In this study, a series of nanocomposite films based on an aromatic polyimide and sulfonic acidfunctionalized magnetic nanoparticles was successfully prepared via an in situ technique. For this purpose, new soluble aromatic polyimide containing sulfone group as a polymeric matrix of the nanocomposites was synthesized. The surfaces of MNP were grafted with 3-mercaptopropyl trimethoxysilane. Then sulfonic acid-functionalized magnetic nanoparticle was obtained by oxidation of the thiol group. Effects of sulfonic acid-functionalized magnetic nanoparticles on thermal, tensile, and magnetic properties of the prepared nanocomposite films were studied. The magnetic nanoparticles containing the sulfonic acid groups could have strong intermolecular bond interactions between the hydroxyl groups of SO3H and the sulfone and carbonyl groups of the polyimide matrix which caused the better dispersion of nanoparticle and exhibited superior mechanical properties, good magnetic properties, and high thermal stability.
