Kinetic studies of biocatalyzed copolyesters of poly(butylene succinate) (PBS) containing fully bio-based dilinoleic diol

• Published in: European polymer journal 2019-07, Vol.116, p.515-525
• Main Authors: Sonseca, Agueda, McClain, Andrew, Puskas, Judit E., El Fray, Miroslawa
• Format: Article
• Language: English
• Subjects: Catalysis; Chemical synthesis; Condensation; Crystallization; Degree of crystallinity; Enzymatic catalysis; Enzymes; Hydrophobicity; NMR; Nuclear magnetic resonance; Polycondensation; Polyesters; Segments; Sequences
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2019.04.038

[Display omitted] •Enzyme catalyzed PBS copolyesters were synthesized in solution.•Kinetic studies revealed formation of segmented copolymers with random to ordered segments distribution.•MALDI-ToF evidenced presence of cyclic structures.•Thermal properties strongly depend on the degree of randomness, sequence length and hard to soft segments ratio. A series of segmented bio-copolyesters based on crystallizable hard segments of poly(butylene succinate) (PBS) and fully bio-based dilinoleic diol (DLAOH), creating dilinoleic succinate (DLS) soft segments, were prepared by enzymatically catalyzed polycondensation. The kinetic studies performed with 1H NMR and SEC have proved incorporation of highly hydrophobic DLAOH into the polymer backbone. We found that the efficacy of DLAOH incorporation was limited by the catalytic pocket size of the enzyme and its hydrophobic nature favouring the formation of long PBS sequences, especially at the early synthesis stages and having an effect on final content of soft segments compared to feed ratio. Based on quantitative 13C NMR analysis we found that copolymers had R-values lower than 1, that is low degree of randomness. Differential scanning calorimetry (DSC) revealed changes in degree of crystallinity and the presence of a phase mixed system.