文献类型：期刊文献

英文题名：Relationship between molecular structure, crystallization behavior, and mechanical properties of long chain branching polypropylene

作者：Zhou, Shuai[1,2];Wang, Weixia[1,2];Xin, Zhong[1,2];Zhao, Shicheng[1,2];Shi, Yaoqi[1,3]

机构：[1]E China Univ Sci & Technol, Shanghai Key Lab Multiphase Mat Chem Engn, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[3]Shanghai Res Inst Chem Ind, Shanghai Key Lab Catalysis Technol Polyolefin, Shanghai 200062, Peoples R China

年份：2016

卷号：51

期号：12

起止页码：5598

外文期刊名：JOURNAL OF MATERIALS SCIENCE

收录：;EI(收录号：20161102103940);WOS:【SCI-EXPANDED(收录号:WOS:000373626000003)】；

基金：The authors thank the Fundamental Research Funds for The Central Universities of China (Grant Nos. 22A201514016, 222201314051), and National Natural Science Funds of China (Grant Nos. 21476085, 21306047) for financial support.

语种：英文

外文关键词：Impact strength - Chains - Differential scanning calorimetry - Crystal structure - Crystallization - Injection molding - Tensile strength - X ray diffraction

摘要：The crystallization behaviors and mechanical properties of both linear isotactic polypropylene (iPP) and long chain branching polypropylene (LCBPP) were investigated with differential scanning calorimetry, polarized optical microscopy, and wide-angle X-ray diffraction. The results indicated that the long chain branching (LCB) structure could act as nucleating agent accelerating the nucleation but impeding the crystal growth of LCBPP, and eventually increased the crystallization peak temperature and decreased the spherulite size of LCBPP. Moreover, with the presence of LCB structure, beta-form polypropylene was generated in LCBPPs under injection molding conditions, and the content of beta-form increased with the increasing of LCB structure content. Benefiting from the combined effect of the LCB structure and beta-form crystal, the LCBPPs revealed not only outstanding toughness but also desired stiffness. The impact strength, flexural modulus and tensile strength of HMSPP3 were increased by, respectively, 260.0, 54.7, and 17.2 % than those of linear iPP. These results are helpful to develop new types of high performance polypropylene.