Isothermal kinetics and thermodynamics studies of curing reaction of epoxy-aromatic diamine reinforced with epoxy functional MWCNT

Abstract

This study reports the cure kinetics and thermodynamics of an epoxy functional multiwall carbon nanotube-containing epoxy nanocomposite obtained by the polymerization of diglycidyl ether of bisphenol A with diaminodiphenyl sulfone as a curing agent through isothermal technique of differential scanning calorimetry. Isothermal kinetic parameters including reaction orders (m, n), rate constants (k ₁, k ₂), activation energy (E _a), and pre-exponential factor (A) were estimated using Kamal autocatalytic model. The model gives a good description of curing kinetics at various temperatures prior to the onset of vitrification. Thermodynamic parameters such as enthalpy (ΔH^# ), entropy (ΔS^# ), and Gibbs free energy (ΔG^# ) changes were also determined using the rate constants from the isothermal kinetic analysis and transition state theory. The thermodynamic functions were shown to be very sensitive parameters for the evaluation of the cure reaction.