多孔材料的抑烟减毒作用及其在木材中的原位生成

发布时间：2018-04-12 18:09

本文选题：金属改性 + 分子筛　；参考：《中南林业科技大学》2015年硕士论文

【摘要】：火灾是全世界范围影响最大的自然灾害之一,给人类社会造成了巨大的生命、财产损失。许多火灾的发生和扩大都与木材缺乏耐火性密切相关,对木材进行阻燃处理对于保障人民的生命财产安全具有重要意义。但是木材经阻燃处理后,由于阻燃剂抑制了木材的充分燃烧,以CO为代表的不完全氧化毒性组分的烟气释放量往往会成倍增加,造成严重的“二次危害”。因此,对木材进行阻燃处理的同时还需进行抑烟、减毒处理,主要目的是降低烟雾和以CO为代表的有毒气体的释放量。分子筛和气凝胶两种多孔材料都具有很大的比表面积,具有一定的吸附、催化和负载能力；过渡金属元素对CO、NOx等不完全氧化组分有很强的催化氧化能力,常用于汽车尾气的净化处理。基于多孔材料和过渡金属元素的这些优点,本文以多孔材料为载体,将对CO具有催化氧化能力的过渡金属元素负载在多孔材料上,然后和阻燃剂——聚磷酸铵(APP)复合用于碎料板阻燃,探索了这两种多孔材料在阻燃碎料板中的抑烟减毒作用,研究了在实木中原位生成APP/气凝胶复合阻燃体系的工艺和抑烟减毒效果。(1)APP对木材碎料板具有高效的阻燃作用,但以CO为代表的有毒气体释放量大幅增加。实验结果表明：纯APP阻燃木材的总热释放量(THR)相对空白样降低了46.9%,总烟释放量(TSP)降低55.7%,但CO平均产量(COY)是空白样的2.09倍,造成严重的“二次危害”。(2)金属改性分子筛-APP复合处理的木材碎料板不仅阻燃效果好,而且烟和毒气释放量均大幅降低。实验结果表明：铁、铜改性分子筛-APP的THR相对空白样分别降低36.8%、39.8%,TSP降低69.3%、72.8%,CO平均产量(COY)降低40.2%、44.5%。分子筛与聚磷酸铵的协同作用可减少无定形炭的生成,使炭层结构稳定,有效防止炭层爆裂,延缓里层木材的燃烧,使得第二放热峰峰值大幅降低并延迟出峰时间,降低木材在火灾中的危险性。(3)气凝胶的阻燃和抑烟减毒效果均比分子筛好,金属改性气凝胶具有优异的抑烟减毒功效,金属元素增加了气凝胶的催化活性,催化效率得到提高。研究结果表明：气凝胶-APP处理碎料板的平均热释放速率(a-HRR)比分子筛低11.1%,THR比分子筛低7.2%；铁、铜改性气凝胶-APP的THR相对空白样分别降低40.3%、42.1%,TSP降低73.1%、75.9%,COY降低49.3%、53.3%。气凝胶的低密度和高孔隙率特性对阻燃、抑烟和减毒方面有积极影响,气凝胶与APP复合阻燃可保证高效阻燃的同时实现少烟低毒。气凝胶优异的隔热性能导致木粉的特征分解温度滞后失重率降低；对残余炭表面的微观结构致密程度分析表明,气凝胶形成的炭层比分子筛更加致密,炭层结构更加稳定,能有效隔绝里层木材和外界的热质传递,对里层木材起到了很好的保护作用。(4)真空-加压浸注处理实木的工艺条件为：常温条件下,利用HCl-HF复合催化剂催化聚磷酸铵/正硅酸乙酯(APP/TEOS)溶液,n(HCl):n(HF)=1.2:1,复合催化剂用量为3%,0.5 MPa压力下保压7 h,载药率可达到20%。研究表明：经过催化、浸注和冷冻干燥等步骤,完成了APP/气凝胶复合物在木材内部的原位生成。原位生成了APP/铁、铜改性气凝胶阻燃实木样品在50 kW/m2的辐射强度下不燃烧,相对空白样的THR分别降低86.8%、90.5%,TSP分别降低了68.8%、71.6%,COY分别降低了72.4%、73.1%,在木材内部原位生成的APP/气凝胶阻燃体系具有优异的阻燃和抑烟减毒效果。存在于气凝胶多孔结构体系中的APP作为客体物质,当发生火灾时释放出来起阻燃作用,金属改性气凝胶作为吸附剂和催化剂,可以将以CO为代表的不完全氧化的毒性组分定向催化转化为低毒或无毒产物,实现抑烟减毒的目的。论文的主要创新点在于,将分子筛和气凝胶两种多孔材料运用到木材阻燃中的抑烟减毒研究,并用具有催化氧化能力的过渡金属元素对两种多孔材料改性,金属改性气凝胶与APP的完美结合可实现木材的高效阻燃和少烟低毒,并据此研究出了一套在木材中原位生成APP/气凝胶的技术方法,为丰富实木阻燃技术和理论提供了科学实验依据。
[Abstract]:Fire is one of the largest natural disasters in the world, caused huge life and property loss to human society. Many fire accidents and expand and lack of wood fire resistance is closely related to flame retardant treatment is important for the protection of people's life and property safety of wood treated by flame retardant wood. However, due to the full the combustion flame retardant inhibited wood, incomplete oxidation of toxic components of flue gas represented by the CO release often doubled, resulting in serious "two danger". Therefore, the flame retardant on wood processing also need to smoke suppression, attenuated processing, the main purpose is to release toxic gases to reduce the smoke and represented by CO. And the two kinds of molecular sieve gel porous material has large surface area, has certain adsorption, catalysis and load capacity; transition metal elements of CO, N Ox components are the incomplete oxidation catalytic oxidation ability is very strong, commonly used in the purification of automobile exhaust. The advantages of porous materials and transition metal elements based on the porous material carrier, transition metals with catalytic oxidation ability of CO supported on porous materials, and then the flame retardant poly ammonium phosphate (APP) composite used for flame retardant particleboard, explore the smoke suppression these two kinds of porous materials on flame retardant Particleboard in reducing toxicity, studied in the in situ process of solid wood composite flame retardant system of APP/ aerogel and smoke suppression effect is attenuated. (1) APP, with flame retardant effect on wood particleboard, but toxic gas represented by the CO release increased significantly. The experimental results show that the total heat release amount of pure APP fire retardant wood (THR) relative to the blank sample decreased by 46.9%, total smoke release (TSP) decreased by 55.7%, but the average yield of CO (COY) Is 2.09 times that of the blank sample, causing serious "two danger". (2) metal modified -APP molecular sieve composite processing wood