Preparation and Physical Properties of Wood-Lignophenol Composites

Abstract

Lignophenols were prepared through a phase-separation system composed of p-cresol and sulfuric acid. Composites of wood meals and lignophenols (Wood-Lignophenol composites) were molded by hot-pressing and their physical properties were examined. The modulus of rupture (MOR) and the modulus of elasticity (MOE) in bending of wood-lignophenol composites were roughly improved along with rising molding pressure and increasing lignophenol content. However, the strength for high lignophenol content (15 wt%, 20 wt%) decreased when the molding pressure was 20 MPa. These results are caused by the gas generated by thermal structural conversion of the lignophenol. On the other hand, water absorption and thickness swelling decreased with increasing lignophenol content. Water absorption and thickness swelling were greatly influenced by molding pressure and the physical properties of the lignophenol, respectively. Bending strength and water-resistance were improved by adding a small amount of NaCl and CaCl2·2H2O, and the effect of CaCl2·2H2O addition was remarkable. © 2007, The Japan Wood Research Society. All rights reserved.