Abstract
The properties and chemical structures of urea-formaldehyde (UF) resins synthesized by three different procedures were investigated. The procedures employed were: 1) methylolation under the conditions of pH 8 and a formaldehyde/urea (F/U) molar ratio of 2, followed by condensation at pH 5 and by additional incorporation of urea, 2) condensation under the conditions of pH 4.5 and a F/U molar ratio of 2.5, followed by the additional incorporation of urea, 3) condensation under the conditions of pH 1 and a F/U molar ration of 3, followed by the additional incorporation of urea.
Keywords
Urea resins,
synthetic conditions,
chemical structures,
bonding strength,
formaldehyde emission
Citation
Ji-you, Gu; Higuchi, Mitsuo; Morita, Mitsuhiro; Hse, Chung-Yun. 1995. Synthetic conditions and chemical structures of urea-formaldehyde resins. I. Properties of the resins synthesized by three different procedures. Japan Wood Research Society 41(12):1115-1121