| AVS 60th International Symposium and Exhibition | |
| Applied Surface Science | Wednesday Sessions |
| Session AS-WeA |
| Session: | Developments in Electron Spectroscopies for Non-Ideal Samples 2 |
| Presenter: | J.A. Ohlhausen, Sandia National Laboratories |
| Authors: | J.A. Ohlhausen, Sandia National Laboratories M.H. Van Benthem, Sandia National Laboratories M.C. Celina, Sandia National Laboratories |
| Correspondent: | Click to Email |
Elastomers made of organic polymers are used in forms such as O-rings, gaskets and electrical wire insulation. Changes in oxidation can lead to significant performance changes as mechanical properties are affected; therefore it is important to be able to directly measure oxidation of these materials. Elastomers have been found to exhibit diffusion limited oxidation whereby the edges are preferentially oxidized over the interior of the part. Much work has been done to characterize ideal elastomer systems; that is, elastomers with no fillers. Fillers, such as oxides and carbon black, confound most chemical analyses. While studies with non-filled elastomers reveal much about the chemistry and mechanical properties in an aged state, the measurement of the oxidation in “real” systems has often involved modulus profiling but much less chemical analyses. We are developing a method that promises to be effective for measuring the oxidation of filled polymer systems based on intrinsic chemical signatures.
Imaging Near Edge X-ray Absorption Fine Structure (NEXAFS) has been found to be a technique that overcomes the major limitations encountered in filled systems. Located at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratories (BNL), imaging NEXAFS is uniquely capable of measuring the local bonding of elements over large length scales. Thus, the oxidation of these polymers can be directly measured using this technique. We are developing the methods to acquire and process data from samples, ultimately providing a direct chemical measure of oxidation.
In this talk, the results from multivariate analysis of the data are used to calculate oxidation. Specific materials, aging conditions, sample preparation, data acquisition, multivariate analysis and results will be discussed.
**Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.