Synthesis of bisphenol a novolac epoxy resins for coating applications

Abstract

Bisphenol A novolacs were synthesized in both melting and solution processes using p-formaldehyde and formalin solution in presence of oxalic acid catalyst, respectively. Hydrogen nuclear magnetic resonance, 1H NMR, investigations show a high methylene bridge contents in the novolacs synthesized in a melting process. These novolacs were analyzed by gel permation chromatography (GPC) and fourier transform infrared spectroscopy (FTIR). The bisphenol A novolac was cured with 1-(2-amino ethyl) piprazine (AEP) as a curing agent for epoxy resins. The cured resins were evaluated as organic coating for steel. The mechanical properties of the cured epoxy resins were evaluated. The chemical resistances of the cured resins were evaluated through salt spray resistance, hot water, solvents, acid and alkali resistance measurements. The data indicate that the cured epoxy resins have excellent chemical resistances as organic coatings among other cured resins. © 2007 Wiley Periodicals, Inc.