Rf represents (i) a covalent bond with the polymeric backbone POL or (ii) a group bonded to said polymeric backbone POL chosen from linear, branched or cyclic C1-C30, preferably linear or branched C1-C10 alkyl divalent groups; ; linear, branched or cyclic C 2 -C 30, preferably linear or branched C 1 -C 10 alkenyl; and linear, branched or cyclic C2-C30 alkynyl; preferably linear or branched C1-C10; said group may comprise one or more heteroatoms chosen from O, N, S, Cl, Br, I, F, P and / or one or more substituents chosen from CO ₂ H, SO ₃ H, PO ₃ H, NH ₂ , OH , SH.

In the case of a reaction between the reducing end of a monosaccharide and derivatives of hydroxylamine or β-aminothiol, Ra to Re represent, independently of each other, -OH, -CH ₃ , NHCOCH ₃ , NH _2, OCH ₂ COOH, COOH, OSO ₃ H, OPO ₃ H; and Rf is as defined above, and therefore formulas (III), (MIa), (IV), (Iva), (V), (Va), (VI) and (VIa) represent L-PS.

Preferably, the polymers according to the present invention comprise:

a polymeric backbone POL resulting from the (co) polymerization of (meth) acrylates, (meth) acrylamides and / or styrenic monomers, or else POL represents a polysaccharide, preferably said backbone having a number-average molecular weight ( Mn) between 2000g / mol and 100,000 g / mol with

PS polysaccharide grafts chosen from dextrans and their derivatives (dextran sulfate, dextran diethylaminoethyl, carboxymethyl dextran), glycosaminoglucans and their derivatives (hyaluronic acid, chondroitins and chondroitin sulphates), celluloses and their derivatives (methylcelluloses, hydroxyalkylcelluloses, ethylhydroxyethylcelluloses, carboxymethylcelluloses), amylose and its derivatives, chitins and their derivatives, carrageenans and their derivatives, oligomaltoses and their derivatives, and their mixtures; said grafts preferably having a number-average molecular weight (Mn) of between 200 and 20000 g / mol; a grafting rate of between 1 and 100%, especially between 20 and 100%, and even more preferentially between 40 and 100%; and

a linker defined by one of formulas (III) to (VI) or (MIa) to (VIa).

Preferably, the polymer according to the invention corresponds to one of the following structures:

in which PS represents the polysaccharide graft and R the polymeric backbone (R = POL).

In particular, it is possible to illustrate the preparation of the polymers according to the invention, and their structure as follows:

Very preferably, the polymer according to the invention comprises at least one repeating unit represented by one of the following formulas, in which the backbone has a number-average molecular mass (Mn) of between 2000 g / mol and 100,000 g / mol and the grafts have a number-average molecular mass (Mn) of between 200 and 20000 g / mol:

It is clear that the polymer may further comprise any comonomer including ethylenic.

The (poly) saccharide PS grafts may be introduced into the final polymer by any method known to those skilled in the art, and in particular: by direct reaction on the already formed polymeric POL skeleton, as illustrated by Scheme 1; it is then a synthesis called 'grafting onto'; by polymerization of monomers carrying a PS polysaccharide graft, alone or in admixture with other monomers (copolymerization); it is a synthesis from macromonomers as illustrated by Scheme 2; by growth of a PS polysaccharide graft from a polysaccharide precursor grafted onto the POL polymer backbone or grafted onto one or more constituent monomers of said polymeric backbone POL; this is illustrated by diagram 3, it is about a synthesis known as 'grafting from'.

It is thus possible to schematize in a nonlimiting manner the obtaining of polysaccharide graft polymers by reaction between a monomer or the polymeric backbone derived from it, functionalized with a hydroxylamine derivative or a β-aminothiol derivative with the reducing end of a or several polysaccharides and respectively forming an oxime or thiazolidine bond:

SUBSTITUTE SHEET (RULE 26)

In the three diagrams above, Rf has the same meaning as before. For the sake of simplicity, dextran and amylose have been used, but this in no way represents a limitation of the scope of the invention.

Some methods of preparation are known from the prior art. One can quote the application WO05014035 which describes the use of Galactose Oxidase to introduce aldehyde functions on glycoproteins carrying galactose groups. The use of polymers carrying functional groups capable of selectively reacting with these aldehydes makes it possible to obtain new glycoproteins functionalized by these same polymers, thus improving their retention time in the human body. This patent highlights the interest of Chemo-Selective Ligation reactions to functionally and selectively functionalize fragile molecules. EP1731540 discloses the synthesis of polymers carrying hydroxylamine functions and their use in the field of glycoprotein analysis. The various sugars present on a protein are released by treatment with a protease and a glycopeptidase. These sugars are then immobilized on the polymer by reaction between their reducing end and the group -ONH ₂ present on the polymer.

US2002 / 0016304 discloses the synthesis of cationic hydrophilic graft polypeptides used to carry nucleic acids. Among the hydrophilic grafts are dextrans, glycosaminoglycans and polyethylene glycols. Here, the dextran is grafted onto the cationic polyamino acid by reductive amination. However, this reductive amination requires the use of reducing agents (NaCNBH ₃ ), which can pose problems of toxicity, degradation of the polymer backbone and purification of the synthesized polymer. The polymer according to the present invention can be obtained in different ways.

SUBSTITUTE SHEET (RULE 26) In a first mode of preparation, it is possible, in a first step, to prepare a functionalized polymer skeleton, that is to say carrying the reactive chemical functions described above, then, in a second step, to graft the functionalized or non-functionalized polysaccharide grafts. reacting the reactive functions carried by the polysaccharide grafts or their reducing end with the reactive functions carried by the polymer backbone. This technique is known to those skilled in the art under the name of 'grafting onto'. In a second mode of preparation, it is possible to prepare in a first stage a functionalized monomer, that is to say carrying the reactive chemical functions described above, then, in a second step, to graft the functionalized or non-functionalized polysaccharide grafts. by reacting the reactive functions carried by the polysaccharide grafts or their reducing end with the reactive functions carried by the monomer. Thus, a "macromonomer" carries the polysaccharide graft which is then polymerized to give the polymer of the invention. This macromonomer may be copolymerized in the presence of one or more other monomers or macromonomers carrying polysaccharide grafts.

Polysaccharides can be polymerized enzymatically from an oligosaccharide precursor. For example, amylose can be obtained by enzymatic polymerization using maltoheptaose as a precursor, potassium salt of α- (D) -glucose-1-phosphate as a monomer and a potato phosphorylase. as a catalyst (see BioMacromolecules 2002, 3, pp. 368-373). A third mode of preparation may consist in polymerizing a monomer carrying a polysaccharide polymerization precursor: a polymeric backbone carrying polysaccharide precursor grafts is thus obtained. The polymer with polysaccharide grafts is then obtained by polymerization from the polymer skeleton carrying the precursor grafts, catalyzed by an enzyme or a bacterium in the presence of a sugar which acts as a monomer. In a fourth mode of preparation, it is possible to synthesize a functionalized polymeric backbone, that is to say carrying the reactive chemical functions described above, then, in a second step, a functionalised polysaccharide precursor can be grafted, while react the reactive functions carried by this polysaccharide precursor or its reducing end (if it is an oligosaccharide such as maltoheptaose) with the reactive functions carried by the polymer backbone. A polymeric backbone carrying polysaccharide precursor grafts is thus obtained. The polymer with polysaccharide grafts is then obtained by polymerization from the polymer skeleton carrying the precursor grafts, catalyzed by an enzyme or a bacterium in the presence of a sugar which acts as a monomer.

The third and fourth embodiments are known to those skilled in the art as 'grafting from'. The polymer according to the invention finds a very particular application in the cosmetic field, particularly in the hair field.

