Differential scanning calorimetric survey of brominated PAN, pitch-based and vapor-grown fibers
✍ Scribed by D.A. Jaworske; J.R. Gaier; C. Maciag; M.E. Slabe
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- English
- Weight
- 351 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0008-6223
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✦ Synopsis
A differential scanning calorimetric survey of brominated PAN, pitch-based and vapor-grown fibers revealed that only vapor-grown fibers heat-treated to temperatures of 2250°C or above exhibited the phase change at 1OOT associated with the two-dimensional melting of bromine, similar to that observed in HOPG. All the pitch-based fibers tested, as well as vapor-grown fibers annealed to 2250°C showed a substantial decrease in resistivity upon bromination but gave no indication of a phase change, suggesting that the bromine in these fibers does not have the long-range order needed to undergo twodimensional melting. The brominated PAN fibers and unannealed vapor-grown fibers showed no phase change and no change in resistivity, indicating that these fibers do not intercalate bromine.