PHYSICAL AND DYNAMIC MECHANICAL-PROPERTIES OF ULTRADRAWN POLYPROPYLENE FILMS

Dynamic mechanical measurements were made on gel films of high molecular weight polypropylene prepared by gelation/crystallization from 1% (w/v) decalin solutions. The measurements were performed at different frequencies in the temperature range from minus 160 degree C to the melting point of the sample. The dry gel films were uniaxially drawn at 150 degree C to various draw ratios ( lambda ) between 6. 5 and 48. The morphology and orientation of the samples were characterized by density, differential scanning calorimetry, infrared dichroism, wide-angle X-ray diffraction, small-angle light scattering, scanning electron microscopy, and dynamic storage modulus. WAXS studies showed that very high degrees of orientation were achieved at the higher draw ratios.