The amount of polymer present in the compositions depends, of course, on the type of composition and the desired properties and can vary within a very wide range, generally between 0.01 and 30% by weight, preferably between 0, 1 and 20% by weight, especially between 0.5 and 10% by weight, or even between 1 and 5% by weight, relative to the weight of the final cosmetic composition.

The compositions according to the invention may be in any of the galenical forms conventionally used for topical application and especially in the form of an aqueous or alcoholic or aqueous-alcoholic solution or suspension, or of an oily solution or suspension, or of a solution. or a dispersion of the lotion or serum type, of a liquid or semi-liquid consistency emulsion of the milk type, obtained by dispersion of a fatty phase in an aqueous phase (O / W) or conversely (W / O) , or a suspension or emulsion of soft consistency of the cream (O / W) or (W / O) type, or of an aqueous or anhydrous gel, of an ointment, of a free or compacted powder to be used such which or to incorporate in an excipient, or any other cosmetic form.

The cosmetic compositions according to the invention comprise, in addition to said polymers, a cosmetically acceptable medium, in particular a cosmetically acceptable medium, that is to say a medium which is compatible with cutaneous tissues such as the skin of the face or of the body, and keratin materials such as hair, eyelashes, eyebrows and nails. Preferably, the cosmetically acceptable medium comprises a solvent or dispersion medium of the polymers according to the invention, which may comprise at least one compound chosen from water, alcohols, polyols, esters, carbonaceous oils, silicone, fluorinated silicone oils, and mixtures thereof.

Preferably, the cosmetically acceptable medium of the compositions according to the invention may comprise water or a mixture of water and hydrophilic organic solvent (s), such as alcohols and especially linear or branched monoalcohols. C, Ce, such as ethanol, tert-butanol, n-butanol, isopropanol or n-propanol, or 2-butoxyethanol; and polyols such as glycerine, di-glycerine, ethylene glycol, propylene glycol, sorbitol, pentylene glycol, and polyethylene glycols, or alternatively ethers of polyols or glycols, especially C2, such as monoethyl ether. and diethylene glycol monomethyl ether and hydrophilic C ₂ -C ₄ aldehydes.

The composition according to the invention may also comprise at least one cosmetically acceptable adjuvant conventionally used in cosmetic compositions, in particular intended to be applied to keratinous fibers. In particular, as a cosmetically acceptable adjuvant, it is possible to mention thickeners and / or thickeners; polymers, associative or not; anionic, nonionic, cationic and / or amphoteric surfactants; propenetrating agents, emulsifiers, perfumes, preservatives, fillers, sunscreens; dyestuffs, proteins, vitamins, provitamins; polymers, fixing or non-fixing, anionic, nonionic, cationic or amphoteric; moisturizing agents, emollients, softening agents; mineral, vegetable or synthetic oils; hydrophilic or lipophilic active agents such as ceramics and pseudoceramides; anti-foam agents, antiperspirants, anti-free radical agents, bactericidal agents and anti-dandruff agents.

Those skilled in the art will take care to choose the possible additives and their amount so that they do not adversely affect the properties of the compositions of the present invention.

Preferably, the composition according to the invention may be in the form of a lotion, thickened or not, a cream, thickened or not, a gel, a foam or any other suitable form. It can optionally be packaged in a pump bottle or in an aerosol container.

The cosmetic composition according to the invention may be in the form of a product for the care, cleaning and / or make-up of the skin of the body or of the face, the lips, the eyelashes, the nails and the hair, a suntan or self-tanning product, a personal hygiene product, a hair product, especially care, cleaning, styling or hair dyeing.

It finds particularly a particularly interesting application in the hair field, including the maintenance of the hairstyle or the shaping of the hair, or the cleaning of the hair. The hair compositions are preferably shampoos, conditioners, body care or gelling gels, lotions or care creams, conditioners, styling lotions, blow-dry lotions, fixing and styling such as lacquers or spray. The lotions may be packaged in various forms, in particular in vaporizers, pump-bottles or in aerosol containers to ensure application of the composition in vaporized form or in the form of foam.

It may especially be in the form of a hair coloring product; or in the form of a composition for permanent, straightening, or discoloration, or in the form of compositions to be rinsed, to be applied before or after a coloring, a discoloration, a permanent or a straightening or between the two stages of a permanent or a straightening.

The composition according to the invention may also be in the form of a care composition, in particular a moisturizing composition, for the skin, the lips and / or the phageres, or in the form of a composition for cleaning the skin, for example a makeup remover or a gel for the bath or shower.

It can also be in the form of a care product, not colored, intended to treat the skin and in particular to moisturize it, smooth it, depigment it, nourish it, protect it from the sun's rays, or give it a specific treatment. . It may also be in the form of a personal hygiene composition, especially in the form of a deodorant product, antiperspirant, or in the form of a depilatory composition.

It may also be in the form of a makeup product, in particular colored, the skin of the body or face, or hair, especially a foundation, possibly with care properties, a blush, a blush, eye shadow, concealer, eye liner; a lipstick makeup product such as a lipstick, possibly with skincare properties, a lip gloss, lip pencils; a make-up product of integuments such as nails, eyelashes, in particular in the form of bread mascara, eyebrows and hair; a temporary tattoo product of the body skin.

Advantageously, the composition according to the invention is a hair styling or conditioning hair composition, and may be in the form of a gel, a mousse, a lotion, a cream or a spray; shampoos or conditioners.

The subject of the invention is also a process for the cosmetic treatment, in particular of makeup, care, cleaning, coloring, shaping of keratin materials, in particular of the skin of the body or face, nails, hair, bristles and / or eyelashes, comprising the application on said materials of a cosmetic composition as defined above. Preferably, it is a cosmetic treatment method for shaping, holding, care and / or conditioning the hair, comprising applying a composition according to the invention to said hair; possibly followed by a rinsing step.

The invention is illustrated in more detail in the following examples, in which the following abbreviations have been used:

AIBN: 2,2 'Azobis (isobutyronitrile) Trigonox 21 S: tert-Butyl peroxy-2-ethylhexanoate

KPS: potassium persulfate

DEAD: Diethyl Azodicarboxylate

Dextran T1: Dextran of Mn = 1000g / mol

Dextran T5: Dextran Mn = 5000g / mol Dextran T10: Dextran Mn = 10000g / mol.

EDC: N- (3-Dimethylaminopropyl) -N'-ethylcarbodiimide

DMAP: 4- (Dimethylamino) pyridine

ABCVA: 4,4'-Azobis (4-cyanovaleric acid) THF: Tetrahydrofuran

Example 1 Synthesis of Grafted Polystyrene Maltotriose

1 / Synthesis of N- (O- (p-vinylbenzyl) oxy) phthalimide

In a 500 ml flask, 32.64 g of N-hydroxyphthalimide (0.2 mol) are placed in 300 ml of 1-methyl-2-pyrrolidone. The mixture is stirred. After solubilization of the N-hydroxyphthalimide in the solvent, 5.76 g of sodium hydride (1.2 eq, 0.24 mol) are added little by little. There is a change of color from yellow to red. Stirring is carried out at room temperature for 1 hour then 30.6 g of p-vinylbenzylchloride (1 eq, 0.20 mol) are added to the reaction medium, and the temperature is brought to 50 ^° C. After 9 hours, the mixture is precipitated. in a large volume of ice water. The solid is filtered and then dried in an oven. 53.5 g of a light yellow powder is obtained, ie a yield of 96%. The structure of the product is confirmed by ¹ H NMR.

