聚苯乙烯对等规聚丙烯β成核及增韧作用

β-Nucleating and Toughening Effect of Polystyrene on Isotactic Polypropylene

采用动态流变仪、扫描电子显微镜、广角X射线衍射仪以及力学性能测试研究了支化结构对聚苯乙烯(PS)诱导等规聚丙烯(iPP)β成核效率及增韧作用的影响。结果表明:支化结构的引入对PS在iPP中的分散性及其β成核效率有很大影响。线形聚苯乙烯(lPS)与iPP基体之间较好的界面相互作用使得lPS具有良好的分散性、较高的β成核效率以及优异的增韧效果。与具有相同主链长度的lPS相比,三臂星形聚苯乙烯(sPS)和梳形支化聚苯乙烯(cPS)中支化结构的引入不利于iPP与PS分子链之间的相互扩散,因而分散性和增韧效果相对较差。当加入质量分数为2%的lPS时,iPP的断裂伸长率和冲击强度得到了显著提高。

The effects of PS with branch structure onβ-nucleating efficiency and toughening of iPP were investigated by dynamic rheological measurements,scanning electron microscopy,wide-angle X-ray diffraction and mechanical property measurements.The results show that the introduction of branch structure for PS has great influence on its dispersibility in iPP andβ-nucleating efficiency.Favorable interfacial interaction between linear polystyrene(lPS)and iPP matrix results in good dispersibility,highβ-nucleating efficiency and excellent toughening effect of lPS on iPP.Compared with the lPS with the same length of backbone,the introduction of branch structure for three-arm star-shaped polystyrene(sPS)and comb-like branched polystyrene(cPS)may not be in favor of the chain diffusion between iPP and PS,therefore relatively poor dispersibility and toughening effect are obtained.The elongation at break and impact strength of iPP were dramatically improved,especially with the addition of 2%lPS.