动态硫化对三元乙丙橡胶/聚丙烯共混体系等温结晶行为和形态结构的影响

Effect of dynamic vulcanization on isothermal crystallization behavior and morphology of ethylene propylene diene monomer/polypropylene blend system

研究了三元乙丙橡胶/聚丙烯(EPDM/PP)共混物和动态硫化EPDM/PP热塑性弹性体(TPV)的等温结晶行为及形态结构,并用Avrami方程对其进行等温结晶动力学分析。结果表明,EPDM/PP共混物和EPDM/PP TPV的等温结晶行为符合Avrami方程,在相同的结晶温度下,TPV比共混物的Avrami指数小,半结晶时间短,结晶速率常数大;EPDM/PP共混物为双连续相结构,而EPDM/PP TPV是以硫化的细小橡胶颗粒为分散相、PP为连续相的"海-岛"结构,橡胶颗粒尺寸约为0.5μm。

The isothermal crystallization behavior and morphology of dynamic vulcanized ethylene pro- pylene diene monomer/polypropylene （EPDM/PP TPV） and EPDM/PP blends were investigated, and the Avrami equation was employed to analyze iso- thermal crystallization kinetics of EPDM/PP TPV and EPDM/PP blends. The results showed that Avrami equation was satisfied for describing the crystallization behavior of the two materials and at the same crystallization temperature, compared with the blends, the TPV had a smaller Avrami expo- nent, shorter crystallization half-time, and a higher crystallization rate constant. EPDM/PP blends had a continuous structure in morphology, while EPDM/ PP TPV had a ＇ sea-island＇ structure where the vul- canized EPDM particles with about 0.5 μm diameter dispersed in the continuous phase of PP matrix.