The structure of urea—formaldehyde resins

Fourier transform infrared (FTIR) spectroscopy has been used as a modern analytical tool to elucidate the structure of urea—formaldehyde (UF) resins. Several low molecular weight condensation products of urea and formaldehyde were synthesized and characterized. Structural differences were observed for prepolymers prepared in alkaline and acidic media. Plausible mechanistic routes are proposed to explain the prepolymer structural differences prepared in different experimental conditions. The structural elucidation of the UF resins is considerably increased and improved by using absorbance magnification to further enhance the observed signals.