Morphology of deformed polypropylene. Quantitative relations by combined x‐ray, optical, and sonic methods

The submicroscopic morphology of uniaxially deformed isotactic polypropylene films has been examined by x‐ray diffraction, infrared dichroism, birefringence, sonic modulus, small‐angle light scattering, density, and electron microscopic techniques. Several new theoretical relationships and techniques have been developed. These include ( 1 ) a two‐phase sonic modulus theory which makes possible the determination of the amorphous orientation function and the intrinsic sonic moduli of the polymer, ( 2 ) a general relationship for the quantitative determination of the infrared transition moment angle and for the quantitative determination of the crystal orientation function from infrared dichroism measurements only, ( 3 ) the determination of the extension ratio of spherulites from the small‐angle light‐scattering patterns of deformed films, ( 4 ) a technique for the experimental determination of the intrinsic birefringence of the crystal and amorphous regions of isotactic polypropylene, ( 5 ) correlation of the polarizability difference determined from solid‐state measurements with that determined from solution measurements, and ( 6 ) other techniques for the rapid determination of orientation functions. Morphological information about uniaxially deformed isotactic polypropylene films, obtained as a consequence of these developments, is reported.