In recent years, donor-acceptor (D-A)-type conjugated polymers have been widely used in the field of organic solar cells (OSCs) and electrochromism (EC). Considering the poor solubility of D-A conjugated polymers, the solvents used in material processing and related device preparation are mostly toxic halogenated solvents, which have become the biggest obstacle to the future commercial process of the OSC and EC field. Herein, we designed and synthesized three novel D-A conjugated polymers, PBDT1-DTBF, PBDT2-DTBF, and PBDT3-DTBF, by introducing polar oligo (ethylene glycol) (OEG) side chains of different lengths in the donor unit benzodithiophene (BDT) as side chain modification. Studies on solubility, optics, electrochemical, photovoltaic and electrochromic properties are conducted, and the influence of the introduction of OEG side chains on its basic properties is also discussed. Studies on solubility and electrochromic properties show unusual trends that need further research. However, since PBDT-DTBF-class polymers and acceptor IT-4F failed to form proper morphology under the low-boiling point solvent THF solvent processing, the photovoltaic performance of prepared devices is not ideal. However, films with THF as processing solvent showed relatively desirable electrochromic properties and films cast from THF display higher CE than CB as the solvent. Therefore, this class of polymers has application feasibility for green solvent processing in the OSC and EC fields. The research provides an idea for the design of green solvent-processable polymer solar cell materials in the future and a meaningful exploration of the application of green solvents in the field of electrochromism.

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High-performance donor-acceptor (D-A) polymers, as an important class of electrochromic (EC) materials, have attracted extensive attention. In this paper, a series of novel poly (aryl amino ketone) (PAAK) and poly (aryl amino sulfone) (PAAS) type high-performance polymers (HPP) with electrochromism were prepared by a simple C-N coupling reaction and were coated on an indium tin oxide (ITO) substrate as EC films. All four polymers were prepared by a nucleophilic substitution reaction using commercially purchased amine monomers with difluoride sulfone/ketone using potassium carbonate as a catalyst. A series of tests were performed to compare and analyze the effects of the different electron-withdrawing abilities of sulfone and carbonyl groups, and the different conjugation lengths of these two TPA structures were connected to the EC properties of the polymer. The different phenyl or biphenyl of the two TPA structures mainly affected the oxidation potential of the polymer, while the sulfone group and the carbonyl group, with a different electron absorption ability, had a greater influence on the energy band and cyclic stability. The optical contrast of PAAS−BT at 850 nm was up to 58% and maintained 450 cycles, indicating that this series of materials had a broad application prospect waiting for further research. In addition to the performance, the raw materials used in this work could be directly and commercially purchased for a low price; the two aniline monomers were priced at about $4 /g and $15 /g, respectively. This method significantly reduces the cost and provides a new idea for subsequent large-scale production and practical applications.