典型有機建筑保溫材料熱解動力學(xué)行為特性研究
發(fā)布時間：2018-10-21 18:26
【摘要】：近些年來,在國家大力倡導(dǎo)建筑節(jié)能的社會背景下,保溫材料特別是有機建筑保溫材料由于其卓越的保溫隔熱性能以及成本低廉、耐壓防水等特性被廣泛應(yīng)用于建筑保溫結(jié)構(gòu)中。然而由于有機類建筑保溫材料遇火易燃且燃燒易釋放有毒煙氣,往往會引發(fā)火災(zāi)并造成巨大的人員傷亡和財產(chǎn)損失。因此,為了更好的預(yù)防火災(zāi)事故的發(fā)生,降低發(fā)生火災(zāi)事故的危險性和嚴重性,深入研究這些易燃建筑保溫材料的火災(zāi)特點顯得尤為必要。論文采用熱重-差示掃描量熱(TG-DSC)聯(lián)用技術(shù),對模塑聚苯乙烯泡沫(EPS)、聚氨酯硬泡(PU)、酚醛泡沫(PF)三種典型有機建筑保溫材料在不同參數(shù)下的熱解動力學(xué)行為進行研究,深入對比分析了氣氛、升溫速率等參數(shù)對三種材料的熱解動力學(xué)參數(shù)及反應(yīng)機理函數(shù)的影響。研究發(fā)現(xiàn):(1)聚苯乙烯泡沫材料在空氣和氮氣氣氛下的熱解曲線形狀相似,都表現(xiàn)為兩個階段,第二階段為主要失重階段且都幾乎沒有熱解殘渣。氮氣氣氛的熱解反應(yīng)起止溫度和峰溫高于空氣,說明有氧存在熱解反應(yīng)更易進行。等轉(zhuǎn)化率法計算空氣氣氛下熱解反應(yīng)為144.55kJ/mol,活化能隨轉(zhuǎn)化率增加而有所增加。氮氣氣氛下為193.34k J/mol,活化能在熱解初期略增加,隨后變化很小。與空氣氣氛相比,氮氣氣氛下活化能值變化非常小,較為穩(wěn)定。利用C-R法求得得到了聚苯乙烯泡沫在空氣氣氛下熱解機理函數(shù)屬于成核和核生長A2/3描述,氮氣氣氛下的反應(yīng)機理函數(shù)屬于反應(yīng)級數(shù)F3描述。(2)聚氨酯硬泡在空氣和氮氣氛圍下的熱解曲線形狀明顯不同,分別分為三個階段和兩個階段,兩種氛圍下的第一階段反應(yīng)溫度區(qū)間接近,這個階段的反應(yīng)過程相似,剩余殘渣量在4%和23%,空氣氣氛熱解反應(yīng)更為徹底�？諝鈿夥障�,聚氨酯泡沫活化能呈現(xiàn)出逐漸增大的趨勢,α在0.1~0.5,活化能值為79.11kJ/mol,0.7~0.9之間,活化能為124.58kJ/mol。氮氣氣氛下為139.33kJ/mol,活化能值隨轉(zhuǎn)化率的增加逐漸增加。兩種氣氛下熱解初始活化能都很小,說明聚氨酯硬泡受熱易發(fā)生熱損。C-R法求得聚氨酯硬泡在空氣氛圍的熱解機理屬于一維擴散D1描述,氮氣氛圍為枝狀成核P-T方程B4描述。(3)酚醛泡沫在空氣氛圍下的熱解曲線隨升溫速率的升高向高溫區(qū)遷移,熱解過程有兩個階段,剩余殘渣約21%且主要熱失重在第二階段。酚醛泡沫受熱就發(fā)生較小熱損且初始階段的持續(xù)時間長。等轉(zhuǎn)化率法求得為45.26kJ/mol,轉(zhuǎn)化率從0.1至0.2的溫度跨度大,主反應(yīng)階段晚且殘渣量大,說明了酚醛不燃、難燃的特點。C-R法求得酚醛泡沫在空氣氛圍的機理函數(shù)為反應(yīng)級數(shù)F3/2描述。(4)三種有機保溫材料對應(yīng)火災(zāi)危險性程度大小依次為聚氨酯硬泡最大、模塑聚苯乙烯次之、酚醛最小。
[Abstract]:In recent years, in the context of the country's strong advocacy of building energy conservation, thermal insulation materials, especially organic building insulation materials, due to its excellent thermal insulation performance and low cost, The characteristics of pressure-proof and water-proof are widely used in building insulation structure. However, due to the flammability of organic building heat preservation materials and the release of toxic smoke easily, it will often lead to fire and cause huge casualties and property losses. Therefore, in order to better prevent the occurrence of fire accidents and reduce the danger and severity of fire accidents, it is particularly necessary to study the fire characteristics of these flammable building insulation materials. In this paper, thermogravimetric differential scanning calorimetry (TG-DSC) was used to study the pyrolysis kinetics of three typical organic building insulating materials, (EPS), polyurethane rigid foam, (PU), phenolic foam (PF), molded polystyrene foam under different parameters. The effects of atmosphere, heating rate and other parameters on the pyrolysis kinetic parameters and reaction mechanism functions of three kinds of materials were compared and analyzed. The results show that: (1) the pyrolysis curves of polystyrene foam materials in air and nitrogen atmosphere are similar, and the second stage is the main weightlessness stage and there is almost no pyrolysis residue in the second stage. The pyrolysis temperature and peak temperature in nitrogen atmosphere were higher than those in air, which indicated that the pyrolysis reaction was easier in aerobic atmosphere. The iso-conversion method was used to calculate the pyrolysis reaction at 144.55kJ / mol in air atmosphere, and the activation energy increased with the increase of conversion. In nitrogen atmosphere, the activation energy increases slightly at the initial stage of pyrolysis, and then changes slightly in the range of 193.34k / mol. Compared with air atmosphere, the change of activation energy in nitrogen atmosphere is very small and stable. By means of C-R method, the pyrolysis mechanism function of polystyrene foam in air atmosphere is