BLOCK COPOLYMERS OF DIENE HAVING THEIR TERMINAL END BLOCKS OF A RANDOM COPOLYMER OF STYRENE AND ALPHA-METHYLSTYRENE; BLOCK COPOLYMERS OF DIENE HAVING THEIR TERMINAL END BLOCKS OF A RANDOM COPOLYMER OF STYRENE OR ALKYLSTYRENE AND AN ALPHA-METHYLSTYRENE

摘要

Abstract of the DisclosureBlock copolymers are prepared having end blockswith random copolymer of styrene and/or alkyl substitutedderivatives and .alpha.-methylstyrene ranges from 1:0.5 to1:2.5, a central block of a polydiene polymer joins theterminal blocks. The block copolymers contain from 10 to90 weight percent of polydiene, the remaining portionbeing of random alkylstyrene-.alpha.-methylstyrene copolymer.The polymers range from medium impact polystyrene typepolymer of low polydiene content to thermoplasticelastomers of high polydiene content.27,797B-F