METHOD OF PRODUCING GRAFT COPOLYMERS OF STYRENE ON POLYDIENES Russian patent published in 2013 - IPC C08F279/02 C08F212/08 C08F4/28 

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry of high-molecular weight compounds and a method of producing graft copolymers of styrene on polydienes, which can be used in chemical industry when producing materials which combine properties of thermoelastic and thermoplastic polymers. This is achieved owing to that, in the method of producing graft copolymers of styrene on polydienes by chemical modification of polydienes, graft polymerisation of styrene on the modified polydiene in the absence of oxygen while heating and separating the graft copolymer, the polydiene used is a polymer selected from a group comprising 1,4-poly-2,3-dimethylbutadiene and 1,4-poly-2-alkkyldiene; chemical modification of the polydiene is carried out by dissolving the polydiene and a radical polymerisation initiator in an organic solvent, adding to the obtained solution 2-methyl-2-nitrosopropane in the absence of light with a wavelength longer than 500 nm, holding the mixture in the absence of oxygen and light with a wavelength longer than 500 nm for not less than 1 hour at temperature not lower than the decay temperature of the initiator, but not higher than 60°C, separating the obtained modified polymer by precipitation in an organic precipitant and drying the modified polymer, wherein before graft polymerisation, the modified polymer is dissolved in styrene or mixture thereof with at least one organic solvent which is miscible with styrene but does not precipitate polydiene and the formed graft copolymer, and oxygen is removed from the obtained solution, and graft polymerisation is carried out at temperature of 90-140°C in the presence of a radical polymerisation initiator whose half-life is not more than 30 minutes at polymerisation temperature.

EFFECT: invention simplifies the method of producing graft copolymers described in the prototype, increases grafting efficiency from 35-49% (prototype) to 95-100% and widens the range of methods of producing graft copolymers of styrene on polydienes.

1 cl, 6 ex