Surface Alterations on Agro-Waste Filler and their Effect on the Properties of Biodegradable Polybutylene adipate-co-terephthalate (PBAT)

Abstract In this study, a novel approach to address the pressing issue of plastic waste in the biosphere that leads to ecological hazards and threatens living beings is presented. Herein, a set of biodegradable composites has been developed through the melt blending of polybutylene adipate-co-terephthalate (PBAT) and rice husk (RH), aiming to discover effective surface modification techniques for enhancing mechanical properties while maintaining biodegradability above 90%. This research studied the diverse surface treatment methodologies applied to raw RH, including alkaline treatment, acetylation, and silane treatment. The novelty of this study lies in its focus on evaluating how these treatments distinctly influence the mechanical properties and biodegradability of RH. Additionally, it seeks to understand the underlying mechanisms driving these performance changes. To further improve the compatibility between hydrophobic PBAT and hydrophilic RH, compatibilizers such as maleic anhydride (MAH) and dicumyl peroxide (DCP), were incorporated. A range of analytical techniques, including scanning electron microscopy (SEM) for morphological analysis, tensile testing to evaluate the mechanical properties of PBAT composites and soil burial test to investigate the biodegradability of the composites. The results indicate that the PBAT/Silane RH/MAH composite exhibited exceptional mechanical properties, with a tensile strength of 22.49 MPa, strain at break of 41.83%, and young modulus of 187.60 MPa. Furthermore, the composites developed exhibited 90% mass loss during a six-month soil burial test, confirming their remarkable biodegradability. The findings present an innovative and practical solution for utilizing RH waste in a wide range of applications, particularly in the production of molded products such as straws.