particleboard not only good flame retardant effect, and smoke and gas emissions were greatly reduced. The experimental results show that the iron and copper modified molecular sieve -APP THR relative to the blank sample decreased 36.8%, 39.8%, 72.8%, TSP decreased by 69.3%, the average yield of CO (COY) decreased 40.2%, the synergistic effect of 44.5%. molecular sieve and ammonium polyphosphate can reduce the formation of amorphous carbon, the carbon layer structure, effectively prevent the carbon layer burst, delaying layer of wood burning, the second exothermic peak sharply to reduce and delay the peak time, reducing the risk of wood in the fire. (3) flame retardant and smoke inhibition of aerogel attenuated effect than molecular sieve, metal modified aerogel has excellent smoke suppression effect of decreasing toxicity, metal elements increased the catalytic activity of the aerogel, catalytic efficiency Improved. Research results show that the average heat treatment of -APP aerogel particleboard release rate (a-HRR) than the 11.1% lower than THR molecular sieve, molecular sieve 7.2%; iron, copper modified aerogels -APP THR relative to the blank sample respectively decreased 40.3%, 42.1%, 75.9%, TSP decreased 73.1%, COY decreased 49.3%. 53.3%. aerogels with low density and high porosity characteristics of flame retardant, have a positive impact on the smoke suppression and reducing toxicity, aerogels and APP composite flame retardant can ensure the realization of efficient flame retardant and low smoke and low toxicity. The aerogel insulation performance excellent characteristics of the wood powder decomposition temperature lag weight loss rate decreased; the dense degree of residual carbon surface the microstructure analysis showed that the carbon aerogel layer formed over molecular sieve carbon layer structure is more compact, more stable, can effectively isolate the layer in wood and external heat and mass transfer, to a very good protective effect on the layer in the wood. (4) vacuum - plus The pressure leaching process conditions of injection treated wood were: room temperature conditions, the use of HCl-HF composite catalyst of ammonium polyphosphate / TEOS (APP/TEOS) solution, n (HCl): n (HF) =1.2:1 composite catalyst is 3% and 0.5 under MPa pressure for 7 h, the drug loading rate can reach 20%. show that the catalytic leaching step injection and freeze drying, in situ completed APP/ aerogel composite in wood. In situ APP/ iron, copper modified aerogels flame retardant wood samples do not burn in the radiation intensity of 50 kW/m2, relative to the blank sample THR were decreased by 86.8%, 90.5%, TSP respectively. Decreased by 68.8%, 71.6%, COY were reduced by 72.4%, 73.1%, in wood in situ formed APP/ aerogel flame retardant system has excellent flame retardant and smoke suppression effect. Attenuated in the aerogel porous structure in the system of APP as the material object, when fire happens, released from Effect of flame retardant, metal modified aerogels as adsorbent and catalyst can be toxic group of incomplete oxidation with CO as the representative of the direct catalytic conversion to low toxic or non-toxic products, achieve smoke suppression attenuated. The main innovation of this paper lies in that the molecular sieve gel and two kinds of smoke suppression fire retardant wood the attenuated study using porous materials, and two kinds of porous material modified by transition metals with catalytic oxidation ability, perfect combination of metal modified aerogels and APP can achieve efficient flame retardant wood and low smoke and low toxicity, and accordingly developed a generation of APP/ aerogel in situ of wood technology and methods, to provide the scientific basis for enriching the theory and technology of flame retardant wood.

【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.4

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