Dynamic mechanical properties and impact strength

Abstract Impact strength and damping as functions of temperature have been compared for eight polymers with typical differences in damping behavior, viz., four methacrylate polymers, a polyphenylene oxide, a polycarbonate, a polyoxymethylene, and a rigid polyethylene. If a damping maximum is caused by a movement within the main polymer chain, it is generally connected with an appreciable increase in impact strength. The temperature of the mechanical damping maximum and that of the transition in the impact strength may, however, differ considerably. If the damping maximum is caused by movements of sidechains only, it has at most a slight influence on the impact strength. Also a polymer with very low damping can have high impact strength and can even show a brittle‐tough transition. This occurs in the case of polyphenylene oxide.