β晶成核剂与纳米蒙脱土在等规聚丙烯中的协同效应

摘要

为使等规聚丙烯(iPP)在增刚的同时增韧,采用β晶型成核剂TMB-5和纳米蒙脱土(MMT)复合的方法进行改性,研究了复合体系的力学性能、晶型结构以及结晶熔融行为.结果表明,TMB-5和纳米MMT在iPP存在协同效应,能够同时改善iPP的刚性和韧性.0.2%的TMB-5和4%的纳米MMT能够使iPP的冲击强度和弯曲弹性模量分别提高120%和8.5%.协同效应还体现TMB-5和纳米MMT复合使用能够提高iPP的结晶峰值温度,其效果优于两者单独添加的效果.广角X射线衍射和差示扫描量热仪表征结果标明,TMB-5和纳米MMT复合后仍然能够诱导iPP获得较高含量的β晶型,揭示了此复合体系协同增刚增韧的原因.%In order to simultaneously improve the stiffness and toughness of isotactic polypropylene (iPP),the compounds of βnucleating agent TMB-5 and nano montmorillonite (nano-MMT) were added to iPP matrix. The effects of the compound system on the mechanical properties,crystal structure,crystallization and melting behavior of iPP were investigated. The results showed that the compounds of TMB-5 and nano-MMT simultaneously improved the stiffness and toughness of iPP,which showed a synergistic effect. The impact strength and flexural modulus of iPP were increased by 120% and 8.5% by the addition of the compounds of 0.2% TMB-5 and 4% nano-MMT,respectively. Meanwhile,the compounds of TMB-5 and nano-MMT could increase the crystallization peak temperature of iPP compared to the single addition of TMB-5 or nano-MMT. The results of wide angle X-ray diffraction and differential scanning calorimeter showed that the compounds still induced the high content of βcrystal form,which was responsible for the improvement of stiffness and toughness of iPP.