Soybean-based Green Adhesive for Environment-friendly Furniture Material

Over the last decade, Sick Building Syndrome has become a significant social issue in Korea and many methods have been considered to maintain comfortable indoor air quality. To reduce toxic substances emitted from wood composite products, the source control is an efficient method through the reduction of formaldehyde content by using natural material-based adhesives for composite wood products production. Among alternative materials, soybean protein is considered an appropriate natural material to replace formaldehyde-based resin and many efforts have been made to produce new products, such as soap, shampoo, ink, resin, adhesive and textile through changing the chemical or physical properties of soybean. To process soybeans into these useful products, the beans are dehulled and the oil is removed by crushing at very high pressure or by solvent extraction. For use soybean as an adhesive, it is processed at temperatures below $70^{\circ}C$ to preserve the alkaline solubility of the proteins. In addition, soybean-based adhesive is undergone treatment process to improve mechanical properties using urea, urease inhibitor N-(n-butyl) thiophosphoric triamide and sodium dodecyl sulfate. The modified soybean-based adhesive exhibited sufficient mechanical properties to use as an adhesive for composite wood products. This paper is a review article to discuss the possibilities of soybean-based adhesive for environment-friendly furniture materials.