Fungal‐Assisted Recycling of Carbon‐Fiber‐Reinforced Polymer Waste via Mechanistically Informed Hybrid Pathways

Abstract

Epoxy‐based carbon‐fiber‐reinforced polymer (CFRP) composites are increasingly used in high‐performance applications, yet their highly cross‐linked and chemically resistant matrices remain difficult to recycle sustainably. Conventional recycling methods typically depend on high temperatures, aggressive chemicals, or intensive mechanical processing, which can degrade fiber integrity and impose substantial environmental burdens. Here, we report a hybrid bio‐enabled recycling strategy that integrates targeted physicochemical pretreatments, fungal‐mediated epoxy degradation, and low‐temperature thermal post‐processing to selectively weaken and remove epoxy matrices under comparatively mild conditions. Acetic‐acid solvolysis, ultraviolet irradiation, and oxidative pretreatments increased epoxy bioavailability through surface oxidation, bond cleavage and defect formation. Among four fungal strains investigated, Aspergillus flavus exhibited the highest degradative activity, achieving 15.5% composite mass loss within 30 days following solvolysis pretreatment, compared with 2.1% for Aspergillus niger . Microscopic and spectroscopic analyses revealed progressive resin thinning, fiber exposure and oxidative–hydrolytic depolymerization, with cumulative mass loss reaching 25.5% over 60 days. The 24–48 h high‐rate interval informed a cyclic treatment that produced increased matrix erosion and fiber exposure. Subsequent low‐temperature treatment at 425°C enabled clean fiber recovery with reduced volatile formation. These findings establish a mechanistically informed biological‐thermal pathway for CFRP recycling that supports progress toward circular composite material systems.