Accelerated Thermo‐Oxidative Aging and Shelf‐Life Prediction of PBAT / PGA / CaCO 3 Biodegradable Plastic Bags Based on Arrhenius Model

With the great demand for plastic bags and the focus on microplastic pollution, biodegradable composites have become an excellent alternative approach. This study aimed to investigate the degradation behavior and predict shelf‐life of poly (butylene adipate‐co‐terephthalate) (PBAT)/Poly (glycolic acid) (PGA)/mineral powder (MD) plastic bags using thermo‐oxidative accelerated aging tests combined with the Arrhenius model. First, the effects of CaCO 3 content (5–15 wt%) on film‐blowing processability, surface microstructure, chemical structure, thermal properties, and key mechanical performance (tensile strength, elongation at break, tear strength) were systematically characterized. Results showed that an appropriate amount of CaCO 3 (≤ 10 wt%) acted as nucleating agents to promote polymer crystallization and neutralize acidic by‐products from hydrolysis, thereby extending the shelf‐life. However, an increased CaCO 3 content (15 wt%) caused agglomeration, weakened interfacial compatibility, and accelerated mechanical degradation. FTIR analysis confirmed that ester group hydrolysis was the primary aging mechanism. Based on the Arrhenius model, all formulations retained 50% of their original mechanical properties for over 2 years at 25°C, with the PBAT/PGA/10MD composite exhibiting the longest shelf‐life (> 3.4 years), which would be sufficient to meet the practical application requirements. This work provides a theoretical basis and technical support for the commercialization of biodegradable plastic bags.