investigating the properties of rice husk/urea formaldehyde resin particleboard by using diisocyanate

in this study, the particleboard was made with rice husk and urea formaldehyde resin of 7, 8, 9 and 10 percent (based on dry weight of rice husk). to improve mechanism of bondability a definite amount of isocyanate resin is introduced to replace the same amount of urea formaldehyde resin. the effect of urea formaldehyde resin and diisocyanate content on bondability was evaluated by studying the mechanical properties (bending strength, internal bond strength) and physical properties (thickness swelling and water absorption). data were statistically analyzed with spss software and comparison was made on the mean values employing a dancan test to identify which groups were significantly different from the rest. generally the results have shown that all mechanical and physical properties of particleboards improve with increasing urea formaldehyde resin content and its partial replacement with diisocyanate as well. in this study the best mechanical and physical properties of particleboard were obtained with 10 percent resin (the sum of 8 percent urea formaldehyde resin and 2 percent diisocyanate).