Isoconversional kinetic analysis of the alkyd/melamine resins curing

Abstract

The curing reaction for the mixtures of alkyd resins based on ricinoleic acid, phthalic anhydride and three polyols (glycerin, trimethylolpropane or ethoxylated pentaerythritol) with two different commercial melamine resins was investigated by differential scanning calorimetry (DSC). The curing kinetics analysis was performed using the isoconversional methods (Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose and Friedman). Isoconversional methods were carried out with three heating rates (5, 10 and 20°C/min) in a scanning temperature range from 40 to 250°C. It was found that the curing activation energy of resin mixtures is influenced by alkyd and melamine resin type due to the catalytic effect of hydroxyl group on the reactions. The dependence of apparent curing degree on time, which was obtained by mathematical transformations of dynamic DSC data using Ozawa-Flynn-Wall method, describes well the isothermal DSC experiments

Synthesis and Characterization of Pentaerythritol Phthalic Anhydride Resin from Soybean Oil

“…loss of the resin) at 167 ºC and the final decomposition temperature at (100 % wt. loss) was 670 ºC which is comparable to the values reported for artists' alkyd paints (470 ºC) and considered to be thermally stable [12] and for PET based alkyd resin (500 ºC) [13,14]. An indication of the presence of large number of hydroxyl (-OH) groups in the synthesized PPR, which increased the stretching power and overall strength that improved its thermal stability.…”