硅灰石形貌对聚丙烯结晶行为的影响  

Effect of Wollastonite Morphology on Crystallization Behaviors of Polypropylene

作　　者：严满清[1] 唐龙祥[2] 刘春华[2] 王平华[2] 

机构地区：[1]安徽大学化工学院,安徽合肥230039 [2]合肥工业大学高分子科学与工程系,安徽合肥230009

出　　处：《现代塑料加工应用》2008年第6期5-8,共4页Modern Plastics Processing and Applications

基　　金：国家自然科学基金项目资助(50573016);安徽省教育厅高校青年教师资助项目(2007jq1020)

摘　　要：采用熔融共混法制备了聚丙烯(PP)/硅灰石复合材料,并对其结晶行为进行研究。用X-射线衍射(XRD)研究了硅灰石的加入及类型对PP的晶体尺寸及类型的影响。结果显示,硅灰石的加入不改变PP的晶型,仍为α晶,而晶粒尺寸变小,表明硅灰石有异相成核作用。相比较而言,针状硅灰石比颗粒状硅灰石的异相成核作用更明显。采用差示扫描量热仪(DSC)在各种不同冷却速率下对复合材料的非等温结晶动力学过程进行研究,并用Jeziorny法来描述这些样品的非等温结晶过程。在相同的冷却速率下,半结晶时间(t′_(1/2))、结晶速率常数(Z_c)等数据表明复合材料的结晶速率比纯PP的快,说明硅灰石具有异相成核作用,与颗粒硅灰石相比,针状硅灰石异相成核作用更明显。PP/wollastonite composites were prepared through melt blending method, and the crystallization behaviors of the composites were studied. The effects of addition and type of wollastonite on the crystal type and size of PP were investigated by means of XRD. The results show that the addition of wollastonite do not change the crystal type, however, the crystal size of PP of composites becomes smaller than that of neat PP, which indicates that wollastonite has heterogeneous nucleation role. In comparison with granular wollastonite, the heterogeneous nucleation role of acicular wollastonite is more obvious. In addition, the nonisothermal crystallization kinetics of PP and PP/wollastonite com- posites were investigated by means of DSC with various cooling rates, and the Avrami analysis modified by Jeziorny was employed to describe the nonisothermal crystallization process of these samples. The results of half-time of crystallization （t1/2） and crystallization velocity constant （Zc） indicate that the crystallization rate of composites is faster than that of PP at given cooling rate, namely two types of wollastonite possess both heterogeneous nucleation role. Compared with the granular wollastonite, the acicular wollastonite affects the crystallization behavior of PP more obviously.

关 键 词：聚丙烯 硅灰石 形貌 复合材料 结晶行为 非等温结晶动力学 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业] U463.5[机械工程—车辆工程]