Abstract:
In this study, nylon 6/clay nanocomposite films were prepared via twin screw extruder attached with blown film set. Nylon 6 was melt blended with organoclay, treated with amine surfactants. The effect of number of long alkyl tail surfactant that used to treated sodim bentonite on the dispersion of clays in nylon 6 nanocomposite films was determined. In addition, the effect of organoclay loading on thermal, mechanical and gas barrier properties of nylon 6/clay nanocomposite films were also studied. In XRD results, nylon 6/clay nanocomposite films, treated with one alkyl tail surfactant (M[subscript 3]T), showed better dispersion of layered silicates than those treated with two alkyl tail surfactant (M[subscript 2](HT)[subscript 2]). However, layered silicates M[subscript 3]T naoncomposite films contained an intercalated structure that was confirmed by TEM image. Moreover, the addition of organoclay into nylon 6 matrix enhanced the formation of gamma–crystalline phase of nylon 6 confirmed by XRD and SDC results. Besides the enhancement of gamma–crystalline phase of nylon 6, the addition of layered silicates leaded to the increase of degree of crystallinity and crystallization temperature (T[subscript c] ). For mechanical properties, M[subscript 3] T nanocomposite films exhibited higher stiffness than M[subscript 2](HT)[subscript 2] nanocomposite films at any inorganic loading. Especially, adding 7 wt% of organoclay into M[subscript 3]T naonocomposite films increased tensile modulus by 167% compared with neat nylon 6 film. Moreover, nylon 6/clay nanocomposite films in machinery direction exhibited higher stiffness than those in transverse direction at any inorganic loading. In addition, oxygen permeability of M[subscript 3]T nanocomposite films exhibited lower than that of M[subscript 2](HT)[subscript 2] nanocomposite films. The oxygen permeabilty of M[subscript 3]T nanocomposite films decreased by 27 percent when organoclay loading approached to 5 wt%.
