Organoclay/functionalized-graphene dual-filler complex for high-performance polyimide nanocomposites

'-[2,2'-bis(trifluoromethyl)-4,4'-biphenylene]bis(4-aminobenzamide) monomers, and a hybrid PAA was prepared by dispersing a complex filler using a solution intercalation method. The PAA hybrid solution was thermally imidized under various heat treatment conditions to obtain PI nanocomposite films. A novel complex filler containing both clay and graphene was synthesized through organic surface modification to improve compatibility and miscibility with the PI matrix. This dual-filler system was designed to enhance the overall performance of the PI hybrid films by exploiting the synergistic effects of both fillers. In this study, a C8-complex filler composed of octyl-modified montmorillonite and octyl-functionalized graphene was utilized. PI hybrid films were fabricated by dispersing the C8-complex filler into the PI matrix at various loadings ranging from 0 to 2.0 wt%. The effects of C8-complex filler content on the dispersion morphology, thermomechanical properties, and optical transparency of the resulting PI hybrid films were systematically investigated.