Comparative study of the aging degradation behaviors of PET under artificially accelerated and typical marine environment.

• DNA sequencing of marine organisms can be applied in marine plastic identification. • Light and humid rather than salts degraded marine PET most. • Salts penetrate into marine PET and cannot be totally removed by cleaning. The aging degradation behaviors of the most common PET plastics in the marine environment were investigated in different conditions, with the combination of "real-world sample/outdoor simulation/aging box accelerated simulation". By obtaining data on the morphology, biological and microbial distribution, mechanical properties, viscosity, color difference, thermal properties, and chemical composition of marine plastics after aging, the influence of typical environmental factors such as light, temperature, high pressure, salinity, moisture, and marine life on the aging degradation behavior of PET plastics were discussed. Among them, light, high pressure heat and humid environment have the most significant effects on degradation, while the high-salt environment has less effect on degradation. In addition, the Pressure Cooker Test (PCT) results showed that the ordinary cleaning process is not enough to remove the inorganic substances that penetrated into the interior of marine plastics, which will have a negative impact on the performance of marine plastics. Therefore, it is necessary to select appropriate recycling methods and processes. This study provides a new idea for the study of the aging degradation behavior of marine plastics, which is important for analyzing the environmental factors affecting the degradation behavior of marine plastics in the marine environment. [ABSTRACT FROM AUTHOR]