Netzsch TG 209 F1 Libra (Netzsch, Germany) was used for TGA, in conjunction with a Bruker Fourier Transform Infrared (FTIR) spectrometer. PEI-C16 samples were placed in an Al₂O₃ crucible and heated from 28 °C to 800 °C at a rate of 10 °C/min under a nitrogen flow of 20 mL/min. The FTIR spectrometer recorded gas-phase spectra every 3 °C within a range of 650-4400 cm ⁻¹ .