A new strategy to improve the gas barrier property of isobutylene-isoprene rubber/clay nanocomposites

A new strategy for preparation of isobutylene-isoprene rubber (IIR)/clay nanocomposites is reported. based on two steps, i.e., preparation of swollen orgnomontmorillonite, followed by shear mixing on a two-roll mill with IIR. The dispersion of clay was investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM images demonstrate that both exfoliated and intercalated nanoclay layers co-exist in these nanocomposites. XRD patterns reveal that the basal spacing of clay increases from 4.2 nm for swollen organic modified silicates to 6.2 nm for those dispersed in nanocompounds, and the dispersion structure is extremely disordered and close to an exfoliated structure. The experimental results show that the mechanical and gas barrier properties of nanocomposites increased with increasing amount of clay. The properties of nanocomposites prepared by the new method, such as shore A hardness, tensile strength, air-tightness and so on, were superior to those of nanocomposites by the solution intercalation and the traditional melt intercalation methods with non-swollen organic clay. The IIR/clay nanocomposites which were prepared by the novel method could be used in rubber products which require a high barrier to gas, such as tire inner-tube and inner-liner. (C) 2007 Published by Elsevier Ltd.