The Effect of Gas Bubble Percolation on the Carbonaceous Mesophase Produced from Acenaphthylene,
Abstract
A study of mesophase formation in acenaphthylene was undertaken in an attempt to determine the effect of gas bubble percolation during pyrolysis on the mesophase microstructure. Samples of acenaphythylene approximately 20 g in size were pyrolyzed in test tubes to various temperatures between 400 C and 500 C. Examination of the pyrolysis residues revealed that mesophase spheres up to 14 micrometer in diameter were formed during heating acenaphthylene to 404 C. During heating to 450 C, the spheres grew in size and coalesced to produce regions of fluid coalesced mesophase up to 2 mm in size. Complete conversion to the mesophase occurred between 466 C and 500 C. The mesophase produced from acenaphthylene was found to contain a small amount ( less than 20%) of the fine fibrous microstructure characteristic of good needle cokes and used in graphite manufacture. Acenaphthylene samples about 20 mg in size were pyrolyzed on a mictoscope hot stage. Mesophase formation, coalescence, and deformation due to gas bubble percolation was observed directly at pyrolysis temperatures between 413 C and 455 C. After mesophase formation began at 413 C, gas bubble percolation through the samples was found to cause coalescence of mesophase droplets, formation of defect structures in coalesced droplets, and deformation or stretching of the coalesced mesophase. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1976
- Accession Number
- ADA044631
Entities
People
- Dennis O. Rester
Organizations
- Naval Ordnance Laboratory