Pyrolysis of wood, cellulose, lignin–brominated epoxy oligomer flame retardant mixtures

The thermal decomposition of brominated epoxy oligomer (BrEpoxy)–natural polymer mixtures were examined by Py-GC/MS and TG/MS techniques in order to clarify the reactions between the components of the mixtures. The natural polymer components were: pine and beech wood, pine and beech milled wood lignin and two types of cellulose (Avicel and Whatman cellulose). It was found that the decomposition of both celluloses shifts to the temperature range of BrEpoxy decomposition. Significantly decreased formation of hydroxyacetaldehyde, hydroxypropanone and levoglucosan and increased yield of levoglucosenone was observed from cellulose–BrEpoxy mixtures. Drastically increased evolution of bromomethane was found from lignin or wood–BrEpoxy mixtures, indicating a radical scavenging reaction of lignin leading to the formation of bromomethane and phenoxy radicals.

► The decomposing brominated flame retardant initiates the decomposition of cellulose.
► The presence of BrEpoxy alters the decomposion products of cellulose.
► The presence of lignin protects the cellulose from the effect of BrEpoxy.
► Bromomethane evolves from decomposing lignin containing material–BrEpoxy mixtures.