Polymer, Vol.168, 209-217, 2019
Curing kinetics of liquid crystalline 4,4 '-diglycidyloxybiphenyl epoxy with various diamines
Liquid-crystalline epoxy resins (LCERs) have been attracting much attention due to their interesting properties. Nevertheless, 4,4'-diglycidyloxybiphenyl (BP) epoxy containing the simplest mesogen structure has only been investigated with a limited number of curing agents. In this study, the kinetic behavior of BP during curing with various aromatic diamines was analyzed by differential scanning calorimetry to provide insight that may lead to increased applicability. It was confirmed that the starting temperature of the curing reaction decreases with the increasing basicity of the amines since initiation of the curing reaction begins entirely via an S(N)2 mechanism. However, the autocatalytic behavior exhibited different characteristics for each diamine, resulting in differences in the kinetic behavior. Moreover, the kinetic parameters such as rate constant and activation energy for each system were determined by fitting the experimental data to an autocatalytic curing model. The information presented here will broaden the applicability and versatility of LCERs.