Study for Reduction of Molecular Weight, Transformation on Higher-order Structure and on the Recovered Mechanism by Fatigue of Polymer

Abstract

Fatigue tests in repeated tension-compression have been carried out on the sample of PS (Polystyrene) and PC (Polycarbonate). The crazes that were observed during fatigue test could be classified into two categories. The craze is generated at the direction of an initial crack in the case of PS by continuous mechanical load. And the craze grows up to the crack in the same direction. The plural crazes were also observed in the case of PC by continuous mechanical load. This craze grows up in the direction of angle of stress and 45 degrees. This report advocates the mechanism and critical fatigue point to find high fatigue-resistance materials of polymers.