in: Polymer Surface Modification: Relevance to Adhesion, Volume 2, Kash L. Mittal, Editor, CRC, New York , New York, pp.215-224, 2023
The surface treatment of Grafil carbon fibers was investigated using selected monomers via plasma polymerization. To have a better understanding of the effects of various plasma treatments employed on the mechanical properties of carbon fibers as well as of carbon fiber/epoxy composites, single filament and three point bending tests were carried out. Surface energies of fibers were determined by measurements of contact angles using the Wilhelmy plate technique. The topography of carbon fiber as well as of fracture surfaces of carbon fiber/epoxy composites, before and after plasma treatments, were investigated by scanning electron microscopy (SEM). A qualitative agreement between an increase in the strength of the plasma polymer coated fibers and an increase in the surface energy of the fibers was observed. It is found that the monomers used during plasma polymerization process at selected plasma conditions lead to significant improvement in both interlaminar shear strength (ILSS) and flexural strength values of the composites.