Formation of anisotropic mesophase from various carbonaceous materials in early stages of carbonization
The low-temperature carbonization of pitches, reduced crudes, synthetic polymers, and various ranks of coals has been studied by polarized-light microscopy, x-ray diffraction, and solvent extraction. Formation of anisotropic mesophase is a function of heat-treatment temperature and residence time for those materials that pass through a fusion stage in the temperature range from 350 to 500 deg C. The nucleation of spherules from the pitches and reduced crude during low-temperature carbonization is proportional to the amount of BETA - resin, which is benzene-insoluble and quinoline-soluble, and the rate of its formation. Addition of sulfur to the pitch turns the texture of mesophase spherules to that of a fine mosaic when the mixtures are heat treated in the temperature range of 350 to 500 deg C. Methylation of the hydroxyl groups in 3,5- dimethyl phenol formaldehyde resin, by reacting with dimethyl sulphate, gives an anisotropic texture that consists actually of tiny spherules together with parent matrix; the original resin gives the typical mosaic texture. The molecular forces in the decomposing carbonaceous materials during low-temperature carbonization are among important factors governing the mesophase transformation. A common mechanism of formation of various anisotropic textures can explain the behavior of coalcokes, pitch, crudes, and polymers. (auth)
- Research Organization:
- National Research Inst. for Pollution and Resources, Kawaguchi, Japan
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-29-020433
- OSTI ID:
- 4329221
- Journal Information:
- Fuel, v. 52, no. 2, pp. 143-148, Other Information: Orig. Receipt Date: 30-JUN-74
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
Formation of the carbonaceous mesophase from a petroleum-derived paving asphalt
Influence of the. cap alpha. /sub 1/ and. cap alpha. /sub 2/ fractions on the low temperature carbonization of coal tar pitch