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开发的新型无卤膨胀阻燃剂ANTI-6对聚丙烯(PP)进行阻燃改性。利用热重分析仪研究了PP/ANTI-6体系的热降解行为,探讨了阻燃性能与热行为的关系。结果发现,ANTI-6阻燃剂的加入使PP的反应活化能在不同阶段均有较大提升,在失重初期(6%),ANTI-6能使得PP快速脱水并生成刚性膨胀炭化物形成防火层。随着温度升高,PP/ANTI-6体系的反应活化能会有所下降;失重大于25%后,反应活化能呈快速上升趋势。PP/ANTI-6体系阻燃性能显著提升的同时,其力学性能变化不大。 相似文献
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为了研究对比聚对苯二甲酸丁二醇酯共聚己二酸丁二醇酯(PBAT)、聚己二酸丁二醇酯(PBA)以及聚对苯二甲酸丁二醇酯(PBT)的热稳定性,采用热失重(TG)分析法研究了三种树脂的热降解行为.使用Kinssinger法、Flynn-Wall-Ozawa法以及Coats-Redern法对三种树脂的热降解表观活化能以及反应机理进行了分析.结果表明:PBAT共聚酯中PBA结构单元的引入,改变了 PBT的分子结构,导致其降解行为与PBT、PBA产生偏差;表现为PBAT在热降解反应的初期,降解活化能略低,但在反应后期,降解活化能逐渐升高,其降解行为介于PBA和PBT之间.Kinssinger法得到了三种树脂在最大分解温度下的表观活化能,分别为 PBA 229.5 kJ/mol、PBAT 220.5 kJ/mol、PBT 220.4 kJ/mol;Flynn-Wall-Ozawa 法得到了不同反应程度下的表观活化能,其中PBA的表观活化能在155~212 kJ/mol之间,PBAT的表观活化能在186~211 kJ/mol,PBT的表观活化能在199~212 kJ/mol;Coats-Redern法计算了不同反应机理下的表观活化能,确定了三种树脂具有相同的界面扩散反应机理,反应级数约为2/3. 相似文献
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用热重分析法(TG)研究了天然橡胶/顺丁橡胶(NR/BR)并用硫化胶在室温至500℃范围的热氧降解动力学。由Coats-Redfern法求得了两个降解阶段的反应级数和活化能,用Doyle法计算了并用胶不同降解程度的表观活化能和频率因子,获得了相应的反应速率常数-温度(k-T)关系,并用Fuoss方程计算了NR和BR氧化的活化能。 相似文献
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以不同软化点的乙烯裂解焦油调制的各向同性沥青为原料。通过热失重和差热分析,得到不同沥青的DTA和TG曲线,并通过计算机拟合逼近处理,求出沥青样品的氧化活化能和反应级数等数据。不同软化点调制的沥青,其氧化级数均为一级反应,而软化点与氧化反应活化能间没有明显规律性关系,但升温速率对氧化反应的影响有明显规律。说明通过热分析可以预测不同沥青的预氧化碳化处理性能。 相似文献
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聚甲醛的热氧降解研究 总被引:1,自引:0,他引:1
本文用动态热重分析方法研究了聚甲醛的热氧降解动力学,采用Ozawa方法,计算了POM热氧降解反应的活化能,反应级数和频率因子。根据寿命和活化能的关系,估算了POM在氮气中的使用寿命。 相似文献
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Composition pressure isotherms of H2 and CO on graphite-ferric chloride rule out the possibility that the modified chemical or catalytic activity of metal intercalated graphite is the result of diffusion of reacting species between the layer planes. The catalytic activity for hydrocarbon synthesis develops by the thermal decomposition of FeCl3 to FeCl2 + Cl2 and is caused only by that fraction that diffuses out of the graphite 相似文献
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V. I. Zinchenko V. V. Nesmelov A. S. Yakimov G. F. Kostin 《Combustion, Explosion, and Shock Waves》1998,34(6):644-650
The properties of two modifications of a thermal protective coating based on phenolformaldehyde resin and carbon fabric with
various portions of the components were studied experimentally. The results are used for mathematical simulation of the ablation
of the materials during thermochemical degradation in a high-enthalpy gas flow. It is shown that a decrease in the mass fraction
of the polymer binder has an ambiguous effect on the rate of ablation because of changes in thermal characteristics and increase
in the thickness of the reacting layer under long-duration external thermal action.
