| Abstract: | The stress-strain behavior and corresponding birefringence of several polymers have been investigated within a limited range of temperatures (from ?65 to 70°F) and strain rates (from 0.0027 to 0.1613 sec?1). One of these materials, a polyethylene resin, has been studied in more detail to ascertain the existence of a simple relationship between stress history, temperature, strain rate and birefringence. When the results were compared with the photoviscoelastic relations developed by E. H. Dill for a simple rheological material, it was concluded that the polyethylene tested does not completely satisfy this model. Polyethylene as well as the other materials investigated—nylon, a polyester, cellulose acetate butyrate, cellulose nitrate—exhibits a linear relation between birefringence and strain, independent of rate within the limits of the present experimental range. |
