Viscoelastic Properties of Heterophase Blends of Homopolymers and Block Copolymers.
CALIFORNIA UNIV BERKELEY DEPT OF CHEMICAL ENGINEERING
Pagination or Media Count:
Stress relaxation and dynamic mechanical measurements were carried out for two types of heterophase polyblends. One is obtained by blending homopolymers of butadiene and styrene high impact polystyrene of HIPS the other by blending homopolymer of butadiene with a triblock copolymer of styrene-butadiene-styrene SBSB. It was found that for HIPS, time temperature superposition is difficult, and the shift factors cannot be adequately interpreted by a reasonable model. For SBSB it is impossible to carry out superposition. Possible mechanisms giving rise to the new transition are discussed. Author