Investigation of Oxidative Degradation in Polymers Using (17)O NMR Spectroscopy [electronic resource].
- Published
- Washington, D.C. : United States. Dept. of Energy, 1999.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy. - Physical Description
- 44 pages : digital, PDF file
- Additional Creators
- Sandia National Laboratories, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
Access Online
- Restrictions on Access
- Free-to-read Unrestricted online access
- Summary
- The thermal oxidation of pentacontane (C₅₀H₁₀₂), and of the homopolymer polyisoprene, has been investigated using ¹⁷O NMR spectroscopy. By performing the oxidation using ¹⁷O labeled O₂ gas, it is possible to easily identify degradation products, even at relatively low concentrations. It is demonstrated that details of the degradation mechanism can be obtained from analysis of the ¹⁷O NMR spectra as a function of total oxidation. Pentacontane reveals the widest variety of reaction products, and exhibits changes in the relative product distributions with increasing O₂ consumption. At low levels of oxygen incorporation, peroxides are the major oxidation product, while at later stages of degradation these species are replaced by increasing concentrations of ketones, alcohols, carboxylic acids and esters. Analyzing the product distribution can help in identification of the different free-radical decomposition pathways of hydroperoxides, including recombination, proton abstraction and chain scission, as well as secondary reactions. The ¹⁷O NMR spectra of thermally oxidized polyisoprene reveal fewer degradation functionalities, but exhibit an increased complexity in the type of observed degradation species due to structural features such as unsaturation and methyl branching. Alcohols and ethers formed from hydrogen abstraction and free radical termination.
- Report Numbers
- E 1.99:sand99-1951j
sand99-1951j - Subject(s)
- Other Subject(s)
- Note
- Published through SciTech Connect.
07/20/1999.
"sand99-1951j"
Macromolecules FT
Alam, Todd M.; Clough, Roger L.; Assink, Roger A.; Gillen, Kenneth T.; Celina, Mathew; Wheeler David R. - Funding Information
- AC04-94AL85000
View MARC record | catkey: 14394226