Microcellular foaming and mechanical properties of iPP-iPPF using supercritical CO2

作者:Zuo, Kailong; Li, Kun; Yun, Zhigeng; He, Guangjian; Islam, Syed Rashedul; Yang, Yang*; Zhang, Xiaoli*; Chen, Jingbo
来源:Journal of Supercritical Fluids, 2022, 190: 105754.
DOI:10.1016/j.supflu.2022.105754

摘要

Isotactic polypropylene (iPP) is one of the most widely used commercial polymers in the industry. However, it is difficult to foam iPP due to its low melt strength. In this work, the foamability and mechanical properties of iPP were investigated by incorporating isotactic polypropylene fiber (iPPF), using a batch foaming method. Compared to the neat iPP foams, smaller cell size and more uniform cell size distribution were obtained for iPP-iPPF. When 30 % iPPF was added, the cell density of iPP-iPPF foam was 1.1 x 1010 cells/cm3 which was twice that of the neat iPP foam. It was attributed to the improved melt strength and heterogeneous nucleation of iPPF in the iPP matrix. In addition, the impact strength of foamed iPP-30iPPF was found to be increased by 136 % compared to its neat iPP counterpart. Furthermore, the tensile strength of the foamed samples also increased with the increasing iPPF content.