Fe2O3／聚磷酸铵对聚氨酯木粉复合发泡材料的阻燃抑烟性能

Incorporation of Fe_2O_3 and ammonium polyphosphate to foamed wood-polyurethane composites for smoke suppression and flame resistance

为研究氧化铁(Fe_2O_3)与聚磷酸铵(APP)对聚氨酯木粉复合发泡材料(FWPC)的阻燃效果和抑烟性能,制备了添加不同质量分数Fe_2O_3和APP的FWPC试样。采用锥形量热仪测试样品的燃烧性能、热重分析仪测试样品的热稳定性;采用傅里叶红外光谱对燃烧后的残炭官能团进行分析,研究添加不同比例的Fe_2O_3和APP对聚氨酯木粉复合发泡材料的阻燃和抑烟性能的影响。结果表明:1)与空白对照样相比,添加质量分数为2%的Fe_2O_3和18%的APP的试样点燃时间(TTI)延迟了66.7%,热释放速率(HRR)和热释放速率峰值(PHRR)分别下降了33.9%和39.8%,有效燃烧热(EHC)也下降了12.6%,说明添加一定比例的Fe_2O_3和APP对FWPC的阻燃作用明显;2)添加3%Fe_2O_3和17%APP时,试样的总烟释放量(TSR)、总烟产量(TSP)和比消光面积(SEA)分别比空白对照样下降38.2%,37.4%和27.1%,说明Fe_2O_3和APP对FWPC具有明确的阻燃及抑烟作用;3)Fe_2O_3和APP同时加入FWPC时,分解温度比空白对照样有所上升,特别是添加2%Fe_2O_3和18%APP试样的质量残余率高达65.0%,说明加入适宜比例的Fe_2O_3和APP可以提高凝聚相阻燃效果,从而提高FWPC的热稳定性;4)傅里叶红外光谱显示,在1 050和1 429 cm^(-1)处,添加Fe_2O_3和APP的试样的吸收峰强度明显弱于空白对照样,这两处强吸收峰分别归属于C—O伸缩振动和CH_2剪式振动或者弯曲振动,表明燃烧产物中存在脂肪族醇类物质,不加阻燃剂的聚氨酯发泡木塑复合材料燃烧完全,而加入Fe_2O_3和APP会影响残炭中官能团的组成结构。总体上看,在FWPC中添加适宜比例的Fe_2O_3和APP后,试样的HRR和TSR均有明显下降,说明2种添加剂对FWPC具有很好的阻燃及抑烟效果。

In order to improve the properties of flame retardant and smoke suppression by adding ferric oxide （Fe2O3) and ammonium polyphosphate （APP） to foamed wood-polyurethane composites （FWPC）, the FWPC samples with different mass fractions of Fe2O3 and APP were prepared. The performances of flame retardant and smoke suppression of the samples were examined by the cone calorimeter, thermogravimetric analyzer and Fourier infrared spectrum. The experimental results showed： 1) compared with the control samples, the ignition time （TTI） of the sample with 2% Fe203 and 18% APP delayed by 66.7%, and the heat release rate （HRR）, the peak of heat release rate （PHRR） and effective heat of combustion （EHC） decreased by 33.9%, 39.8% and 12.6%, respectively, which showed that the effect of flame retardant with a certain proportion of Fe203 and APP on the FWPC was obvious. 2） Compared with the control samples, the values of total smoke release （TSR）, total smoke production （TSP） and specific extinction area （SEA） of the samples with 3% Fe203 and 17% APP decreased by 38.2%, 37.4% and 27.1%, respectively, which indicated that Fe203 and APP had clear flame retardant and smoke suppression effect on the FWPC. 3) Com-pared with the control samples, the decomposed temperature of the samples with Fe203 and APP was still high, espe-cially the carbon residue of the sample with 2% Fe203 and 18% APP was as high as 65%. The results indicated that the suitable ratio of Fe203 and APP can provide the condensed phase with flame retardant effect, thereby improving the thermal stability of FWPC. 4） According to the Fourier infrared spectroscopy, compared with the control samples, the intensity of the absorption peak of samples with Fe203 and APP was obviously weakened in the wave number of 1 050 cm^-1 and 1 429 cm^-1, in which, two strong absorption peaks were attributed to C--O stretching vibration and CH2 sheafing vibration or bending vibration. This is the evidence of the existence of aliphatic alcohols in combustion products. The FWPC without flame retardant was burned completely, while the modified samples was not bumed promptly because Fe203 and APP affected the structure of carbon functional group. Generally, after adding proper pro-portion of Fe203 and APP to the FWPC, HRR and TSR of the samples decreased obviously, indicating that the two additives had appropriate effect of flame retardant and smoke suppression on the FWPC.