skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: 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., CA (US)
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. doi:10.2172/792649.
Dinh, L, and Balooch, M. Wed . "Desorption Kinetics of H2O, H2, CO, and CO2 from Silica Reinforced Polysiloxane". United States. doi: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},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1999},
month = {8}
}

Technical Report:

Save / Share: