Abstract
Phthalic acid (benzene-1,2-dicarboxylic acid, PA) and trimesic acid (benzene-1,3,5-tricarboxylic acid, TA) have been reacted with 3-aminopropyltriethoxysilane (APTES) at 110 °C and 220 °C (molar ratios 1:1 and 1:2). The reaction at 110 °C resulted in the formation of the corresponding poly(amic acid), whereas the thermal imidization at 220 °C gives rise to the formation of a cyclic polyimide moiety as shown by means of Fourier transform infrared spectroscopy (FT-IR). X-ray powder diffraction (XRPD) measurements revealed that a specific periodic arrangement in the as-prepared materials had been formed. Thermogravimetric analysis (TGA) made evident that the organic-inorganic nanocomposite materials showed improved thermal properties. The reaction of PA with APTES (1:1) at 220 °C is assumed to yield a ladder-like polysilsesquioxane.