Novel Fluorene and Pyrrole Comprising Copolymers: Effect of Copolymer Feed Ratio on Electrochromic and Electrochemical Properties

Herein, synthesis of two homopolymers namely, poly-2,2′-(9,9-dioctyl-9h-fluorene-2,7-diyl)bisthiophene (PBT), poly-pyrrole-3-carboxylic acid (PP3CA) and fluorene and pyrrole comprising five novel copolymers (CoP1, CoP2, CoP3, CoP4, CoP5) were electrochemically synthesized. Each electrolytic solution was prepared with different monomer feed ratios to investigate the effect of comonomer ratio on electrochromic and electrochemical properties. After synthesis, homopolymers and copolymers were compared in terms of their electrochemical, spectroelectrochemical and colorimetry properties. The number of studies on electrochromic characterization of pristine P3CA group was limited in literature, hence in this study P3CA was electrochemically inserted into the polymer chain via copolymerization.CoP1 with 1:1 (BT: P3CA) monomer feed ratio exhibited the lower optical band gap and red shifted neutral state absorption compared to PP3CA, additionally light yellow color of PP3CA turned out to be multichromic for CoP1with the insertion of BT unit via electrocopolymerization.