PEG-Coating as a Promotional Tool for Improving Biodegradability and Preserving Mechanical Properties of Enzyme-Embedded Polyesters

Enzyme embedding, which enhances polymer degradation by embedding enzymes directly into the material matrix, has recently gained significant attention. This study explored the development of high-performance biodegradable plastics by embedding enzyme Humicola insolens cutinase (HiC) coated with polyethylene glycol (PEG) of 400-20,000 g/mol. Thermal stability tests showed that PEG coating did not reduce enzyme activity during processing at temperatures up to 150 °C. In poly(butylene succinate) (PBS) films, embedding PEG-coated HiC, particularly 5000 g/mol, significantly enhanced degradation rates and preserved mechanical properties, with the optimal weight ratio of HiC to PEG being 10:1. SEM analysis revealed uniform enzyme dispersion as key factors in film performance. PEG-coated enzymes were also effective in poly(ethylene succinate) (PES) films. Biochemical oxygen demand (BOD) biodegradation tests confirmed the environmental compatibility of PEG. This study indicates the potential of PEG-coated enzymes to make enzyme-embedded biodegradable plastics enhance degradability and mechanical performance, with keeping environmental compatibility.