Synthesis and thermomechanical characterization of polyimides reinforced with the sol–gel derived nanoparticles

Polyimide-based nanocomposites prepared by the in situ generation of inorganic nanoparticles (silica) through the sol–gel process were characterized by kinetics of water uptake, ther mogravimetry and dynamic mechanical analysis.Silica particles turned out to possess a rather loose inner structure characterized by enhanced water diffusivities andby dynamic elasticity moduli comparable to that of the pristine, glassy PI. Thermal stability and thermomechanical properties of nano composites in the glassy state remained nearly the same as those of the pristine PI, while a significant reinforcement effect was observed for the rubbery PI matrix.