Abstract:

The effect of urea addition number and interval on the performance of urea-formaldehyde resins and the properties of plywood were studied by response surface methodology for the first time. The main chemical groups were qualitative analyzed using FTIR for exploring the effect of urea addition number and interval on these groups. The results showed that the solid content and curing time of UF (urea-formaldehyde) resins can not be notably affected by the number of additions and the interval of urea. and the viscosity, hydromethyl content, free formaldehyde content of the UF resins and properties of plywood were prominently affected by the number of additions and the interval between additions of urea. The main chemical groups of UF resins were influenced by the number of additions and the interval of urea. When the number of additions were two and the interval of urea was 20 min, the performance of UF resins and the properties of plywood were better.

Key words: urea, ureaformaldehyde(UF) resins, response surface methodology, FTIR