Study on synthesis of the low free formaldehyde urea-formaldehyde resin adhesive

This study aimed at exploring a producing method of urea-formaldehyde resin adhesive that contained low free formaldehyde.By reducing the molar ratio of formaldehyde to urea,choosing appropriate melamine amount and adding time and adding urea wisely,a low dissociated formaldehyde urea-formaldehyde resin adhesive was synthesized.The experimental results turned out: adjusting the molar ratio of formaldehyde to urea to 1.1,adding 2% of melamine in medium time,using the ratio of urea wisely to 60:15:25,a low toxic urea-formaldehyde resin adhesive was obtained which contained lower than 0.1% dissociated formaldehyde.This adhesive had good properties,low costs and short producing time whose plywood had high bonding strength.