SYNTHESIS AND CHARACTERISATION OF BISPHENOL A NOVOLAC EPOXY RESINS FOR COATING APPLICATIONS

Abstract

Bisphenol A novolacs were synthesized in a melting process using para formaldehyde, and in a solution process using formalin solution and oxalic acid catalyst. 1H-NMR investigations show a higher content of methylene bridges in the novolacs synthesized by the melting process. These novolacs were analyzed by GPC and FT-IR spectroscopy. The bisphenol A novolac was cured with 1,2-amino ethyl piperazine (AEP ) as a curing agent for epoxy resins. The networks synthesized were evaluated as organic coatings for steel. The mechanical properties of the cured epoxy resins were tested and 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 resistance as organic coatings among other resins.