Synthesis and electrical properties of 1,2,4,5-tetramethylbenzene-crosslinked conjugated polymer and copolymers

Abstract

Many organic polymer research groups have studied PPV and its derivatives. We synthesized crosslinked conjugated conducting polymer via water soluble precursor route. 1,2,4,5-Tetramethylbenzene crosslinked conjugated polymer and copolymers with poly(2,5-dimethoxyphenylene vinylene) unit were characterized by thermogravimetry(TGA, DSC), NMR, IR and UV-VIS spectrophotometry. The actual compositions of the copolymers were determined by elemental analysis. Homo film was brittle and it was not stretched. It was undopable with $I_2$ but the maximum conductivity of $FeCl_3$ doped homo film was $2.90\times10^{-6}$ (S/cm). Copolymers were not nearly stretched. They showed maximum conductivities of 33.47 (S/cm) and 68.33 (S/cm) respectively, when doped with $I_2$ and $FeCl_3$. As the contents of tetramethylbenzene units increased, the maximum conductivity of copolymers decreased. In contrast to the copolymers with PDMPV, copolymers with PPV were stretched very well and showed the maximum conductivity of $4.8\times10^{-2}$ (S/cm), when doped with $I_2$.