Abstract
Vinylester resin having hydroxymethyl group (VEDA) was synthesized by the reaction of epoxy resin having hydroxymethyl group with acrylic acid. Effect of hydroxymethyl group on properties of cured resin was studied. VEDA was mixed with commercial vinylester resin in various ratios. The mixed vinylester resin was cured with dicumyl peroxide (DCP) as a catalyst. Glass transition temperature (Tg) of cured vinylester resin increased with increasing concentration of VEDA. This result was considered to be due to the increase of crosslinking density of the cured resin by condensation reaction of hydroxymethyl group. Tensile shear strength of adhesive was improved by the addition of VEDA to a commercial vinylester resin. This result was considered to be due to improve adhesion strength between cured resin and steel surface by introducing hydroxymethyl group. Next, urethane-modified vinylester resin was synthesized by the reaction of VEDA with isocyanate prepolymer. Tensile shear strength of adhesive was improved by introducing hydroxymethyl group and urethane linkage, and Tg of urethane-modified vinylester resin was nearly the same as that of unmodified resin.
