BIODEGRADABLE POLYMER-BASED COMPOSITES FILLED WITH BIOCHAR FOR TUNABLE RELEASE OF CARVACROL

Bio-composites are commonly obtained by combining biodegradable polymers with fillers collected from natural resources. In this context, biochar (BC) is attracting high interest as filler for polymer-based composites due to its challenging properties, including ecosustainability. This study aimed to prepare and characterize bio-composites with antimicrobial properties evaluating the role of the filler in the release kinetics. In particular, BC as filler and carvacrol (CRV) as antimicrobial agent, were incorporated via melt-compounding in poly(butylene adipate-co-terephthalate) (PBAT) samples. The rheological, tensile, and antimicrobial properties of the obtained bio-composites were evaluated paying particular attention to the influence of BC concentration, i.e., 5, 10, and 20 wt%, on the investigated properties. Moreover, the influence of BC content on the release kinetics of carvacrol was studied and mathematically modeled to evaluate the release mechanism. The results showed that the presence of biochar modified the carvacrol release in comparison with the unfilled system thus allowing to tune the release kinetics.