Patent ID: 8598289

Claim:
A method for preparing an amphiphilic copolymer, in emulsion in an aqueous medium, said method consisting of: preparing an aqueous solution of a compound of formula (I) below: R 1 —S—C(═S)—S—CR 3 R 4 —C(═O)—OR 2 (I) in which: R 1 represents a linear or branched alkyl group, an alkenyl group having one or more —C═C— bonds, or an alkynyl group having one or more —C≡C— bonds, said groups having from 8 to 18 carbon atoms; R 2 represents an R 5 —[—CH 2 CH 2 —] n — group in which R 5 is a hydrophilic group and 20≦n≦150; R 3 and R 4 each represent, independently of one another, H, an alkyl group having from 1 to 4 carbon atoms or a nitrile group, at least one among R 3 and R 4 being other than H; said aqueous solution being free of free surfactant, successively adding to said solution one or more hydrophobic monomers of formula (II) below: R 6 —CR 7 ═CH 2 (II) in which: R 6 represents a phenyl group or an alkoxycarbonyl group in which the alkoxy group has from 1 to 8 carbon atoms and optionally bearing one or more functional groups, and R 7 represents a hydrogen atom or a methyl radical, then a free-radical polymerization initiator; and then in bringing said aqueous solution to a temperature of 5-95° C.