Synthesis and characterization of conducting polymer grafted polyphosphazenes

Substances can be classified in three main groups according to their electrical conductivity; conductor, insulator and semiconductor. Evolving technology and increasing energy demand forces industry to develop new materials that have metallic or semiconducting properties for application. For example, in a solar cell or in an OLED electrode material must be electrically conductive while providing sufficient light transparency. Electrical conductivity of polymers can find applications to process such as transistors, sensors, electrochromic mirrors, radar camouflage, electrostatic packaging materials. Today's silicon-based semiconductor technology requires high-purity silicon, special production methods in clean rooms to process successful devices. Therefore, the processing of silicon-based devices is not easy and cheap. As an alternative to this technology the materials developed based on conducting polymers is relatively easy. PEDOT, PPy and PANI are the most attractive and studied types of the conducting polymers due to the stability, high electrical conductivity and easy preparation procedures. Regarding both the scientific community and industry a lot of work take place in the technological applications and continues at a great pace. The main problems encountered in high-tech applications of PEDOT, PPy and PANI are insolubility or infusibility and low mechanical properties. Several attempts have been considered to increase solubility and thus make them process-able. In this respect, development of new types of PEDOT, PPy and PANI polymers that can provide sufficient mechanical properties, solubility, electrical conductivity are very important to overcome the problems encountered during the processing and thus technological applications. Polyphosphazenes are an important class of inorganic polymers that are known to be thermally and oxidatively stable and the physical and chemical properties of the polymers can be fine-tuned according to the substituted group. The scope of this thesis is to constitute the superior properties of polyphosphazenes with 3,4-ethylenedioxythiophen (EDOT) and pyrrole. The thiophene, pyrrole and acid (sulfonic and phosphonic acid) group bearing novel polyphosphazenes are synthesized and then polymerised via chemical oxidation to yield PEDOT and PPy grafted polyphosphazenes. After purification of the obtained polymers, structures of these novel polymers characterised by spectroscopic techniques. Thermal, electrochemical, surface and conductivity properties of the new polymers are investigated. Keywords: Graft polymer, PEDOT, Polypyrrole, Polyphosphazene, Conductive polymer