成核剂CaCO_3对聚丙烯开孔发泡性能影响的研究

Study on the Effect of CaCO_3 on Open-cell Foaming Performance of Polypropylene

将高熔体强度聚丙烯(HMSPP)、线型低密度聚乙烯(LLDPE)、成核剂CaCO3共混后在自制超临界CO2动态发泡模拟机上发泡制备了聚丙烯开孔泡沫材料,研究了CaCO3的粒径和含量对聚丙烯开孔发泡性能的影响。结果表明:2 500目CaCO3在HMSPP/LLDPE共混体系中的分散效果比5 000目CaCO3的好。添加2 500目和5 000目CaCO3后,发泡样品的发泡倍率减小,泡孔密度增大,泡孔直径减小,泡孔形貌变得规则,泡孔直径分布变窄,泡孔均匀性增加。添加3%的2 500目和5 000目CaCO3时发泡性能最好。在共混体系中添加成核剂CaCO3能够提高发泡样品的开孔性能。

PP open-cell foam was prepared from the blends of high melt-strength polypropylene （HMSPP）, linear low-density polyethylene （LLDPE） and nucleating agent CaCO3 on a self-designed dynamic foaming simulation device. The effect of particle size and content of CaCO 3 on PP open-cell foaming performance was investigated. The results showed that 2 500 mesh CaCO3 diffused better than 5 000 mesh CaCO3 in HMSPP/LLDPE blends. As CaCO3 was added, the expansion ratio decreased, cell density increased,＇ cell diameter decreased, cell shape became regular, distribution of cell diameter became narrow, cell became more uniform. The foaming performance of HMSPP/LLDPE blends with 3% 2 500 mesh or 5 000 mesh CaCO3 was best. As CaCO3 was added, open-cell performance increased.