Uron Structure Reducing Free Formaldehyde Content and Emission Level of UF Resin and Plywood

摘要

Three types of uron resin which contains much more uron cycle structure were prepared, and several mixed urea-formaldehyde (UF) resins were obtained by mixing uron resins with normal UF resins in this paper. The effects of uron structure and its amount on reducing free formaldehyde content of UF resins and formaldehyde emission value of its bonded plywood were studied by testing the curing time and free formaldehyde content of the resin, manufacturing plywood, testing free formaldehyde emission and bonding strength of the plywood, and analyzing ~(13)C-NMR spectrum of the resins. It is indicated that; (1) The Uron resins can reduce free formaldehyde content and its emission of UF resin and plywood, the former can reach 76% and the latter to 84% of the original emission; (2) The manufacturing time of uron resin can be shortened to 8 hours; (3) The mixed UF resins with 20% uron resin have a perfect performance.