3 Results and discussion
3.1 TG results
TG can yield important information on a polymer system, such as the volatile content and decomposition temperature. The DTG curve of the polyurethane film is shown in Fig. 2. It is observed that the polyurethane experience three steps to degrade, which likes most thermal degradation studies on other polyurethanes [2]. The first step occurs at the range 150–250 °C. Since we aim to study the primary thermal degradation, 175 °C is chosen for time-dependent IR spectra.