Crystal structure of nylon 6/inorganic layered silicate nanocomposite film

Crystal structure of nanocomposite films composed of nylon 6 matrix and synthetic layered silicate as a filler (NCN 6) was analytically investigated using infrared spectroscopy (IR), differential scanning calorimetry (DSC),and X-ray scattering/diffraction. IR spectra indicated that the silicate layers have planar orientation, and Avrami indices obtained from isothermal DSC measurement indicated that the spherulites in the NCN 6 films were crystallized in a two-dimensional fashion. Moreover, X-ray analysis revealed that the fiber axis of gamma-nylon 6 crystallites is parallel to the film surface in contrast with the pure nylon 6 crystallites, which are randomly oriented. As a result, for the NCN 6 films it was considered that the two-dimensional spherulites grown out of silicate layers have planar orientation parallel to the film surface, and this model was able to interpret qualitatively the high gas barrier of NCN 6 films.