EFFECT OF PLASMA POLYMERIZATION ON CARBON-FIBERS USED FOR FIBER EPOXYCOMPOSITES/

The surface of carbon fibers were modified by plasma polymerization of different monomers such as dioxane and xylene in a radio frequency sp uttering device. Argon, as carrier gas, and air, as a reactive compone nt, were used under different plasma conditions. The operating conditi ons for plasma treatment were first optimized to yield the highest dep osition rates with minimum power input. The topography of carbon fiber s as well as of fracture surfaces of carbon fiber/epoxy composites sur faces, before and after plasma treatments, were investigated by scanni ng electron microscopy (SEM). The surface of untreated and treated car bon fibers was examined by using ESCA. The plasma polymers obtained we re characterized by FTIR spectroscopy. The effects of plasma treatment on the surface of carbon fibers and on the mechanical properties of c arbon fiber/epoxy composites were investigated. Dioxane and xylene pla sma coating were found to be effective in enhancing the interfacial ad hesion between carbon fiber and epoxy matrix as well as increasing the tensile strength of carbon fibers. (C) 1995 Academic Press, Inc.