文献类型：期刊文献

英文题名：Strategy for preparation of microcellular rigid polyurethane foams with uniform fine cells and high expansion ratio using supercritical CO2 as blowing agent

作者：Yang, Ze[1];Hu, Dongdong[1];Liu, Tao[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：153

外文期刊名：JOURNAL OF SUPERCRITICAL FLUIDS

收录：;EI(收录号：20193607391282);WOS:【SCI-EXPANDED(收录号:WOS:000491683700014)】；

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

语种：英文

外文关键词：Microcellular rigid polyurethane; Supercritical carbon dioxide; Rapid depressurization foaming process; Two-Step pressurization process; Cell morphology

摘要：In order to avoid a bi-modal cell distribution in rapid depressurization foaming processes of rigid polyurethane (PU) using supercritical CO2 as blowing agent, a new strategy called two-step pressurization process was developed with lower CO2 saturation pressure and higher curing pressure. Both lower saturation pressure and shorter saturation time not only reduced CO2 entrainment but also led to less dissolved CO2, suppressing the continuous happening of cell nucleation induced by curing reaction. Higher curing pressure and faster depressurization rate would be beneficial for higher cell density and smaller cell size. For polyol C-1 /PAPI-135C system, under the optimum CO2 saturation pressure of 8 MPa, 1 h saturation time followed with curing pressure of 15 MPa to 20 MPa and depressurization rate over 400 MPa/s, rigid PU foams could achieve expansion ratio of 9-10, average cell size of 2 mu m-3 mu m and cell density of 3 x 10(11)/cm(3) to 5 x 10(11)/cm(3). (C) 2019 Elsevier B.V. All rights reserved.