# Making Carbon-Fiber Reinforced Epoxy-Amine Thermoset Composites More Circular through Chemical Recycling by Catalyzed Solvolysis

## TL;DR

This paper introduces a chemical recycling method for carbon-fiber reinforced epoxy composites, enabling reuse of materials without degradation.

## Contribution

A novel catalyzed solvolysis process is developed for recycling thermoset composites at low temperature and mild pH.

## Key findings

- Carbon fibers are fully recovered with original mechanical properties.
- Recovered oligomers can be reused to fabricate new composites.
- The process is validated on real end-of-life aerospace and sports equipment parts.

## Abstract

The use of carbon-fiber reinforced thermoset polymers
(CFRPs) is
continuously growing in a wide range of manufacturing sectors, particularly
when high performance, lightweight design, and corrosion resistance
are required. However, their multimaterial cross-linked structure
hinders their recyclability, resulting in the extensive generation
of heterogeneous wastes. Nowadays, the correct management of end-of-life
(EoL) thermosetting composites remains an open and unsolved issue.
In this respect, this work presents a chemical recycling process of
a model CFRP from an epoxy-amine network, operated at atmospheric
pressure, relatively low temperature (≤200 °C), and mild
pH (4–5), allowed by the modification of a Lewis acid catalyst.
This process leads to complete liberation of the reinforcing carbon
fibers without dimensional alteration, with mechanical characteristics
fully comparable to the corresponding virgin fibers, and with the
formation of a reusable oligomeric fraction. The recovered components
are successfully upcycled by fabricating second-generation CFRPs.
Finally, the solvolysis process is validated on real EoL composite
parts from aerospace and sports equipment products. This work proposes
an economically feasible, safe, and scalable approach to efficiently
recycle amine-cured epoxy-based CFRPs, with reusability of all fractions
and minimization of any secondary waste generation.