Studies on the curing kinetics of epoxy resins using silicon containing amide-amines

Abstract

Curing kinetics of diglycidyl ether of bisphenol-A (DGEBA) in the presence of novel silicon containing amide-amines were investigated by the dynamic differential scanning calorimetry. Silicon containing amide-amines were prepared by reacting 2.5 moles of 4,4'-diaminodiphenyl ether (E)/4,4'-diaminodiphenyl methane (M)/3,3'-diaminodiphenyl sulfone (mS)/bis(m-aminophenyl) methyl phosphine oxide (B) with one mole of bis(4-chlorobenzoyl) dimethyl silane. The multiple heating rate method (5, 10, 15 and 20°C min-1) was used to study the curing kinetics of epoxy resins in the presence of stoichiometric amounts of amide-amines having molecular masses in the range of 660 to 760 g mol-1. The peak exotherm temperature depends on the heating rate as well as on the structure of amide-amines. Activation energy of curing reaction as determined in accordance to the Ozawa's method was found to be dependent on the structure of amine. The thermal stability of the isothermally cured resins was also evaluated using dynamic thermogravimetry in a nitrogen atmosphere. The char yield was the highest in case of resins cured with amide-amines having both phosphorus and silicon atoms.