FLEXIBILITY IMPROVEMENT OF EPOXY-RESIN BY USING GAMMA-BUTYROLACTONE

The addition reaction of gamma-butyrolactone with epoxy resin was carr ied out in CCl4 solution, with BF3:MEA added as a catalyst. The trioxa spiro-ortho-estering structure of prepolymer was obtained first. The r ing structure was opened to form a crosslinked structure of polymer at higher temperature. The structures of prepolymer and polymer have bee n indentified by the infrared spectra. The thermal stability of polyme r was evaluated by thermogravimetric analysis. It was found that the g lassy temperature of the polymer increased, and that the thermal stabi lity of the polymer in the early stage decreased with an increase in t he amount of BF3:MEA catalyst added. Moreover, the mechanical properti es of a laminate made of gamma-butyrolactone-modified epoxy resin with glass fiber cloth have been measured. The results indicated that the break energy decreased and the flexibility increased with an increase in the content of the modified resin in the laminate.