Characterization and Selection of Polymer Materials for Binary Munitions Storage.
Abstract
The purpose of this study was to investigate the materials properties required for storage of DF (methylphosphonic difluoride) over extended periods of time at temperatures as high as 70 C, anticipating more severe environmental requirements. Specimens of nominally 96/4 ethylene/propylene copolymer were examined by SEM, GPC, FTSIR, X-ray diffraction, and tensile testing. Specimens fabricated into containers and exposed to DF for eight years were compared to control samples of the same vintage and to newly processed polymer sheets of the same resin type. The modular weight distributions were broad, with M sub w values of 160,000 to 170,000 and M sub n values of 24,000 to 30,000. These values were unaffected by exposure to DF with the exception of the interior sidewall, which had been in contact with liquid DF and showed a narrow surface layer of discolored cross-linked material. X-ray diffraction showed the expected 60% crystallinity, but also revealed a pattern of residual stress. However, no loss in mechanical properties was observed. The environmental stress cracking process is the major factor contributing to premature failure in DF containers, with polymer oxidation playing only a secondary role. Materials and processing factors affecting performance are discussed. Further work continues in this area.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1983
- Accession Number
- ADA132428
Entities
People
- C. Richard Desper
Organizations
- United States Army Research Laboratory