HIGH TEMPERATURE RESISTANT ELASTOMER COMPOUNDS
Abstract
The mechanism by which butyl rubger undergoes thermal degradation in the temperature region 300 to 400 F has been investigated. Gas chromatograph techniques have been used to identify the degradation products and to determine their rates of formation. This investigation indicates that degradation upon heating may be initiated at (1) reactive sites already present in the polymer such as catalyst residues, branching, and terminal unsaturation, (2) oxygenated groups such as hydroperoxides formed during exposure to oxygen and which are unstable at low temperature and (3) other oxygenated groups more stable than hydroperoxides and which do not decompose below 400 F. Compounding evaluations were made of resin cured butyl, reclaimed silicone rubber and ethylene propylene rubber. A high temperature, high vacuum stress relaxation apparatus was designed and constructed. A limited evaluation program has indicated the design is satisfactory and the apparatus should prove useful for evaluation of polymers in high vacuum and at temperatures up to 500 F. Minor modification would permit testing in an inert gas atmosphere.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1965
- Accession Number
- AD0475842
Entities
People
- David L. Jividen
- Floyd M. Smith
- George R. Thurman
- Jack D. Rigby
- Marlyn J. Brock