Regulation of Phase Separation in PP/EPR In-Reactor Alloy and Its Effect on Crystallization Kinetics

详细信息    查看全文

• 作者：Yi-Min Liu ; Zai-Zai Tong ; Jie Huang ; Bing Zhou ; Jun-Ting Xu ; Zhi-Sheng Fu ; Zhi-Qiang Fan
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：November 20, 2013
• 年：2013
• 卷：52
• 期：46
• 页码：16239-16246
• 全文大小：356K
• 年卷期：v.52,no.46(November 20, 2013)
• ISSN：1520-5045

文摘

The low molecular weight ethylene鈥損ropylene random copolymer (LEPR) in a polypropylene (PP)/EPR in-reactor alloy is replaced by high molecular weight EPR (HEPR). It is found that the phase separation rate of PP/HEPR alloy is much slower than that of PP/LEPR alloy. The effect of phase separation on the crystallization kinetics of PP/HEPR alloy is studied and compared with that of PP/LEPR alloy. The pre-phase-separated PP/HEPR alloy exhibits a faster spherulitic growth rate and overall crystallization rate, as compared with the directly quenched one. This is contrary to the PP/LEPR alloy and is interpreted in terms of the relative rate of crystallization and phase separation based on phase diagram. It is also observed that directly quenched PP/HEPR alloy has a larger long period after crystallization. This can be attributed to more inclusion of EPR-rich phase into inter-lamellae, which is advantageous to the mechanical properties.