Energy & Fuels 1987,1, 121-122
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Communications 13C CP/MAS NMR Study of Changes in Molecular Mobility of Coal after Pyrolysis at 590 OC Sir: It is generally accepted that the organic part of coal can be considered as being composed of two components. The first component is the macromolecular, insoluble, three-dimensional network composed of condensed aromatic and hydroaromatic units held together by chemical cross-links formed by ether, methylene, or alkyl bridges. The second molecular component includes compounds having relatively low or medium molecular mass (