Thermo Gravimetric Analyzer (TGA) spectra were recorded on a computer-controlled TG Q50 system (TA, New Castle, PA, USA) after drying at 100 °C, under the following operational conditions: heating rate 10 °C/min, temperature range 100–600 °C, sample weight about 5.0 mg, using the film sample in platinum crucibles, 60 mL/min N2 flow.