| This thesis describes the synthesis of a substituted conducting polymer, poly(aniline boronic acid), in the presence of excess D-fructose and fluoride. Under these polymerization conditions, an anionic tetrahedral boronate species along the polyaniline backbone leads to the self-doped state of the polymer. The properties of this polymer have been investigated including its optical properties, redox activity, molecular weight, conductivity and thermal stability. Due to the boronic acid-saccharide equilibrium reaction, the self-doped state of poly(anilineboronic acid) can be switched to a non self-doped state in a phosphate buffered saline (pH 7.4) and exhibits redox activity in a wide pH range (pH 1-13). The polymer also has a number average molecular weight of 1,100,000 g-mol-1 and a weight-average molecular weight of 1,807,000 g-mol-1 with a polydispersity of approximately 1.7. The high molecular weight is maintained following removal of boronic acid groups via an ipso-substitution reaction, suggesting that the boronic ester crosslinks do not contribute significantly to the high molecular weight observed. According to thermogravimetric analysis results, the thermal stability of the polymer is greater than that of HCl-doped polyaniline and other self-doped forms of polyaniline. Unlike polyaniline, which experiences complete decomposition of the backbone near 400°C, self-doped poly(anilineboronic acid) remains largely intact, possessing a conductivity near 0.01 S-cm-1. (Abstract shortened by UMI.)... |
