大分子相容剂改性纳米CaCO3 / PP复合材料的非等温结晶行为

熔融混炼制备了4 种大分子相容剂改性的纳米CaCO₃ / PP 复合材料, 用DSC 和WXRD 研究了复合材料中PP 的结晶与熔融行为。结果表明, 纳米CaCO₃对PP 结晶存在异相成核作用, 并诱导PP 形成β晶。相容剂丙烯酸接枝聚丙烯( PP-g-AA) 和马来酸酐接枝聚丙烯( PP-g-MA) 也存在异相成核作用, 提高PP 结晶温度。PP-g-AA、PP-g-MA 和马来酸酐接枝乙烯2辛烯共聚物(POE-g-MA) 与纳米CaCO₃存在异相成核协同作用, 进一步提高PP 的结晶和熔融温度, PP-g-MA 和POE-g-MA 还促使纳米CaCO₃诱导PP 生成β晶。但马来酸酐接枝乙烯2醋酸乙烯酯共聚物( EVA-g-MA) 则阻碍纳米CaCO₃对PP 的异相成核作用。实验结果表明纳米CaCO₃ / PP 复合材料中PP 结晶的异相成核作用与纳米CaCO₃ / PP 界面的相互作用有关, 而纳米CaCO₃ / PP 界面的相互作用与相容剂的结构有关。 

Non-isothermal crystallization behavior of nano-CaCO3 / PP compositesmodif ied by macromolecular compatibilizers

The nano-CaCO3 / PP composites modified by four kinds of compatibilizers were prepared respectively.The crystallization and melting behavior of PP - base composites were investigated using DSC and WXRD. Theresult s indicate that the addition of nano-CaCO3 increases the crystallization temperature of PP and induces the formation ofβ-PP crystal due to the heterogeneous nucleation of nano-CaCO3 . The heterogeneous nucleation of PP-g-AAand PP-g-MA is also observed for PP crystallization. The synergism of heterogeneous nucleation of nano-CaCO3and PP-g-AA ( PP-g-MA or POE-g-MA) further increases the crystallization and melting temperatures of nano-CaCO3 / PP composites. Addition of PP-g-MA and POE-g-MA induces the formation of moreβ2PP crystal in nano-CaCO3 / PP composites. However , addition of EVA-g-MA decreases the heterogeneous nucleation of nano-CaCO3 .The result s suggest that the heterogeneous nucleation of PP in nano-CaCO3 / PP composites depends on the interfacial interaction between nano-CaCO3 and PP , which is influenced by compatibilizers.