Accelerated Weathering and Compostability of Biodegradable Polymers With and Without Agave Fibers

ABSTRACT The increased susceptibility of biodegradable polymers to degradation can be a drawback in certain applications, limiting their usage. Weathering exposure significantly impacts the properties of biopolymers and alters their compostability. This study analyzed the effects of accelerated weathering (up to 768 h) on the physical, thermal, rheological, and mechanical properties of poly(lactic acid) (PLA), MaterBi (MB), and poly(hydroxybutyrate‐ co ‐valerate) (PHBV), as well as their biocomposites with agave fibers (30 wt.%). Additionally, biodegradation under composting conditions was assessed. Physical characterization revealed notable color changes: PLA became whiter, while MB and PHBV showed increased lightness. The biocomposites also demonstrated increased porosity. The melt flow index (MFI) of PLA and MB significantly increased, indicating polymer chain scission, whereas PHBV remained more stable. Thermal analysis revealed reductions in both crystallization and melting temperatures, especially for PLA. Mechanical tests revealed a decrease in tensile, flexural, and impact strengths for PLA and MB over time. The biocomposites showed improved mechanical properties in the short term but followed a similar degradation pattern as the neat biopolymers. Ultimately, prior weathering exposure accelerated the disintegration of the materials during composting, emphasizing a key interaction between abiotic and biotic degradation processes.