Lipase-catalyzed synthesis and characterization of polymers by cyclodextrin as support architecture

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• 作者：Wenhui Liu ; Fang Wang ; ^{wangfang@mail.buct.edu.cn} ; Tianwei Tan ; ^{twtan@mail.buct.edu.cn} ; Biqiang Chen
• 关键词：Aliphatic polyesters ; Lipase Candida sp.99-125 ; ¦Â-Cyclodextrin ; Supporting architecture ; Bulkpolymerization
• 刊名：Carbohydrate Polymers
• 出版年：2013
• 出版时间：30 January, 2013
• 年：2013
• 卷：92
• 期：1
• 页码：633-640
• 全文大小：1065 K

文摘

Diesters and diols were successfully converted into aliphatic polyesters by enzymatic lipase Candida sp.99-125 catalysis, with ¦Â-cyclodextrin acting as supporting architecture (in a similar way as chaperone proteins). No organic solvents were used. The polytransesterification was a much greener process, being solvent-free and without metal residues. Lipase Candida sp.99-125 showed a high catalytic activity for bulkpolymerization of diesters and diols with various numbers of methylene groups in their chains. ¦Â-Cyclodextrin encircled the linear polymer chain and maintained the chain in a proper configuration to avoid its coagulation. Lipase initiated the polymerization and ¦Â-cyclodextrin threaded onto the polymer chain to control the structure for producing high molecular weight polyesters. From a combination of diesters and diols, polyesters with a high molecular weight of 62,100 Da were obtained at 70 ¡ãC. The corresponding polyesters showed an excellent thermal stability till 350 ¡ãC and had a strong ability to crystallize with up to 72 % crystallinity, contributing to their high storage modulus.