Synthesis, Characterization, and Enhanced Antibacterial Activity of Chitosan-Based Biodegradable Conducting Graft Copolymers

In this study, synthesis, characterization, and antibacterial activity of chitosan-based biodegradable conducting graft copolymers namely polyaniline-g-chitosan, polypyrrole-g-chitosan, and polythiophene-g-chitosan with chemical oxidation method using (NH4)(2)S2O8 and FeCl3 as initiators were investigated. Characterizations of the materials were carried out by means of Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, UV-vis, thermogravimetric analysis, scanning electron microscope, transmission electron microscope, and temperature-dependent electrical conductivity measurements. The grafting yield, grafting efficiency, particle sizes, dielectric constants, and densities of the conducting graft copolymers were determined. Grafting process improved the conductivities and thermal stabilities of the copolymers. The conducting polymer-g-chitosan copolymers were also tested against Klebsiella pneumoniae, Escherichia coli, Bacillus megaterium, Enterococcus faecalis, Staphylococcus aureus microorganisms and relatively higher or equipotent antibacterial activities were determined against the microorganisms compared with Penicillin, Amikacin, Erythromycin, Rifampicin, and Trimethoprim antibiotics. POLYM. COMPOS. 36:497-509, 2015. (c) 2014 Society of Plastics Engineers