High-molecular-weight copolyesters of dihydroxybenzophenones by ‘induced‘ copolyesterification using TsCl/DMF/Py as a condensing agent

✍ Scribed by Fukuji Higashi; Chen-Han Ong; Yoshiharu Okada

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 133 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990915)37:18<3625::aid-pola10>3.0.co;2-v

✦ Synopsis

Dihydroxybenzophenones and 4,4Ј-dihydroxydiphenylsulfone, which yield high-molecular-weight polyesters only difficultly by conventional methods, gave highmolecular-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.