Effect of sodium carboxymethyl cellulose (Na-CMC) added to urea-formaldehyde resin on particleboard properties

Abstract

This study investigated the effect of sodium carboxymethyl cellulose (Na-CMC) added to urea-formaldehyde (UF) resin on particleboard production and its effects on the properties of the boards. The Na-CMC/UF was prepared at the selected blending levels of 0/100, 5/95, 10/90, 15/85, 20/80, 25/75, 30/70, 35/65, 40/60, 45/55, and 50/50. In the production of test panels, 55% coniferous and 45% broadleaved wood chips were used. The physical and mechanical properties of the particleboard panels were determined and evaluated. According to the results, the addition of Na-CMC at the level of between 5% and 20% improved the internal bond (IB) strength by 6%– 40%. The best IB strength (0.63 N/mm2) was found in the panels with the 20% Na-CMC admixture. Although an increase in bending strength (modulus of rupture-MOR) was observed with an increase in the amount of Na-CMC used, it was found that the bending modulus of elasticity (MOE) was reduced in comparison with the control sample. The lowest MOE was determined as 1451 N/mm2 in the 50% Na-CMC-doped test panels. It was determined that the use of Na-CMC negatively affected the water absorption and thickness swelling values. As a result, it was concluded that UF resin containing up to 20% Na-CMC solution can be used in particleboards produced for applications in which the physical properties are not important.