2 / synthesis of [O- (p-vinylbenzyl) oxyamine

10 g of N- (O- (p-vinylbenzyl) oxy) phthalimide (35.8 mmol) are placed in a 250 ml flask in the presence of 150 ml of ethanol, with stirring. 5.3 ml of butylamine (1.5eq, 54mmol) are added. The environment becomes gradually homogeneous. It is left stirring for 4 hours at room temperature. 50% of the solvent is then removed by rotary evaporator and then diethyl ether is added to obtain a 50/50 volume proportion with the ethanol. 32.5 ml of 5.5N HCl (5 eq., 178 mmol) are then added; The [O- (p-vinylbenzyl) oxy] amine hydrochloride is thus precipitated. The white powder thus obtained is filtered and then dried under reduced pressure. A mass of 5.4 g of product is recovered, ie a yield of 81%. In order to obtain the free hydroxylamine, the hydrochloride of [O- (p- vinylbenzyl) oxy] amine in methyl-THF and then excess triethylamine (5 ml) is added. At first, the medium is homogenized and then the triethylamine hydrochloride precipitates. It is filtered under vacuum and then the filtrate is evaporated under vacuum. 3 g of a viscous transparent oil are obtained (yield 70%). The structure of the product is confirmed by ¹ H NMR.

3 / synthesis of N- [Q- (p-vinylbenzyl) oxylamine grafted maltotriose

2.8 g of maltotriose (5.5 mmol) are placed in 6 ml of pH = 4 buffer solution. After solubilization, 1 g of O- (p-vinylbenzyl) oxy] amine (6.7 mmol, 1.2 eq) are added. . The reaction medium is heated at 75 ° C. for 8 hours. The medium is then precipitated in THF and a white powder is obtained which is filtered and dried under vacuum.

3.3 g of white powder is obtained, ie a yield of 95%. The structure of the product is confirmed by ¹ H NMR

4 / Polymerization of N- [4- (p-vinylbenzyl) oxyamine grafted maltotriose

0.5 g of N- [O- (p-vinylbenzyl) oxy] amine grafted with maltotriose is solubilized in 1.16 g of water. After solubilization, 5 mg of potassium persulfate are added. The mixture is brought to 90 ^° C. After 6 hours, the reaction medium is precipitated in ethanol.

After filtration and drying, 0.465 g of poly (N- [O- (p-vinylbenzyl) oxy] amine grafted with maltotriose is obtained, ie a yield of 93%. The structure of the polymer is confirmed by ¹ H NMR.

Example 2 Synthesis of poly (2-aminooxyethyl methacrylate) grafted maltotriose

1 / synthesis of methacrylate O- (2-hydroxyethyl) phthalimide

13.8 g of hydroxyphthalimide (84.6 mmol, 1.1 eq) are solubilized in 240 ml of THF in a 500 ml flask. 10 g of HEMA (76.8 mmol, 1 eq) and 22.15 g of triphenylphosphine (84.4 mmol, 1.1 eq) are added. The flask is placed under argon then in a bath of ice water. When the temperature is close to 10 ⁰ C, we add 36.8 g of DEAD (84.5 mmol, 1.1 eq) little by little. The temperature is maintained between 5 and 15 ° C and then allowed to react for 12 hours at room temperature. The reaction medium is then diluted with 1 liter of dichloromethane and then washed with water until complete disappearance of the orange color in the aqueous phase. The organic phase is then concentrated under reduced pressure and then purified on a silica column (eluent: 70/30 heptane / ethyl acetate).

11.4 g of a colorless oil are obtained, giving a yield of 55%. The structure of the product is confirmed by ¹ H NMR.

2 / Synthesis of (2-hydroxyethyl) phthalimide polymethacrylate

0.5 g of (2-hydroxyethyl) phthalimide methacrylate previously synthesized are placed in 0.5 g of N-methylpyrrolidone. 11.5 microliters of Trigonox21 S are added and the mixture is then heated at 90 ^° C. The reaction is stopped after 6 hours, then the polymer is precipitated in ethanol and filtered.

A mass of 0.3 g is obtained, ie a yield of 60%. The structure of the polymer is confirmed by ¹ H NMR.

3 / Synthesis of 2-aminooxymethyl polymethacrylate

1 g of (2-hydroxyethyl) phthalimide polymethacrylate (3.63 mmol of phthalimide groups) are solubilized in 6 ml of dichloromethane, then 1.8 ml of butylamine (5 eq., 18.1 mmol) are added. The medium is placed under argon at room temperature; it remains homogeneous throughout the reaction. After 24 hours, the polymer is precipitated in diethyl ether and 0.45 g of 2-aminoxyethyl polymethacrylate is obtained, giving a yield of 85%. NMR ¹ H shows the disappearance of the phthalimide groups which allows confirms the effectiveness of the reaction.

4 / synthesis of 2-aminoxyethyl polymethacrylate grafted maltotriose

920 mg of maltotriose (1.83 mmol) are solubilized in 2.14 ml of buffered water pH = 4. 300 mg of polymer (1.1 eq of hydroxylamine functions relative to the reducing end of maltotriose) are added. The mixture is left stirring for 24 hours at 75 ° C. and then the medium is diluted in 2 ml of buffered water pH = 4 and the polymer is precipitated twice in THF.

After drying in an oven, 1.1 g of a white powder is recovered, hence a yield of 90%. The grafting rate of maltotriose is evaluated by ¹ H NMR at 83%.

Example 3 Synthesis of poly (2-aminooxyethyl methacrylate) grafted with a Dextran of Mn 1000 q / mol (Dextran TD

1.1 g of Dextran T1 (1.1 mmol) are solubilized in 2.6 ml of buffered water pH = 4. 200 mg of poly [O- (2-hydroxyethyl) amine] polymer prepared above (1.2 eq of hydroxylamine functions relative to the reducing end of Dextran T1) are added. The mixture is left stirring for 24 hours at 75 ° C. and then the medium is diluted in 3 ml of buffered water pH = 4, and the polymer is precipitated twice in THF.

After drying in an oven, 1.1 g of a white powder is recovered, hence a yield of 85%. The degree of grafting of Dextran T1 is evaluated by ¹ H NMR at 84%.

Example 4 Synthesis of polv (2- (aminooxyacetamido) ethyl methacrylate) grafted with a dextran of Mn 1000q / mol (Dextran T1)

1 / Synthesis of 2- (aminooxyacetamido) ethyl methacrylate

In a three-necked flask of 500 ml, 260 g of dichloromethane, 5 g of 2-aminoethylmethacrylate hydrochloride (30.2 mmol, 1 eq), 5.77 g of (Boc-aminooxy) acetic acid are added. acid (30.2 mmol, 1 eq) and 4.59 g K ₂ CO ₃ (33.2 mmol, 1 eq). This mixture is put under argon and then cooled with an ice bath before adding 0.37 g of DMAP (3.02 THTiOl, 0.1 eq) and 5.16 g of EDC (33.2 mmol, 1.1 g). eq). After the addition is complete, the mixture is stirred at room temperature for 48 hours, then the K 2 CO 3 is filtered, the dichloromethane is evaporated and the reaction medium is purified on a silica column (eluent: 20/80 h epta ne / ethyl acetate ).

There is thus obtained 3.7 g of a transparent oil (AE MA-Ac-O NH Boc), from which a yield of 45%, the structure of which is confirmed by ¹ H NMR. This monomer is deprotected by treatment with sodium hydroxide. trifluoroacetic acid (25th molar) in the presence of water (TFA / water: 5/1 by mass) for 24 hours at room temperature. The water and TFA are then evaporated under reduced pressure and 2- (aminooxyacetamido) ethyl methacrylate (AEMA-Ac-ONH ₂ ) is obtained quantitatively. The structure and efficiency of the deprotection are confirmed by ¹ H NMR.

