阻燃型木塑复合材料热解燃烧特性及产物研究

以改性天然碳水化合物结合碱式硫酸镁晶须(MHSH)混杂纤维为协效剂,结合膨胀阻燃剂(IFR)制备了阻燃型聚丁二酸丁二醇酯(PBS)木纤维复合材料。利用极限氧指数和垂直燃烧测试研究了复合材料的阻燃性能,并采用TG/DTA-MS对复合材料的热解过程、吸放热量和热解燃烧气体产物进行了分析。结果表明,5%的木薯渣作为碳源代替PBS提高了材料的阻燃性能。IFR/木薯渣/MHSH阻燃剂能够有效提高PBS的燃烧初始温度,并缩小燃烧温度范围。阻燃材料燃烧时,首先是IFR受热分解产生不可燃气体氨气在材料表层形成第一层阻燃保护层;其次,材料迅速燃烧产生的炭层形成第二层阻燃保护层;最后,在高温段MHSH分解形成第三层协效阻燃保护层。因此,最终形成了由外层不可燃气体氨气和内层天然碳水化合物MHSH膨胀炭层构成的气-固阻燃屏障,从而有效地提高了复合材料的阻燃性能。

Study on pyrolytic combustion characteristics and products of flame retardant wood plastic composite

The flame retardancy poly(butylene succinate)(PBS)wood fiber composites were prepared by using IFR and modified natural carbohydrates-MHSH.The flame retardant properties of the composites were studied by using the limiting oxygen index and vertical combustion test.TG/DTA-MS was used to analyze the pyrolysis process,heat absorption and pyrolysis combustion gas products of the composites.Experimental data showed that 5%of cassava dregs could be used as a carbon source instead of PBS to improve the flame retardant performance of the composites.IFR/cassava dregs/MHSH flame retardant could effectively increase the initial burning temperature of PBS,and reduced the burning temperature range.When the flame retardant composites were burned,first,the non-combustible gas ammonia generated by the thermal decomposition of IFR formed the first flame-retardant protective layer on the surface of the composites.Second,the carbon layer produced by the rapid burning of the composites formed a second flame-retardant protective layer.Finally,MHSH was decomposed to form a third layer of synergistic flame-retardant protective layer in the high temperature section.As a result,agas-solid flame retardant barrier composed of an outer non-flammable gas ammonia and an inner natural carbohydrate-MHSH expanded carbon layer was formed.Thereby,the flame retardancy of the composites were effectively improved.