Comparative Study of the Storage Stability between a Melamine-Urea-Formaldehyde and a Urea-Formaldehyde Resin

Abstract Amino resin wood adhesives used for medium-density fiberboard (MDF), a melamine-urea-formaldehyde (MUF) resin and a urea-formaldehyde (UF) resin, were each synthesized with an overall formaldehyde/urea molar ratio of 1.10. The storage stability of the resins was monitored by their gel times and viscosity changes, as well as by a multiple light scattering method. The storage stability tended to be affected by the temperature at which the resins were stored. MUF resin had a higher storage stability at a storage temperature above room temperature, whereas UF resin exhibited the best storage stability at 10°C with overall good stability at all tested temperatures from 10°C to 40°C.