Improved mechanical properties of a polar polythiophene through copolymerization or blending with urethanes

Abstract: Polar polythiophenes with oligoethylene glycol side chains are a developing class of materials that are great candidates for energy harvesting and storage as well as bioelectronics. The polar side chains enhance the compatibility with molecular dopants and improve the electrical conductivity and thermal stability of the doped material. However, polar polythiophenes are extremely soft at room temperature due to a sub-zero glass transition temperature. To enhance the usefulness of these polymers in electronic devices, strategies are needed for tuning their mechanical properties, particularly increasing their robustness. In this thesis we report our efforts to copolymerize a polar polythiophene with urethane blocks to increase the toughness of the material without unduly reducing its electrical and electrochemical properties. Further, we describe wet spinning blend of a polar polythiophene with polyurethane into fibers. The resulting fibers with low hysteresis exhibit elasticity and stretchability, yet higher stiffness.