obtained, which belongs to the description of nucleation and nuclear growth A _ 2 / 3. The reaction mechanism function in nitrogen atmosphere belongs to the description of reaction order F3. (2) the pyrolysis curve of polyurethane rigid foam in air and nitrogen atmosphere is obviously different, which is divided into three stages and two stages, respectively. The reaction temperature range of the first stage is close to that in the two kinds of atmosphere. The reaction process in this stage is similar, the residual residue is 4% and 23%, and the pyrolysis in air atmosphere is more thorough. In the air atmosphere, the activation energy of polyurethane foam showed an increasing trend, 偽 was 0.1 鈩，
本文編號：2285970
[Abstract]:In recent years, in the context of the country's strong advocacy of building energy conservation, thermal insulation materials, especially organic building insulation materials, due to its excellent thermal insulation performance and low cost, The characteristics of pressure-proof and water-proof are widely used in building insulation structure. However, due to the flammability of organic building heat preservation materials and the release of toxic smoke easily, it will often lead to fire and cause huge casualties and property losses. Therefore, in order to better prevent the occurrence of fire accidents and reduce the danger and severity of fire accidents, it is particularly necessary to study the fire characteristics of these flammable building insulation materials. In this paper, thermogravimetric differential scanning calorimetry (TG-DSC) was used to study the pyrolysis kinetics of three typical organic building insulating materials, (EPS), polyurethane rigid foam, (PU), phenolic foam (PF), molded polystyrene foam under different parameters. The effects of atmosphere, heating rate and other parameters on the pyrolysis kinetic parameters and reaction mechanism functions of three kinds of materials were compared and analyzed. The results show that: (1) the pyrolysis curves of polystyrene foam materials in air and nitrogen atmosphere are similar, and the second stage is the main weightlessness stage and there is almost no pyrolysis residue in the second stage. The pyrolysis temperature and peak temperature in nitrogen atmosphere were higher than those in air, which indicated that the pyrolysis reaction was easier in aerobic atmosphere. The iso-conversion method was used to calculate the pyrolysis reaction at 144.55kJ / mol in air atmosphere, and the activation energy increased with the increase of conversion. In nitrogen atmosphere, the activation energy increases slightly at the initial stage of pyrolysis, and then changes slightly in the range of 193.34k / mol. Compared with air atmosphere, the change of activation energy in nitrogen atmosphere is very small and stable. By means of C-R method, the pyrolysis mechanism function of polystyrene foam in air atmosphere is obtained, which belongs to the description of nucleation and nuclear growth A _ 2 / 3. The reaction mechanism function in nitrogen atmosphere belongs to the description of reaction order F3. (2) the pyrolysis curve of polyurethane rigid foam in air and nitrogen atmosphere is obviously different, which is divided into three stages and two stages, respectively. The reaction temperature range of the first stage is close to that in the two kinds of atmosphere. The reaction process in this stage is similar, the residual residue is 4% and 23%, and the pyrolysis in air atmosphere is more thorough. In the air atmosphere, the activation energy of polyurethane foam showed an increasing trend, 偽 was 0.1 鈩，
本文編號：2285970
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