Poly(butylene succinate-<i>co</i>-adipate)/Croatina Grape Skin Biocomposites with Antioxidant Properties and Enhanced Biodegradation Rate

The development of biobased composites with enhanced properties represents a timely research approach toward the obtainment of functional and sustainable materials for different end-use applications as an alternative to conventional non-renewable resources. Here, biocomposites based on the embedding of Croatina grape skins, rich in antioxidants, in poly(butylene succinate-co-adipate) are presented. Croatina grape skins were treated with a solvent-free, eco-friendly, mechanochemical process in order to obtain particles with reduced sizes, thus improving their homogeneous dispersibility in the polymeric matrix. The biomass was then sieved in different fractions according to their size and characterized in terms of chemical composition and morphology. The skins were added to the melt-mixed polymer matrix with varying filler sizes and amounts. The realized composites were characterized by examining their morphological, mechanical, barrier and antioxidant properties. Finally, the biodegradability of the biocomposites was assessed through soil burial degradation tests. Results demonstrate that the composites show remarkable antioxidant activity combined with an improved biodegradation rate. Interestingly, the processing of the biomasses and the composites completely avoided complex extraction procedures and the use of organic solvents, thus highlighting the environmental sustainability of this approach.