Preparation of Polyimide-Clay Nanocomposites and Their Performance

A series of polyimide (PI)-organically modified clay nanocomposites were made to enhance tensile modulus, thermal stability of PI. PI was made from 3, 3', 4, 4'-biphenyl tetracarboxylic dianhydride (BPDA), p-phenylediamine (PDA). Montmorillonite (MMT), one type of layered clay, was treated by dodecylamine salt. XRD indicated that organically modified montmorillonite (OMMT) layers were exfoliated and dispersed into PI-film. Tensile measurements indicated that small amount of OMMT (up to 3%) increased tensile modulus nicely. The glass transition temperatures (Tg) of the nano-composites are higher than those of pristine PI. Thermal gravimetric analysis (TGA) showed that nanocomposites have higher decomposition temperatures in comparison with the original PI. Keywords: Polyimide; Organically modified clay; Nanocomposites; Dodecylamine.