EPR-g-PS热塑弹性体的形态结构

电子显微镜观察表明,以乙丙橡胶(EPR)为主干,聚苯乙烯(PS)为支链的接枝共聚物EPR-g-PS的基本形态是高度分散的聚苯乙烯微区(约几百?)存在于乙丙橡胶连续相中的两相体系,随接枝共聚物中聚苯乙烯含量增加,微区形态发生变化,少量的接枝共聚物在PS与EPR共混物中起“增容剂”作用,使分散相微区变得小而均匀,多重玻璃化转变的存在进一步证实了接枝共聚物相分离的形态结构。

MORPHOLOGY OF EPR-g-PS THERMOPLASTIC ELASTOMER

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.