Study of curing kinetics and thermal degradation of UV curable epoxy acrylate resin

Abstract

Blends of epoxy acrylate resins (acid values 3, 6.5 & 10 mg KOH/gm Solid) with monofunctional monomers (ethoxylated phenol monoacrylate) were prepared by physical mixing, having weight ratio 50:50. These blends were cured by using UV radiations in presence of photo initiator (Darocure 1173). The thermal degradation kinetics of these resin blends were studied, using thermo gravimetric analysis in nitrogen atmosphere at a heating rate of 10°C/min. by applying Coats-Red fern equation. According to the analysis, all the coating films degrade in two steps. In the first step of degradation kinetics, R 2M follows 1.75 order (n=1.75) and all other coating films follow second order (n=2) kinetics. In second step, R2M & R3M follow half order (n=0.5) kinetics and R1M follow first order (n=1) degradation kinetics. Order of the reaction is obtained on the basis of best fit analysis, and all the parameters were confirmed by regression analysis. From the reaction order, value of activation energy (E) and pre exponential factor (Z) were calculated by the slop and intercept of the plot between X and Y, respectively.