Isoconversional analysis of non-isothermal curing process of epoxy resin/epoxide polyhedral oligomeric silsesquioxane composites

Polyhedral Oligomeric Silsesquioxane (POSS) with highly reactive epoxy groups will have a strong effect on the curing process and the final structure of epoxy resin (EP) composites. The Kissinger and isoconversional methods are widely used in treatment of the non-isothermal curing process during a DSC run. Results obtained from Kissinger analysis showed that the curing activation energy E of the EP/epoxide POSS system is effectively lowered after addition of POSS. More precise analysis, including the Coats-Redfern and Friedman methods, showed that introduction of epoxide POSS greatly accelerated the curing process of EP. The activation energy of the composites was much lower than that of the pure resin in the early stage. Subsequently, it increased with the increase in conversion. Combining the results obtained from glass transition temperature measurement, it was clear that the dispersion state of POSS has a huge effect on the curing kinetics of the EP/POSS composites.