Thermopolymerization inhibitors generated via radiolysis of lignin

Abstract

The pyrogenic conversion of lignin to a phenolic tar can be significantly enhanced by combining dry distillation with simultaneous electron-beam treatment of lignin. The tar produced by the combined method contains three times more benzenediols in comparison with conventional pyrogenic distillation method. As shown, the tar of radiation-thermal origin can inhibit the thermopolymerization of certain monomers, such as styrene. The inhibiting ability of tar exceeds that of synthetic phenolic inhibitors. In the presence of 0.025 wt% of the tar, the induction period of styrene thermopolymerization at 120 °С is at least 120 min. Radiation-thermal formation of phenolic tar obeys the chain mechanism and thereby, is a highly efficient process.