Effect of Surface Engineering Processes on the Surface Properties and Adhesive Bonding of Graphite/Epoxy Composites (Preprint)
Abstract
The effect of surface engineering processes such as grit-blasting and plasma etching on the surface energy and composition of graphite/epoxy composites that were cured at 177 C was determined. As-tooled composites had about 73% carbon, 20% oxygen, and 5% nitrogen on the surface. Grit-blasting with 80- or 220-grit garnet resulted in an increase of several percent in the carbon concentration and a similar decrease in the oxygen concentration. However, grit-blasting with 220-grit alumina resulted in a decrease in the carbon concentration of a few percent and a similar increase in oxygen concentration. Etching as-tooled composites in O2 plasmas resulted in a decrease in the carbon concentration and an increase in the oxygen concentration of about 10%. Derivatization of the composite surfaces with trifluoroacetic anhydride and pentafluorobenzalde-hyde enabled the relative numbers of hydroxyl and amino groups on the surfaces to be determined and showed that the surface properties of the composites were dominated by the hydroxyl groups. As-tooled composites had a total surface energy of approximately 35 mJ/sq m; the polar components were small, meaning that the surface energies were mostly dispersive. After grit-blasting with 80- or 220-grit garnet or 220-grit alumina, the polar component of the surface energy increased significantly and the total surface energy was approximately 50 mJ/sq m.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2007
- Accession Number
- ADA475187
Entities
People
- B. Roby
- F. James Boerio
- R. G. Dillingham
- R. H. Bossi
Organizations
- University of Cincinnati