Degradation performances of CL-modified PBSCL copolyesters in different environments

Abstract

In order to improve the poor degradability of polybutylene succinate (PBS) in marine environment, a series of copolyesters called poly(butylene succinate-co-ε-caprolactone)s (PBSCLs) were synthesized by one-pot melt polycondensation technique. Such copolyesters had excellent mechanical properties, with tensile strengths from 26.4 MPa to 47.6 MPa and elongation at break around 450%. In addition, the introduction of CL segment decreased the crystallinity and increased the hydrophilicity. Furthermore, four different degradation environments were settled to investigate the enzymatic hydrolysis, compost degradation, non-enzymatic hydrolysis, and natural seawater degradation performances of PBSCL copolyesters. The biodegradation and hydrolysis performances of the copolyesters were significantly different compared with PBS. Faster degradation of the copolyesters was detected not only in buffer solution with CALB and compost, but also in buffer solution and natural seawater. Besides, different degradation mechanisms, namely bulk erosion and surface erosion, coexisted during non-enzymatic hydrolysis and natural seawater degradation process. The higher CL content, the more the degradation mechanism of the copolyester was inclined to the latter.