The effect of boric acid on the physical and mechanical properties of particleboard made to Urea-formaldehyde resin (UF)

This investigation with aim of modified and improve the water resistance of Urea formaldehyde (UF) with help of adding Boric acid to this resin was performed. In this survey the purpose additive as a variable factor at four levels 1, 2, 3 and 4 was used compare to the dry weight of adhesive. After preparation the composites, Physical and mechanical properties were examined according to the ASTM, D1013-04. The results showed that the using of these additive caused increasing the water absorption and thickness swelling resistance of 2 and 24 hours after immersion in water, with these resin. Also using of these additive caused increasing the internal bonding in case of 24 hours after immersion in water, compared to the control sample but in case of dry caused decrease compared to the control sample. However was not lower than standard level. With increasing Boric acid levels to 2 percent, bending strength of the samples made compare to the control sample increased and after this level was decrease. Also with increasing the levels of specify to the 4 percent modulus of elasticity of boards made compare to the control sample were increased.