Thermal stabilities and cure kinetics of DGEBA/cycloaliphatic epoxy blend system

The effects of different DGEBA and cycloaliphatic epoxy blend composition ratios on the thermal stabilities and cure kinetics were respectively studied by TGA and dynamic DSC. In this work, 1 mol% N-benzylpyrazinium hexafluoroantimonate (BPH) was used as an ionic initiator for cure. From TGA results of DGEBA-CAE system, the thermal stabilities based on the initial decomposition temperature (IDT), temperature of maximum weight loss(T_max) and integral procedural decomposition temperature (IPDT) increased with increasing the DGEBA composition. These results could be explained by means of increasing the long repeat unit, bulk side-group, stable aromatic ring structures, and increasing the reactivity between the -OH functional group of epoxy and BPH. The cure activation energies obtained from Ozawa equation decreased with increasing the CAE composition, resulting in high reactivity. This is due to the inherent chemical structure and low viscosity of CAE resin. Consequently, the 40 mol% of CAE composition was optimum for the thermal and processing conditions in this system.