The role of TPS in promoting the disintegration of LDPE/TPS blends to unravel the degradation mechanism of plastic films.

This study explores the role of thermoplastic starch (TPS) in accelerating the degradation of low-density polyethylene (LDPE), a widely used single-use plastic that contributes significantly to environmental pollution. By blending TPS with LDPE, the research focuses on the abiotic degradation of these plastic films under simulated environmental conditions through photo-oxidation via accelerated weathering tests. Over a 10-week period-representing approximately nine months of natural exposure-the films were exposed to light, air, moisture, and heat. The degradation mechanisms were analyzed using Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC), while film disintegration was closely monitored. An additional 8-week seedling experiment assessed the impact of the degraded films on plant growth. Results indicated that LDPE/TPS blends began disintegrating after 6 weeks (approximately 5.4 months), achieving a 36 % degradation rate and reaching complete disintegration at 10 weeks. This surpassed the degradation performance of both standard biodegradable plastics and Oxo-PE. The primary degradation driver was water infiltration, which induced film swelling and contraction, leading to LDPE molecular chain breakdown. These findings provide critical insights into the disintegration mechanisms of LDPE/TPS blends and present a promising approach to accelerating plastic degradation, potentially reducing environmental plastic waste.