Studies of the conductive polymer polyaniline and polyarylenes derived from bis-ortho-diynylarene (BODA) monomers: Syntheses, characterizations, solution properties and microfabrication

This study includes two types of polymers. The first is inherently conductive polymer polyaniline and the second is polyarylenes derived from bis- ortho-diynylarene (BODA) monomers. The systematic investigation of polymerization of aniline and reaction conditions was examined to optimize the yield. The structure of the polymer, its oxidation states and the salt form were characterized using UV-VIS, FTIR, WAXD and GPC. The thermal behavior and stability of these forms were investigated by TGA. The solubility properties were studied using Membrane Osmometry. A series of studies have been carried out on polyaniline emeraldine base (EB), leucoemeraldine base (LEB) and pernigraniline base (PN) in an effort to determine the molecular weights by membrane osmometry. The osmotic pressures were determined on various concentrations of EB, LEB and PN solutions in the solvent N-methylpyrrolidinone (NMP). The reduced osmotic pressure of EB, LEB and PN base forms of polyaniline in NMP were measured, molecular weights determined and the theta temperatures determined.; Also, this study includes the synthesis of inherently conductive polyaniline using the optimized process described herein to prepare polyaniline/carbon nanotube (PANI/MWNT) composite films. The PANI/MWNTs composites were fabricated by in-situ polymerization and ex-situ solution mixing. The electrical conductivities of hydrochloric acid doped PANI film and PANI/MWNT composite film were measured. The PANI/MWNTs composites were also investigated by spectroscopic methods, including UV-VIS, FTIR, and WAXD. The morphology of the composite film was examined by TEM and SEM.; The second part of this study focuses on the preparation of new carbon precursors from BODA monomers which undergo thermal step-growth polymerization to reactive and processable intermediates. Fabrication, followed by thermal cure and carbonization result in solid or hollow carbon fiber prototypes with interesting thermal and electrical properties. The BODA polymerization and fiber formation were investigated by TGA, DSC, WAXD, GPC and Raman Spectroscopy. The conductivities of fibers were measured by a two-probe technique. The surface morphology and dimensionality of the fibers were examined by SEM.; Also, BODA-derived microstructures and microgratings were prepared. The BODA-derived microstructures were prepared by micromolding and micro-transfer molding using “soft lithography technique”. In addition, this study includes the synthesis of new nitrogen-containing monomers and examination of the polymerization conditions, characterization and processibility of these polymers.