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SynopsisGlassy isotactic propylene (PP) films of thickness up to 0.3 mm were obtained by an ultraquenching technique. The structure and properties of the as-quenched and subsequently crystallized samples were characterized*by various techniques. Electron microscopy indicates the glass has no structure larger than 25 A. X-ray diffraction shows PP crystallizes from the glass into a smectic structure at ca. -20°$ and then transforms to monoclinic microcrystals at ca. 40OC; a nodular structure (80 to 100 A in diameter) was observed on the surface. The transformation temperature increases with the f i l m thickness. Annealing above the a-relaxation temperature results in an increase in the nodule size. A correspondence was found between the diameter of the nodules observed on the surface and long spacings obtained by small-angle X-ray scattering from the bulk. Dynamic mechanical spectra show the presence of two relaxation-like peaks at ca. -10°C and 10°C for the as-ultraquenched samples. X-ray scattering, differential scanning calorimetry (DSC), and torsion pendulum measurements show PP crystallizes from the glass at a temperature, depending on the rate of heating, that corresponds to the lower relaxation peak temperature.

Evidence is presented indicating that polyethylene crystals grow in the form of hollow pyramids as well as lamellar crystals. Modes of packing the folded molecules consistent with the nonplanar structure are proposed. Observed electron diffraction patterns and dark-field micrographs are related to the pyramidal morphology. Various sources are described for the screw dislocations which result in spiral growths on crystals of polyethylene and polyoxymethylene.

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The thickness of single crystal lamellae of polyethylene, crystallized from solution, is found to increase greatly during annealing at temperatures above 110°C. The change is observed with small‐angle x‐ray diffraction and electron microscopy. The increase in thickness of the lamellae takes place at the expense of their lateral perfection; holes develop within the lamellae. All evidence indicates that a major refolding of the molecules occurs; this emphasizes the need for a new concept of the amount of motion and freedom that polymer molecules can have in the solid state. A similar process apparently occurs during the annealing of bulk samples crystallized from the melt.

Wide-angle (WAXS) and small-angle X-ray scattering (SAXS) studies of dry granular zein, zein fibers, zein-oleic acid resin, and zein-oleic acid films are reported. WAXS patterns showed two diffuse rings for these samples indicative of noncrystalline structures. Measured d-spacings of ϳ 4.6 Å and ϳ 10.5 Å were found for zein-oleic acid resins and films, consistent with the presence of ␣-helical segments. The granular zein and zein fibers had ϳ 4.6-Å and ϳ 9.5-Å spacings. Neither the films nor the fibers showed evidence of orientation of the molecular axes. SAXS studies of zein-oleic acid films indicated that the structure of the films was affected by preparation method. Biaxially drawn resin films showed periodicities of ϳ 170 Å along the film surface direction and ϳ 135 Å in the thickness direction, while the cast films had weaker intensity periodicities of ca. 80 Å for all beam directions; a weak, diffuse 45-Å spacing was also observed for both samples. The 170-Å periodicity was present in the resin before deformation and following uniaxial deformation. No SAXS periodicity was observed for the granular zein or zein fibers. Several structural models are presented for the resin films that are consistent with reports in the literature that zein, in solution, consist of prism-like particles consisting of four or more molecules.

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