Flexible and Stretchable Vitrimers for Sustainable Electronics.

Abstract

The rapid increase in electronic waste (e-waste) necessitates sustainable materials that combine functionality with recyclability. Here, we introduce a novel approach for creating flexible vitrimers─reprocessable polymers with dynamic covalent bonds─for use in electronic applications, such as wiring and connectors. By extending polymer chains and employing transesterification reaction, we develop vitrimers that exhibit tunable viscoelastic properties, high stretchability (over 250% tensile strain), and enhanced toughness (up to 466 J/m³). Our vitrimers demonstrate a topological freezing temperature (T_v) of 185-248 °C, adjustable through catalyst concentration and chain length. The materials are synthesized by using a two-step process involving widely available industrial chemicals. Molecular dynamics simulations provide insight into how chain extension and network topology affect viscoelasticity, supporting the experimental findings. Using transesterification, covalent bonding between flexible and rigid vitrimers can be achieved. We prototype a functional USB cable that successfully transfers power and data, showcases repairability, and is recyclable through a solvent-based process. These results highlight the potential of flexible vitrimers in reducing e-waste and advancing sustainable electronic manufacturing.