Introduction and Influence of Water in the Preparation of Crosslinked PVC Foam by Isocyanate  

作　　者：BI Xiang LI Minggang LU Min YOU Jiangan XUE Jian YU Haihui JIANG Zhiwei TANG Tao 

机构地区：[1]College of Chemical Engineering,Northeast Electric Power University,Jilin 132011,P.R.China [2]State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,P.R.China [3]College of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026,P.R.China

出　　处：《Chemical Research in Chinese Universities》2023年第5期782-789,共8页高等学校化学研究（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(No.52173050);the National Key Research and Development Program of China(No.2021YFB3702800).

摘　　要：In the preparation process of crosslinked polyvinyl chloride(c-PVC)foam by isocyanate,the formulated mixture is generally required to be carried out under the condition of isolated water,so as to avoid the mixing difficulties caused by the reaction between the introduced water and isocyanate.In this paper,NaHCO_(3) was added to the mixture to indirectly introduce water into the system,and the effects of NaHCO_(3) on the cell structure and curing time of c-PVC foam were investigated.The results showed that NaHCO_(3) not only played a role of foaming agent,but also was a good nucleating agent for cells.At the same time,the introduction of NaHCO_(3) held back the exudation of modified diphenylmethane-4,4'-diisocyanate(MDI)on the cell wall.The effects of NaHCO_(3) on the cell structure and aggregation structure of c-PVC foam were studied by thermogravimetric analysis,infrared spectroscopy and scanning electron microscopy.The results showed that decomposition of NaHCO_(3) occurred during the molding stage,which made small amount of MDI react with water to form polyurea,improved the compatibility of MDI with PVC and inhibited the exudation of MDI.

关 键 词：Crosslinked PVC foam ISOCYANATE Water CURING Sodium bicarbonate 

分 类 号：O6[理学—化学]