Fig. 2. FTIR spectra of TGDDM/DICY system in different curing stages. ((a)4000–2000 cm⁻¹; (b) 2000–400 cm⁻¹) (A) prepolymer, (B) 100 °C/1 h, (C) 100 °C/1 h + 130 °C/1 h, (D) 100 °C/1 h + 130 °C/1 h + 160 °C/1 h, (E) 100 °C/1 h + 130 °C/1 h + 160 °C/1 h + 190 °C/1 h, (F) 100 °C/1 h + 130 °C/1 h + 160 °C/1 h + 190 °C/1 h + 220 °C/1 h, (G) 100 °C/1 h + 130 °C/1 h + 160 °C/1 h + 190 °C/1 h + 220 °C/1 h + 250 °C/1 h, respectively.