Comparison of “all trans” enzymatically prepared unsaturated polyesters with chemically synthesized and industrial polyesters

The synthesis of unsaturated polyesters (UP) by high‐temperature polycondensation is accompanied by isomerization of the double bond from the cis to the trans configuration. The presence of the trans double bonds facilitates crosslinking and may have an important influence on rheological and mechanical properties of the UP and the cured end product. All‐trans polyesters are not available on the market. A study of “all‐trans” low‐temperature polycondensation based on chemical and enzymatic lipase catalysis was recently reported. This paper presents the characteristics of lipase‐synthesized UP vs. general‐purpose UP, as obtained by X‐ray, differential scanning calorimetry (DSC), and other methods. In contrast to the commercial amorphous UP, crystallinity was found in the “alltrans” enzymatically and chemically synthesized UP. The crystallinity of the enzymatically and chemically synthesized UP. The crystallinity of the enzymatically synthesized UP was confirmed by higher values of elasticity. DSC analyses complemented the results obtained by other methodologies.