Recycling of carbon fiber reinforced plastic containing amine-cured epoxy resin using supercritical and subcritical fluids

• Published in: The Journal of supercritical fluids 2017-01, Vol.119, p.44-51
• Main Authors: Okajima, Idzumi, Watanabe, Kaori, Haramiishi, Shogo, Nakamura, Mizuki, Shimamura, Yoshinobu, Sako, Takeshi
• Format: Article
• Language: English
• Subjects: CFRP; Epoxy resin; Kinetic analysis; Supercritical acetone
• ISSN: 0896-8446; 1872-8162
• DOI: 10.1016/j.supflu.2016.08.015

[Display omitted] •Amine-cured epoxy resin was degraded with supercritical fluids.•Supercritical acetone performed the best in degrading the epoxy resin.•Tensile strength reduction of the recovered carbon fibers was negligible. Chemical recycling of carbon fiber reinforced plastic (CFRP) containing an amine-cured epoxy as the matrix resin was investigated with a process using supercritical alcohols or ketones as solvents. Amine-cured epoxy resin was decomposed by a supercritical solvent (methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, acetone, or methyl ethyl ketone) at 320°C in the reaction time range 6–120min. The decomposition rate depended on the solvent, and super- and subcritical acetone were ultimately selected as optimal for rapidly degrading the matrix resin. The decomposition rate of the epoxy resin using supercritical acetone was expressed by a surface reaction and shrinking core model. The recovered carbon fibers from the CFRP retained the shape of the plain fabric sheets and their tensile strength reduction was negligible.