文献类型：期刊文献

英文题名：Foaming window for preparation of microcellular rigid polyurethanes using supercritical carbon dioxide as blowing agent

作者：Yang, Ze[1];Liu, Tao[1];Hu, Dongdong[1];Xu, Zhimei[1];Zhao, Ling[1,2]

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

年份：2019

卷号：147

起止页码：254

外文期刊名：JOURNAL OF SUPERCRITICAL FLUIDS

收录：;EI(收录号：20184706111654);WOS:【SCI-EXPANDED(收录号:WOS:000462690700028)】；

基金：The authors are grateful to the National Key Research and Development Program of China (2016YFB0302202) and National Science Foundation of China (21676092).

语种：英文

外文关键词：Microcellular rigid polyurethane; Supercritical carbon dioxide; In-situ viscosity measurement; Time foaming window; Viscosity foaming window

摘要：Rigid polyurethane (PU) microcellular foams with high expansion ratio and uniform cell morphology can be prepared directly using supercritical carbon dioxide (CO2) as blowing agent. The in-situ viscosity measurements during PU polymerization in high-pressure CO2 were adopted to investigate the melt strength change as well as the PU foaming windows. It was found that a certain viscosity window existed for available foaming, which changed little with the foaming temperature or CO2 pressure, but the required reaction time to reach this viscosity foaming windows changed a lot because the existence of CO2 significantly delayed the viscosity rising. Furthermore, the viscosity foaming windows varied with different PU formula systems, e.g., about (300-400) Pa.s for C-1/PAPI-135C system which could be foamed with cell size smaller than 10 mu m, and about (245-400) Pa.s for R090/PM200 system which was foamed with bigger cell size of (20-40) mu m.