硅灰石填充聚丙烯复合材料性能的研究

STUDY ON THE PROPERTIES OF POLYPROPYLENE WOLLASTONITE COMPOSITES

本文研究了硅灰石填充聚丙烯(含乙烯22％)复合材料的热学、广角X-射线衍射和动态力学性质。复合材料中β晶含量随硅灰石含量增高而增加。试样的熔融及结晶行为表明,所有硅灰石填充试样均含有α和β两种晶型,4个结晶熔融转变;而未填充试样只有a晶型,2个结晶熔化转变。在DSC曲线上,β晶在升温过程中转变成α晶型。硅灰石填料对聚丙烯动态力学性能的影响表明,硅灰石起到了增强剂和β晶成核剂的双重作用,填料硅灰石已进入聚丙烯的结晶相。

A study has made on the thermal, x-ray diffraction, and dynamic mechanical characterit-tics of polypropylene (pp) (containing 22% ethylene) filled with wollastonite. Differentlevels of β-form crystallinity were produced in the pp by mixing wollastonite. All the sa-mples filled with wollastonite contain both β and a-forms and four melting transitions wereobserved instead of two for the unfilled pp. The crystals were found to be changed from β-form to a-form on heating. The relative proportions of β-form present in the specimens was measured from the x-raydiffraction diagram by an empirical ratio K.The K value increases with increasing the con-tent of wollastonite fillers. Wollastonite in the composite is as a reinforecement and nucleator for β-form crystalsof pp and it is bound into crystalline phases of pp.