Advancing Polypropylene/Bamboo Fiber Composites With a Novel PPgMA Pre‐Coating Technique

ABSTRACT This study presents an innovative approach to enhancing the efficiency of maleic anhydride (MA) content in polypropylene/bamboo fiber composites (PP/BF) without compromising the inherent properties of PP. While maleic anhydride‐grafted polypropylene (PPgMA) is widely used as a coupling agent, our method introduces a novel pre‐mixing treatment of short BF with PPgMA, improving the mechanical properties of the composites. Unlike conventional methods where PPgMA is added during compounding, our approach involves pre‐coating BF with PPgMA before mixing with the polypropylene matrix. This ensures direct and optimized interaction between the hydroxyl groups of BF and MA groups of PPgMA, leading to superior interfacial bonding. The efficacy of this method was validated through single‐fiber pull‐out testing, XPS, and SEM. Specimens were prepared using an internal mixer and compression molding, followed by mechanical testing. Thermal stability was assessed using TGA, while structural properties were characterized using SEM, FTIR, and XRD. Micro‐CT examined BF length distribution, and water absorption testing evaluated composite absorptive capacity. Results demonstrated significant enhancements: tensile strength increased by 63%, flexural strength by 28%, and impact strength by 22% compared to untreated composites. These improvements were achieved without increasing the overall MA content, addressing a key limitation in current fiber‐matrix interaction strategies.