Preparation and properties of polyimide/Silica hybrid nanocomposites

In this study, a commercially available nano-sized silica (SiO2) was surface-modified via esterification with oleic acid (OA), a relatively inexpensive and hydrophobic modifier. The surface-modified silica (SiO2-OA) nanoparticles were used to disperse in the poly(amic acid) solutions of a commercial polyimide (PI), used for two-layer film, and thermally imidized to form a series of PI/silica nanocomposites. The effects of the addition of SiO2-OA nanoparticles on the properties of the as-prepared PI/silica nanocomposites were studied. The results indicated that the as-prepared PI/silica nanocomposites exhibited improvements in the dynamic mechanical property, thermal stability, water resistance, and thermal expansion.