Morphology of graft copolymer EPE-g-PS

EP copolymer (EPR) with polystyrene (PS) grafts

prepared through maeromer copolymerization

has been studied by transmission electron microscopy(TEM). Results show that the copolymer consists of two-phases with PS microdomains several hundred A in size dispersed in EPR rubber matrix. The mierodomains change in shape from spheric to rod-like as PS-content in the copoly-mers increases. Small amount of EPR-g-PS in EPS+PS blends acts as an "emulsifier"

making the microdomains in the blends smaller and the dispersion more homogeneous. Multi-transition behavior of the copolymers confirms the existence of separated phases.