Plasma Modification of Graphite Fibers and Its Effect on Composite Properties

摘要

A new method is explored to improve mechanical properties of carbon/graphite (C/G) fiber reinforced composites through chemical modification of the fiber surface. C/G fiber surface was altered by plasma polymerization of acrylonitrile. Modified surface was characterized with ESCA, FTIR, SEM, and wetting angle measurements, using a pyrolytic graphite block, as a model surface to C/G fiber. Acrylonitrile plasma treatment permanently changed the graphite surface to a more polar one with a crtical surface energy for wetting, gamma c, of 54 dynes/cm. Compared to unmodified fibers, plasma treated C/G fiber resulted in substantial improvements in both interlaminar shear and flexural strengths when incorporated uniaxially in epoxy matrices.