All-Bamboo Fiber Thermosetting Plastics with Excellent Mechanical Properties, Degradability and High Water Resistance

Petroleum-based plastics are non-renewable and degrade poorly, persisting in the environment and causing serious ecological pollution, so urgent development of alternatives is needed. In this study, all-bamboo fiber thermosetting plastics (BTPs) were successfully prepared through selective sodium periodate oxidation of bamboo fibers followed by hot-pressing. The results demonstrate that the oxidation treatment effectively enhanced fiber reactivity and facilitated the formation of dense composite materials during hot-pressing. Compared with petroleum-based plastics (e.g., PVC), BTPs exhibit outstanding mechanical properties: flexural strength reaches 100.73 MPa, tensile strength reaches 83.31 MPa, while the 72 h water absorption and thickness swelling rates are as low as 5.36% and 4.59%, respectively. This study also reveals the mechanism by which residual lignin affects material microstructure formation through competitive oxidation reactions. Although it imparts initial hydrophobicity, it hinders complete fiber activation, leading to the formation of micro-defects. Furthermore, BTPs can completely degrade in 1% NaOH solution within 24 h, demonstrating excellent degradability. This research provides a new strategy for developing high-performance, degradable all-bamboo-based materials and promotes the value-added utilization of bamboo resources.