A step change in the recycling of composite materials

Solvolysis was applied to carbon fibres and an epoxy resin separately. Neat water as well as acetone, ethanol and 2-propanol were used neat or in mixture with water; neat water was also used expanded with carbon dioxide and oxygen and finally solvolysis assisted with ultrasound was tested. The comparison of the results showed that mixtures with water were more efficient than neat water and the other neat solvents. The best combination was acetone/water in ratio 8:2 in volume. However this did not enable to decrease the operating temperature below 350 °C, nor expansion of water with carbon dioxide and oxygen, and the pressure could reach up to almost 330 bar. Nevertheless complementary experiments are necessary to really assess the interest of those conditions. The fibres could be significantly affected by the conditions, the mixture acetone/water in ratio 8:2 being a good compromise.