Critical Effects of Polyethylene Addition on the Autoclave Foaming Behavior of Polypropylene and the Melting Behavior of Polypropylene Foams Blown with n-Pentane and CO2
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- 作者：Xiaoqin Lan ; Wentao Zhai ; Wenge Zheng
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2013
- 出版时间：April 24, 2013
- 年：2013
- 卷：52
- 期：16
- 页码：5655-5665
- 全文大小：862K
- 年卷期：v.52,no.16(April 24, 2013)
- ISSN：1520-5045
文摘
Polypropylene (PP) bead foams were prepared by autoclave foaming using n-pentane and CO2 as the blowing agents. PP foams blown with n-pentane had foaming temperatures of 92鈥?6 掳C, expansion ratios of 10鈥?0 times, and a signal Tm at 150.1 掳C, while PP foams blown with CO2 had foaming temperatures of 151鈥?53 掳C, expansion ratios of 8鈥?0 times, and dual melting peaks at 164.0 and 140.9 掳C. Polyethylene (PE) addition was used to improve the foaming behavior of PP and to induce the formation of dual and multiple Tm in PP/PE foams. A differential scanning calorimetry procedure was carried out to simulate the steam-chest molding of bead foams. Interbead bonding was found to be determined by the heat of fusion of Tmc (crystal melting of the newly formed crystals during fast cooling), 螖Hmc. Recrystallization of the PE component contributed to the increase of 螖Hmc, which potentially improved interbead bonding of the molded PP/PE bead foams.