Abstract: This invention is directed to the production of organic-inorganic composite bodies demonstrating electrical insulating characteristics consisting essentially of lithium and/or sodium water-swelling crystals selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structurally-compatible species selected from the group of talc, fluortalc, polylithionite, fluorpolylithionite, phlogopite, and fluorphlogopite, wherein the Li.sup.30 and/or Na.sup.+ ions from the interlayer of said lithium and/or sodium water-swelling mica crystals have been exchanged with an organic polycation, the galleries of said crystals containing an organic polymer exhibiting very low permittivity resulting from the transformation of the organic polycation. The preferred organic polycation is a poly(p-xylene-.alpha.

Abstract: This invention is principally directed to the production of an organic-inorganic composite body demonstrating electrical insulating behavior consisting essentially of lithium and/or sodium water-swelling mica crystals selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structurally-compatible species selected from the group of talc, fluortalc, polyithionite, fluorpolylithionite, phlogopite, and fluorphlogopite, wherein the Li.sup.+ and/or Na.sup.+ ions from the interlayer of said lithium and/or sodium water-swelling mica crystals have been exchanged with ions of a transition metal having multiple oxidation states, the galleries of said crystals containing an organic polymer exhibiting very low permittivity. The preferred organic polymer exhibiting very low permittivity is the emeraldine base form of polyaniline.