交联剂对动态硫化PP／EPDM中PP晶体及EPDM形态结构的影响

针对ＰＰ／ＥＰＤＭ动态硫化中有机过氧化物交联剂Ａ用量对试样拉伸，弯曲和冲击等性能所产生的较大的影响，采用偏光显微镜研究了不同交联剂Ａ用量下动态硫化ＰＰ／ＥＰＤＭ中连续相ＰＰ的晶体结构和分散相ＥＰＤＭ的形态结构特征。

Effect of vulcanizing agent on structures of crystal of PP and morphology of EPDM in dynamic vulcanized PP/EPDM blends

Owing to the big influence of the dosage of the vulcanizing agent on the tensile,flexural and impact properties of dynamic vulcanized PP/EPDM blends,the polarizing microscope was used to investigate the crystal structure of continuous phase PP and morphology of the dispersed phase EPDM in PP/EPDM blends with different dosages of vulcanizing agent. The results showed that with proper amount of the vulcanizing agent,the degradation of PP did not occur, and EPDM could be completely cured and homogeneously dispersed in PP phase as fine particles,which formed the buffer layer and resulted in the fine homogeneous spherulites and the unclear crystal face,so the impact toughness was improved without the much damage of tensile and flexural properties. When too much vulcanizing agent was used,PP degradated intensly,large particles of EPDM were formed,which decreased the interface with PP.So their above effects on PP spherulites reduced,not only the tensile and flexural properties but also the impact toughness decreased.