建筑外墙保温材料的热分解与燃烧性分析
1、胶粉聚苯颗粒的热分解与燃烧特性胶粉聚苯颗粒保温浆料是一种有机无机复合的保温隔热材料,聚苯颗粒的体积大约在80%左右,导热系数为0.06W/(m?K),燃烧等级为B1级,属于难燃材料。胶粉聚苯颗粒在受热时,通常包含的聚苯颗粒会软化并熔化,但不会发生燃烧。由于聚苯颗粒被无机料包裹,其熔融后将形成封闭的空腔,此时该保温材料的导热系数会更低、传热更慢,受热全过程材料体积变化率为零。
1. Thermal decomposition and combustion characteristics of rubber powder polyphenyl granule thermal insulation slurry is an organic-inorganic composite thermal insulation material. The volume of polyphenyl granule is about 80%, thermal conductivity is 0.06W/(m?K), combustion grade is B1, which belongs to non-flammable materials. Rubber powder polyphenylene particles usually contain polyphenylene particles which soften and melt when heated, but do not burn. Because polyphenyl particles are encapsulated by inorganic materials, a closed cavity will be formed after melting. At this time, the thermal conductivity of the thermal insulation material will be lower and the heat transfer will be slower, and the volume change rate of the material will be zero during the whole heating process.
2、聚苯乙烯的热分解与燃烧特性聚苯乙烯泡沫材料是热塑性高分子保温隔热材料,导热系数为0.041W/(m?K)。受热时,通常发生软化和熔化。聚苯板的热变形温度仅为70~98℃,差异取决于选用配方和后处理方法,玻璃化温度为100℃。聚苯乙烯全部由碳氢元素组成,本质上极易燃烧,未经阻燃处理,氧指数仅为18%;燃烧时热释放量较大,同时生成大量烟,受火后收缩、熔化,导致外保温系统内产生空腔,轰燃状态下燃烧剧烈,燃烧的滴落物具有引燃性。
2, polystyrene thermal decomposition and combustion characteristics polystyrene foam material is thermoplastic polymer thermal insulation material, thermal conductivity is 0.041W/ (M? K). Softening and melting usually occur when heated. The thermal deformation temperature of polyphenylene sheet is only 70 ~ 98 C. The difference depends on the choice of formulation and post-treatment method, and the glass transition temperature is 100 C. Polystyrene is composed of hydrocarbon elements, which is very flammable in nature. Without flame retardant treatment, the oxygen index is only 18%. When burning, the heat release is large, and a large amount of smoke is generated, which shrinks and melts after being fired, resulting in a cavity in the external thermal insulation system, which burns fiercely in the state of bombardment and ignites the droplets.
3、聚氨酯的热分解与燃烧特性硬质泡沫聚氨酯是一种高分子热固性保温隔热材料,导热系数为0.024W/(m?K),在所有外墙用有机保温材料中是最优的。聚氨酯一般在202℃以下不会分解,用ASTMD1929测定聚氨酯泡沫的点燃温度为强制点燃温度310℃,自燃温度415℃;聚氨酯泡沫本质上属于高度易燃材料,未做阻燃处理时氧指数仅为16.5%;热固性材料在受热时通常分解出易燃气体,受火后形成炭化层,热分解和燃烧的产物主要有氰化氢、CO、异氰酸酯等,对聚氨酯燃烧的毒性研究也比较多。
3, polyurethane thermal decomposition and combustion characteristics rigid foam polyurethane is a polymer thermosetting thermal insulation material, thermal conductivity is 0.024W/ (M? K), in all external walls with organic thermal insulation material is the best. Polyurethane is generally not decomposed below 202 degrees Celsius. The ignition temperature of polyurethane foam is determined by ASTMD1929. The ignition temperature is 310 C, the spontaneous combustion temperature is 415 centigrade. The polyurethane foam is highly flammable material in nature, and the oxygen index is only 16.5% when the flame retardant treatment is not done. Thermosetting materials usually decompose inflammable gas when heated, and are subject to fire. Thermal decomposition and combustion products mainly include hydrogen cyanide, carbon monoxide, isocyanate and so on. There are many studies on the toxicity of polyurethane combustion.
4、酚醛树脂的热分解与燃烧特性酚醛树脂泡沫材料是高效保温材料之一,导热系数为0.025W/(m?K)。该材料遇火焰火源时不易燃烧,在400℃以上时只灼烧或阴燃,无火焰。除去火源后可能会阴燃一段时间,发烟量很小,几乎全部成炭。但关于其燃烧毒性的研究较少,报道的数据也不完全。酚醛树脂泡沫材料是目前高效有机保温中阻燃性能最优的一种材料。
4. The thermal decomposition and combustion characteristics of phenolic resin. Phenolic resin foam material is one of the highly effective thermal insulation materials with a thermal conductivity of 0.025W/ (M? K). This material is not easy to burn when it is flame source. It burns or smoldering at 400 degree or above. After removing the fire source, it may smoldering for a period of time, and the volume of smoke is very small, almost all of which are charcoal. However, the research on its toxicity is less and the data reported are incomplete. Phenolic resin foam is the best flame retardant material in high efficiency organic insulation.
外墙外保温系统的采用不燃性材料或不具有传播火焰的难燃性材料时,外墙外保温系统几乎不存在防火安全性问题。但是,在我国目前的技术条件下,聚苯乙烯泡沫和硬泡聚氨酯等可燃材料在建筑外墙外保温系统中的使用最为广泛,这是产生外保温系统防火安全性问题的起因,而随着节能标准的逐步提高,这个问题将更加凸显。因此,随着此类可燃有机保温材料的大面积应用和使用厚度的不断增加,建筑外墙火灾或火灾的蔓延问题应引起人们足够的重视。
When the exterior wall thermal insulation system uses non-combustible materials or non-combustible materials which do not spread flame, there is almost no fire safety problem in the exterior wall thermal insulation system. However, under the current technical conditions in China, the use of polystyrene foam and rigid polyurethane and other combustible materials is the most widely used in building external thermal insulation system, which is the cause of the fire safety problem of external insulation system, and with the gradual improvement of energy saving standards, this problem will become more prominent. Therefore, with the wide application and increasing thickness of this kind of combustible organic thermal insulation material, people should pay enough attention to the problem of building exterior wall fire or fire spread.