Influence of monomer composition of poly(butylene succinate-co-hexamethylene succinate)s on their enzymatic hydrolysis by Fusarium solani cutinase

Poly(butylene succinate) (PBS), poly(hexamethylene succinate) (PHS) and three kinds of poly(butylene succinate-co-hexamethylene succinate)s (P(BS-co-HS)s) were enzymatically hydrolyzed by Fusarium solani cutinase. The results showed that the characteristics of the enzymatic hydrolysis of these polyesters were mainly affected by crystallinity, thermal properties and the BS/HS ratio. The enzymatic hydrolysis rates of the polyesters are as follows: P(BS-co-HS52) approximate to P(BS-co-HS71) > PHS > P(BS-co-HS32) > PBS. Furthermore, with increasing HS content, both the degree of crystallinity (X-c) and melting temperature (T-m) of the polyesters first decreased and then increased. P(BS-co-HS52) and P(BS-co-HS71) had the lowest X-c and the lowest T-m, thus had the highest hydrolysis rate; this shows that the hydrolysis rate is affected by X-c and T-m. The results also showed that BS/HS ratio could affect the physical properties and degradability of polyesters. Thus, it is possible to prepare polyesters with various physical properties and degradability for different applications by adjusting BS/HS ratio. The crystalline and amorphous regions of the polyesters were both hydrolyzed, during which parts of the crystalline regions were converted into the amorphous regions. Finally, we found that the crystal structure and thermal stability of the polyesters were not affected by the enzymatic hydrolysis.

Automated summary

This study found that the enzymatic hydrolysis of poly(butylene succinate) (PBS), poly(hexamethylene succinate) (PHS), and poly(butylene succinate-co-hexamethylene succinate) (P(BS-co-HS)) copolymers is influenced by their crystallinity, thermal properties, and the ratio of BS to HS. By adjusting the BS/HS ratio, it is possible to prepare polyesters with different physical properties and degradability for various applications. During enzymatic hydrolysis, both the crystalline and amorphous regions of the polyesters are hydrolyzed, with some of the crystalline regions converting into amorphous regions. Notably, the enzymatic hydrolysis does not affect the crystal structure and thermal stability of the polyesters.