Evaluation of melamine-modified urea-formaldehyde resin binders for particleboard

Melamine-modified urea-formaldehyde (MUF) resins, based on 5, 10, and 25 percent melamine addition of the resin solids weight, were synthesized in the laboratory as particleboard (PB) binders and compared with a control urea-formaldehyde resin that was formulated similar in mole ratio to that used to bond PB in the United States. PBs were manufactured with the synthesized resins at 5 minutes hot-press time (162 degrees C) and at 6 percent resin solids level on an ovendry particle weight basis. The PBs were tested for physical strength and dimensional stability properties according to the procedure of ASTM D 1037. Formaldehyde emission levels from the PBs were measured per the procedure of ASTM D 5582. As the melamine addition in the resin formulation of the MUF resins was increased, dimensional stability properties were significantly increased. Panel internal bond strength was decreased with increasing amounts of the melamine in the MUF resins; however, these differences were not statistically significant.