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Combustion of PTFE: The Effects of Gravity and Pigmentation on Ultrafine Particle GenerationUltrafine particles generated during polymer thermodegradation are a major health hazard, owing to their unique pathway of processing in the lung. This hazard in manned spacecraft is poorly understood, because the particulate products of polymer thermodegradation are generated under low gravity conditions. Particulate generated from the degradation of PolyTetraFluoroEthylene (PTFE), insulation coating for 20 AWG copper wire (representative of spacecraft application) under intense ohmic heating were studied in terrestrial gravity and microgravity. Microgravity tests were done in a 1.2-second drop tower at the Colorado School of Mines (CSM). Thermophoretic sampling was used for particulate collection. Transmission Electron Microscopy (TEM) and Scanning Transmission Electron Microscopy (STEM) were used to examine the smoke particulates. Image software was used to calculate particle size distribution. In addition to gravity, the color of PTFE insulation has an overwhelming effect on size, shape and morphology of the particulate. Nanometer-sized primary particles were found in all cases, and aggregation and size distribution was dependent on both color and gravity; higher aggregation occurred in low gravity. Particulates from white, black, red and yellow colored PTFE insulations were studied. Elemental analysis of the particulates shows the presence of inorganic pigments.
Document ID
19970020588
Document Type
Conference Paper
Authors
McKinnon, J. Thomas (Colorado School of Mines Golden, CO United States)
Srivastava, Rajiv (Colorado School of Mines Golden, CO United States)
Todd, Paul (Colorado Univ. Boulder, CO United States)
Date Acquired
August 17, 2013
Publication Date
May 1, 1997
Publication Information
Publication: Fourth International Microgravity Combustion Workshop
Subject Category
Materials Processing
Funding Number(s)
CONTRACT_GRANT: NAG3-1628
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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IDRelationTitle19970020547Analytic PrimaryFourth International Microgravity Combustion Workshop
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