Preventing Benzoquinone-Based Catalyst Aggregation Enables the One-Step Synthesis of Highly Conductive Poly(benzodifurandione) without Post-Reaction Purification

Abstract

Conductive polymers have become crucial in advancing various electronic applications. While p-type materials like poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) are widely used and produced at scale, the development of high-performance n-type polymers has lagged due to challenges in synthesis and scalability. In this work, a novel method is introduced to synthesize the highly conductive n-type polymer poly(benzodifurandione) (PBFDO) using α-tocopherylquinone (α-TQ) as a catalyst. This approach eliminates the need for post-reaction dialysis, a major obstacle to large-scale PBFDO production. By preventing catalyst aggregation, high electrical conductivity (>1320 S cm⁻¹) is achieved, which remains stable in air for over 180 d, significantly simplifying the process. The α-TQ-synthesized PBFDO also exhibits excellent thermoelectric properties, with a power factor exceeding 100 µW m⁻¹ K⁻², placing it among the highest-performing n-type thermoelectric polymers. Additionally, residual α-TQ acts as a plasticizer, reducing the elastic modulus by over tenfold while maintaining high conductivity, making this material suitable for mechanically compliant electronics. Similarly, residual α-TQ lowers the thermal conductivity of PBFDO by more than an order of magnitude. The process is scalable, as demonstrated by producing high-conductivity ink in a 20 L reactor. This work presents an efficient and sustainable approach for large-scale n-type polymer production.