Accession Number : ADA304557

Title :   Investigation of the Feasibility of Developing Low Permeability Polymeric Films.

Descriptive Note : Contractor rept. 1 Apr 70-Sep 30 71,

Corporate Author : BOEING AEROSPACE CO SEATTLE WA

Personal Author(s) : Hoggatt, J. T.

PDF Url : ADA304557

Report Date : DEC 1971

Pagination or Media Count : 97

Abstract : The objective of this program was to determine tbe feasibility of reducing the gas permeability rate of Mylar and Kapton films without drastically effecting their flexibility characteristics at cryogenic temperatures. This feasibility was established using a concept of diffusion bonding two layers of metallized films together forming a film-metal-film sandwich laminate. The permeability of Kapton film to gaseous helium was reduced from a nominal 10(exp -9) cc - mm/sq cm sec. cm Hg to 10(exp -13) cc - mm/sq cm - sec. cm Hg with some values as low as 10(exp -15) cc - mm/sq cm - sec - cm Hg being obtained. Similar reductions occurred in the liquid hydrogen permeability at -252 deg C (-423 deg F). In the course of the program the permeability, flexibility and bond strength of plain, metallized and diffusion bond film were determined at +25 deg C (+70 deg F), -195 deg C (-320 deg F) and -252 deg C (-423 deg F). The cryogenic flexibility of Kapton film was reduced slightly due to the metallization process but no additional loss in flexibility resulted from the diffusion bonding process. jg

Descriptors :   *PERMEABILITY, *GASES, *POLYMERIC FILMS, LOW TEMPERATURE, LAYERS, LAMINATES, METAL FILMS, DIFFUSION BONDING, STRENGTH(MECHANICS), MERCURY, HELIUM, LIQUID HYDROGEN, CRYOGENICS, METALLIZING.

Subject Categories : Coatings, Colorants and Finishes
      Polymer Chemistry
      Laminates and Composite Materials
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE