Development of a bio-based wood adhesive is a significant goal for several wood-based material industries. In this study, a novel adhesive based upon sucrose and ammonium dihydrogen phosphate (ADP) was formulated in hopes of furthering this industrial goal through realization of a sustainable adhesive with mechanical properties and water resistance comparable to the synthetic resins used today. Finished particleboards exhibited excellent mechanical properties and water resistance at the revealed optimal adhesive conditions. In fact, the board properties fulfilled in principle the requirements of JIS A 5908 18 type standard, however this occured at production conditions for the actual state of development as reported here, which are still different to usual industrial conditions. Thermal analysis revealed addition of ADP resulted in decreases to the thermal thresholds associated with degradation and curing of sucrose. Spectral results of FT-IR elucidated that furanic ring chemistry was involved during adhesive curing. A possible polycondensation reaction pathway was proposed from this data in an attempt to explain why the adhesive exhibited such favorable bonding properties.
During the course of our studies, we have learned that solid wood has significant deformability characteristics under specific conditions, resulting from slippage occurring among wood cells when wood treated with small-molecular resins is compressed under heat. Furthermore, the deformed shapes obtained are maintained when the resin introduced into the wood cells is cured.In this study, the lateral extrusion of thin discs of wood treated with thermosetting phenol resin is performed to apply this flowlike deformation behavior of wood to wood-forming techniques. Resin-treated thin discs of wood placed in a heating container were compressed by a punch, and under constant pressure the wood flowed into the cavity of a mold. Successful molding conditions were achieved by varying the pressure, temperature and wood fiber direction for the extrusion ratio of 42. The mechanical properties of the wood plastic composite (WPC) sheets obtained by this extrusion process are affected by the fiber direction of the wood in the extrudate, which is almost equivalent to the longitudinal direction of the cellulose crystals of wood. The maximum bending strength of the WPC sheets obtained was about 180MPa, which is suitable for engineering plastics