The Chemical Structure of UF Resins

Abstract
The structure of urea-formaldehyde (UF) resin was studied in light of the influence of various synthesis parameters on the chemical structure of the resulting resin solutions. The structural variability was analyzed by 13C nuclear magnetic resonance spectroscopy (NMR). Using appropriate pulse techniques, quantitative determination of the proportion of various functional groups was obtained. The parameters of formaldehyde/urea mole ratio, pH control, extent of reaction, and concentration of reactants were shown to affect the final resin structure. Variation of these parameters influenced the extent of branching, the rate of condensation, and the proportion of di-methylene ethers and cyclic uron structures.