ANWENDUNG DER POLARISATIONSOPTIK ZUR KLÄRUNG VON MATERIALSTRUKTUR- UND FESTIGKEITSPROBLEMEN VON KUNSTSTOFFEN

Abstract

The set of isochromatics and isoclinics appearing at the polarisation-optical investigation of plastics may be originated by very different causes a) Stress-/piezo-optic/ -birefringence for plastics in the glassy state, b) Orientation birefringence for polymers in the entropy-elastic state. Depending on whether linear polymers (thermoplastics) or polymers with a spatial network (thermosetting or rubbery plastics) are observed, in extreme cases the birefringence may be the image of high rubberlike deformation or that of a viscous flow. With falling temperature these phenomena may be even fixed ("frozen in") in the plastic body. In order to draw correct consequences from the experimental results it is necessary to make a distinct separation of the originating causes of the birefringence. In the present work the technical application of this method is shown by way of examples.