Thioctic Acid-Derived Reversibly Cross-Linked Plastics and Carbon Fiber-Reinforced Polymer Composites With High Mechanical Robustness and Excellent Chemical Recyclability.

Abstract

Replacing petroleum-derived monomers with bio-based alternatives offers a promising route to reducing the environmental footprint of plastics. However, only a few polymeric materials designed in this way can selectively recover valuable petroleum-derived segments. Herein, we report a novel strategy to construct petroleum/bio-based hybrid plastics with high tensile strength and chemical recyclability, by cross-linking thioctic acid and aromatic petroleum-derived epoxy monomers through dynamic imine, disulfide, and hydrogen bonds, denoted as TAE. Benefiting from the reversibly cross-linked network, TAE exhibits excellent mechanical properties (Young's modulus of ∼2.52 GPa, tensile strength of ∼82.1 MPa) and remarkable water stability. TAE was further combined with carbon fibers (CFs) to produce CF-TAE composites with outstanding mechanical performance comparable to commercial CF-epoxy thermoset composites. The dynamic imine bonds can be broken by immersing the TAE plastic sheets in a mixed solvent of a polar organic solvent and acidic solution, enabling the non-destructive recovery of CFs and the petroleum-derived monomer. Meanwhile, the residual bio-based components can be safely discarded without environmental concerns. This work addresses critical challenges in the design of sustainable polymeric materials, providing a promising strategy toward next-generation recyclable plastics and fiber-reinforced composites.