Insights into the accelerated aging of sustainable biocomposites based on Mater-Bi and grape pomace

In the context of sustainable materials for outdoor applications, the use of bio-based and biodegradable composites reinforced with agro-industrial waste represents a promising strategy. However, exposure to sunlight and oxygen can lead to photo-oxidation, potentially compromising both performance and biodegradability. In this study, Mater-Bi (MB) was compounded with 10 and 20 wt% grape pomace (GP), a by-product rich in polyphenols, and the resulting biocomposites were subjected to accelerated aging. The impact of photo-oxidation was evaluated through rheological, thermal, and mechanical analyses, alongside biodegradation tests in soil. The results revealed that while neat MB undergoes significant degradation upon aging, the GP-filled composites exhibited better resistance to photo-oxidative damage. Importantly, the biodegradation behaviour of the aged samples was also investigated, highlighting how prior oxidative degradation influences the subsequent disintegration of the material in a natural environment. The findings underscore the importance of assessing the end-of-life performance of biocomposites after environmental weathering, to ensure their sustainability under real-life outdoor conditions.