A triple action mechanism synergistic interface based on tannic acid/poly (ethylene glycol)/Fe3+ formation for improving the properties of short bamboo fiber/PBSA biocomposites

Bamboo fibers (BFs) reinforced polymer composites face significant challenges in enhancing composite properties due to poor interfacial compatibility. This study is based on the coordination and molecular cross-linking reactions between tannic acid (TA), Fe³⁺, and polyethylene glycol (PEG). A triple-action mechanism interface integrating rigid-flexible balanced, molecular cross-linking and mechanical interlocking was obtained in BFs/PBSA composites by a simple one-pot water reaction and hot pressing process. The interface significantly improved the performance of the composites. Specifically, the tensile strength, tensile modulus, flexural strength, flexural modulus, and impact strength of the composites were increased by 20 %, 13 %, 38 %, 14 %, and 54 %, respectively, while the maximum energy storage modulus was enhanced by 71 %. Additionally, the initial and maximum degradation temperatures increased by 17.1 °C and 19.2 °C, respectively, and water absorption decreased by 34 %. These results demonstrate the promising potential of the interface for preparing high-performance plant fiber-reinforced polymer composites.