Nitro-derivatives of lignin

An appreciable part of the lignin molecule is aromatic in character. Hence it would be expected to take part readily in the reaction of nitration. It has been found, however, that the capacity of lignin to undergo oxidation predominates especially in the presence of dilute nitric acid. This can be explained by the fact that the aromatic part of the lignin molecule derives from pyrocatechol. The reaction of lignin with nitric acid forms the basis of a method of separating cellulose from wood pulp, that consists in treating this mass with dilute nitric acid (3-10%). [Pg.433]

The reaction may be applied in analysis or as an industrial process. Thus Krais [57] obtained patents for producing cellulose from wood pulp by means of 3-6% nitric acid. [Pg.433]

The earliest experiments devoted to the nitration of lignin, previously isolated [Pg.433]

Several authors have examined the effect on lignin of nitric acid or its mixture with sulphuric acid. [Pg.434]

Powell and Whittaker [61] nitrated lignin with mixed nitric and sulphuric acid at —5°C. The nitration product was isolated by precipitation with water and ice. [Pg.434]

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