Fabrication and characterization of poly(benzimidazole-amide)/functionalized titania nanocomposites containing phthalimide and benzimidazole pendent groups

In the present study, novel poly(benzimidazole-amide)/titania (PBIA/TiO2) nanocomposites containing phthalimide and benzimidazole pendent groups with different amounts of modified titania nanoparticles (TiO2 NPs) were successfully fabricated through ultrasonic irradiation technique. Due to the high surface energy and tendency for agglomeration, the surface TiO2 NPs was modified by a coupling agent as (3-methacryloxypropyl)trimethoxysilane (MPS) to form MPS-TiO2 nanoparticles. FTIR spectroscopy confirmed that MPS was successfully grafted onto the TiO2 nanoparticles surface through Ti-O-Si chemical bonds. Thermogravimetric analysis (TGA) revealed a surface coverage of the coupling molecule of 2.8 wt.%. The resulting nanocomposites were fully characterized by FTIR spectra, X-ray diffraction (XRD) patterns, scanning electron microscopy (SEM), and TGA. SEM analyses of nanocomposites were performed in order to investigate the dispersion of nanofillers in the PBIA matrix. The TGA results of PBIA/TiO2 nanocomposites showed that the thermal stability is obviously improved the presence of MPS-TiO2 NPs in comparison with the pure PBIA and that this increase is higher when the NP content increases.