首页 | 本学科首页   官方微博 | 高级检索  
     检索      


High-molecular-weight copolyesters of dihydroxybenzophenones by ‘induced‘ copolyesterification using TsCl/DMF/Py as a condensing agent
Authors:Fukuji Higashi  Chen-Han Ong  Yoshiharu Okada
Abstract:Dihydroxybenzophenones and 4,4′-dihydroxydiphenylsulfone, which yield high-molecular-weight polyesters only difficultly by conventional methods, gave high-molecular-weight copolyesters through a two-stage copolycondensation involving initial induction of oligomerization with selected monomers followed by copolycondensation. The copolycondensation was studied by examining such factors as the kinds of initial monomers, their amounts, initial reaction times, and the order of reaction, and the results are explained in terms of oligomer distribution in the initial oligomerization as determined by GPC. Copolycondensation was also facilitated by lowering the temperature at the second stage of reaction. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3625–3631, 1999
Keywords:initial oligomerization  initial monomers  oligomer distribution  copolycondensation
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号