Phenolic products of the high-temperature radiolysis of lignin

Abstract

The products of the radiation-stimulated dry distillation of coniferous hydrolytic lignin at a residual pressure of 1–5 torr have been obtained and analyzed. The tar distilled off under irradiation conditions predominantly contains phenols, including about 33% benzenediols. Among the benzenediols, the fraction of catechols is 69%. Phenoxyl radicals are considered to be direct precursors of the phenolic products. It has been found that the formation of benzenediols can be due to the rupture of the ether bond in the methoxy group. Among secondary processes, the reactions of the addition of ^•H and ^•CH₃ radicals to the benzene ring have been considered.