TEM Studies of Protective Al Coatings on Kapton H


Polymeric materials undergo rapid erosion when exposed to the harsh low-earth-orbit (LEO) environment. Coatings can reduce the erosion rate of polyimide Kapton from atomic oxygen (AO) attack. Specifically, we are investigating how thin Al coatings can protect Kapton. Protective Al layers with variations in layer thickness and growth conditions were deposited on Kapton H. The quality of these protective coatings were evaluated by mass loss measurement and compared to Kapton alone and the SiO2 coating, where dramatically decreased erosion rate was noted. To understand how these coatings protect Kapton as well as how the AO interacts with the coatings, we are investigating the microstructure of these coated materials by plane view and cross-sectional transmission electron microscopy (TEM) methods. To understand the AO degradation mechanism, we attempted to correlate the mass loss with growth conditions and microstructures. We noted a slight improvement in erosion resistance of the Al coating due to the presence of the dendrimer, but a major improvement when the Al coating is deposited under ultrahigh vacuum conditions.

This is a preview of subscription content, access via your institution.


  1. 1.

    D.G. Zimicik, M. R. Wertheimer, K. B. Balmain & R. C. Tennyson, J. Spacecraft 28, 652 (1991).

    Article  Google Scholar 

  2. 2.

    B.A., Banks, M.J. Mirtich, S.K Rutledge and D.M Swec, “Sputtered Coatings for Protection of Spacecraft Polymers,” presented at The 11th ICMC Conference, San Diego, California, and April 9.13, 1984; published in Thin Solid Films, 127, 1985.

    Google Scholar 

  3. 3.

    B.A. Banks, S.K. Rutledge, L. Gebauer and C. LaMoreaux, “SiOX Coatings for Atomic Oxygen Protection of Polyimide Kapton in Low Earth Orbit,” AIAA 92.2151, presented at The Coatings Technologies for Aerospace Systems Specialist Conference, Dallas, Texas, April 16.17, 1992.

    Google Scholar 

  4. 4.

    B.A Banks, S.K. Rutledge and M. Cales, “Performance Characterization of EUREKA Retroreflectors with Fluoropolymer Filled SiOx Protective Coatings,” Proceedings of the Third LDEF Post-Retrieval Symposium, NASA Langley Research Center, Williamsburg, VA, November 8.12, 1993.

    Google Scholar 

  5. 5.

    M.J. Forkapa, B.A. Banks, S.K. Rutledge, C.R. Stidham, D. Ma, and E. Sechkar, “Atomic Oxygen Durability Testing of an International Space Station Solar Array Validation Coupon, presented at The Third International Space Conference, Toronto, Canada, April 25.26, 1996.

    Google Scholar 

  6. 6.

    A. Snyder and K.K. de Groh, “The Dependence of Atomic Oxygen Undercutting of Protected Polyimide Kapton H Upon Defect Size,” presented at the 8th International Symposium on Materials in a Space Environments and the Fifth International Conference on Protection of Materials and Structures for LEO Space Environment, Arcachon, France, and June 5–9, 2000.

    Google Scholar 

  7. 7.

    F. Xu, L. Li, J. C. Yang, S. C. Street, J. A. Barnard, Microsc. Microanal. 8 (Suppl. 2), 1120 (2002).

    Article  Google Scholar 

  8. 8.

    R.E. Smallman, Modern Physical Metallurgy, fourth ed. (Butterworth & Co (Publishers) Ltd, London, 1985) pp.146–8.

    Google Scholar 

Download references


The authors would like to thank Mr. Michael McCarthy at International Instrument Sales, Dr. Gregory M Becker at RMC, Mr. Helmut Gnaegi at Diatome Ltd, Biel, Switzerland and Mr. Joseph Suhan at Carnegie-Mellon University for the help with cross-sections using ultramicrotome. One of the authors (J Yang) was supported through NASA Faculty Fellowship. The research has been supported by MURI-AFOSR (#F49620-01-1-0336).

Author information



Corresponding author

Correspondence to Judith C. Yang.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Yang, J.C., Xu, H., Li, L. et al. TEM Studies of Protective Al Coatings on Kapton H. MRS Online Proceedings Library 851, 535–540 (2004). https://doi.org/10.1557/PROC-851-NN9.8

Download citation