Preparation and Thermal Analysis of Ferric Doped PVA-PVP-PPy Composite Films

The preparation and thermal analysis of flexible blend films of pyrrole (Py) polymerized in aqueous solution of poly (vinyl alcohol) (PVA) and poly (vinyl pyrrolidone) (PVP) is described. In-situ polymerization of pyrrole in aqueous solution of PVA and PVP containing ferric chloride (FeCl(3)) was achieved through vapor sorption, and the films obtained were studied using Differential Scanning Calorimetry (DSC), Thermo-Gravimetric Analysis (TGA) and Differential Thermal Analysis (DTA). No melting endotherm is seen in the DSC and DTA scans of the composite films, indicating that the sample is amorphous. Degradation of the sample is found to occur at lower temperatures, with increase in doping level (wt% of FeCl(3)). DSC study was performed between 40 degrees C and 400 degrees C. Below 1.2 wt % DL, degradation of the sample occurs in two stages, the first at 310 degrees C and the second at 440 degrees C, as seen from DTA and TGA scans. The broad endotherm between 80 degrees C and 120 degrees C is due to volatization of moisture (water) absorbed by the sample. Multiple endotherms are observed in DSC and DTA scans of the composite films, for FeCl3 doping levels above 3.8 wt %, and the sample degrades in many different stages at lower temperature, with increase in doping level, as revealed by weight losses in the TGA curve.