METHOD FOR PRODUCTION OF GRAFT BLOCK COPOLYMERS Russian patent published in 1999 - IPC

FIELD: polymer production. SUBSTANCE: method of preparing graft block copolymers of vinylaromatic compounds and conjugated dienes by coupling initial block copolymers with terminal lithium atoms and coupling agent containing 3 to 7 epoxy groups per molecule is distinguished by that coupled are block copolymers with general formula S-B-Li, where S is monovinylaromatic hydrocarbon block, B conjugated diene block, containing up to 40 wt % of monovinylaromatic hydrocarbon. EFFECT: enabled preparation of block copolymers with central polydiene block and lower content of styrene manifesting good mechanical and optic properties. 7 cl, 3 tbl, 8 ex