Study on the effect of amino-functionalized alumina on the curing kinetics of epoxy composites

The curing kinetics of epoxy/amino-functionalized alumina composites was investigated by non-isothermal differential scanning calorimetry (DSC) experiments. DSC bimodal curves can be divided into pre-stage and post-stage curing processes. The two-stage curing processes accord with not only KAS but also Vyazovkin iso-conversional equations. In the pre-stage process, the apparent activation energy (E-a) of epoxy/alumina composites decreases gradually with increasing the alumina content. In the post-stage process, E-a of the composites decreases slowly at first and then increases. The results show that curing catalytic reaction control is dominant in the pre-stage process, but diffusion control and reaction control have a competitive effect in the post-stage curing, which indicates that amino-functionalized alumina has a dual effect on the curing of epoxy resin. In Epoxy/41Alumina composite, the catalytic effect of amino-functionalized alumina is stronger than its inhibition effect, resulting in minimum E-a. The simulated curves calculated by SB(m, n) model show a good agreement with that experimentally determined.