BLOCK COPOLYMERS HAVING IMPROVED PROPERTIES, METHOD OF PREPARATION THEREOF, AND COMPOSITION BASED THEREON Russian patent published in 2001 - IPC

FIELD: chemistry of polymers. SUBSTANCE: described is linear triblock copolymer comprising two terminal polystyrene units prepared from pure styrene or from at least 95% of styrene, and balance being other copolymer, and one polybutadiene middle unit prepared from pure butadiene or at least 95 wt % of butadiene and balance being other comonomer. In this case, amount of styrene component in said triblock copolymer varies from 10 to 55 wt % based on total weight of triblock copolymer, two terminal polystyrene units have actual molecular weight within 5000 to 25,000, M_w/M_n molecular weight distribution is equal or greater than 1.15, weight ratio between two terminal polystyrene units is within 0.85 to 1.15 and apparent total molecular weight of triblock copolymer is within 15,000 to 300,000, triblock copolymer containing free polystyrene in amount of 7 wt %. Also described are method of preparing thereof and composition based thereon. EFFECT: color, heat resistant and mechanically strong new bloc, copolymers. 16 cl, 2 tbl