Effect of structure of aromatic imide–amines on curing behavior and thermal stability of diglycidyl ether of bisphenol‐A

Abstract

AbstractThe curing behavior of diglycidyl ether of bisphenol‐A (DGEBA) with aromatic imide–amines having aryl ether, sulfone, and methylene linkages was studied using differential scanning calorimetry (DSC). Six imide–amines of varying structure were synthesized by reacting 1 mol of naphthalene 1,4,5,8‐tetracarboxylic dianhydride (N) or 4,4′‐oxodiphthalic anhydride (O) with excess (>2 mol) of 4,4′‐diaminodiphenylether [E] or 4,4′‐diaminodiphenyl methane [M] or 4,4′‐diaminodiphenyl sulfone [S]. The imide–amines prepared by reacting O or N with S, M, and E have been designated as OS/NS; OM/NM, and OE/NE, respectively. Structural characterization of imide–amines was done using FTIR, 1H NMR, 13C NMR, and elemental analysis. The curing behavior of DGEBA in the presence of stoichiometric amount of imide–amines was investigated by recording DSC scans. A broad exothermic transition was observed and the peak exotherm temperature was found to be dependent on the structure of imide–amines. The peak exotherm temperature (Tp) was lowest in case of imide–amines OE and highest in case of imide–amines NS/OS. Thermal stability of isothermally cured DGEBA in the presence of imide–amines was evaluated by dynamic thermogravimetry. The char yield was highest for resin cured with imide–amines NE. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008