Differential scanning calorimetry (DSC) was used to evaluate the curing kinetics of two
commercial urea-formaldehyde (UF) adhesives having different formaldehyde to urea
(F/U) ratio of 1.112 (UF1) and 1.086 (UF2). DSC measurements were done in dynamic
scanning regime with heating rates of 5, 10, 15 and 20 °C/min in order to determine the
activation energy for each adhesive. Obtained data were analyzed using isoconversional
methods with application of Ozawa–Flynn–Wall and Kissinger–Akahira–Sunose kinetic
models. In addition, different catalyst levels were tested at the heating rate of 10 °C/min.
The results showed that the adhesive with higher F/U ratio achieved higher activation
energy, while having lower peak temperature of curing reaction. It was also noticed that
the increase of catalyst level influenced the increase of reaction enthalpy of the adhesive
with lower F/U ratio.