An elastomeric material being a reaction product of (A) a component consisting essentially of dihydric phenols having an average molecular weight ranging from 110 to about 140 and (B) a component consisting essentially of organic diepoxides each having the general formula OCH2CHCHz-OROCHz-6HCH26 in which R is an alkylene radical of from 2 to 12 carbon atoms in the presence of a tertiary amine cata