ENZYMATIC-SYNTHESIS OF ALKYDS

Lipases were used as catalysts in the synthesis of “all‐trans” polyester oligomers in organic solvents. Esters of fumaric acid and 1,4‐butane diol served as the substrates in the enzyme‐catalyzed polytransesterification. No isomerization of the double bond was found under the mild conditions of enzymatic catalysis used by us, as opposed to the extensive isomerization found during chemical polycondensation. The alkoxy leaving group of the ester fumarate was found to be responsible for the rate of transesterification. Low (Mw ≃ 600–800) and high (Mw = 1250) molecular weight alkyds were synthesized depending on whether tetrahedrofuran or acetonitrile, respectively, was used as the solvent. Copyright © 1990 John Wiley & Sons, Inc.