2 / grafting of Dextran T1 on 2- (aminooxyacetamido) ethyl methacrylate and polymerization

1.71 g of 2- (aminooxyacetamido) ethyl methacrylate (5.41 mmol, 3eq) are solubilized in 15 g of water. The pH of the solution is adjusted to 4 by addition of a 5N sodium hydroxide solution. 1.8 g of Dextran T1 (1.8 mmol, 1 eq) are then added and the mixture is stirred at room temperature for 48 hours. The reaction medium is then precipitated in 100 ml of THF: the white precipitate thus obtained is filtered and then dried under reduced pressure. 1.8 g of grafted monomer Dextran T1 are recovered. The degree of functionalization is estimated at 91% by ¹ H NMR. The polymerization of this monomer is carried out by solubilizing 0.5 g of 2- (aminooxyacetamido) ethyl methacrylate grafted Dextran T1 in 2 ml of water and then adding 10 mg from ABCVA. The pH of the solution is adjusted to 7 by adding a solution 1 N sodium hydroxide solution and then the reaction medium is heated at 70 ^° C. for 4 hours. The polymerization is controlled by the disappearance of the double bonds in ¹ H NMR. The mixture is then precipitated in 50 ml of THF and after filtration and drying, 0.4 g of a white powder is recovered, giving a yield of 80%.

Example 5 Synthesis of poly (2- (aminooxyacetamido) ethyl methacrylate) grafted with a Dextran of Mn 5000q / mol (Dextran T5)

1 / Polymerization of 2- (Boc-aminooxyacetamido) ethyl methacrylate (AEMA-Ac-ONHBoc)

1 g of AE MA-Ac-O NH Boc protected monomer prepared in step 1 of example 4 (4.96 mmol) is solubilized in 2 g of N-methylpyrrolidone and then 40 mg of AIBN (0, 24mmol). The medium is placed under argon and then heated at 80 ^° C. for 6h30. The polymerization is controlled by the disappearance of double bonds in ¹ H NMR. At the end of the reaction, the reaction medium is precipitated in 50 ml of water. After filtration and drying under reduced pressure, 800 mg of white powder is recovered, hence a yield of 80%.

2 / deprotection of 2- (Boc-aminooxyacetamido) ethyl polymethacrylate and Dextran T5 graft

800 mg of the polymer synthesized above are placed in 3.7 ml of water and 3.7 ml of trifluoroacetic acid. After 24 hours, it is confirmed that the deprotection is complete by ¹ H NMR. The water and trifluoroacetic acid are evaporated, and then 550 mg of the deprotected polymer are placed in 8 ml of water. The pH is adjusted to 4 by adding a solution of 5N NaOH and 7.28 g of Dextran T5 are added. After 48 hours, we The reaction medium is precipitated in 100 ml of THF, filtered and the powder obtained is dried under reduced pressure.

8 g of poly (2- (aminooxyacetamido) methacrylate) grafted with Dextran T5 are obtained. ¹ H NMR confirms that the grafting rate is greater than 90%.

Example 6 Synthesis of polv (3- (aminooxyacetamido) propyl methacrylamide) grafted with a Dextran of Mn 5000q / mol (Dextran T5)

1 / Synthesis of 3- (Boc-aminooxyacetamido) propyl methacrylamide (APMAm-Ac-ON H Boc)

APMAm-Ac-ON H Boc

In a three-necked 500 ml, 200 g of dichloromethane, 4 g of N-3- (aminopropyl) methacrylamide hydrochloride (22.4 mmol, 0.92 eq), 4.65 g of (Boc-aminooxy) acetic acid ( 24.3 mmol, 1 eq), 3.7 g of K ₂ CO ₃ (26.8 mmol, 1 eq) and 297 mg of DMAP (2.43 mmol, 0.1 eq). This mixture is put under argon and then cooled with an ice bath before adding 4.16 g of EDC (26.8 mmol, 1.1 eq). After the addition is complete, the mixture is left to stir at room temperature for 48 hours and then the K2CO3 is filtered off. The organic phase is washed 3 times with 100 ml of ammonium hydrochloride and twice with 100 ml of water. The organic phase is recovered and the dichloromethane is evaporated under reduced pressure. The reaction medium is purified on a silica column (eluent: 50/50 heptane / isopropanol). 4.8 g of a transparent oil are obtained, giving a yield of 68%, and the structure is confirmed by ¹ H NMR.

2 / Polymerization and deprotection of 3- (Boc-aminooxyacetamido) propyl methacrylamide

1 g of the AP MAm -Ac-O NH Boc monomer (3.17 mmol) previously synthesized in 1 g of ethanol are solubilized and then 20 mg of AIBN (0.122 mmol) are added. The reaction medium is placed under argon and then heated at 70 ^° C. for 8 hours. The polymerization is controlled by the disappearance of the double bonds in ¹ H NMR. At the end of the reaction, the polymer is precipitated in 50 ml of diethyl ether. After filtration and drying, 625 mg of a white powder is obtained, the structure of which is confirmed by ¹ H NMR (90% yield). The deprotection is carried out by solubilizing 330 mg of the above polymer in 1 g of water and 2 g of water. , 98 g of trifluoroacetic acid. After 5 hours, the reaction medium is evaporated; a total deprotection of the polymer is confirmed by ¹ H NMR.

3 / grafting Dextran T5000 to 3- (aminooxyacetamido) propyl polymethacrylamide

The whole of the above 3- (aminooxyacetamido) propyl polymethacrylamide is solubilized in 5 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. Then 4.19 g of Dextran T5 is added and then allowed to react at room temperature for 48 hours. The reaction medium is precipitated in 50 ml of ethanol. After filtration and drying, 4 g of a white powder are recovered. The degree of grafting of Dextran T5 is estimated at 65% by ¹ H NMR.

Example 7 Synthesis of polv (methacrylamide of 3- (aminooxyacetamido) propyl) grafted with Dextran of Mn 10000q / mol (Dextran T10) The protocol of Example 6 is repeated until the grafting of Dextran. The grafting of the polysaccharide is carried out by solubilizing 330 mg of poly (3- (aminooxyacetamido) propyl methacrylamide) in 20 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 8.37 g of Dextran T10 are then added and the mixture is left to react at ambient temperature for 72 hours. The reaction medium is then precipitated in 600 ml of ethanol. After filtration and drying, 8.1 g of a white powder are recovered. The degree of grafting of Dextran T10 is estimated at 40% by ¹ H NMR

Example 8 Synthesis of a 3- (aminooxyacetamido) propyl methacrylamide copolymer with dimethylaminopropyl methacrylamide followed by grafting with a Dextran of Mn 5000q / mol (Dextran T5)

1 / copolymerization of 3- (Boc-aminooxyacetamido) propyl methacrylamide with dimethylaminopropylmethacrylamide 6 g of 3- (Boc-aminooxyacetamido) propyl methacrylamide (17.1 mmol, 0.75 eq), 0.972 g of dimethylaminopropylmethacrylamide (5, 71 mmol, 0.25 eq) and 142 mg of AIBN (0.038 eq) in 7 g of ethanol. The reaction medium is placed under argon and then heated at 70 ^° C. for 10 hours. The polymerization is controlled by the disappearance of the double bonds in ¹ H NMR. At the end of the reaction, the polymer is precipitated in 200 ml of diethyl ether. After filtration and drying, 5.3 g of polymer is recovered, the ¹ H NMR of which makes it possible to determine the composition: 76 mol% of 3- (Boc-aminooxyacetamido) propyl methacrylamide and 24 mol% of dimethylaminopropylmethacrylamide (yield 76%).

