RECENT DEVELOPMENTS IN MODIFICATION TECHNIQUE FOR WOOD AND WOOD-BASED COMPOSITES

Wood modification processes used in wood and wood-based composite industry are non-toxic in service and when disposed at the end of life does not result in the generation of any toxic residues Wood modification improves wood performance and leads to improved water repellency, rebuilding duced shrinkage and swelling, higher decay resistance, reduced extractive contents, lower equilibrium moisture content and increased thermal insulating capacity. More recently the interest in heat treatment processes has been renewed. This renewed interest is due to the declining production of durable timber, to the increasing demand for sustainable building materials, to the deforestation of especially sub-topical forests, and to the increased introduction of governmental restrictive regulations reducing the use of toxic chemicals. Thermal-modification is environmentally frienly moficiation for wood material. There is also other modification techniques are acetylation, furfurylation, resin impregnation, plasma treatment, silanes, maleics, alkali treatment, methacrylate, and other chemical treatments; (i.e. stearic acid in ethyl alcohol solution and permanganate treatment). In this study, the modification techniques, their effects physical and mechanical,properties of wood and wood-based panels were reviewed.