Extreme wear resistance in carbon nanotube and other nanocarbon filled polytetrafluoroethylene
Authors
Makowiec, Mary Elizabeth
ORCID
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Other Contributors
Blanchet, Thierry A.
Koratkar, Nikhil A. A.
Picu, Catalin R.
Ozisik, Rahmi
Koratkar, Nikhil A. A.
Picu, Catalin R.
Ozisik, Rahmi
Issue Date
2018-05
Keywords
Mechanical engineering
Degree
PhD
Terms of Use
This electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.
Full Citation
Abstract
This dissertation is focused on identifying and analyzing effective nanoscale fillers that reduce the wear rate of sintered polytetrafluoroethylene (PTFE) composites above and beyond the wear rate reduction typically seen from microscale fillers, which typically reduce the wear rate of PTFE by up to 2 orders of magnitude. This work identifies two such nanoscale fillers, carboxyl-functionalized carbon nanotubes and mesoporous nanocarbon, both of which show great promise as PTFE fillers, reducing the wear rate by over three orders of magnitude. This dissertation goes on to explore potential mechanisms by which the fillers reduce the wear rate. In particular, several interesting findings were made. In a similar, but melt-processible fluoropolymer, FEP, which may have better distributed filler through the composite, nanoscale carbon-filled composites had poorer low wear rate performance than when these carbon nanofillers were in PTFE composites, while previously identified nanoscale alpha-phase alumina filled composites had similar wear rates in both polymers, suggesting that there may be different methods of wear reduction caused by these two groups of effective nanoscale fillers. FTIR-ATR analysis demonstrated higher levels of carboxyl ions on the worn surfaces of PTFE composites, which may indicate that PTFE chain scission and metal chelation could be occurring, which can improve the quality not only of the nanocomposite wear surfaces, but also of their transfer films formed atop the mating countersurfaces. In addition, XRD scans indicated that there may be a shift in the crystalline phases that are present at the ambient test temperature employed in wear testing here, which may improve PTFE’s innate resistance to wear and may also result in the production of smaller wear debris.
Description
May 2018
School of Engineering
School of Engineering
Department
Dept. of Mechanical, Aerospace, and Nuclear Engineering
Publisher
Rensselaer Polytechnic Institute, Troy, NY
Relationships
Rensselaer Theses and Dissertations Online Collection
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