## Abstract Experiments have been carried out to determine the nature and extent of respiratory losses during the curing of ryegrass hay. Fructosans and the total soluble fructose residues decreased almost continuously throughout the drying period. Sucrose contents decreased initially and then incr
Chemical changes during the mild air oxidation of pitch
β Scribed by J.B. Barr; I.C. Lewis
- Publisher
- Elsevier Science
- Year
- 1978
- Tongue
- English
- Weight
- 652 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0008-6223
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β¦ Synopsis
Ahstraet-The chemical changes occurring during mild oxidation of petroleum and coal tar pitch were studied by elementary analysis, solubility measurements, IR and nuclear magnetic resonance spectroscopy and chromatography. The oxidized pitches were compared with pitches which were distilled to give similar softening points. A mild oxidation was shown to induce dehydrogenative polymerization of the pitch components without introducing appreciable amounts of oxygen into the products. The greater reactivity of the petroleum pitch constituents to oxygen is attributed to the presence of alkyl substituents. Study of the mesophase formation and X-ray analysis of the derived graphites showed that mild air oxidation did not affect the subsequent graphitic development.
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X-ray absorption near edge structure (XANES) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to study the chemistry of organically bound sulphur species in coal during mild coal oxidation. Spectra of preserved and oxidized samples were obtained and compared. Both techniques indicat