Study On The Modification Of Urea-Formaldehyde Resin Adhesive

Urea-formaldehyde resin (UF resin) adhesive has become a major plastic types of wood-based panel production, the market demand is one of the largest adhesive,because of high bonding strength, simple, cheap, abundant source of raw materials. However, it can release formaldehyde and the amount of free formaldehyde is very high, it is a serious health hazard to people. In recent years, with increased awareness of environmental protection, production and useage of low toxicity UF resin is imperative.The article considered the production practice, through the synthesis of urea-formaldehyde resin adhesive research and the introduction of modifier type and amount of discussion, study of the modified UF resin plate made of the mechanical properties and the free formaldehyde content developed a new type of effective low toxicity of urea formaldehyde adhesive.Synthesis technique and formula of modified UF resin adhesive is optimized by experiments. Results show that when Formaldehyde and urea molar ratio is1.2, the amount of PVA and melamine is2%and3%, respectively, the water resistance and viscosity of UF resin increases, pH change slightly. Synthesis of new urea-formaldehyde resin modified, the modifying agent sodium alginate was3%, is added on pre-term, Urea-formaldehyde resin adhesive degree is1023mPa·S, free formaldehyde content is0.298%.In laboratory conditions, the hot temperature is150℃, pressing time is5min, glue content is5%, pressure is7MPa, use low toxicity and suppression of urea formaldehyde resin modified straw board, board of free formaldehyde emission is8.4mg/100g, to achieve a "Decorative material-plywood and their products release formaldehyde limit" Indoor E1Standard.