Curing Kinetics of Liquid Crystalline Epoxy Resins Based on Bisphenol-S Mesogen with DDE by Nonisothermal DSC Data

摘要

The curing kinetics for a system of Sulfonyl bis(4,1-phenylene)bis[4-(2,3-epoxypro pyloxy)benzoate] (p-SBPEPB) with 4,4'-diaminodiphenyl ether (DDE) were investigated by nonisothermal differential scanning calorimetry (DSC). The dependencies of the apparent activation energy Ea and the conversion a during overall curing reaction were revealed by Ozawa's method. The results shown the Ea decreased drastially from 107 to 75KJ/mol with α in the initial stages (α = 0-20%), the average apparent activation energy Ea of p-SBPEPB/DDE is 82.81KJ/mol and was relatively constant in the 0.5 to 0.9 conversion interval. Some parameters were evaluated using the two kinetic models of Sestdk-Berggren (S-B) equation and JMA model. The liquid crystalline (LC) phase had formed and was fixed in the system during the curing process.