碱木质素基氮磷阻燃剂提升速生杨木的阻燃抑烟性能OA

Biomass-based flame retardants have garnered considerable attention due to their sustainability,highlighting the urgent need for efficient and user-friendly biomass-based flame retardants.In this context,sodium monochloroacetate was used to carboxymethylate industrial alkali lignin,yielding carboxymethylated alkali lignin(CAL)with excellent water solubility.Melamine-urea-glyoxal resin(MUG)was synthesized using glyoxal,urea,and melamine as raw materials for flame retardant encapsulation.CAL,MUG,and diammonium phosphate(DAP)were then compounded to prepare a lignin-based flame retardant.By applying vacuum-assisted pressure impregnation treatment to poplar(Populus ussuriensis),lignin-based flame retardant-treated wood was prepared.The effects of CAL,MUG,and DAP on the physical and mechanical properties,chemical structure,microscopic morphology,and combustion performance of the poplar were investigated.The results indicated that carboxymethylation effectively improved the water solubility of alkali lignin(AL).The pressure impregnation modification enabled the lignin-based flame retardant to be uniformly distributed on the wood cell walls,where MUG crosslinked with the wood to form a strong and compact structure,improving its bending strength to 118.7 MPa.The flame retardant·s loss rate with MUG addition was 51.51%,and it further reduced to 42.55%when the CAL,MUG,and DAP were combined in the composite flame retardant.Cone calorimeter analysis revealed that the heat release rate of the modified wood treated with the CAL,MUG,and DAP composite flame retardant decreased by 33.20%,the total heat release decreased by 20.35%,and the total smoke-release decreased by 78.51%compared to untreated wood.Analysis of the morphology and chemical structure of the char residue indicated that the synergistic effect of nitrogen and phosphorus in the flame retardant altered the charring pathway of CAL and wood,promoting the formation of a dense and robust char layer.The findings indicate that the composite lignin-based flame retardant-treated wood effectively delays the combustion and flame spread,significantly extending the escape time during a fire.