Development of a sugarcane-bagasse/furfuryl-alcohol green composite with high mechanical performance, water resistance, and flame retardancy

With the increasing shortage of wood resources and the rising demand for sustainable materials, the development of green composites from agroforestry residues has attracted growing attention. This study focuses on the utilization of sugarcane bagasse (SCB) as the primary raw material and environment friendly biobased furfuryl alcohol resin (FAR) to prepare green bagasse composite (BC). The different particle sizes (10/30 and 30/50 mesh), FAR contents (30 wt% and 50 wt%), and different hot-pressing temperatures (160℃, 180℃, and 200℃) was investigated on the properties of BC. Results indicated that increasing hot-pressing temperature and FAR content significantly enhanced the IB, MOR, and MOE values. The optimal sample (BC30/50–50 %-200℃) exhibited an IB of 1.36 MPa, MOR of 14.93 MPa, and MOE of 1.55 GPa. The IB remained at 0.65 MPa after 2 h boiling-water treatment, surpassing the requirements of GB/T 4897–2015 for P5-grade particleboard, thereby confirming high wet-heat resistance. Moreover, the BC exhibited a low thermal conductivity of 0.09 W/(m·K), outperforming many reported biomass-based composites. Notably, the BC exhibits satisfactory flame retardancy achieved solely through its intrinsic constituents, with no external flame retardants required. Mechanistic analysis indicates that FAR reacts with cellulose and lignin in SCB to form a dense cross-linked network, thereby enhancing interfacial adhesion. Overall, BC not only demonstrate superior mechanical, wet-heat resistance, and thermal insulation properties, but also possess inherent flame safety, providing a potential pathway for the high-value utilization of SCB and the development of green low-carbon composites with potential applications in building material. • A sugarcane-bagasse/furfuryl-alcohol green composite (BC) was prepared. • FAR cross-linked with SCB in situ, significantly improving interface compatibility. • The BC shown a good mechanical performance and water-tolerance. • The IB of BC can remain 0.65 MPa after 2 h boiling-water treatment. • BC's flame-retardant and thermal-insulating natures show its potential as a building material.