In situ atomic oxygen erosion study of fluoropolymer films using X-ray photoelectron spectroscopy

• Published in: Journal of applied polymer science Vol. 92; no. 3; pp. 1977 - 1983
• Main Authors: Gonzalez, Rene I., Phillips, Shawn H., Hoflund, Gar B.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 05.05.2004; Wiley
• Subjects: Applied sciences; atomic oxygen; Exact sciences and technology; fluorine; fluoropolymers; low earth orbit (LEO); Physicochemistry of polymers; polymer; Polymer industry, paints, wood; polymer, space, fluorine, fluoropolymers; space; Technology of polymers; Linear polymer; Tetrafluoroethylene polymer; Fluorine containing polymer; Vinylidene fluoride polymer; High density ethylene polymer
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.20009

The surfaces of a homologous series of fluoropolymers were characterized in situ using X‐ray photoelectron spectroscopy before and after a 15‐min exposure to the flux produced by a unique hyperthermal atomic oxygen (AO) source, which produces a flux of about of 1015 atoms cm−2 s−1. The linear polymers investigated in this study include high‐density polyethylene (HDPE), poly(vinyl fluoride) (PVF), poly(vinylidene fluoride) (PVdF), and poly(tetrafluoroethylene) (PTFE). They possess a similar base structure with increasing fluorine‐to‐carbon ratios of 0, 1 : 2, 1 : 1, and 2 : 1, respectively. No interaction of the AO with the nonfluorine‐containing linear polymer HDPE was detected over this short exposure. However, a correlation exists between the chemical composition of the fluorinated polymers and the induced chemical and structural alterations occurring in the near‐surface region as a result of exposure to AO. The data indicate that AO initially attacks the fluorine portion of the polymers, resulting in a substantial decrease in the near‐surface fluorine concentration. The near‐surface fluorine‐to‐carbon ratios of PVF, PVdF, and PTFE decreased during the 15‐min AO exposure by 68, 39, and 18.5%, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1977–1983, 2004