Moreover, the TGA integrated with an FTIR gas analyzer identified the gases evolved in the mass loss region. The FTIR spectra of the evolved gases were assessed at six temperatures (Figures and, right side); the chosen based on the temperature range corresponds to the mass loss observed in each residue. The TGA-FTIR spectra for PEI-C16-Cl displayed an absorbance peak at 2345 cm -1 at 70 and 200 °C, assigned to residual CO2, which disappeared at elevated temperatures. As the polymer started degrading at 300 °C, two distinct peaks emerged at 942 and 966 cm -1 , ascribed to ammonia (Figures and). The ammoniaassociated absorbance peaks disappeared at 400 and 500 °C in the PEI-C16-Cl spectra, suggesting quaternary ammonium cation decomposition.