Influence Of The Intumescent Flame-retardant Amino Resin On Toxic Smoke Compositions Of Wood Materials

In this study,three types of wood materials like Wood（Eucalyptus saligna Smith）,Plywood,and Flame-retardant Plywood were selected.The smoke emission and composition of those wood materials were investigated by the CONE,GC-MS,and UV-VIS spectrophotometer.And the influence of the intumescent flame-retardant amino resin on smoke toxicity of wood materials was discussed.The main conclusions are as follows:（1）Smoke RegularityThe regularity of smoke production and temperature was consistent with that of mass lose rate.They were higher in ignition stage and char combustion stage as the higher mass lose rate,and lower in charring stage and smoldering stage as the lower mass lose rate.The amino resin promoted the integrality of the char layers,which inhibiting the smoke release in the earlier combustion process,leading to the intensive smoke release in the later combustion process.The intumescent flame retardants and the amino resin（IFR-MUF）could greatly decrease the smoke temperature.（2）Inorganic GasesThe CO₂ emission rate was higher in the ignition stage and the char combustion stage,and lower in charring stage and smoldering stage,which was consistent with the mass loss rate.The CO emission rate reached its maximum at the smoldering stag.At 30 kW/m²,the CO emission rate in the charring stage increased obviouslyThe HCN emission yields of Plywood and FR-Plywood was 0.31 mg/g,1.85mg/g at 50 kW/m².Compared with Wood,the HCN emission yields of Plywood and FR-Plywood increased by 5 and 30 times.The emission yield of HCN of Plywood and FR-Plywood was 0.51 mg/g,1.91 mg/g at 30 kW/m²,and that of Plywood and FR-Plywood increased by 20 and 100 times compared with Wood.Higher HCN emission rate was generated at lower radiance level as HCN can be oxidized to NO_x at higher radiance level.The NO_x emission yield of Plywood and FR-Plywood was 0.88 mg/g,1.00 mg/g at 50 kW/m²,and that of Plywood and FR-Plywood were increased by 2.6 and 3 times compared with Wood.The NO_x emission yield of FR-Plywood at 30 kW/m² was 76.7% lower than that at 50 kW/m².（3）Volatile Organic Compounds（VOCs）The VOCs was mainly composed of alkenes and oxygenated volatile organic compounds（O-VOCs）,which accounted for 53%-70%,followed by alkanes,benzene series and haloalkane,with very few alkenyl halides and aryl halides.Lower radiance level could promoted the generation of VOCs.The emission yields of Wood,Plywood and FR-Plywood were 3.22 mg/g,3.37 mg/g and 5.16 mg/g at 50 kW/m²,respectively,and that at 30 kW/m² were increased by 76.2%,65.5% and 209.1%,respectively.Except for halogeno benzenes,the yields of other composition of VOCs were all increased at 30 kW/m² compared with those at 50 kW/m².IFR could promoted the VOCs yield,especially at 30 kW/m².Compared with Plywood,the VOCs yield of FR-Plywood jumped from 3.37 mg/g to 5.16 mg/g at 50 kW/m²,and jumped from 5.58 mg/g to 15.94 mg/g at 30 kW/m².（4）Polycyclic Aromatic Hydrocarbons（PAHs）The amino resin reduced the total PAHs（T-PAHs）yield,while IFR increased the T-PAHs,but the whole had little effect on the T-PAHs yield.Higher T-PAHs yield ocurred at 50 kW/m².Based on the toxicity of BaP,the PAHs yields of Plywood and FR-Plywood were 0.886 μg/g,0.629 μg/g and 1.170 μg/g at 50 kW/m²,and 0.065 μg/g,0.015 μg/g and 0.023 μg/g at 30 kW/m²,respectively.The PAHs toxicity of plywood was the lowest at both radiance levels.High radiance level could raise the T-PAHs toxicity.