Preparation of an environment-friendly fiberboard with high mechanical strength using delignified wood fiber

This paper reports environment-friendly fiberboard with high mechanical strength using delignified wood fibers and chitosan adhesive. The influence of delignification on chemical structure and microstructure of wood fibers and mechanical strength and water resistance of fiberboards was studied. The results showed delignification effectively removed hemicellulose and a part of lignin, decomposed some large-sized lignin into small fragments distributed on wood fiber surface, and exposed cellulose bundles. The mechanical strength and water resistance of fiberboards using wood fibers delignified for 3 h reached optimal and were far higher than the requirement of the Chinese national standard. The large improvement in internal bonding strength (IB) and thickness swell (24 h TS) was mainly attributed to the delignification, while that in modulus of rupture (MOR) and modulus of elasticity (MOE) was principally due to the addition of chitosan adhesive. This study can open a new path for production of scalable environment-friendly high-performance wooden composite. • An environment-friendly fiberboard was prepared using delignified wood fibers. • This environment-friendly fiberboard has excellent mechanical performance. • Delignification effectively removed hemicellulose and exposed cellulose. • Delignification decomposed large-sized lignin into small fragments. • Chitosan effectually improved rigidity of fiberboard.