MECHANICAL-PROPERTIES AND DEFORMATION MECHANISMS OF POLY(STYRENE-B-BUTYLMETHACRYLATE) DIBLOCK COPOLYMERS

The mechanical properties of poly(styrene-b-butylmethacrylate) diblock copolymers (PS-b-PBMA) with different lengths of polystyrene block we re investigated. The copolymers display a composition range where the tensile strength of the block copolymers exceeds the values of the cor responding homopolymers. The mechanical properties of PS-b-PBMA dibloc k copolymers with lamellar structure are compared with bicontinuous an d perforated lamellar structures. The investigation of the deformation mechanisms has shown that the craze structure and craze growth are st rongly influenced by the microphase separated structures. The enhancem ent of mechanical properties of PS-b-PBMA diblock copolymers is discus sed with respect to a possible correlation between phase behavior, mor phology, deformation mechanisms and interface formation. (C) 1998 John Wiley & Sons, Ltd.