文献类型：期刊文献

英文题名：Rheological, crystallization and foaming behaviors of high melt strength polypropylene in the presence of polyvinyl acetate

作者：Li, Yu[1];Pan, Chunmeng[1];Xin, Zhong[1];Zhou, Shuai[1];Meng, Xin[1];Zhao, Shicheng[1]

机构：[1]East China Univ Sci & Technol, Shanghai Key Lab Multiphase Mat Chem Engn, Dept Prod Engn, Shanghai 200237, Peoples R China

年份：2018

卷号：25

期号：2

外文期刊名：JOURNAL OF POLYMER RESEARCH

收录：;EI(收录号：20180404680805);WOS:【SCI-EXPANDED(收录号:WOS:000423197500001)】；

基金：The authors gratefully acknowledge the financial support of this work by National Key R&D Program of China (2016YFB0302201), National Natural Science Foundation of China (Grants 21476085 and 21606084), the Fundamental Research Funds for the Central Universities (222201717025), and financial support of Ministry of Science and Technology of People's Republic of China (The people's Republic of China 863 Program, Grant No. 2015AA034003).

语种：英文

外文关键词：Polyvinyl acetate; High melt strength polypropylene; Rheological behavior; Crystallization behavior; Foaming behavior

摘要：Polyvinyl acetate (PVAc) is a kind of CO2-philic materials with high solubility of CO2. For improving the supercritical carbon dioxide (Sc-CO2) foaming behavior of isotactic polypropylene (iPP), a highmelt strength polypropylene (HMSPP) was prepared using styrene (St) as grafting monomer. The effect of PVAc on the preparation, rheological, crystallization and foaming behaviors ofHMSPP was investigated. The high temperature gel permeation chromatography (HT-GPC) results showed that the PVAc had a promotive effect on melt grafting reaction. With the addition of PVAc, the weight-average molecular weight (M-w) of HMSPP increased from 217,158 to 240,733 g/mol. Thus, theHMSPP presented higher complex viscosity and storage modular, and lower loss angle, which indicated that the melt viscosity and melt strength of HMSPP was increased by adding PVAc. The crystallization behavior of HMSPP was investigated using differential scanning calorimetry (DSC). Double crystallization peaks were observed on the DSC cooling curves of HMSPP in the presence of PVAc, which was ascribed to incomplete molten of iPP with long chain branching (LCB) structure at low end melting temperature. Moreover, the prepared HMSPP exhibited better foaming behavior in the presence of PVAc. With the addition of PVAc, the average cell diameter of HMSPP decreased from 93 to 59 mu m, and the cell density increased from 2.83 x 10(7) to 9.79 x 10(7) cell/cm(3).