滑石粉、碳酸钙填充聚丙烯复合材料等温结晶行为的对比研究

用熔融共混法分别制备了聚丙烯（PP）/滑石粉、PP/碳酸钙(CaCO3)复合材料，用差示扫描量热法(DSC)考察了PP及其复合材料的等温结晶过程，并用Avrami方程对纯PP及PP/滑石粉、PP/CaCO3复合材料的等温结晶动力学行为进行了分析。结果表明，PP、PP/滑石粉及PP/CaCO3复合材料的Avrami指数均小于2.3，存在均相成核和异相成核双重成核机理，且其结晶速率常数和结晶速率均随着结晶温度的升高而减小；在该体系中，滑石粉对基体PP有明显的异相成核作用，使PP的结晶速率加快、结晶时间缩短；而CaCO3则没有明显的异相成核作用。

Study on the Isothermal Crystallization Behavior of PP

PP/talc and PP/CaCO3 composites were prepared via melt mixing method using Haake rheometer. The isothermal crystallization behavior of PP and the composites were investigated using differential scanning calorimetry(DSC). The effects of talc and calcium carbonate on the isothermal crystallization behavior of PP were compared. It showed that all the Avrami indexes of PP, neat or in the composites, were lower than 2.3, which showed that both homogeneous and heterogeneous nucleation mechanisms occurred in these systems. The crystallization rate decreased with increasing crystallization temperature. It was found that the effect of talc promoted the heterogeneous nucleation significantly, whereas the effect of CaCO3 was moderate.