An Investigation of the Relationship Between Polymer Structure and Mechanical Properties

Abstract

Much progress in the understanding of the mechanical properties of high polymeric substances has been made in the past few years. The theory of the mechanical properties of rubberlike systems has been developed by Guth, James, Gee, Treloar, and others; those of fiberlike materials have been studied by Mark, Harris, Eyring, Halsey, and others; and, also, a theory for the double refraction of these materials has been developed by Kuhn and Treloar. In this paper some of these developments are critically reviewed and correlated. The general problems involved in specifying the viscoelastic properties of a polymer are considered and the role of the prevailing theories within this framework is discussed. The application of the technique of simultaneous measurement of stress and birefringence for time-dependent behavior of these systems is considered. It is shown that through its use the mechanical behavior of complex systems may be resolved into more fundamental contributions. The method is applied in an experimental survey of the mechanicat-optical properties of ma terials varying in nature from ideal rubbers to polycrystalline plastics.