Preparation and Characterization of the Flexible Polypyrrole Film with High Densityt Fenc CHEN and XIANGHONG PENG Thermal properties of polypyrrole film: The TGA curves of the polypyrrole film with the current density of 1 and 5 The FTIR spectra of polypyrrole film are shown in Fig. 1. The peak at 1508 cm'(-C=C-) and 1408 cm' (-C-N-) are assigned to the asymmetric and symmetric stretching vibration of the polypyrrole, respectively. The peak at 698 cm’ belongs to C-H ring-wagging vibration of the polypyrrole ring’. Raman spectra are shown in the Fig. 2, the Raman spectra of polypyrrole include the peaks at 977, 1050, 1350 and 1578 cm'7*. The small peaks near 977 and 1050 cm" have been asso- ciated with the polaron structure. the broad peak snear 1350 and 1578 cm' should correspond to ring stretching mode of the polymer backbone and conjugated structure, respectively”*’. Morphologies and flexible of polypyrrole film: The SEM images of polypyrrole film are shown in Fig. 4. The surface of polypyrrole film exhibited a more homogeneous and semi- microsphere with compact layer (Fig. 4a). The magnified image of a semmicrosphere indicate there exhibit the complex density polypyrrole layer which benefit for the flexible properties of film, as shown in Fig. 4b. In the initial polymerization, a small amount of water can influence the formation of the intermediate cation and reduce the amount of the dissolved intermediate polypyrrole. The water also reduces rejection between the intermediate cation and makes pyrrole form orderly pile molecular chain. So the pyrrole is assembled to form the semimicrosphere in an acetonitrile/water (99/1) mA/cm’ are shown in Fig. 3. The first weight lose of poly- pyrrole film is caused by removing dopant and the second weight lose correspond the polymer degradation. The weight loss of polypyrrole film are about 23.19 and 29.23 % under 1 and 5 mA/cm’current density, respectively, indicating that the film synthesis at | mA/cm’ own good The density of the polypyrrole film is 1. thermal stability. 7 and 1.03 g/cm* with the current density of 1 and 5 mA/cm’, respectively. As reported, the density of polypyrrole film is usually from 0.6 to 0.8 g/cm’ by electrochemical method, the high density poly- pyrrole film is 1.4 g/cm’ with current density of 0.02-0.05 mA/cm’ at -40 °C temperature’. In this wor k, the high density polypyrrole films have been synthesized at room temperature. Preparation and Characterization of the Flexible Polypyrrole Film with High Density 5603 It is observed that polypyrrole film show no folding traces when the film is folded 180° for 20 times, as shown in Fig. 4d. After bending 100 times, the film shows little breaking trace. The result indicates that the film has excellent flexibile properties which can be folded by large angle or strength. The flexible material has the potential application for the flexible supercapacitor electrode. The flexible properties of polypyrrole film due to its homogeneous surface and high density.
