Curing of epoxy resin using imide-amines

摘要

The curing behavior of diglycidyl ether of bisphenol-A (DGEBA) was investigated by differential scanning calorimetry, using varying molar ratios of imideamines and 4,4'-diaminodiphenyl sulfone (DDS). The imideamines were prepared by reacting 1 mol of pyromellitic dianhydride (P) with excess (2.5 mol) of 4,4'-diaminodiphenyl ether (E), 4,4'-diaminodiphenyl methane (M), or 4,4'diaminodiphenyl sulfone (S) and designated as PE, PM, PS. Structural characterization was done using FTIR, H-1 NMR, C-13 NMR spectroscopic techniques and elemental analysis. The mixture of imide-amines and DDS at ratio of 0: 1, 0.25: 0.75, 0.5: 0.5,0.75: 0.25, and I : 0 were used to investigate the curing behavior of DGEBA. The multiple heating rate method (5, 10, 15, and 20 degrees C/min) was used to study the curing kinetics of epoxy resins. The peak exotherm temperature was found to be dependent on the heating rate, structure of imide-amine, and also on the ratio of imide-amine: DDS used. Activation energy was highest in case of epoxy cured using a mixture of DDS: imide-amine of a ratio of 0.75: 0.25. Thermal stability of the isothermally cured resins was also evaluated in a nitrogen atmosphere using dynamic thermogravimetry. The char yield was highest in case of resins cured using mixture of DDS: PS (0.25: 0.75; EPS-3), DDS: PM (0.25: 0.75; EPM-3), and DDS: PE (0.75: 0.25; EPE-1). (c) 2006 Wiley Periodicals, Inc.