2 / deprotection and grafting of Dextran T5

1 g of the copolymer synthesized above is used which is dissolved in 3 g of water and 9 g of trifluoroacetic acid. Stirring is allowed for 20 hours at room temperature and then the reaction medium is evaporated. A total deprotection of the polymer is confirmed by ¹ H NMR. The medium is redissolved in 10 g of water and then the pH is adjusted to 4 by adding a solution of 5N NaOH. 10.8 g of Dextran T5 are then added and the mixture is stirred for 48 hours at room temperature. The reaction medium is precipitated in 600 ml of THF; after filtration and drying, 10 g of a copolymer containing 76 mol% of 3- (aminooxyacetamido) propyl methacrylamide and 24 mol% of dimethylaminopropyl methacrylamide were grafted onto which 59% of Dextran T5 was grafted (confirmed by ¹ H NMR). ). Example 9 Synthesis of a copolymer of 3- (aminooxyacetamido) propyl methacrylamide with dimethylaminopropyl methacrylamide followed by grafting with a Dextran of Mn 10,000q / mol (Dextran T10)

The protocol of Example 8 is repeated until the grafting of Dextran. The grafting of the polysaccharide is carried out by solubilizing 510 mg of the methacrylamide copolymer of 3- (aminooxyacetamido) propyl (76%) and dimethylaminopropyl methacrylamide (24%) in 20 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. Dextran T10 (15.2 g) is added and allowed to react at room temperature for 48 hours. The reaction medium is then precipitated in 600 ml of THF; after filtration and drying, 16.3 g of a white powder are obtained. The degree of grafting of Dextran T10 is estimated at 54% by ¹ H NMR.

EXAMPLE 10 Synthesis of a copolymer of 3- (aminooxyacetamido) propyl methacrylamide (76 mol%) with dimethylaminopropyl methacrylamide (24 mol%) and then grafting with a dextran of Mn 1000 g / mol (Dextran TD

The protocol of Example 8 is repeated until the grafting of Dextran. The grafting of the polysaccharide is carried out by solubilizing 3 g of the methacrylamide copolymer of 3- (aminooxyacetamido) propyl (76%) and of dimethylaminopropyl methacrylamide (24%) in 17 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 6.2 g of Dextran T1 are then added, and the reaction is left at room temperature for 24 hours. The reaction medium is then precipitated in 600 ml of ethanol. After filtration and drying, 8 g of a white powder are recovered. The degree of grafting of Dextran T1 is estimated at 95% by ¹ H NMR.

Example 11: Synthesis of a copolymer of 3- (aminooxyacetamido) propyl methacrylamide (48 mol%) with dimethylaminopropyl methacrylamide (52 mol%) and then grafting with a dextran of 1000 g / mol (Dextran TD

1 / copolymerization of 3- (Boc-aminooxyacetamido) propyl methacrylamide with dimethylaminopropylmethacrylamide 4 g of 3- (Boc-aminooxyacetamido) propyl methacrylamide (11.4 mmol, 0.5 eq), 1.94 g of dimethylaminopropylmethacrylamide (11 4mmol, 0.5eq) and 123mg of AIBN (0.033eq) in 6g of ethanol. The reaction medium is placed under argon and then heated at 70 ^° C. for 10 hours. The polymerization is controlled by the disappearance of the double bonds in ¹ H NMR. At the end of the reaction, the polymer is precipitated in 200 ml of diethyl ether. After filtration and drying, 4.2 g of polymer are recovered, the ¹ H NMR of which makes it possible to determine the composition: 48 mol% of 3- (Boc-aminooxyacetamido) propyl methacrylamide and 52 mol% of dimethylaminopropylmethacrylamide (yield 71%). 2 / deprotection and grafting of Dextran T1

3 g of the above-synthesized ethers are used which are dissolved in 9.1 g of water and 27.1 g of trifluoroacetic acid. Stirring is allowed for 20 hours at room temperature and then the reaction medium is evaporated. A total deprotection of the polymer is confirmed by ¹ H NMR. The medium is redissolved in 13 g of water and then the pH is adjusted to 4 by addition of a 5N NaOH solution. 4.57 g of Dextran T1 are then added and the mixture is stirred for 24 hours at room temperature. The reaction medium is precipitated in 600 ml of ethanol; after filtration and drying, 6.5 g of a copolymer containing 48 mol% of 3- (aminooxyacetamido) propyl methacrylamide and 52 mol% of dimethylaminopropylmethacrylamide were grafted onto which 89% of Dextran T1 (NMR-confirmed) was grafted. ^1H).

Example 12 Synthesis of a methacrylamide copolymer of 3- (aminooxyacetamido) propyl (48 mol%) with dimethylaminopropyl methacrylamide (52 mol%) and then grafting with a Dextran of Mn 5000q / mol (Dextran T5)

The protocol of Example 11 is repeated until the grafting of Dextran. The grafting of the polysaccharide is carried out by solubilizing 1 g of the copolymer of 3- (aminooxyacetamido) propyl methacrylamide (48 mol%) and of dimethylaminopropyl methacrylamide (52 mol%) in 17 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 6.58 g of Dextran T5 are then added, and the reaction is left at room temperature for 24 hours. The reaction medium is then precipitated in 600 ml of ethanol. After filtration and drying, 6.5 g of a white powder are recovered. The degree of grafting of Dextran T5 is estimated at 76% by ¹ H NMR.

Example 13 Synthesis of Polv (3- (Aminooxyacetamido) Propyl Methacrylamide) Grafted with D-Glucuronic Acid The procedure of Example 6 is repeated until the sugar is grafted. The grafting of D-glucuronic acid is carried out by solubilizing 800 mg of poly (3- (aminooxyacetamido) propyl methacrylamide) in 4 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 475 mg of sodium salt of D-glucuronic acid are then added, and the reaction is then left at room temperature for 24 hours. The reaction medium is then precipitated in 600 ml of ethanol. After filtration and drying, 650 mg of a white powder are recovered. The grafting of D-glucuronic acid is complete (confirmed by ¹ H NMR)

Example 14 Synthesis of Polv (3- (Aminooxyacetamido) Propyl Methacrylamide) Grafted with D - (+) Mannose

The protocol of Example 6 is repeated until the sugar is grafted. The grafting of D (+) mannose is carried out by solubilizing 800 mg of poly (3- (aminooxyacetamido) propyl methacrylamide) in 4 ml of water. The pH of the solution is adjusted to 4 by adding a solution of 5N NaOH. 366 mg of D - (+) - Mannose are then added, and the reaction is left at room temperature for 24 hours. The reaction medium is then precipitated in 600 ml of ethanol. After filtration and drying, 650 mg of a white powder is recovered. The grafting of D (+) mannose is complete (confirmed by ¹ H NMR)

Example 15 Synthesis of Poly (3- (Aminooxyacetamido) Propyl Methacrylamide) Grafted with D-(+) Glucose-6-Phosphate Sodium Salt

The protocol of Example 6 is repeated until the sugar is grafted. The grafting of the sodium salt of D - (+) glucose-6-phosphate is carried out by solubilizing 800 mg of poly (3- (aminooxyacetamido) propyl methacrylamide) in 4 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 573 mg of sodium salt of D - (+) glucose-6-phosphate are then added, and the reaction is then left at room temperature for 24 hours. The reaction medium is then precipitated in 600 ml of ethanol. After filtration and drying, 1.24 g of a white powder are recovered. The grafting of D - (+) glucose-6-phosphate is complete (confirmed by

¹ H NMR).

Example 16 Synthesis of Polv (3- (Aminooxyacetamido) Propyl Methacrylamide) Grafted with D - (+) Fucose

The protocol of Example 6 is repeated until the sugar is grafted. The grafting of D (+) Fucose is carried out by solubilizing 1.5 g of poly (3- (aminooxyacetamido) propyl methacrylamide) in 8 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 915 mg of D - (+) - Fucose are then added, and the reaction is left at room temperature for 24 hours. The reaction medium is then precipitated in 600 ml of ethanol. After filtration and drying, 1.25 g of a white powder are recovered. The grafting of D (+) Fucose is complete (confirmed by ¹ H NMR).

