文献类型：期刊文献

英文题名：Application of a CO2 Pressure Swing Saturation Strategy in PP Semi-Solid-State Batch Foaming: Evaluation of Foamability by Experiments and Numerical Simulations

作者：Chen, Yichong[1];Xia, Chengzhi[1];Liu, Tao[1];Hu, Dongdong[1];Xu, Zhimei[1];Zhao, Ling[1,2]

机构：[1]East China Univ Sci & Technol, Shanghai Key Lab Multiphase Mat Chem Engn, Shanghai 200237, Peoples R China;[2]Xinjiang Univ, Coll Chem & Chem Engn, Urumqi 830046, Peoples R China

年份：2020

卷号：59

期号：11

起止页码：4924

外文期刊名：INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

收录：;EI(收录号：20201508386305);WOS:【SCI-EXPANDED(收录号:WOS:000526416200009)】；

基金：This work was supported by the National Key Research and Development Program of China (2016YFB0302200).

语种：英文

外文关键词：Differential scanning calorimetry - Expansion - Polypropylenes

摘要：Compared with extrusion foaming, semi-solid-state batch foaming with CO2 can produce foams with small bubble size and high expansion ratio using the polymers with regular melt strength as the raw material. However, due to the presence of crystal regions, semi-solid-state batch foaming of polypropylene (PP) is a challenge. In situ melting and rheological behaviors of PP were measured using high-pressure differential scanning calorimetry and high-pressure rheometer, respectively. Through the CO2 pressure swing saturation strategy, the PP matrix can dissolve more CO2 in a shorter time, thereby effectively widening the foaming temperature range, increasing the expansion ratio, and shortening the saturation time. The Gotsis' model was used to correlate the high-pressure rheological data to obtain the characteristic relaxation time and rigid modulus of PP, and then, the bubble growth stability during the foaming process was simulated. According to the Considere criterion, unstable growth factors were introduced to judge the quality of the foaming results. It was found that when the unstable growth factor was higher than 0.3, the bubbles began to collapse and rupture.