Investigating the Oxidation of Bioplastics and Their Blends via Hydrothermal Fenton Reaction

초록

Biodegradable plastics (BPs) have been used to replace conventional plastics due to their environmental friendliness and ease of degradation. However, their rapid aging in the environment transforms them into micro and nano plastics quickly, creating a more hazardous situation. In this study, a hybrid method was developed for the effective oxidation of four bioplastics: Polylactic Acid (PLA), Polybutylene Adipate Terephthalate (PBAT), Polyhydroxyalkanoate (PHA), and Polybutylene Succinate (PBS) using the Hydrothermal Fenton Reaction (HFR). The study also examined combinations of bio-based and fossil-based plastics (PLA+PBAT; PHA+PBS) in different ratios. The effects of time (2?16 h), temperature (40?160 °C), H2O2 dose (50?500 mM), Fe+2 dose (100?2000 mg/L), and MPs dose (0.25?2.5 mg/L) on oxidation efficiency were investigated. Under optimal conditions, PLA, PBAT, PHA, and PBS exhibited weight losses of 72.58%, 59.01%, 76.55%, and 72.57%, respectively. SEM analysis revealed that the surface was altered after the reaction, creating cavities (Fig. 1). FTIR analysis confirmed oxidation in the bioplastics by the emergence of the C=O (carbonyl) group post-reaction. The oxygen atomic percentage changed from 34.9% to 37.9% for PLA, 28.5% to 26.9% for PBAT, 28.6% to 28.4% for PHA, and 30.7% to 68.9% for PBS. We anticipate that the results of this research will provide insights into the oxidation behavior of BPs and their mixtures.