Title: Validation of CFRP Surface Preparation using Water Contact Angle

Authors: Matthew Nichols, Rose Roberts, Giles Dillingham, Sam Newton, Monika Rakoczy

DOI: 10.33599/nasampe/c.24.0270

Abstract: Carbon-fiber reinforced polymers (CFRPs) are an increasingly popular class of materials with applications in several industries, such as structural materials for adhesively bonded vehicles. A central component in achieving reliable adhesive performance is high quality surface preparation prior to bonding. In this study, water contact angle was used to gauge the quality of several different surface preparation methods on unidirectional toughened prepreg CFRP panels. Panels were prepared using manual solvent cleaning followed by manual abrasion of varying intensities, grit blasting, or plasma treatment. An array of one hundred water contact angle measurements were taken across the panel surfaces to map any spatial variation in surface state. Panels were then aged under ambient conditions (~21 °C, 40 % RH) and characterized with water contact angle at different time intervals to track the stability of these treatments. Panels were found to be sensitive to the specific choice of surface preparation materials (e.g. stearated vs non-stearated abrasive paper, fresh vs aged grit blast media) which had a significant effect on surface energy. A select set of preparation methods were chosen for adhesion performance testing. Prepared surfaces were bonded into lap shear and double cantilever beam specimens to compare adhesion performance between the treatment types. These CFRP surfaces were found to be sensitive to changes in surface preparation methodology and aging.

References: 1. Hart-Smith, L. ""Adhesive bonding of composite structures - Progress to date and some remaining challenges"" Journal of Composites Technology and Research 24 (2002), DOI: 133-151. 2. Banea, M. & da Silva, L. ""Adhesively bonded joints in composite materials: an overview"" Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 223, (2009): 1-18. 3. Mark Strobel, Christopher S. Lyons, “An Essay on Contact Angle Measurements”, Plasma Processes and Polymers: 10.1002/ppap.201000041. 4. Crane, R., Dillingham, G. & Oakley, B. Progress in the Reliability of Bonded Composite Structures. Appl Compos Mater 24, 221–233 (2017). https://doi.org/10.1007/s10443-016-9523-2. 5. Crane RL, Dillingham G., Composite Bond Inspection. J Mater Sci 43 20 6682–6694 (2008). 6. Gilpin, A.D., B.R. Oakley, R.G. Dillingham, Water contact angle as a quantitative measure of total polyethylene surface energy, J. Adhesion Sci. Technol. 29 9 2015 DOI: 10.1080/01694243.2015.1006906 7. F. J. Boerio , B. Roby , R. G. Dillingham , R. H. Bossi & R. H. Bossi (2007), “Effect of Surface Engineering Processes on the Surface Properties and Adhesive Bonding of Graphite/Epoxy Composites”, Proceeding of the 39th International SAMPE Technical Conference, 2007. 8. D. K. Owens and R. C. Wendt, ""Estimation of the Surface Free Energy of Polymers,"" J. App. Poly. Sci 13 1741-1747 (1969) https://doi.org/10.1002/app.1969.070130815 9. Parker, B. & Waghorne, R. ""Surface pretreatment of carbon fiber-reinforced composites for adhesive bonding"" Composites 13(1982): DOI: 280-288 10. F. J. Boerio , B. Roby , R. G. Dillingham , R. H. Bossi & R. L. Crane (2006) “Effect of Grit-Blasting on the Surface Energy of Graphite/Epoxy Composites”, The Journal of Adhesion, 82:1, 19-37, DOI: 10.1080/00218460500418516 11. Boerio, F. J., B. Roby, R. G. Dillingham, and R. H. Bossi. ""Effect of surface engineering processes on the surface properties and adhesive bonding of graphite/epoxy composites."" In Proceeding of the 39th International SAMPE Technical Conference. 2007. 12. Hart-Smith, L. J.: ""Adhesive Bonding of Composite Structures--Progress to Date and Some Remaining Challenges,"" Journal of Composites Technology & Research, JCTRER, Vol. 24, No. 3, July 2002, pp. 133-153. 13. Bárdos, L., Baránková, H. “Cold atmospheric plasma: Sources, processes, and applications.” Thin Solid Films 518 (2010): 6705-6713. DOI: 10.1016/j.tsf.2010.07.044 14. Dighton, C., Rezai, A., Ogin, S. L., Watts, J. F. “Atmospheric plasma treatment of CFRP composites to enhance structural bonding investigated using surface analytical techniques.” International Journal of Adhesion and Adhesives 91(2019): 142-149, DOI: 10.1016/j.ijadhadh.2019.03.010 15. Kanerva, M. & Saarela, O. ""The peel ply surface treatment for adhesive bonding of composites: A review"" International Journal of Adhesion and Adhesives 43(2013), 60-69.

Conference: CAMX 2024 | San Diego CA

Publication Date: 2024/9/9

SKU: TP24-0000000270

Pages: 16

Price: $32.00