Investigation of aqueous sodium dichromate oxidation for coal structural studies

To determine optimum conditions, the aqueous Na₂Cr₂O₇ oxidation as applied to coals, coal products, model compounds and polymers was investigated in detail. It was found that this oxidation preferentially attacks aliphatic and alicyclic methylene linkages with minimum degradation of most aromatic ring systems, as suggested earlier. However, aliphatic-rich macromolecules, probably related to exinites, were found to be selectively oxidized and isolated as long-chain aliphatic dicarboxylic acids under buffer-controlled oxidation conditions.