Silane Treatment on Rice Husk Filler and Its Effect on the Properties of Biodegradable Polybutylene Adipate‐Co‐Terephthalate

ABSTRACT This study investigates the effect of 3‐aminopropyltriethoxysilane (APTES) concentration on the surface modification of rice husk (RH) for developing polybutylene adipate‐co‐terephthalate (PBAT) composites with varying filler loadings (30–50 wt%). Silane‐treated RH was incorporated into PBAT via melt blending to enhance mechanical and thermal properties. The novelty lies in systematically correlating APTES concentration with RH loading, offering insights into their synergistic impact on composite microstructure and overall performance. Our approach provides a comprehensive understanding of how controlled silane treatment improved interfacial adhesion, mechanical strength, thermal stability, and maintained biodegradability. Characterization was performed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X‐ray diffraction (XRD), tensile testing, thermogravimetric analysis (TGA), water absorption, and soil burial tests. SEM revealed a more homogeneous morphology with fewer voids. The 70PBAT/30Silane RH‐2% composite achieved the best mechanical performance, outperforming 4% and 6% silane‐treated composites, with tensile strength improvements of 7% and 10%, and Young's modulus increases of 12% and 4%, respectively. Tensile properties indicated that for a filler loading of 30 wt%, a 2% silane concentration is sufficient, while a maximum of 6% is required for 40 wt%, and a minimum of 4% is necessary for 50 wt% filler loading. TGA showed enhanced thermal stability with higher filler content, while soil burial tests confirmed 90% mass loss after 6 months, indicating excellent biodegradability. These results highlight the potential of silane‐treated PBAT/RH composites for sustainable molded products such as trays.