Studies on syntheses and properties of novel CeO2/polyimide nanocomposite films from Ce(Phen)3 complex

A series of cerium dioxide (CeO2)/polyimide (PI) nanocomposites were successfully prepared from Ce(Phen)3 and polyamic acid (PAA) via the solution direct-dispersing method, followed by a step thermal imidization process. TGA and XPS studies showed that the cerium complex decomposed to form CeO2 during the thermal imidization process at 300 °C. SEM observation showed that the formed CeO2 as nanoparticles was well dispersed in polyimide matrix with a size of about 50-100 nm for samples with different contents of CeO2. Thermal analysis indicated that the introduction of CeO2 decreased the thermal stability of nanocomposite films due to the decomposition of Ce(Phen)3 in the imidization process, while the glass transition temperature (Tg) increased obviously, especially nanocomposite films with high loading of CeO2 exhibited a trend of disappearance of Tg. DMTA and static tensile measurements showed that the storage modulus of nanocomposite films increased, while the elongation at break decreased with increasing CeO2 content.