iPP/PET原位微纤复合材料的超临界二氧化碳发泡行为  

Isotactic Polypropylene/Polyethylene Terephthalate in Situ Microfibrillar Composites Foams Using Supercritical CO_2

作　　者：韦良强[1] 黄安荣[1] 孙静[1] 董珈豪 罗珊珊 宁德阳 Liangqiang Wei;Anrong Huang;Jing Sun;Jiahao Dong;Shanshan Luo;Deyang Ning(National Engineering Research Center for Compounding and Modification of Polymer Materials,Guiyang 550014,China;College of Manufacturing Science and Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]国家复合改性聚合物材料工程技术研究中心,贵州贵阳550014 [2]四川大学制造科学与工程学院.四川成都610065

出　　处：《高分子材料科学与工程》2018年第7期66-71,共6页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(21664004); 黔科合基础[2017]1090

摘　　要：利用微纳层叠共挤技术中独特的剪切拉伸复合流动场作用实现聚对苯二甲酸乙二醇酯(PET)在聚丙烯(i PP)中的原位微纤化,研究了PET的原位微纤化对i PP/PET复合材料发泡行为的影响。扫描电子显微镜结果显示,经过微纳层叠共挤装置挤出后,PET在i PP中形成直径为0.2~1μm的微纤。PET微纤化显著地改善了i PP的结晶性能、流变性能及发泡性能。差示扫描量热测试结果表明,PET微纤对i PP具有明显的异相成核作用,能提高i PP的结晶温度和熔点;拉伸流变行为分析发现,PET微纤的形成使得i PP产生明显的应变硬化现象;通过超临界二氧化碳发泡发现,i PP/PET原位微纤复合材料的泡孔比纯i PP更加稳定,尺寸更小,密度更大,且泡孔内存在三维微纤网络结构。The isotactic polypropylene（ i PP）/polyethylene terephthalate（ PET） in situ microfibrillar composites were prepared by micro-nano-stack co-extrusion technique based on its strong shear-elongational mixed flow field,and its effect on the foaming behavior of i PP was studied. The scanning electron micrographs illustrate that the micro-nano-stack co-extrusion process elongates the dispersed PET phase in the i PP matrix into high-aspect-ratio microfibrils with the diameter of 0. 2 ~ 1 μm. The formation of PET microfibrils greatly affect the crystalline behaviors,rheological and foaming properties of i PP. The differential scanning calorimetry results reveal that the heterogeneous nucleation sites provided by the PET microfibrils enhance the crystallization and melting temperature of i PP. Uniaxial extensional viscosity test shows a strain-hardening behavior in the i PP/PET microfibrillar composites,which cannot be observed in the neat i PP. Supercritical CO2 was used to investigate the effect of the PET microfibrils on the foaming behavior of i PP. Results reveal that the presence of PET microfibrils in i PP yields foams that exhibit smaller cell size,larger cell density and entangled microfibrils networks exist in cell.

关 键 词：发泡 原位微纤 超临界二氧化碳 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]