Aliphatic bridges, concentrations products

TABLE III. Relative Concentrations of Aliphatic Bridges in Transall lated Products from Fresh and Oxidized San Juan Coal... 

With regard to the results of our infrared study, a word of caution is appropriate. The large decreases in the concentration of the aliphatic bridges after oxidation, as measured by transalkylation (Table III), cannot be expected to match those indicated in the difference infrared spectra between oxidized and fresh coals. This is because the spectra measure the total aliphatic content of the samples, namely aliphatic bridges, hydroaromatics, and aliphatic side chains. In contrast, results in Table II show differences in relative concentrations of the aliphatic bridges, which represent only a part of the total aliphatics. Furthermore, concentrations measured by transalkylation correspond to only the soluble fractions of the reaction products some of the more complex transalkylation products may be retained in the residue itself. 

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