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

Abstract

synopsisThe 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 (I) a twophase sonic modulus theory which makes possible the determination of the amorphous orientation function and the intrinsic sonic moduli of the polymer, (8) 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 dete&mation of the intrinsic birefringence of the crystal and amorphous regions of isotactic polypropylene, (6) correlation of the polarisability 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. 1741 EXPERIMENTAL Preparation of FilmsCompression-Molded Unoriented Films. Profax 6523 was compressionmolded into 5-mil films at 550°F. for 10 min., cooled to 400"F., and treated in the following manner: ( I ) quenched in a Dry Ice-cellosolve bath (-65°C.); (2) quenched in tap water (20°C.); (3) placed in hot tap water (55°C.); (4) press cooled.Cast and Annealed Polypropylene Films. Profax 6320 was cast from the melt (ca. 280°C.) on a 20°C. roll at approximately 5 ft./min. The drawn films were produced by transferring cast film to a 110°C. roll and hot drawing over a 5-ft. gap to a room temperature roll. Sections of each of the films about 12 X 8 in. were annealed at fixed length for 15 min. at 110°C. and allowed to age for at least two months before being examined. DensityDensities were measured in a 3A alcohol-water density gradient coluinii at 23.2 f 0.1"C. X-Ray DiffractionX-ray diffraction measurements were made with a I'hilips diffractoineter equipped with a copper target, nickel filter, and a scintillation counter detector system. The measured intensities were corrected for polarization, absorption, background, and incoherent scattering. Calculations were made on a Bendix GlCiD computer. BirefringenceBoth birefringence and sonic velocity were measured on the %me strips of 1-5-mil film. These strips were 1 mm. wide and 15-25 cm. long. The thickness at each point examined was measured with a Pratt and Whitney Electro-Limit Gage. The retardation of the sample was measured in a Zeiss polarizing microscope with the use of a Zeiss interference filter to produce X = 546 mp monochromatic light. Both quartz and calcite Ehringhaus compensators were used to measure the retardation. S...

Oriented structure of PP/LLDPE multilayer and blends films

“…Spectra portions of interest in the case of LLDPE and PP are Table 1 Polymer resins used in this work and some of their characteristics K1 vibration is well referenced and associated with the PP crystalline phase [18,19] and 1153 cm K1 was assigned to the amorphous phase [20]. The 973 cm K1 vibration was observed to be associated with both crystalline and amorphous phases [21].T h e 1256 cm K1 is a mixed vibration (amorphous and crystalline phase), having a transition moment angle with chain axis of 38.58 [22]. The 840, 998 and 1165 cm K1 are among the strong vibrations and are associated with a-PP helical crystal.…”

Ultradrawing of Isotactic Polypropylene Films Produced by Gelation/Crystallization from Solutions

“…This value is the highest one reported for polypropylene and is rather close to 33.1 x 10-3 corresponding to the intrinsic crystal birefringence estimated by Samuels using X-ray diffraction and the measurement of sonic modulus. 16 Figure 7 shows SAXS patterns (through view) for the films that were drawn up to A= 20. The pattern for an original film shows a circular-type diffuse scattering characterizing random orientation of crystal lamellae with respect to the direction normal to the film surface.…”

A process-structure-property study of anisotropic PMDA-ODA films

“…20 In this figure, the intersection of the dashed lines represents threeStructure Development by Various Processes dimensional isotropy ( f x Å f y Å f z Å 0). The dashed lines represent uniaxial symmetry about a particWith the ability to determine the three-dimenular principal axis of the material; data points sional orientation functions, the investigator can lying off of the dashed lines exhibit multiaxial now compare the structures developed by various orientation.…”