Effect of cassava flour as urea-formaldehyde adhesive extender on the bonding strength of plywood

Extenders are added to adhesive formulations to reduce resin utilization leading to cost savings. In this work, urea-formaldehyde resin was synthesized in the laboratory and cassava .flour was added to the urea formaldehyde resin in adhesive mix formulations for interior plywood manufacturing using a laboratory press. These formulations were compared with similar ones using wheat .flour as extender. There were five extension levels (/5.6, 31.2, 46.8, 62.4 and 78.1%) and three pressing times (4, 5 and 6 minutes). The results indicate that the effect of extender type on plywood bonding strength was not significant, while the level of extension has highly significant effect on the plywood bonding strength. The higher the level of resin extension, the lower the plywood bonding strength. The physicochemical
properties of the synthesized resins and formulations, are reported.