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Two species of iodide ions (I3− and I5−) are found in iodine—nylon 6 complexes. Orientation of I5− arrays (most likely I2/I3− complex) along the polymer chain and I3− ions perpendicular to the chain axis in uniaxially drawn films and in films with planar orientation suggests that there is and intrinsic relation between the direction of iodide ion arrays and nylon 6 chains. When an unoriented film of nylon 6 in the amorphous or the α crystalline form is treated with an aqueous solution of iodine—potassium iodide, the I3− species in the resulting iodine—nylon complex lie in planes parallel to the surface of the film, and I2/I3− units are oriented normal to the surface of the film. The γ form obtained by desorbing the iodine from this complex shows considerable uniaxial rientation with the nylon chains oriented perpendicular to the plane of the film; this orientation is maintained during the γ to α transition. It is proposed that the iodine‐induced orientation of the nylon 6 chains is due to the nucleating effects of the iodide ion species as the iodine diffuses unidirectionally into the film.

SynopsisWater vapor transmission rates can be reduced by as much as 50% in polyethylene by using talc as a filler. The oxygen permeability as well as water vapor transmission rates are similarly reduced by talc in nylon 6 films. The films show low elongation at break and reduced breaking strength in the presence of talc. The yield strength and the modulus increase with the amount of talc, whereas the elongation at yield decreases. The mechanical and the barrier properties change with the size of the filler, the smaller size being more favorable. Talc probably acts as a nucleating agent and increases the crystallinity in polyethylene and nylon. Polyethylene unit cells in talc-filled films are oriented with the (110) planes parallel to the (001) planes of talc. Nylon 6 crystals, which are in the Q form in the presence of talc, are oriented with the hydrogen bonded sheets, the (002) planes, parallel to the (001) planes of talc. In both polyethylene and nylon 6, talc is oriented with the c-axis normal to the plane of the film, i.e., with the broad faces of talc flakes in the plane of the film. Lattice matching between the polymer and talc suggests epitaxy to be a contributing factor for the observed orientation of polyethylene and nylon 6 crystals. EXPERIMENTALPolyethylene films were extruded at 216°C through a 3 in diameter tubular film die and blown into 5 in diameter, -1.5 mil thick films. Nylon films were extruded at 266°C through a 4 in diameter tubular die and blown into 2 mil thick, 8 in diameter films. Polyethylene films were produced from Allied resins of three different molecular weights with melt indices

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Extrusion experiments on thirteen polymers in our laboratory and extrusion and forging studies on nine polymers in other laboratories reveal that solid‐state extrusion and malleability occur in semi‐crystalline polymers that have a crystalline relaxation, αc at the temperature Tαc, and do not occur in semicrystalline polymers devoid of αc. The solid‐state extrusion takes place in the temperature range of Tαc ≤ T < Tm with Tm being the melting point. In this temperature, range, the polymeric crystals show a measure of disorder, observed by several techniques and by small heats and entropies of fusion. A survey of the literature indicates that, in general, polymers which have a αc and are solid‐state extrudable have shallow and broad bottoms to the energy‐wells describing their most stable crystalline conformations, and polymers showing no αc have steep‐walled energy‐wells for the same conformations.