复合成核剂对聚丙烯结晶行为的影响

以超细橡胶粒子与有机磷酸盐成核剂复配的方法制备了一种新型复合成核剂,通过示差扫描量热法(DSC)比较了复合成核剂改性PP以及有机磷酸盐成核剂改性PP的结晶温度、等温结晶行为及等温结晶动力学;利用扫描电子显微镜(SEM)的能谱附件和透射电子显微镜(TEM)研究了复合成核剂的微观形态及其在PP中的分散情况.研究结果表明,复合成核剂中超细橡胶粒子作为载体使有机磷酸盐成核剂附着在其表面,提高了成核剂在聚丙烯中的分散性,因而提高了成核剂的成核效率,当成核剂用量较小时,即可明显提高PP的结晶速率和力学性能.

THE EFFECT OF COMPOUND NUCLEATING AGENT ON THE CRYSTALLIZATION BEHAVIOR OF POLYPROPYLENE

A new type of nucleating agent(NA),compound nucleating agent made of ultra-fine rubber particles and organic phosphate,was applied to modify polypropylene(PP) resin.It is found that the new NA is a high efficiency nucleating agent.A small amount of organic phosphate NA can increase the crystallization rate and crystallization temperature of PP obviously.For example,a PP with crystallization temperature of 118.5℃ may have a crystallization temperature raised up to 125.6℃ while it is modified with 0.1% of this new NA containing only 0.02% organic phosphate NA.It is impossible to reach so high crystallization temperature if we use so small amount of pure organic phosphate NA.The morphology study showed that ultra-fine rubber particles acted as carriers of organic phosphate NA.The organic phosphate NA in compound NA could disperse better with the rubber particle dispersion in the PP matrix.Good dispersion of organic phosphate NA resulted in the high nucleating efficiency of new NA;therefore,PP modified with this new NA had high crystallization rate,high crystallization temperature and good mechanical properties while only a small amount of organic phosphate NA was used.