Modification of urea-formaldehyde resin adhesive with silicone emulsion

Using contrast experiments, effect of feeding time and added amount of silicone emulsion on modification result of the urea-formuldehyde (UF) resin was investigated.Three-tier poplar polywood was prepared by pressing with the obtained modified UF resin and the formaldehyde emission and bonding strength of the polywood were determined.The results showed that the best molar ratio of formaldehyde and orea is 1.2; when 5% silicone by weight of total resin was added during the last synthesis period, the modified resin can get higher bonding strength, lower free formaldehyde and formaldehyde emission.