Synthesis and Characterization of Novel Poly(Amide-Imide-Sulfone)/TiO₂ Nanocomposites via Sol–Gel Route

Nanoscale titanium dioxide (TiO₂) particles in poly(amide-imide-sulfone) (PAIS) were successfully fabricated by an in-situ sol–gel process. Bis[4,4′-(trimelliticamido)phenyl] sulfone (3) was synthesized as a new dianhydride. This monomer was characterized by its FT-IR, ¹HNMR and ¹³CNMR spectra. The poly(amic acid) precursors was prepared by reaction of dianhydride 3 with 4,4′-diaminodiphenyl sulfone, which was further mixed with tetrabutyl orthotitanate (Ti(OBu)₄) and actylacetone and then heated to complete polymerization and production of nanocomposite. The nanocomposites were characterized by different methods such as FT-IR, UV-Vis, XRD spectroscopy and thermal gravimetric analysis (TGA). Transmission electron microscope (TEM) and scanning electron microscope (SEM) images show that the TiO₂ phase is well dispersed in the polymer matrix. The titanium content in the composites was varied from 0 to 20 wt.%. The effects of TiO₂ content on the composites properties were also investigated.