## 3 Results and Discussion  
Free radical copolymerization of 1-vinyl-1,2,4-triazoleole with \(N\)-vinylcarbazole was carried out at different comonomer ratios in a dimethylacetamide solution under the action of an azobisisobutyronitrile initiator in a sealed ampule in an argon atmosphere. Copolymerization proceeds at a temperature of 60 \({}^{\circ}\)C. The concentration of VT and VK comonomers in the solution and the concentration of the initiator were 3 M and 3 \(\times\) 10\({}^{-2}\) M, respectively (Scheme 1 and Table 1). The compositions of the copolymers were determined from the UV spectra measured at 344 nm (VK absorption band). The extinction coefficients for the comonomer and monomer were taken as equal to the extinction coefficient of the polyvinylcarbazole \(\varepsilon\) = 3500 L/(mol-cm). The molecular weight distribution of the obtained P1-P3 copolymers was studied using gel permeation chromatography (Figure 1). The molecular weight of P1-P3 copolymers depends on their composition. It should be noted that with an increase in the carbazole units in the copolymer and a decrease in the vinyltriazole units, the weight-average molecular weight decreased from 201 to 175 kDa upon passing from the P1 to P3 copolymer. The dispersity (\(D\)) of the prepared P1-P3 copolymers was in the range of 1.76-1.79, i.e., the value of \(D\) did not change significantly (Table 1). Thus, the synthesized copolymers showed a unimodal molecular weight distribution. The FT-IR spectra of the synthesized P1-P3 copolymers are shown in Figure 2. In the P1-P3 spectra, the absorption bands of stretching vibrations of the double bonds of the initial VT and VK monomers disappeared at 1640 cm\({}^{-1}\). This indicates the absence of the initial 1-vinyl-1,2,4-triazole and \(N\)-vinylcarbazole comonomers in the copolymer. The IR spectra of the P1-P3 copolymers show that the characteristic absorption bands of stretching and bending vibrations at 3110-3114 (C-H) and 2932-2934 cm\({}^{-1}\) (CH\({}_{2}\)) were retained for the polymer chain. The IR spectra of P1-P3 poly(VT-_co_-VK) copolymers contained characteristic bands of stretching and bending vibrations of the triazole ring at 1503-1505 (C=N), 1434 (C-N), 1275-1276 (N-N), 1139-1140 (C-H), 1003-1004 (C-H), and 661-663 cm\({}^{-1}\) (C-N). The presence of the carbazole units in the IR spectra of P1-P3 copolymers was confirmed by absorption bands at 1597, 1483-1485, 1452, 1333-1334, 1222-1224, 744-747, and 720-723 cm\({}^{-1}\). Figure 1: Molecular weight distribution of P1–P3 poly(VT-_co_-VK) copolymers (Table 1). Thermal oxidative degradation of P1-P3 poly(VT-_co_-VK) copolymers was studied by thermogravimetric analysis and differential scanning calorimetry. At 50-115 \({}^{\circ}\)C, the adsorbed water was released, accompanied by an endothermic effect and a weight loss of 3% (Figure 3). In the range of 330-450 \({}^{\circ}\)C, thermal degradation of the copolymer was observed, which was accompanied by an exothermic effect with a maximum at 335 \({}^{\circ}\)C. The weight loss of the sample in this case was 64%. The triazole and carbazole rings were abstracted with subsequent oxidation to H\({}_{2}\)O, NO, and CO\({}_{2}\). The next stage of polymer degradation was at 470-640 \({}^{\circ}\)C. The weight loss of the copolymer was 22%. This stage was characterized by the burning out of the carbon skeleton of the polymer chain of the copolymer and the release of C, NO, and CO\({}_{2}\) as a result of the oxidation of decomposition products. The study of thermal oxidative degradation indicated that the thermal stability of the copolymers ranged from 330 to 350 \({}^{\circ}\)C.  
In the \({}^{1}\)H NMR spectra of the obtained P1-P3 copolymers, there were no signals of the protons of the \(N\)-vinyl group, but broadened signals of the protons of the methylene groups of the main polymer chain were observed in the region of 1.40-2.25 ppm (a, e), and broad signals of methine protons of the main polymer chain at 2.6-4.15 ppm (b, f) (Figure 4).