METHOD OF PURIFYING BLOCK COPOLYMER (VERSIONS) Russian patent published in 2012 - IPC C08F6/06 

FIELD: chemistry.

SUBSTANCE: invention describes versions of a method of purifying a block copolymer, involving dissolution a block copolymer in a first solvent system to obtain a first solution, merging the first solution with a second solvent system to obtain a block copolymer precipitated from the mother solution, separating the block copolymer precipitated from the mother solution to obtain a purified block copolymer, adding acetone to the purified block copolymer to obtain a mixture of purified block copolymer and acetone, adding a third solvent system to said mixture of purified block copolymer and acetone, wherein the third system is a precipitant of at least two types of blocks of the purified block copolymer to obtain a mixture of the purified block copolymer and a mixture of solvents, and separating the purified block copolymer from the mixture of solvents to obtain an end purified block copolymer, characterised by that it employs a first solvent system which is capable of dissolving polyisobutene blocks of the block copolymer, and a second solvent system which dissolves the polystyrene terminal block of the block copolymer better than it dissolves the polyisobutene block of the block copolymer.

EFFECT: reduced content of residual monomer in the block copolymer.

24 cl, 1 tbl, 2 ex