Surface analysis and adhesion in fluoropolymer
Authors
Dwight, David Walter
ORCID
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Other Contributors
Ross, Sydney, 1915-
Janz, George J.
Wait, Samuel C., Jr.
Hollinger, Henry B.
Janz, George J.
Wait, Samuel C., Jr.
Hollinger, Henry B.
Issue Date
1976-05
Keywords
Physical chemistry
Degree
PhD
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This electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.
Full Citation
Abstract
A semi-empirical way to elucidate adhesive bonding phenomena is based on the surface analysis method guided by qualitative fracture mechanics theory. The latter emphasizesinherent flaws, viscoelastic and
plastic response of materials, crazing, crack propagation and interfacial separation; our method determines the extent of each mechanism. In untreated fluoropolymers, surface molecules transfer to the adhesive even though bond strength is negligible. Surface treatment increases the surface energy via a hydrocarbon layer, the thickness of which varies from ~20A ("Teflon" FEP, Type C or gold-crystallized) to >500A with sodium etching. Increased adhesive bond strength is equivalent and
fracture occurs relatively deep in the fluoropolymer with an amount of plastic deformation related to strength. When the surface treatment is depleted by heat or light, bond strength varies with surface composition.
Cohesive failure occurs in both "Teflon" FEP and "Teflon" PFA used as hot-melt adhesives, but FEP separates much closer to the substrate and with little deformation compared with PFA, which helps to explain the order of magnitude greater strength of the latter.
Description
May 1976
School of
School of
Department
Dept. of
Publisher
Rensselaer Polytechnic Institute, Troy, NY
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Rensselaer Theses and Dissertations Online Collection
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