BOND PERFORMANCE OF FORMALDEHYDE-BASED RESINS SYNTHESIZED WITH CONDENSATE GENERATED DURING KILN-DRYING STEP OF WOOD

Abstract

This research investigated the potential use of condensate generated during vacuum drying with high frequency of wood in the synthesis of urea-formaldehde (UF) and melamine-formaldehyde (MUF) resins. The liquid condensate (5 wt%) of total resin composition) of walnut, beech or oak was replaced with deionized water used in the synthesis of UF and MUF resins. The condensate did not affect the properties of the UF and MUF resins in terms of density, solid content, viscosity, pH, and gel time as compared with the control resins. The control UF and MUF resins did not show a significant difference with the bond strength of UF and MUF resins at dry and wet conditions, except for the oak-UF resin. As for the dry condition, the control resin had the highest bond strength with a value of 12.9 N.mm(-2), followed by beech-UF resin (12.6 N.mm(-2)), walnut-UF resin (12.1 N.mm(-2)), and oak-UF resin (11.8 N.mm(-2)), respectively. A similar trend was observed for the wet condition. All the modified UF and MUF resins complied with the minimum requirements of EN 12765 standard at dry and wet conditions. The results of this research can be useful for environmentally friend solution of the waste condensate discarded to the ground water.