Urea-formaldehyde resin (UF), also known as urea-formaldehyde resin, is a polycondensation of urea and formaldehyde under the action of a catalyst (alkaline or acid catalyst) to form an initial urea-formaldehyde resin, and then under the action of a curing agent or auxiliary agent to form an insoluble and insoluble final stage Thermosetting resin. The cured urea-formaldehyde resin is lighter in color than phenolic resin, translucent, resistant to weak acid and alkali, has good insulation performance, excellent wear resistance, and is cheap. It is the most used type of adhesive, especially in the wood processing industry. In the manufacture of various wood-based panels, urea-formaldehyde resin and its modified products account for about 90% of the total amount of adhesives. However, urea-formaldehyde resin is easily decomposed in the presence of strong acid and strong alkali, and has poor weather resistance, poor initial viscosity, large shrinkage, high brittleness, water resistance, and easy aging. The wood-based panels produced with urea-formaldehyde resin have formaldehyde release in the process of manufacturing and use. problem, so it must be modified.
