Surface alterations on rice husk filler and their effect on the properties of biodegradable polybutylene adipate‐co‐terephthalate

Abstract This study presents a novel approach to address the current issue of plastic waste in the biosphere, which poses ecological hazards and threatens living beings. 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, acetylation, and silane treatments. 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, a compatibilizer such as maleic anhydride (MAH) was added. A range of analytical techniques, including scanning electron microscopy (SEM), tensile testing, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact angle measurement, and soil burial test, was employed 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, a strain at break of 41.83%, and Young's 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. Highlights Rice husk, an agricultural waste serves as an effective renewable filler in PBAT composites. Impact of alkali, silane and acetylation treatments on rice husk dispersion, compatibility and interfacial adhesion in PBAT composites. Synergistic effect of surface treatment and compatibilizer on improving the tensile properties of PBAT composites by 20% Incorporation of rice husk in PBAT produces biodegradable polymer composites, achieving over 90% degradation in soil within six months.