Enzyme-Catalyzed Preparation of Aliphatic Polythioester by Direct Polycondensation of Diacid Diester and Dithiol

✍ Scribed by Makoto Kato; Kazunobu Toshima; Shuichi Matsumura

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 168 KB
• Volume: 27
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.200500836

✦ Synopsis

Abstract

Summary: Aliphatic dithiol‐diacid type polythioesters were first enzymatically prepared by the direct polycondensation of hexane‐1,6‐dithiol and diacid diesters using the immobilized lipase from Candida antarctica (lipase CA). As a typical example, diethyl sebacate and hexane‐1,6‐dithiol were polymerized using lipase CA in bulk in the presence of molecular sieves 4A to produce the corresponding polythioester with an $\overline M _{\rm w}$ of 10 200 in 90% yield. Both the melting and crystallization temperatures of the produced polythioesters were higher when compared to those of the corresponding polyoxyesters. A higher molecular weight polythioester was produced using lipase in a two‐step procedure, i.e., cyclization with subsequent ring‐opening polymerization.

Preparation of polythioester and melting temperature of various polythioesters and polyoxyesters.

magnified imagePreparation of polythioester and melting temperature of various polythioesters and polyoxyesters.