Steam Injection-pressing Preparation and Forming Mechanism of Binderless Ramie Stem Particleboard for Modern Furniture

Binderless ramie stem particleboard was prepared by steam injection pressing in this paper. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), high performance liquid chromatography analysis (HPLC) and specific surface area (BET) were used to analyze the forming mechanism. The results show that the number of active hydroxyl in cellulose molecule was increased by the synergistic effect of the water and heat, which could form hydrogen bonds (O-H…H), Van der Waals forces to enhance mechanical properties of resulting board. In addition, part of hemicellulose in ramie stem particles were hydrolyzed by the synergistic effect of the water and heat, and the hydrolysate could be subjected to polycondensation reaction to generate polycondensation furan resin which was similar to adhesives. The hydrolysate also could be subjected to polycondensation reaction with the lignin having a phenolic hydroxyl structure to generate a kind of condensation compound which was similar to phenolic resin adhesive. Moreover, the lignin in ramie stem particles were fully expanded and part of lignin was evenly distributed by the synergistic effect of the water and heat, which could improve the physical and mechanical properties of binderless particleboard to some extent.