Translated fromFizika Goreniya i Vzryva, Vol. 34, No. 4, pp. 48–55, November–December 1998. 相似文献
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Axial and radial thermal dispersion coefficients are estimated under nonreacting and reacting conditions in an almost adiabatic packed bed using steady state temperature profiles and dynamic data simultaneously.Under nonreacting conditions it is concluded that in order to obtain reliable estimates of axial thermal dispersion coefficients it is necessary to incUnder reacting conditions the parameter estimates obtained for the thermal residence time and the axial thermal dispersion coefficient differ significa 相似文献
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The rates of the thermal decomposition (dehydroacetoxylation) and the activation energies of the following three samples have been determined: A) acetylated methyl ricinoleate; B) methyl ester mixture of vicinally unsaturated acetoxyoctadecenoates prepared by reacting methyl oleate and mercuric acetate in acetic acid; C) methyl ester mixture of vicinally unsaturated acetoxyoctadecadienoates prepared by reacting methyl linoleate and mercuric acetate in acetic acid. The thermal decomposition is shown to be a first-order reaction. 相似文献
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This article concerns the thermal phenomena occurring in a reacting solid-gas porous medium. The practical application envisaged is the use of these media in chemical heat pumps (CHPs).
The procedure chosen allowed us to almost totally separate the determination of the kinetic characteristics of the medium, presented in the previous article, from the study of the thermal phenomena presented here.
The thermal parameters were estimated or identified, depending on their influence, quite satisfactorily.
Moreover, we show that it is possible to exploit more limited experimental data, by modifying the procedure, to obtain a sufficiently good understanding of the reacting medium. This technique was applied in the study of the effect of mixing a conducting binder with the medium on its thermal parameters.
This model is also used to test configurations having different thicknesses of the reacting bed. 相似文献
The procedure chosen allowed us to almost totally separate the determination of the kinetic characteristics of the medium, presented in the previous article, from the study of the thermal phenomena presented here.
The thermal parameters were estimated or identified, depending on their influence, quite satisfactorily.
Moreover, we show that it is possible to exploit more limited experimental data, by modifying the procedure, to obtain a sufficiently good understanding of the reacting medium. This technique was applied in the study of the effect of mixing a conducting binder with the medium on its thermal parameters.
This model is also used to test configurations having different thicknesses of the reacting bed. 相似文献
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A modification process of some commercial brominated epoxy resins by reacting them with phosphoric or poly(phosphoric acid) is described. The influence of the reactants ratio on the thermal stability of the modified resins was investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The resin obtained from complete esterification of phosphoric acid showed the highest thermal stability. In addition, the resins prepared by reacting phosphoric acid with brominated epoxy resins of different molecular weight were thermally characterized by DSC and TGA. Most of the modified resins were thermally more stable than the corresponding unmodified resins. The chemical reactions that possibly take place during the process are discussed. Furthermore, the structure of the modified resins was investigated by Fourier-transform-infrared (FT–IR) spectroscopy. 相似文献
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线形和星形聚L-丙交酯大分子单体的合成 总被引:2,自引:0,他引:2
以辛酸亚锡为催化剂,分别以聚乙二醇、甲基丙烯酸羟乙酯、三羟甲基丙烷、季戊四醇、甘露醇和山梨醇等和L-丙交酯反应,得到末端为羟基的线形和星形聚L-丙交酯。通过和甲基丙烯酰氯反应,在上述线形和星形聚L-丙交酯成功引入双键,得到了相应的反应性大分子单体,其双键的存在经红外谱图和高锰酸钾试验得到证实。通过在过氧化二苯甲酰引发下的热交联,研究了上述大分子单体的反应性,发现端基数对交联产物的性质有一定影响。溶解试验、凝胶含量测定和热重分析表明,端基数目较多的大分子单体的交联产物有较高的凝胶含量,交联密度较大,热性能较好。 相似文献
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Richard Pokorny Jarrett A. Rice Michael J. Schweiger Pavel Hrma 《Journal of the American Ceramic Society》2013,96(6):1891-1898
The cold cap is a layer of reacting glass batch floating on the surface of melt in an all‐electric continuous glass melter. The heat needed for the conversion of the melter feed to molten glass must be transferred to and through the cold cap. Since the heat flux into the cold cap influences the rate of melting, the heat conductivity is a key property of the reacting feed. We designed an experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples (TC) that monitors the evolution of the temperature field while the crucible is heated at a constant rate. Then we used two methods to calculate the heat conductivity and thermal diffusivity of the reacting feed: the approximation of the temperature field by polynomial functions and the finite‐volume method (FVM) coupled with least‐squares analysis. Up to 680°C, the heat conductivity of the reacting melter feed was represented by a linear function of temperature. 相似文献
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利用C5馏分生产TAME的现状及展望 总被引:8,自引:0,他引:8
甲基叔戊基醚(TAME) 由C5 馏分中的异戊烯和甲醇反应制得。介绍了国外CDTECH、UOP、IFP、ARCO、SNAM、NESTE等公司的TAME工艺技术,其中,催化蒸馏工艺是最先进的。还介绍了国内的TAME研究及开发情况。目前,国内的TAME 还处于起步阶段,只有抚顺建有一套催化裂化轻汽油醚化工业化装置。利用C5 馏分合成TAME 是急待研究、开发的课题。 相似文献