Example 17 Synthesis of poly (3- (aminooxyacetamido) propyl methacrylamide) grafted with L - (-) Fucose

The protocol of Example 6 is repeated until the sugar is grafted. The grafting of L (-) Fucose is carried out by solubilizing 1.5 g of poly (3- (aminooxyacetamido) propyl methacrylamide) in 8 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 915 mg of L - (-) - Fucose are then added, and the reaction is left at room temperature for 24 hours. The reaction medium is then precipitated in 600 ml of ethanol. After filtration and drying, 0.96 g of a white powder is recovered. The grafting of L (-) Fucose is total (confirmed by ¹ H NMR)

Example 18: Synthesis of a copolymer of 3- (aminooxyacetamido) propyl methacrylamide (76 mol%) with dimethylaminopropyl methacrylamide (24%) and then grafting with a sulfated Dextran of Mn = 5000 g / mol (Dextran Sulfate T5)

The protocol of Example 8 is repeated until the grafting of Dextran. The grafting of the polysaccharide is carried out by solubilizing 90 mg of the 3- (aminooxyacetamido) propyl methacrylamide copolymer (76%) and dimethylaminopropyl methacrylamide (24%) in 2 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 930 mg of Dextran sulfate T5 (Dextran of Mn = 5000 g / mol, with a degree of substitution of sulphate groups of 2.3) are then added, and the reaction is then left at room temperature for 24 hours. The reaction medium is then precipitated in 60 ml of ethanol. After filtration and drying, 700 mg of a white powder are recovered. The degree of grafting of Dextran sulfate T5 is estimated at 33% by 1 H NMR.

EXAMPLE 19 Synthesis of Polv (3- (Aminooxyacetamido) Propyl Methacrylamide) Grafted with L (+) Rhamnose The protocol of Example 6 is repeated until the sugar is grafted. The grafting of L (+) Rhamnose is carried out by solubilizing 1.5 g of poly (3- (aminooxyacetamido) propyl methacrylamide) in 4 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 970 mg of L (+) Rhamnose are then added, and the reaction is left at room temperature for 24 hours. The reaction medium is then precipitated in 300 ml of ethanol. After filtration and drying, 1.9 g of a white powder are recovered. The grafting of L (+) Rhamnose is complete (confirmed by 1 H NMR).

Example 20 Synthesis of poly (3- (aminooxyacetamido) propyl methacrylamide) grafted with D (+) Galactose

The protocol of Example 6 is repeated until the sugar is grafted. The grafting of D (+) Galactose is carried out by solubilizing 1.5 g of poly (3- (aminooxyacetamido) propyl methacrylamide) in 4 ml of water. The pH of the solution is adjusted to 4 by addition of a solution of 5N NaOH. 970 mg of D (+) Galactose are then added and the reaction is left at room temperature for 24 hours. The reaction medium is then precipitated in 300 ml of ethanol. After filtration and drying, 2 g of a white powder are recovered. The grafting of D (+) Galactose is complete (confirmed by 1 H NMR).

Example 21: Evaluation Results

The sliding character of the polymers according to the invention is evaluated using a pion-disk type tribometer; a solution of 3% by weight of polymer is deposited on a moving substrate which is brought into contact with a ball. The friction force between the ball and the moving substrate is then measured. The lower the friction force between the two surfaces, the greater the slipperiness of the polymer.

Friction in the presence of water (in the absence of polymer) is used as a reference.

In particular, there is a marked decrease in frictional forces for polymers with grafted maltotriose or Dextran T1 grafts compared to ungrafted maltotriose and dextran T1. The polymers according to the invention have a good sliding character.

Example 22: Washing Cosmetic Composition

A shampoo comprising (% by weight) is prepared:

1% MA (active ingredient) of polymer of Example 6

12.5% of lauryl ether sulfate.

We obtain a foaming solution, which is applied to locks of hair

SA 20 of 1g, at a rate of 0.3 g of solution per wick. Leave for 3 minutes and rinse with water; we untangle the hair.

A similar composition can be prepared with the polymers of Examples 1 to

5 and 7 to 20. Example 23: Styling Lotion

We introduce into a pump bottle:

1% MA (active ingredient) of polymer of Example 6

- 6% fixing polymer Styleze W 20 - 2% glycerol

- conservative qs - qs 100% water

A styling lotion is obtained.

A similar composition can be prepared with the polymers of Examples 1 to 5 and 7 to 20.

EXAMPLE 24 Aerosol Styling Spray

A hydroalcoholic solution comprising, in g of active material: polyvinylpyrrolidone 2.5 g - polymer of Example 6 0.65 g

- glycerol 10 g

- ethanol 15 g

water 36 g - DME 36 g A similar composition can be prepared with the polymers of Examples 1 to 5 and 7 to 20.

Example 25: Mascara

A mascara is prepared having the following composition: - waxes 24 g

- Amino-2-methyl-2-propanediol-1, 3 0.2 g - Triethanolamine 2.4 g

- Stearic acid 5.4 g

- Dimethicone copolyol (DOW-CORNING Q2-5220) 0.2 g - Sodium polymethacrylate 0.25 g MA

Polymer of Example 6 (MA) 2 g

- Pigments 6 g

Preservatives qs - Water qs 100 g A similar composition can be prepared with the polymers of Examples 1 to 5 and 7 to 20.

Example 26: Foaming cream for cleaning

A composition comprising (% by weight) is prepared: polymer of Example 6 (MA) 7%

- PEG-8 7%

- fatty acids 29%

N-octanoyl-5-salicylic acid (Mexoryl SAB from CHIMEX) 0.3% - Glyceryl stearate SE 5%

cocoyl-glucoside (at 50% active ingredient) (ie 1% of MA) 2%

Tetrasodium EDTA 0.2%

- KOH 7%

- Conservative qs

- Water qs 100%

The aqueous phase consisting of water-soluble ingredients (water, preservatives, EDTA, PEG-8, polymer of example 1) is brought to 80 ^° C. The fatty phase, consisting of fatty acids, glyceryl stearate and n -octanoyl-5 salicylic, is heated to 80 ⁰ C and added with stirring to the aqueous phase. The cocoyl glucoside is then added and the KOH is solubilized in part of the water. Stirring is maintained for 10 minutes at 80 ° C., then the mixture is cooled with stirring. A similar composition can be prepared with the polymers of Examples 1 to 5 and 7 to 20.

Example 27: Cleansing gel for the body

A composition comprising (% by weight of MA) is prepared:

polymer of example 6 (MA) 3% - fatty acids 7%

- Potassium hydroxide 2.1%

- Laureth sodium sulfate 1%

- Cocobetaine 5%

- Glycerin 4% - Potassium chloride 2.5%

- Sodium chloride 1%

- Cocamide MEA 0,5%

- Hydroxypropyl methylcellulose 0,25%

- Perfume, dye qs - water qs 100%

EXAMPLE 28 Composition for Permanent Hair Deformation A composition comprising (% by weight) is prepared:

- Thioglycolic acid 9%

- Ammonia at 20% of NH ₃ 9%

- Ammonium carbonate 4.5%

- Cocoylamidopropylbetaine / glycerol monolaurate (25/5) 0.4% MA - 0.4% EDTA

Polymer of Example 6 (MA) 2% - Water qs 100%

The permanent deformation compositions above are applied for 15 minutes. on wet hair previously wrapped on styling rollers, then rinsed thoroughly with water. A solution of oxygenated water at 8 volumes and pH 3 is then applied for 5 minutes, then rinsed again, the rollers are removed and dried. A similar composition can be prepared with the polymers of Examples 1 to 5 and 7 to 20.

Example 29: Body care oil

A moisturizing oil for dry skin is prepared using the following constituents:

caprylic / capric triglycerides 6.5 g

- propylene glycol dicaprylate / dicaprate 22 g

cetearyl octanoate and isopropyl myristate 5 g

- isostearyl neopentanoate 2.5 g - peanut oil 5.25 g

polymer of Example 6 (MA) 0.5 g

palmitic acid 0.2 g

- antioxidant, preservatives, perfume qs

cyclometh icon qs 100 g A similar composition can be prepared with the polymers of Examples 1 to 5 and 7 to 20.

