Effect of a diluent on corrosion behavior of isophthalic type unsaturated polyester resin

摘要

The object of this study was to clarify the effect of a diluent on corrosion behavior of isophthalic type unsaturated polyester resin. The corrosive environment used was 30wt% nitric acid solution at 80°C. Two types of diluent, reacting type and remaining type were used. As the results of change of flexural strength for reacting type, corrosion behavior was classified into two steps that corresponded to physical degradation by swelling and hydrolytic corrosion. Corrosion behavior for remaining type, on the other hand, was classified into three steps that corresponded to physical degradation by swelling, the formation of pits and hydrolytic corrosion. The formation of pits caused the severe decrease of strength and the blister formation gave an abrupt increase of corrosion depth.