Block and graft copolymers by selective cationic initiation. IV. Physical properties of bigraft copolymers

The physical properties of bigraft copolymers, i.e., Nordel-g-polystyrene-g-poly(α-methylstyrene) and Nordel-g-polystyrene-g-polyisobutylene, have been studied in terms of stress strain behavior, glass transition temperature, dynamic mechanical data, intrinsic viscosity versus temperature profile and solubility properties. These products are thermoplastic elastomers and show the presence of incompatible domains. T_g and dynamic-mechanical data indicate an aggregation of the polystyrene and poly(α-methylstyrene) phases.