Biodegradation behavior of poly (glycolic acid) (PGA) and poly (butylene adipate-co-terephthalate) (PBAT) blend films in simulation marine environment

Polyglycolic acid (PGA) and poly (butylene adipate-co-terephthalate) (PBAT), as widely applied biodegradable polymers, the degradation behavior of their blends in marine environments has not been proven. This study investigated the changes of macroscopic and microscopic morphology, thermal properties, crystalline and chemical structure, degradation rate of PGA/PBAT blends with different ratios in the simulation marine environment containing sediments and marine organisms. The results showed that degradation primarily occurred due to ester bond breakage, and PGA exhibited a faster degradation rate than PBAT films. The amorphous region degraded more rapidly than the crystalline region, and the thermal stability of the materials decreased. The degradation of PGA and PBAT blends followed their respective single degradation laws and the compatibility of blend samples decreased after degradation. The degradation rate of the samples was obtained by measuring the biochemical oxygen demand, which indicated that a higher PGA content could result in a faster degradation rate for PGA/PBAT films. This study provides an efficient method for constructing materials with controlled biodegradability.