Curing and thermal properties of novolak epoxy resins

摘要

Formaldehyde resins at various molar ratios of monomers p-aminophenol/cyclohexanone/p-nonylphenol/p-formaldehyde (pAP/CHx/p-NF/p-FA) under acid catalysis have been obtained. The resulted resins were reacted with a large excess of epichlorohydrin and transformed in a multifunctional novolak epoxy resins. These resins were characterized by H-1-NMR, infrared spectroscopy and elemental analysis. The curing and thermal behaviour of these epoxy resin/DDM systems were investigated using differential scanning calorimetry (DSC) and thermogravimetry (TG) techniques. The activation energies of the curing reactions are situated in the range of 54-75 kJ/mol. The cured products have good thermal properties, and activation energies of degradation reactions have values between 32 to 52 kJ/mol.