Determination of Activation Energy of Cyanet Ester and Epoxy Resins Using Dynamic Mechanical Analysis

The activation energy associated with the glass transition relaxation of thermosets has been determined by using the three-point bending clamp provided. In the present study, the dynamic mechanical analyzer NETZSCH Instruments DMA 242E was used to characterize two different types of thermoset resin. Each sample was given a linear heating speed of 5°C/min at four discrete frequencies in the temperature range RT °C to +250 °C.The activation energy for both transitions was determined by an Arrhenius plot from dynamic properties measured at different frequencies. The experimental results showed that the evaluation of activation energy is affected by the test frequency as well as the criterion by which the glass transition temperature (Tg ) is established. It has been found that the activation energy based on the loss tangent (tan δ) peak is more reliable than on the loss modulus (E”) peak.