Dynamic mechanical characterization of epoxy/epoxycyclohexyl–POSS nanocomposites

In this study, an epoxy matrix containing 1, 2 and 5% of a polyhedral oligomeric silsesquioxane (POSS) was analyzed by dynamic mechanical analysis (DMA) in isothermal and non-isothermal runs in order to evaluate the interactions between the epoxy/POSS systems obtained. Non-isothermal DMA curves showed that, upon POSS addiction, the storage modulus in the rubbery region (Er) and the loss modulus decrease due changes caused in the average crosslink densities in the epoxy/POSS systems. The glass transition temperature (Tg) keep the same trend for all nanocomposites studied and there was higher activation energy (Ea) values with the incorporation of the nanofiller due an enhancement in the cohesive energy density. Through isothermal DMA curves studied, it is noted an increase in the Kauzmann temperature and the fragility concept proposed by Angell upon POSS addiction, suggesting a formation of a kinetically weaker system.