In the paper, nanocomposites based on diisopropylammonium iodide (DIPAI.) and Al2O3 nanoparticles (sized 100 nm) have been synthesized with varying a volume fraction of the latter (0.05, 0.10, 0.20). Temperature dependences of the permittivity and a signal of differential thermal analysis of the samples (in the range of 300 – 400 K) were studied in heating and cooling modes. Their infrared spectra were recorded at room temperature as well. An analysis of the measured temperature dependences indicated a change in the sequence of phase transitions in nanocomposites compared with the pure DIPAI. The totality of the results obtained allowed us to conclude that a change in hydrogen bonds with the participation of amino groups manifested itself in the nanocomposite structure took place. This can lead to the appearance of a ferroelectric state in the DIPAI.