Effects of mixing variables and talc fillers on tensile and impact fatigue properties of some thermoplastic blends of poly(vinyl chloride) with acrylonitrile‐butadiene copolymer rubber

Abstract

AbstractAn apparatus is described which measures simultaneously a relative change in vibrational damping and in transient electrical charging of a wafer specimen of plastic during the interval immediately following an impact blow. When impacting cycles are repeated regularly (at an energy less than the destructive level for nonfatigued specimen), the curves relating either electrical or mechanical responses to the number of impact blows show significant changes of slope at coincident intervals of the impact fatigue history, and either of these correlated effects can be used to indicate successive changes in microstructure which lead to the ultimate fracture endpoint of the fatigue test. These fatigue tests were used to study the effect of compositional and mixing variables on the properties of some heterophase thermoplastics. This study demonstrated that impact fatigue resistance can be poor in some plastic compositions which are rated to have superior impact resistance by tensile testing. Also, some special fillers in the correct quantity may improve fatigue resistance even though such filler loading will degrade other desirable tensile properties.