Impact of condensation degree of melamine-formaldehyde resins on their curing behavior and on the final properties of high-pressure laminates

Melamine-formaldehyde is the most common resin used in the production of high-pressure laminates and low-pressure laminates (melamine impregnated paper), due to its properties of durability, good fire, and heat resistance and good moisture resistance. High-pressure laminate is a common choice for horizontal and vertical applications in the construction and furniture industries, thanks to its durability and versatility. The manufacture of such laminates commonly starts with the impregnation of decorative and kraft papers with thermosetting resins and after a drying process, the impregnated paper sheets are bonded together by high pressure and temperature pressing. The aim of this work was to evaluate the influence of the melamine-formaldehyde resins condensation degree after synthesis on high-pressure laminates performance. For that purpose, melamine-formaldehyde resins with different condensation degree were synthetized and characterized. Fourier-transform infrared-attenuated total reflection spectroscopy and dynamic mechanical analysis were used to study the chemical and mechanical cure of melamine-formaldehyde resins. Melamine-formaldehyde condensation degree has shown to have influence on resin pot-life, on characteristic reaction temperatures, on the degree of cross-linking achieved, and finally on the surface quality of high-pressure laminates.