Effects of Heat Sterilization and Vacuum Exposure on Some Low-Density Heat-Shield Materials.

Abstract

The effects of dry heat sterilization for 92 hours at 135 deg C in flowing nitrogen and 200 hours of exposure at 66 deg C to pressures in the 10(-5)-N/m(2) range upon the thermochemical properties of five blown-foamed and five molded composite heat-shield materials have been determined. Differential thermal analysis (DTA) was employed to follow the changes which occurred in each material as a result of sterilization and vacuum exposure. The results show that, on the whole, the composite materials have greater sterilization mass losses than the foamed materials and that the high-vacuum losses of both types of material are approximately equal. During high-vacuum exposure, the mass loss was approximately 1 percent after 200 hours of exposure, and at 200 hours the rate of mass loss ranged between 2.5 x 10 (-4) and 11.1 x 10(-4) percent per hour for most of the materials.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1970
Accession Number
ADA310201

Entities

People

  • George F. Sykes Jr

Organizations

  • Langley Research Center

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Ablative Materials
  • Aging (Materials)
  • Composite Materials
  • Differential Thermal Analysis
  • Endothermic Reactions
  • Heat Energy
  • Heat Shields
  • Low Density
  • Material Degradation Processes
  • Materials
  • Materials Processing
  • Polymer Degradation
  • Polymers
  • Resins
  • Silicone Plastics
  • Thermal Analysis
  • Thermal Properties

Fields of Study

  • Agricultural and Food sciences

Readers

  • Battery Technology and Engineering
  • Combustion and Flow Dynamics.
  • Mechanical Engineering/Mechanics of Materials.