The curing kinetics of blends of diglycidyl ether of bisphenol A (DGEBA), cycloaliphatic epoxy resins, and carboxyl-terminated butadiene-acrylonitrile random copolymer (CTBN) in presence of 4,4'-diamino diphenyl sulfone (DDS) as the curing agent was Studied by nonisothermal differential scanning calorimetry (DSC) technique at different heating rates. The kinetic parameters of the curing process were determined by isoconversional method given by Malek for the kinetic analysis of the data obtained by the thermal treatment. A two-parameter (m, n) autocatalytic model (Sestak-Berggren equation) was found to be the most adequate selected to describe the cure kinetics of the Studied epoxy resins. The values of E. were found to be 88.6 kJ mol(-1) and 61.6 kJ mol(-1), respectively, for the studied two sample series. Nonisothermal DSC curves obtained using the experimental data show a good agreement with that theoretically calculated. (c) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 3119-3126, 2009