Measurements of the Photoelastic and Elastic Constants of Drawn Films and Extruded Rods of Polypropylene with Brillouin Light Scattering.
UTAH UNIV SALT LAKE CITY DEPT OF CHEMISTRY
Pagination or Media Count:
The elastic constants C11, C33, C44, C13 of oriented polypropylene films are measured with Brillouin scattering and are compared with the elastic constants obtained from extruded polypropylene rods. The photoelastic constants P12, P13 and P31 of the extruded rod samples are measured by comparison to a polymethylmethacrylate reference scatterer. In the film samples, the relative values of the photoelastic constants P11, P33, P13 and P31 are measured by comparison of the quasilongitudinal and quasitransverse intensities at several directions of sound propagation. Within the experimental error, P13, P31 and P12 are found to be unaffected by extrusion or stretching. P11 and P33 are found to change in relation to P31 in the film samples. The results are interpreted by considering the chain morphology and the theory of photoelastic interaction. The changes in the Brillouin intensities are due to changes in the elastic constants rather than due to the photoelastic constants. Author
- Test Facilities, Equipment and Methods