Enzymatic syntheses of alkyds. II: Lipase‐catalyzed polytransesterification of dichloroethyl fumarate with aliphatic and aromatic diols

Abstract

'fC\ll-trans" alkyds (unsaturated polyesters) were prepared by lipase-catalyzed polytransesterifications of diesters of fumaric acid and 1,4-butane diol. Industrially prepared alkyds, however, contain aromaticity in their backbone, which is introduced by phthalic acid derivatives and/or isomers. Thus, in this study, the specificity of lipases toward aromatic esters, diesters, and diols was investigated in order to find a means of introducing aromaticity in the lipase-catalyzed synthesis of "all-trans" alkyds. It was found that lipases from Pseudomonas and Mucor efficiently catalyzed the polytransesterification of dichloroethyl fumarate with aromatic diols such as benzene dimethanol. Crystallinity was found in the "alltrans" alkyds synthesized in acetonitrile. In order to determine whether this property was due to the nature of diol or the frequency of the double bond in the backbone of the polyester, other alkyds were prepared in which the length of the diol was changed as well as the number of carbons (odd or even) in the diol and the chemical nature of the diol (primary or secondary). In all cases crystallinity was found. It thus seems that the stereochemistry of the double bond is responsible for this property. Molecular weights, which were determined by gel permeation chromatography (GPC) analyses, were comparable with those of the industrially prepared alkyds.

Bacterial lipases

“…No isomerization of the double bond was observed under the mild conditions of the lipase-catalyzed reaction, in contrast to the extensive isomerization found during chemical polycondensation [208,209]. No isomerization of the double bond was observed under the mild conditions of the lipase-catalyzed reaction, in contrast to the extensive isomerization found during chemical polycondensation [208,209].…”

Enzyme-Catalyzed Synthesis and Chemical Recycling of Polyesters

“…The molecular weights of the resulting polyesters were M -w = 600-2 200. [45] Regioselective polymerization may be one of the characteristic features of the enzyme-catalyzed polymerization. The polycondensation of sucrose and adipic acid derivatives by an alkaline protease from a Bacillus sp.…”

Enantioselective enzymatic acetylation of racemic [4-[4?,6? (E)]]-6-[4,4-bis(4-fluorophenyl)-3-(1-methyl-1H-tetrazol-5-yl)-1,3-butadienyl]-tetrahydro-4-hydroxy-2H-pyran-2-one

“…The reaction was conducted at 37°C and 150 rpm. Substrate and product concentrations were determined by GC assay and optical purity was determined by chiral HPLC wicz and Keese 1989 ;Klibanov 1986;Dordick 1989;Khmelnitsky et al 1988;Engel et al 1991;Geresh and Gilboa 1991;Hirata et al 1990;Kirchner et al 1985;Macrae 1983; Y a m a d a and Shimizu 1988). Lipases are commercially used in interesterification reactions in the oil and fat industry to modify the composition and physical properties o f triglycerides (Matsuo et al 1981).…”