Example 30: Facial Cream

A moisturizing care cream for normal and combination skin is prepared using the following constituents:

- petrolatum 4 g

- hydrogenated polyisobutene 6.5 g

- cetyl alcohol 2.7 g

- sorbitan tristearate 0.5 g - PEG 40 stearate 3.2 g

- myristyl myristate 3 g

- glyceryl stearate 3 g

- shea butter 2 g

- cyclometh icon 5 g - stearic acid 0.2 g

- sodium hydroxide 0.5 g - sodium citrate 0.1 g

polymer of Example 6 (MA) 1 g

- antioxidant, preservatives, perfume qs - water qs 100 g

A similar composition can be prepared with the polymers of Examples 1 to 5 and 7 to 20. Example 31: Moisturizing cosmetic composition

A moisturizing composition is prepared using the following constituents

Phase A1:

- Sucrose distearate 2%

- Sorbitan stearate oxyethylenated with 4 EO (TWEEN 61) 1, 4%

- Stearic acid 0.75%

- stearyl heptanoate (PCL solid®) 5.5%

- Vaseline 2.1%

- Oils (avocado and jojoba) 8.6%

- 3.7% volatile silicone oil

Phase A2:

- Silicone Gum (Q2-1403 Fluid) 4%

- Perfume, preservative qs

Phase B:

- Methyl paraben 0.3%

- 0.4% Triethanolamine

polymer of Example 6 (MA) 1%

- Water qs 100%

Phase C:

- Carboxyvinyl polymers (CARBOPOL 980) 0.3%

- Water 9.7%

Phases A1 and B are brought to 65 ° C before being mixed with stirring. The dispersion is homogenized (between ²⁰ × ¹⁰ ⁶ Pa and 60 × 10 ⁶ Pa) to obtain a dispersion whose oil globule size is less than 500 nm. Phase A2 is dispersed at room temperature in the first dispersion, with vigorous stirring. Phase C, previously prepared, is then added. A moisturizing emulsion adapted for dry skin is obtained. A similar composition can be prepared with the polymers of Examples 1 to 5 and 7 to 20.

Example 32: Conditioner

A composition comprising (% by weight) is prepared:

- Behenyl trimethylammonium chloride 80% in a mixture of water / isopropanol (15/85) 1% - cationic emulsion DC 929 (Dow Corning) 4%

methyl p-hydroxybenzoate 0.2%

polymer of Example 6 (MA) 3% - water qs 100%

The conditioner is applied to damp hair. Let it sit for 2 minutes and rinse.

Claims

1. Polymer structure: (POL) - (L-PS) _x where

POL represents a polymeric backbone having a number-average molecular weight (Mn) of between 1000 and 5,000,000 g / mol.

PS represents a (poly) saccharide grafted onto POL via a linker L,

x represents a non-zero integer characteristic of the number of PS grafts and

L represents a linker chosen from those of formula:

in which : Ra to Re represent, independently of each other, -OH, -CH ₃ , NHCOCH ₃ , NH ₂ , OCH ₂ COOH, COOH, OSO ₃ H, OPO ₃ H, or -O-linked to the polysaccharide graft; at least one of Ra to Re representing -O-linked to the polysaccharide graft;

- Rf represents

(i) a covalent bond with the polymeric backbone POL or (ii) a group bonded to said polymeric backbone POL selected from divalent linear, branched or cyclic C1-C30, preferably linear or branched C1-C10 alkyl groups; linear, branched or cyclic C 2 -C 30, preferably linear or branched C 1 -C 10 alkenyl; and linear, branched or cyclic C2-C30 alkynyl; preferably linear or branched C1-C10; said group may comprise one or more heteroatoms chosen from O, N, S, Cl, Br, I, F, P and / or one or more substituents chosen from CO ₂ H, SO ₃ H, PO ₃ H, NH ₂ , OH , SH.

2. Polymer according to claim 1, in which the polymer backbone is derived from the polymerization of one or more ethylenic monomers chosen from those of formula: R ¹ R ² C = CR ³ R ⁴ in which R ¹ , R ² , R ³ and R ⁴ represent independently of one another,

a hydrogen or halogen atom,

a linear, branched and / or cyclic, saturated or unsaturated C 1 -C 20 alkyl group, which may be substituted by one or more halogen atoms and / or one or more OH groups,

a C2-C10 linear or branched alkenyl or alkynyl group, which may be substituted with one or more halogen atoms,

a C 3 -C 8 cycloalkyl group which may be substituted with one or more halogen atoms, a cyano group,

an aryl group,

a group -C (= Y) R ⁵ , -CH ₂ C (= Y) R ⁵ , -C (= Y) NR ⁶ R ⁷ , -YC (= Y) R ⁵ , -NR ⁶ C (= Y) ) R ⁵ , -OR ⁵ , -SO ₂ R ⁵ , -OSO ₂ R ⁵ , -NR ⁸ SO ₂ R ⁵ , -P (R ⁵ ) ₂ , -P (= Y) (R ⁵ ) ₂ , -YP (R ⁵ ) ₂ , -YP (= Y) (R ⁵ ) ₂ or -N (R ⁸ ) ₂ optionally quaternized with an additional R ⁸ , wherein: Y is NR ⁸ , S or O,

R ⁵ represents a linear, branched or cyclic, saturated or unsaturated, optionally hydroxylated C 1 _-2 O, mono- or poly (alkyleneoxy) alkyl group, optionally etherified, hydroxylated, -OM (with M = alkali metal); aryloxy or heterocyclyloxy,

R ⁶ and R ⁷ independently of one another, a hydrogen atom or an alkyl group, linear, branched or cyclic, saturated or unsaturated Ci _-20 or for- 3 to 8-membered ring, R ⁸ represents a hydrogen atom, a linear, branched or cyclic, saturated or unsaturated C 1 -C 20 alkyl group or a aryl,

- -C (= O) -XR ⁹ -Z or -Z -R ⁹ wherein R ⁹ represents a radical valent di- (hydro) carbonaceous Cl O _-2 saturated or unsaturated, linear, branched or cyclic, optionally halogenated and possibly containing one or more heteroatoms, X represents a NR ¹⁰ group or an oxygen atom, and Z represents a group - N (R ¹⁰ ) ₂ , -SR ¹⁰ or P (R ¹⁰ ) ₂ with R ¹⁰ representing , independently of one another, a hydrogen atom or a saturated or unsaturated, linear, branched or cyclic, optionally halogenated C ₂ -C hydrocarbon-based group which may comprise one or more heteroatoms, the nitrogen atom or present in X and / or Z (when present) capable of being protonated or quaternized by C 1 -C ₂ alkyl radicals,

a group -R ⁹ -NR ¹⁰ -Acide or -C (= O) -XR ⁹ -NR ¹⁰ -Acide in which X, R ⁹ and R ¹⁰ are as defined above, and Acid represents a carboxylic acid function - that, sulfonic or phosphonic;

a radical comprising at least one silicon atom and in particular a radical-R-siloxane, -CONHR-siloxane, -COOR-siloxane, or OCO-R-siloxane, in which R is a linear alkyl, alkylthio or alkoxy radical, branched or cyclic, saturated or unsaturated, C _1-20 , aryloxy or heterocyclyloxy.

