Preparation of modified hydrolysis lignin and its use for filling epoxy polymers and enhancing their flame resistance

The reaction of hydrolysis lignin with orthophosphoric acid and urea under the conditions of reactant fusion without a solvent was studied. The influence of the reactant ratio and of the reaction temperature and time on the degree of chemical binding of phosphorus and nitrogen with lignin was examined. The modification products can be used as fire-retardant fillers for epoxy compounds.