Polyesters by lipase-catalyzed polycondensation of unsaturated and epoxidized long-chain alpha,omega-dicarboxylic acid methyl esters with diols

Long-chain, symmetrically unsaturated alpha,omega -dicarboxylic acid methyl esters (C-18, C-20, C-26) were obtained by the catalytic metathetical cond ensation of 9-decenoic, 10-undecenoic, and 13-tetradecenoic acid methyl est ers, respectively, with the homogeneous Grubbs catalyst bis(tricyclohexyl p hosphine) benzylidene ruthenium dichloride dissolved in methylene chloride. The dicarboxylic acid esters were epoxidized chemoenzymatically with H2O2/ methyl acetate with Novozym 435 (R), an immobilized lipase B from Candida a ntarctica. Polyesters from symmetrically unsaturated or epoxidized alpha,om ega -dicarboxylic acid methyl esters with 1,3-propanediol or 1,4-butanediol , respectively, were achieved by enzymatic polycondensation with the same b iocatalyst applied. With 1,3-propanediol as a substrate, the linear unsatur ated and epoxidized polyesters had molecular weights of 1950-3300 g/mol and melting points of 47-75 degreesC, whereas with 1,4-butanediol as a substra te, the resulting polyesters showed higher molecular weights, 7900-11,600 g /mol, with similar melting points of 55-74 degreesC. (C) 2001 John Wiley & Sons, Inc.