Coating Properties of Di- and Tri-functional Epoxy Resin Using Novel Epoxy Based Polyamide as Curing Agent

Abstract

Bis ester namely 1, 1'-(1-methylethylidene) bis 14-1 l-(l-imino-4-ethyl benzoate)-2 -propanolyloxy) ]benzene was synthesized by the reaction of epoxy resin, diglycidyl ether of bisphenol-A-(DGEBA) and 4-amino ethyl benzoate (4-AEB) using triethyl amine as catalyst. The synthesized bisester was reacted with two different aliphatic diamines viz., 1, 4-butylene diamine (BDA) and 1, 6-hexamethylene diamine (HMDA) to obtain respective polyamide resins (PAS) abbreviated as DGEBA-4-AEB:BDA and DGEBA-4-AEB:HMDA respectively.The PAS synthesized were used as a curing agent for the difunctional epoxy resin, (DGEBA) and trifunctional epoxy resin, (TGPAP) in three different ratios. Using triethylamine as a catalyst and PAS as a curing agent, DGEBA and TGPAP were polymerized on mild steel panels at 120°C for 1 hr. The coated panels thus obtained were tested for scratch hardness, flexibility, impact strength and chemical resistancy.It appears from the results that epoxy resins, DGEBA based polyamides can successfully be used as a curing agent for the coating application.