聚丙烯／顺丁橡胶动态硫化共混物的交联行为和结晶性能的研究

Study on the Crosslinking and Crystallization Behavior of PP / BR Dynamically Vulcanized Blends

研究了聚丙烯（ＰＰ）／顺丁橡胶（ＢＲ）动态硫化共混物橡胶相的交联行为、动态硫化共混物的结晶行为和结晶结构。结果表明，顺丁橡胶的加人对ＰＰ的熔点无明显影响，但结晶度降低。动态硫化共混物在低于熔点处另有一熔化转变。动态硫化使共混物中ＰＰ的结晶速率提高。纯ＰＰ含有少量β－晶型，橡胶的加入使ＰＰ的β－晶型消失，而动态硫化又使共混物中ＰＰ含有少量β－晶型。橡胶的加入并未影响ＰＰ的晶格，但能抑制ＰＰ球晶的增长，具有ＰＰ的部分成核剂作用。动态硫化使ＰＰ和ＢＲ两相界面处有相互渗透作用，提高了二者相容性。

he crosslinking behavior of PP / BR dynamically vulcanized blends was examined with extraction tests. The effect of dynamical vulcanization on the crystallization behavior of PP/ BR blends has been studied by means of polarizing microscopy, WAXD,DSC. It was found that the effects of the addition of BR could decrease the degree of crystallization of PP component in the blends and prevent its spherulite formation and keep melting point of PP unchanged, but there existedanother molten transition in front of the melting point in the case of dynamically vulcanized blends. It was also found that the overall crystallization rate of the dynamically vulcanized blends was faster than that of simple blends. X-ray diffraction studies revealed that there existed the β-form crystallite of PP in pure PP and dynamically vulcanized blends but did not in simple blends. On the basis of the phenomena mentioned above, it was proved that though no compatibility between PP and BR, there exsisted interfacial penetration between two Phases and the interfacial compatibility of PP/ BR blends could be improved by dynamical vulcanization.