Thermal Transitions and Mechanical Properties of the Films of Chemically Prepared Polyaniline.

摘要

The mechanical and thermal properties of the solution-cast films of chemically prepared polyaniline have been studied by means of dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The glass transition temperature (Tg) of the polyaniline films in emeraldine base form was determined and characterized for the first time to be in the range of ca. 105 to 220 C for the films containing ca.16 to 0% of 1-methyl-2-pyrrolidinone (NMP) residual solvent, respectively, from a decrease in the storage modulus in DMA and from DSC studies. Depending on the content of NMP, the thin films of polyaniline have a storage modulus of ca. 200 MPa to 2 GPa at temperatures below Tg. Other thermal transitions and reactions in the temperature range of ca. 25 to 500 C are also characterized by infrared spectroscopy, x-ray diffraction and cyclic voltammetry and are discussed in relation to the mechanical properties of polyaniline.