MULTIFUNCTIONAL EPOXY-RESINS

The curing behavior of epoxy resins prepared by reacting epichlorohydr in with 4,4'-diaminodiphenyl methane (DADPM)/4,4'-diaminodiphenyl ethe r (DADPE) or 4,4'-diaminodiphenyl sulfone (DDS) was investigated using DDS and tris- (m-aminophenyl) phosphine oxide (TAP) as curing agents. A broad exothermic transition with two maxima were observed in the te mperature range of 100-315-degrees-C when TAP was used as the curing a gent. The effect of varying DDS concentration on curing behavior of ep oxy resin was also investigated. Peak exotherm temperature (T(exo)) de creased with increasing concentration of DDS, whereas heat of curing ( DELTAH) increased with an increase in amine concentration up to an opt imum value and then decreased. Thermal stability of the resins, cured isothermally at 200-degrees-C for 3 h, was investigated using thermogr avimetric analysis in a nitrogen atmosphere. Glass fiber-reinforced mu ltifunctional epoxy resin laminates were fabricated and the mechanical properties were evaluated. (C) 1993 John Wiley & Sons, Inc.