熔融温度对PP中成核剂的异相成核作用的影响

用DSC研究了熔融温度对不同类型成核剂成核PP的异相成核作用的稳定性的影响。观察到随熔融温度提高，纯PP的成核作用稳定，降温结晶温度基本不变。而有机磷酸盐类成核剂成核PP的结果温度比纯PP的高，而且异相成核作用受熔融温度的影响也很小。但山梨醇类成核剂成核PP的异相成核作用随熔融温度提高，结晶温度逐步降低明显，表明其异相成核作用对热不稳定。

EFFECT OF MELTING TEMPERATURE ON HETEROGENEOUS NUCLEATION OF POLYPROPYLENE NUCLEATED WITH DIFFERENT NUCLEATING AGENTS

Effect of melting temperatures on heterogeneous nucleation of polypropylene (PP) nucleated with different nucleating agents was investigated by DSC. For the pure PP, the peak temperature of crystallization was little change with increasing the melting temperature, indicating that nucleation of PP is thermal stable. For the PP nucleated with an organic phosphate (PPA), the peak temperature of crystallization and heat of crystallization of PP were higher than that of pure PP and were little influenced with increasing the melting temperatute. For PP nucleated with two kinds of sorbitol derivatives (PPB and PPD), the peak temperature of crystailization and heat of crystallization of PP decreased with increasing the melting temperature. These results indicate that the thermal stability of heterogeneous nucleation of PP nucleated with nucleating agent A is higher than that of nucleating agent B and D.