3. Polymer according to claim 2, in which the polymer backbone is derived from the polymerization of one or more ethylenic monomers chosen from, alone or as a mixture:

acrylic acid, methacrylic acid, straight-chain, branched or cyclic C 1 -C ₂₀ alkyl (meth) acrylates, such as methyl methacrylate, ethyl methacrylate, methacrylate; pyl, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate and cyclohexyl methacrylate; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate and tert-butyl acrylate,

C 6-20 aryl (meth) acrylates,

C1-4 hydroxyalkyl (meth) acrylates, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,

vinyl ethers, such as vinylisobutyl ether,

aliphatic, cycloaliphatic or aromatic (meth) acrylamides, such as tert-butylacrylamide, undecylacrylamide or N-octylacrylamide; and di (C 1-4 alkyl) (meth) acrylamides, styrene and its derivatives,

- (meth) acrylic monomers, (meth) acrylamides or vinyl fluorinated or perfluorinated group, especially perfluoroalkyl chain (meth) acrylic esters such as perfluorooctylethyl (meth) acrylate, - (meth) acrylic monomers, (meth) ) silicone acrylamides or vinyls, such as (meth) acryloxypropyltris (trimethylsiloxy) silane,

the (meth) acrylic or vinyl monomers comprising an optionally neutralized or quaternized amine functional group, such as dimethylaminoethyl (meth) acrylate, dimethylaminoethylmethacrylamide, vinylamine, vinylpyridine, diallyldimethylammonium chloride, dimethylaminopropyl methacrylamide, aminopropyl methacrylamide, 2-aminoethyl methacrylate;

The polymer of claim 1, wherein the polymeric backbone is a polyester, polycarbonate, polyamide, polyimide, polyurethane, polyurea, polysaccharide, polysiloxane, polyphenol, polyether, polypeptide. .

5. Polymer according to one of the preceding claims, wherein the polymeric backbone has a number-average molecular weight (Mn) of between 2,000 and 1,000,000, preferably between 2,000 and 100,000 g / mol.

6. Polymer according to one of the preceding claims, wherein the degree of grafting is between 1 and 100%, especially between 20 and 100%, and even more preferably between 40 and 100%; said grafting ratio being the ratio (x 100) between the number of repeating units of the POL polymer backbone grafted by polysaccharide grafts (x), and the total number of repeating units of the polymer backbone (or degree of polymerization).

7. Polymer according to one of the preceding claims, wherein the (poly) saccharide graft is selected from, alone or in mixture: - fructans including inulin; glucans;

modified or unmodified starches, such as those derived, for example, from cereals such as wheat, corn or rice, from vegetables such as sweet pea, from tubers such as potatoes or cassava; amylose, amylopectin, glycogen;

dextrans and their derivatives, such as dextran sulfate, dextran diethylaminoethyl and carboxymethyl dextran;

celluloses and their derivatives such as methylcelluloses, hydroxyalkylcelluloses and loses, ethylhydroxyethylcelluloses, carboxymethylcelluloses;

glycosaminoglucans such as hyaluronic acid, chondroitins and chondroitin sulphates;

- Arabic gums, Tragacanth gums, Ghatti gums, Karaya gums, locust bean gums, gellan gums, curdlan gums, xanthan gums;

8. Polymer according to one of the preceding claims, wherein the (poly) saccharide grafts are defined by the sequence of units (I) and / or (II) of formula:

(D ⁽ " ⁾ in which Ra to Re represent, independently of each other, -OH, -O- (repeating unit of the polysaccharide) -CH ₃

-NHCOCH ₃ -NH2

-OCH ₂ COOH -COOH -OSO ₃ H -OPO ₃ H with the proviso that at least one of Ra to Re is -O- (repeating unit of polysaccharide) or OH, and that one of Ra to Re is a covalent bond with Unker L; preferably only one of Ra to Re across the (poly) saccharide is a covalent bond.

9. Polymer according to one of the preceding claims, wherein the polysaccharide grafts are selected from dextrans and their derivatives (dextran sulfate, dextran diethylaminoethyl, carboxymethyl dextran), glycosaminoglycans and derivatives thereof (hyaluronic acid, chondroitins and chondroitin sulphates), celluloses and their derivatives (methylcelluloses, hydroxyalkylcelluloses, ethylhydroxyethylcelluloses, carboxymethylcelluloses), amylose and its derivatives, chitins and their derivatives, carrageenans and derivatives thereof, oligomers and toses and their derivatives; and their mixtures.

10. Polymer according to one of the preceding claims, wherein each (poly) saccharide graft PS has a number-average molecular weight (Mn) of between 100 and 100,000 g / mol, in particular between 150 and 50,000 g / mol and preferably between 200 and and 20,000 g / mol.

11. Polymer structure: (POL) - (L-PS) _x where

POL represents a polymeric backbone, L represents a linker,

PS represents a (poly) saccharide grafted onto POL via the linker L, and

x represents a non-zero integer characteristic of the number of PS grafts; obtainable by Chemo-Selective Ligation reaction between aldehyde functions or ketones carried by the (poly) saccharide or the polymer backbone and at least one of the following compounds: H ₂ N-LI-R, HR 1 N-L1-R, H ₂ NO- L1 -R, H ₂ NO- (O) C-TA-R, H ₂ NO- (O) C-NH-LI -R, H ₂ NO- (S) C -NH-LI-R, HR1 NO-L1-R, HR1 NO- (O) C-LI-R, HR1 NO- (O) C-NH-LI-R, HR1 NO- (S) C-NH- LI-R, H ₂ N-NH-L 1 -R, H ₂ N-NH- (O) C-LI-R, H ₂ N-NH- (O) CO-LI-R, H ₂ N-NH- (O) C-NH-LI-R, H ₂ N-NH- (S) C-LI-R, H ₂ N-NH- (S) CO-LI-R, H ₂ N-NH- (S) C-NH-LI-R, H ₂ N-CHRI-CH (LI-R) -SH, H ₂ N-CH (LI-IR) -CHR-SH, H ₂ N-NH-SO ₂ -LI-R , X-CH ₂ -X'-L 1 -R, in which:

- R or R1 represent, independently of one another, the polymeric backbone POL or a (poly) saccharide graft PS or a hydrogen atom or a group chosen from (i) linear, branched or cyclic C1-C alkyl C30, preferably linear or branched C1-C10; (ii) linear, branched or cyclic C2-C30 alkenyl, preferably linear or branched C1-C10, (iii) linear, branched or cyclic C2-C30 alkynyl; preferably linear or branched C1-C10; this group may comprise one or more heteroatoms chosen from O, N, S, Cl, Br, I, F, P and / or one or more substituents chosen from CO ₂ H, SO ₃ H, PO ₃ H, NH ₂ , OH , SH; it being understood that only one of the groups R or R1 represents a (poly) saccharide PS or a polymeric backbone POL.

12. Cosmetic composition comprising, in a cosmetically acceptable medium, at least one polymer as defined in one of claims 1 to 11.

13. The composition of claim 12, wherein the polymer is present in an amount of between 0.01 and 30% by weight, preferably between 0.1 and 20% by weight, especially between 0.5 and 10% by weight. or between 1 and 5% by weight, relative to the weight of the cosmetic composition.

14. Composition according to one of Claims 12 to 13, in which the cosmetically acceptable medium comprises at least one compound chosen from water, alcohols, polyols, esters, carbonaceous oils, silicone oils and oils. fluorinated silicone, gelling agents and / or thickeners; polymers, associative or not; anionic, nonionic, cationic and / or ampho- tological surfactants; propenetrating agents, emulsifiers, perfumes, preservatives, fillers, sunscreens; dyestuffs, proteins, vitamins, provitamins; polymers, fixing or non-fixing, anionic, nonionic, cationic or amphoteric; moisturizing agents, emollients, softening agents; mineral, vegetable or synthetic oils; hydrophilic or lipophilic active agents such as ceramides and pseudoceramides; anti-foam agents, antiperspirants, anti-free radical agents, bactericidal agents and anti-dandruff agents.

15. Composition according to one of claims 12 to 14, being in the form of a care product, cleaning and / or makeup of the skin of the body or face, lips, eyelashes, nails and hair, a sunscreen or self-tanning product, a personal care product, a hair product, in particular care, cleaning, styling or hair dyeing.

16. A process for the cosmetic treatment of keratin materials comprising the application on said materials of a cosmetic composition as defined in one of claims 12 to 15.