Synergistic enhancement of peroxyformic acid-refined long bamboo fibers via aqueous epoxy resin reinforcement for superior mechanical properties

Conventional bamboo fibers suffer from low mechanical strength, high hydrophilicity, and poor interfacial compatibility, leading to reduced durability in composites. This study focuses on the preparation of high-performance long bamboo fibers and the reinforcing effect of water-based epoxy resin. A peroxyformic acid-assisted roller pressing and combing method was developed to extract long bamboo fibers with minimal mechanical degradation. The treatment effectively removed hemicellulose and lignin while preserving cellulose integrity. Under optimized conditions (20 % acid concentration, 41 °C, 9.5 h), the theoretical cellulose extraction rate reached 60.46 %. Subsequent vacuum-assisted impregnation with a low-viscosity water-based epoxy significantly enhanced the tensile strength of the treated fibers, achieving 658.58 MPa, a 58.5 % improvement. Tensile force-deformation curve analysis confirmed the mechanical reinforcement. Moreover, the alkali resistance of the reinforced fibers was notably improved, with only a 6.18 % reduction in tensile strength after 28 days of alkaline exposure. These findings indicate that the modified bamboo fibers overcome the limitations of conventional fibers and offer a sustainable reinforcement option for cement-based composites. • The peroxyformic acid-assisted method effectively producing high-quality long bamboo fibers. • The peroxyformic acid-assisted method removes hemicellulose and lignin with minimal cellulose damage. • The treatment significantly increases the physical and mechanical properties of bamboo fibers.