The Biorefinery Research and Engineering Center of the Ministry of Education, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, PR China.
Carbohydr Polym. 2013 Jan 30;92(1):633-40. doi: 10.1016/j.carbpol.2012.09.064. Epub 2012 Oct 2.
Diesters and diols were successfully converted into aliphatic polyesters by enzymatic lipase Candida sp.99-125 catalysis, with β-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. β-Cyclodextrin encircled the linear polymer chain and maintained the chain in a proper configuration to avoid its coagulation. Lipase initiated the polymerization and β-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 °C. The corresponding polyesters showed an excellent thermal stability till 350 °C and had a strong ability to crystallize with up to 72% crystallinity, contributing to their high storage modulus.
脂肪族聚酯可通过脂肪酶 Candida sp.99-125 催化酯交换反应和二醇反应合成，β-环糊精作为支持结构（类似于伴侣蛋白）。该过程不使用有机溶剂。聚脂交换反应是一种更环保的过程，因为它是无溶剂的，并且没有金属残留。脂肪酶 Candida sp.99-125 对不同链长的脂肪族二酯和二醇的均聚反应具有很高的催化活性。β-环糊精包围线性聚合物链，并保持链的适当构象以避免其聚集。脂肪酶引发聚合反应，β-环糊精穿入聚合物链以控制结构，从而生产出高分子量的聚酯。从二酯和二醇的组合中，在 70°C 下获得了分子量为 62100Da 的高分子量聚酯。相应的聚酯在 350°C 下表现出优异的热稳定性，结晶度高达 72%，具有很强的结晶能力，这有助于其具有较高的储能模量。
