Adhesive properties of modified soybean flour in wheat straw particleboard

The objective of this research was to improve mechanical properties and water resistance of wheat straw-soy flour particleboard by chemically modifying soy flour. Urea and urease inhibitor N-(n-butyl) thiophosphoric triamide (n BTPT) were used to modify the proteins. Boric acid and citric acid along sodium hypophosphite monohydrate were used to modify soy carbohydrates. Sodium hydroxide was used to unfold protein molecules. The combined effect of the chemicals was also studied. Particleboard bonded by urea and high concentrations of nBTPT treated soy flour improved mechanical properties, that bonded by boric acid treated soy flour had better water resistance. The adhesive made from soy flour treated with 1.5 M urea, 0.4% nBTPT, 7% citric acid, 4% NaH2PO2, 3% boric acid, and 1.85% NaOH, produced particleboard with the maximum mechanical strength and water resistance. (C) 2003 Elsevier Ltd. All rights reserved.