A Comparison of Adhesion Behavior of Urea-Formaldehyde Resins with Melamine-Urea-Formaldehyde Resins in Bonding Wood

This paper reports a comparison of adhesion behavior urea-formaldehyde (UF) with those melamine-urea-formaldehyde (MU) resins in bonding wood by analyzing the results published literatures. For this purpose, UF prepared blending low-viscosity resin (LVR) high-viscosity (HVR) at five different and two formaldehyde/urea (F/U) molar ratios (1.0 1.2) was compared MUF synthesized either simultaneous reaction (MUF-A resins) or multi-step (MUF-B three melamine contents (5, 10, 20 wt%). As (LVR:HVR) ratio increased from 100:0 to 0:100, viscosity mass (Mw Mn) blended while gelation time decreased. The interphase features such as maximum storage modulus (E′max), penetration depth, bond-line thickness then decreased increased. In addition, both MUF-A MUF-B also showed an increase Mw Mn content 5% 20%. However, E′max, These indicated that heavily depends on highly cohesion resins.