Epoxy/resole blends - A study of its degradation kinetics

The degradation kinetics of blends of resole with epoxy resin, having diffe rent weight ratios, has been studied by dynamic thermogravimetric analysis in nitrogen atmosphere at a heating rate of 15 degreesC/min. These blends w ere prepared by physical mixing and were cured with 40% polyamide (based on blend resin and polyamide). The degradation of each sample followed 0.67(t h) order degradation kinetics, which was calculated by Coats and Redfern eq uation using best-fit analysis. This was further confirmed by linear regres sion analysis. The validity of data was checked by t-test statistical analy sis. From this value of reaction order, activation energy (E) and pre-expon ential factor (Z) were calculated. It was found that the activation energy increased while pre-exponential factor decreased as the resole content in t he blend decreased from 100 to zero weight percent.