Polyester and polycarbonate synthesis by in vitro enzyme catalysis

Abstract

Enzyme technology has significantly expanded in scope and impact over the past 10 years to include organic transformations in non-traditional environments. This is in part due to an increased understanding and capability of using enzyme catalysis in a wide variety of organic solvents, at interfaces, and at high temperatures and pressures. This review focuses on a relatively new but rapidly expanding research activity where in vitro enzyme catalysis is used for the synthesis of non-natural polyesters and polycarbonates. The inclination to use of enzymes for polymer synthesis has been fueled by a desire to carry out these reactions in the absence of heavy metals, at lower temperatures, and with increased selectivity. Aspects of this work that include enzyme-catalyzed step-growth condensation reactions, chain-growth ring-opening polymerizations, and corresponding transesterification of macromolecular substrates are discussed.

Enzymatic Synthesis of Polyesters via Ring-Opening Polymerization

“…More recently, the enzyme-catalyzed synthesis of polycarbonates has been reported in which no undesirable decarboxylation occurred. There are two routes to the synthesis of polycarbonates, i.e., by ring-opening polymerization of a cyclic carbonate diester and polycondensation of a carbonate and diol [126][127][128][129][130][131].…”

Polycondensation of Sebacic Acid with Primary and Secondary Hydroxyl Groups Containing Diols Catalyzed by Candida antarctica Lipase B

“…Biotransformation, where enzymes are used as catalysts, was recognized as an alternative to the conventional chemical routes to aliphatic polyesters, and lipasecatalyzed polymerization has recently been investigated because it has mild reaction conditions, does not use potentially harmful metal catalysts, and does not need protection-deprotection steps. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] In the lipase-catalyzed polycondensation of the diol=diacid systems, the recent research has focused on the polycondensation between unactivated free diacids and primary hydroxyl-containing diols. [22][23][24][25][26][27][28][29][30][31] For the diols containing both primary and secondary hydroxyl groups, the lipasecatalyzed esterification was reported to occur preferentially at the primary hydroxyl groups with the exception of glycerol.…”

Applications of Enzymes in Synthesis and Modification of Polymers

“…Além disso, a catálise enzimática ocorre em geral de forma bastante eficiente sob condições mais brandas de temperatura e pressão, 4 demanda reduzida (ou nenhuma) quantidade de solventes orgânicos, 5 não proporciona a formação de produtos secundários e os produtos finais são de fácil separação e recuperação. [6][7][8] Tais vantagens ficam claras especialmente quando são empregados biocatalisadores na forma imobilizada, a qual é uma técnica amplamente reportada pela literatura. 9,10 A biocatálise foi reconhecida na década de 1990 como uma área nova na síntese de polímeros de precisão.…”