COMPARATIVE-STUDIES ON THE CURING KINETICS AND THERMAL-STABILITY OF TETRAFUNCTIONAL EPOXY-RESINS USING VARIOUS AMINES AS CURING AGENTS

The curing reactions of the epoxy resins tetraglycidyl diaminodiphenyl methane (TGDDM) and tetraglycidyl methylenebis (o-toluidine) (TGMBT) using diaminodiphenyl sulfone (DDS), diaminodiphenyl methane (DDM) and diethylenetriamine (DETA) as curing agents were studied kinetically b y differential scanning calorimetry. The dynamic scans in the temperat ure range 20-degrees-300-degrees-C were analyzed to estimate the activ ation energy and the order of reaction for the curing process using so me empirical relations. The activation energy for the various epoxy sy stems is observed in the range 71.9-110.2 kJ.mol-1. The cured epoxy re sins were studied for kinetics of thermal degradation by thermogravime try in a static air atmosphere at a heating rate of 10 deg.min-1. The thermal degradation reactions were found to proceed in a single step h aving an activation energy in the range 27.6-51.4 kJ.mol-1.