U.S. Department of EnergyOffice of Scientific and Technical Information
Desorption Kinetics of H2O, H2, CO, and CO2 from Silica Reinforced Polysiloxane
Abstract
We performed temperature programmed desorption up to 500K on silica-reinforced polysiloxane in both solid and foamed forms (M9787 and M9750 respectively). Our data show that H{sub 2}O was the dominant desorbing species in both forms of silicone (on the order of 100 {micro}g of physisorbed water and 900 {micro}g of chemisorbed water per gram of polymer), which are expected to be very hydrophilic when dehydrated. Detailed studies of the TPD spectra of H{sub 2}O from the silicones and from the fumed silica fillers suggest that H{sub 2}O molecules preferentially adsorbed on the surface of silica particles contained in the silicones with activation energies of desorption of 15 {+-} 3 kcal/mol and 50 {+-} 10 kcal/mol. There was strong evidence of H{sub 2} desorption below 400K from the silicones. The equivalent concentration of H{sub 2} in the silicones was 0.44 {micro}g of H{sub 2} per gram of silicone. Other species desorbing from the silicones were CO, and CO{sub 2} with concentrations on the order of 2.5 {micro}g, and 1.6 {micro}g per gram of silicone and activation energies of desorption of 10 {+-} 2 kcal/mol and 9.5 {+-} 1.5 kcal/mol, respectively.
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Org.:
- USDOE Office of Defense Programs (DP) (US)
- OSTI Identifier:
- 792649
- Report Number(s):
- UCRL-ID-135387
TRN: US200304%%551
- DOE Contract Number:
- W-7405-Eng-48
- Resource Type:
- Technical Report
- Resource Relation:
- Other Information: PBD: 11 Aug 1999
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; DESORPTION; FILLERS; KINETICS; SILICA; SILICONES; SPECTRA; WATER
Citation Formats
Dinh, L, and Balooch, M. Desorption Kinetics of H2O, H2, CO, and CO2 from Silica Reinforced Polysiloxane. United States: N. p., 1999.
Web. doi:10.2172/792649.
Dinh, L, & Balooch, M. Desorption Kinetics of H2O, H2, CO, and CO2 from Silica Reinforced Polysiloxane. United States. https://doi.org/10.2172/792649
Dinh, L, and Balooch, M. 1999.
"Desorption Kinetics of H2O, H2, CO, and CO2 from Silica Reinforced Polysiloxane". United States. https://doi.org/10.2172/792649. https://www.osti.gov/servlets/purl/792649.
@article{osti_792649,
title = {Desorption Kinetics of H2O, H2, CO, and CO2 from Silica Reinforced Polysiloxane},
author = {Dinh, L and Balooch, M},
abstractNote = {We performed temperature programmed desorption up to 500K on silica-reinforced polysiloxane in both solid and foamed forms (M9787 and M9750 respectively). Our data show that H{sub 2}O was the dominant desorbing species in both forms of silicone (on the order of 100 {micro}g of physisorbed water and 900 {micro}g of chemisorbed water per gram of polymer), which are expected to be very hydrophilic when dehydrated. Detailed studies of the TPD spectra of H{sub 2}O from the silicones and from the fumed silica fillers suggest that H{sub 2}O molecules preferentially adsorbed on the surface of silica particles contained in the silicones with activation energies of desorption of 15 {+-} 3 kcal/mol and 50 {+-} 10 kcal/mol. There was strong evidence of H{sub 2} desorption below 400K from the silicones. The equivalent concentration of H{sub 2} in the silicones was 0.44 {micro}g of H{sub 2} per gram of silicone. Other species desorbing from the silicones were CO, and CO{sub 2} with concentrations on the order of 2.5 {micro}g, and 1.6 {micro}g per gram of silicone and activation energies of desorption of 10 {+-} 2 kcal/mol and 9.5 {+-} 1.5 kcal/mol, respectively.},
doi = {10.2172/792649},
url = {https://www.osti.gov/biblio/792649},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Aug 11 00:00:00 EDT 1999},
month = {Wed Aug 11 00:00:00 EDT 1999}
}