B

Lipase

Polycondensation of dicarboxylic acids or their derivatives with glycols

X02CRC0,X + H0R'0H

Lipase

-XOH

X: H, alkyl, halogenated alkyl, vinyl, etc. Polycondensation of oxyacids or their esters

H0RC02X

Lipase

-XOH

O II

-hORC-h

X: H, alkyl, halogenated alkyl, vinyl, etc.

Scheme 1

n n reaction by hydrolysis, have been employed as catalyst for the reverse reaction of hydrolysis, leading to polymer production by a bond-forming reaction.

Lipase is an enzyme which catalyzes the hydrolysis of fatty acid esters normally in an aqueous environment in living systems. However, lipases are sometimes stable in organic solvents and can be used as catalyst for esterifications and transesterifications. By utilizing such catalytic specificities of lipase, functional aliphatic polyesters have been synthesized by various polymerization modes. Typical reaction types of lipase-catalyzed polymerization leading to polyesters are summarized in Scheme 1. Lipase-catalyzed polymerizations also produced polycarbonates and polyphosphates.

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