EFFECT OF BLOCK-COPOLYMER ARCHITECTURE ON COMPATIBILITY .2. EPOXIDIZED STYRENE-BUTADIENE STAR BLOCK-COPOLYMERS WITH CHLORINATED POLYMERS

The compatibility behaviour of an epoxidized styrene-butadiene three-a rm block copolymer ((ESB)3) with chlorinated polyethylene (CPE) at two degrees of chlorination (36 and 48 wt%) and with poly(vinyl chloride) was investigated over the complete composition range. The techniques used were dynamic mechanical analysis, differential scanning calorimet ry and tensile testing. The results were compared with epoxidized bloc k copolymer blends of different architectures, studied before: a linea r ESB, a branched E(SB)n and an SBS. The results indicate that miscibi lity is reduced along the series ESB > (ESB)3 > E(SB)n, at the same le vel of epoxidation. Additional data on tensile properties on (ESB)3 an d E(SB)n blends are also reported. A method is also described to obtai n epoxidized semicrystalline poly(hydrocarbons), which when blended wi th CPE showed a T(m) depression. This allowed the determination of the interaction parameter chi12 of epoxidized poly(hydrocarbon)/chlorinat ed polymer using the well established method.