Melamine–Formaldehyde Resins without Urea for Wood Panels

Pure melamine–formaldehyde (MF) resins as adhesives for wood panels in which urea was not added during manufacture gave good bonding results for wood panels. The best performing formulation was found to be the one with a relatively low formaldehyde/melamine molar ratio while still being a fast-curing resin. This was confirmed by thermomechanical analysis scans of the resins and by pressing and testing laboratory wood particleboard. Its performance was explained by comparative gel permeation chromatography analysis of the resins, and by density profile analysis of the panels prepared with the resin.