A new type of clay-polyether nanocomposite has been prepared by the
self-polymerization of diglycidyl ether of bisphenol A in the galleries of
acidic alkylammonium ion exchanged forms of montmorillonite. The acid
catalyzed intragallery polymerization process leads to the spontaneous
exfoliation to the 10Å-thick clay layers. Intra- and extragallery
polymerization processes are distinguishable by DSC.
Clay-polyimide hybrid composites have also been prepared by the
intercalation of polyamic acid in montmorillonites and subsequent thermal
conversion to polyimide. In contrast to the completely exfoliated
clay-polyether system, the polyimide system contain regularly intercalated
clay aggregates in the polymer matrix. Although regular face-face clay layer
aggregation is extensive, the clay-polyimide hybrid composite films exhibit
greatly improved CO2 barrier properties.