共查询到19条相似文献,搜索用时 328 毫秒
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研究连串反应的动力学有十分重要的意义,文献[1,2]建立了两种连串一级反应的热动力学研究法.我们在前文[1]的基础上,建立了模拟热谱曲线法.该法可以直接从热导式量热计的热谱曲线上解析出连串一级反应中两步反应的速率常数.应用该法测定了邻苯二甲酸二乙酯和丁二酸... 相似文献
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本文建立了一种只需要精选一级反应热谱曲线上2个任意时刻的峰高,而不需要任何其它数据即可算得其反应速度常数的新算法.研究了三乙胺和碘乙烷在二甲亚砜中的季铵化反应,其速度常数的计算值和文献值吻合很好,证明了本法的正确性. 相似文献
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模拟热谱曲线法(Ⅰ)——简单级数化学反应 总被引:8,自引:1,他引:8
提出模拟各种简单级数化学反应的普适热谱曲线方程△=ate^-kβt,建立了一种新的热动力学研究法--模拟热谱曲线法,导出了简单级数化学反应的动力学参数Kn和速率常数kn的计算式。实验说明该方法对研究慢反应及较快的反应均适用,还能用于求热动力学体系的冷却常数。 相似文献
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Cheng S.-Q. Huang Z. Meng X.-G. Zeng X.-C. 《Journal of Thermal Analysis and Calorimetry》2000,63(2):415-421
This paper presents a novel data processing method for thermokinetics of faster first-order reaction on the basis of the double-parameter
theoretical model of a conduction calorimeter, in which the rate constant of a first-order reaction can be calculated from
only four peak height data from the same thermoanalytical curve without using any peak-area. The saponifications of ethyl
acetate and methyl acetate in aqueous solution and ethyl benzoate in aqueous alcohol have been studied to test the validity
of this method. The rate constants calculated with this method are in fair agreement with those in literature; hence the validity
of this method is demonstrated.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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根据化学反应动力学和热动力学基本理论, 建立了简单级数反应的热动力学对比参量方程, 提出了一种新的热动力学研究法--对比参量法. 利用该法可以从一张热谱图上同时解析出化学反应的速率常数、半衰期和热动力学体系的冷却常数. 实验结果验证了方法的正确性. 相似文献
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Y.-Q. Zhang X.-C. Zeng Y. Chen X.-G. Meng A.-M. Tian 《Journal of Thermal Analysis and Calorimetry》1999,58(2):463-475
On the basis of the theory of thermokinetics proposed in the literature, a novel thermokinetic method for determination of the reaction rate, the characteristic parameter method, is proposed in this paper. Mathematical models were established to determine the kinetic parameters and rate constants. In order to test the validity of this method, the saponifications of ethyl benzoate, ethyl acetate and ethyl propionate, and the formation of hexamethylenetetramine were studied with this method. The rate constants calculated with this method are in agreement with those in the literature, and the characteristic parameter method is therefore believed to be correct.In the light of the characteristic parameter method, we have developed further two thermo-kinetic methods, the thermoanalytical single and multi-curve methods, which are convenient for simultaneous determination of the reaction order and the rate constant. The reaction orders and rate constants of the saponifications of ethyl acetate and ethyl butyrate and the ring-opening reaction of epichlorohydrin with hydrobromic acid were determined with these methods, and their validity was verified by the experimental results.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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根据热动力学的基础理论, 应用一级反应的无量纲参数法, 在20和30 ℃下测定了乙酸乙酯、丙酸乙酯和丁酸乙酯在乙醇-水混合溶剂中皂化反应速度常数, 并计算了它们的活化能, 结果在误差范围内与文献值相符合。还计算了这三个反应体系的活化自由能。本文讨论了反应物初始浓度和反应的速度常数与量热计冷却常数的关系。 相似文献
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等浓度三级反应的热动力学研究 总被引:5,自引:0,他引:5
根据热动力学基础理论,本文首次建立和讨论了等浓度三级反应的无量纲参数法.测定了20℃时环氧氯丙烷与氢溴酸反应的速率常数,实验的重现性很好,计算此反应的速率常数在误差范围内与文献值相符合.证明了等浓度三级反应无纲参数法的正确性,拓宽了无量纲参数法的应用范围. 相似文献
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利用FTIR光谱仪研究PU/PMMA IPN初期反应动力学 总被引:2,自引:0,他引:2
本文用FTIR光谱仪研完聚醚聚氨酯/聚甲基丙烯酸甲酯(PU/PMMA)互穿聚合物网络(IPN)的初期反应动力学.实验结果表明:该体系IPN在生成过程中动力学不同步是造成相容性较差的原因之一,提高反应温度和增加PMMA的引发剂用量有利于反应同步进行.增加PMMA的含量,使PU反应速度加快是PMMA"溶剂效应”的结果;增加PU含量,使PMMA反应速度减慢是PU的“笼壁效应”结果.聚醚聚氨酯及聚甲基丙烯酸甲酯初期反应均属一级反应动力学. 相似文献
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Characteristic parameter method for studying kinetics of opposing reactions in calorimeter 总被引:1,自引:0,他引:1
According to the theoretical basis of thermokinetics, the integral and differential thermokinetic equations of opposing reactions have been derived, and a novel thermokinetic research method, the characteristic parameter method for opposing reactions which taking place in a batch conduction calorimeter under isothermal condition, has been proposed in this paper. Only needing the characteristic thermoanalytical data corresponding to tm and 2tm from the same curve, the rate constants of forward and backward reactions and equilibrium constant can be calculated simultaneously with this method. In order to test the validity of this method, the proton-transfer reactions of nitroethane with ammonia at 15 and 25°C, and with trihydroxymethyl aminomethane (Tris) at 15 and 30°C have been studied, respectively. The results of rate constants and equilibrium constants calculated with this method are in agreement with those in the literature. Therefore, the characteristic parameter method for opposing reaction is believed to be correct.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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Elena Ceausescu R. Bordeianu Anca Ion E. Buzdugan Rodica Stancu Irina Cerchez 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):1539-1553
A new method for deriving the initiation rate constant for a slowinitiated living polymerization process in which all reactions are first order with respect to all participants is presented. The method is based upon an approximate analytical solution of the set of differential equations modeling this class of processes. The solution is found by asymptotic expansion of the unknown functions, using a dimensionless parameter which characterizes the process. 相似文献