The steam injection pressing molding mechanism of bindless bamboo particleboard

Bindless bamboo particleboard which takes bamboo particle as its raw material was prepared by steam injection pressing in this paper.Fourier transform infrared spectroscopy(FT-IR),solid-state nuclear magnetic resonance spectral analysis(CP/MAS 13C NMR),high performance liquid chromatography analysis(HPLC) and specific surface area(BET) were used to analyze the molding mechanism of bindless bamboo particboard.The results showed that the number of active hydroxyl in cellulose molecule was increased by the synergistic effect of the water and heat,active hydroxyl groups could form hydrogen bonds(O—H…H),van der Waals forces was formed between each of the two bamboo particles in the process of steam injection pressing;part of hemicellulose in bamboo particle was hydrolyzed by the synergistic effect of the water and heat,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.In addition,the lignin in bamboo particle was fully expanded and part of lignin was evenly distributed between each of the two bamboo particles by the synergistic effect of the water and heat,which could improve the physical and mechanical properties of bindless particleboard to some extent.