Preparation of diol-dicarboxylate type polyesters by the enzyme-catalyzed polymerization and some properties

High-molecular weight polyesters were prepared via the ring-opening polymerization of cyclic oligomers which were produced by the condensation of diols and dicarboxylates by lipase in a diluted toluene solution. Thus, dimethyl fumarate, maleate and succinate with 1,6-hexanediol and 1,4-butanediol were reacted forming cyclic oligomers in diluted toluene solution by Candida antarctica lipase. The cyclic oligomer was readily polymerized by the same lipase in more concentrated solution to produce a high-molecular weight polyester. On the other hand, molecular weights of polyesters produced via the direct polycondensation of diols and dicarboxylates decreased considerably when compared to those produced by the ring-opening polymerization of cyclic oligomers.