Interface properties of carbon fiber/epoxy resin composite improved by supercritical water and oxygen in supercritical water

The interface properties between the carbon fibers and epoxy resin were improved by the supercritical water and oxygen in supercritical water because the surface roughness and the functional groups containing oxygen were increased obviously compared with that of untreated carbon fibers. This was favorable to improvement of the adhesive strength between the carbon fibers and the resin. The maximal IFSS of the carbon fiber/epoxy resin composite treated by the supercritical water and the oxygen in supercritical water were 58.3 and 92.8 MPa, respectively, which increased by approximately 10% and 75% for 52.9 MPa of the untreated carbon fiber/epoxy resin composite.