1,3—二氯丙烯水解反应动力学

本文研究了顺及反－１,３－氯丙烯混合物水解反应过程的动力学。结果表明,利用１０％ａＯＨ水溶液,在６５￣８０℃的条件下,顺及反－１,３－二氯丙烯的水解反应均为二级反应,顺、反异构体的表观活化能分别为８７．５１ＫＪ·ｍｏｌ＾－１和１１３．６０ＫＪ·ｍｏｌ＾－１,反应速率常数Ｋ顺＝２．６２×１０＾１０ｅｘｐ（－１０５２５．６／Ｔ）,ｋ反＝１．０９×１０＾１４ｅｘｐ（－１３６６３．１／Ｔ）。     

四氢萘加氢裂化反应动力学

在连续流动的微反装置上,研究了四氢萘加氢裂化反应动力学,探讨了加氢裂化催化剂活性中心与反应表现活化能的关系。结果表明,四氢萘加的氢裂化反应为拟一级反应。在８．５ＭＰａ时,其表观活化能为１３２．７４８ｋＪ．ｍｏｌ＾－１。在６．５ＭＰａ时,当反应温度高于３６０℃,强酸中心与弱酸中心同时活化,活化能从８７．２７４ｋＪ．ｍｏｌ＾－１提高到１０３．２７６ｋＪ．ｍｏｌ＾－１。     

乙酸异戊酯杂多酸催化合成及其动力学研究

研究了以钨硅酸为催化剂,苯为带水剂乙酸和异戊醇直接酯化合成乙酸异戊酯的优化反应条件,该杂多酸催化反应的速率方程为－ｄＣＡ／ｄｔ＝ｋＡｃＡｃＢ,反应表现活化能Ｅａ＝１４２．５７ｋＪ／ｍｏｌ,反应速率常数ｋＡ（Ｌ·ｍｏｌ＾－１·ｍｉｎ＾－１）＝７．７５×１０＾１７ｅｘｐ（－１７１４８．２／Ｔ）。     

配位化合物Cu（p—tol）2Cl2标准生成焓的测定

使用具有恒定温度的反应热量计，以溶解热法及针对配位反应所设计的热化学循环，得到该反应的标准反应焓ΔｒＨ＾θｍ（２９８．１５Ｋ）＝－２７．９２４ｋＪ．ｍｏｌ＾－１，并求得配合物Ｃｕ（ｐ－ｔｏｌ）２Ｃｌ２的标准生成焓，其值推荐为ΔｆＨ＾θｍ「Ｃｕ（ｐ－ｔｏｌ）２Ｃｌ２．ｓ」＝－３４３．３７４ｋＪ．ｍｏｌ＾－１。     

异苯橡胶环化反应动力学研究圾产物微细结构表征

本采用红外光谱法研究了前无报导的聚异苯橡胶环化反应动力学，测定了标题反应的动力学参数：反应级数ｎ＝１；活化能Ｅａ＝５３．２ｋｊ·ｍｏｌ＾－１；指前因子Ａ＝２．２４×１０＾６ｍｉｎ＾－１，确立了该反应速率常数ｋｔ与ｓ反应温度Ｔ之间的函数关系为：Ｌｎ（ｋＴ／ｍｉｎ＾－１）＝１４．６２－６．４０×１０＾３Ｋ／Ｔ并采用核磁共振法分析了标题反应的产物环化异苯橡胶的微细结构，提出了标题反应的可能机理，并对活     

在H2SO4—HOAc水溶液体系中咔唑3—位偶合的动力学特征

本文研究了Ｈ２ＳＯ４－ＨＯＡｃ中咔唑化合物３－位上与芳胺重氮盐偶合的反应级数，讨论了该反应有关ｔ，ＣＢＯ，ＸＢ的一些动力学特征。实验结果证明，该偶合反应为典型的二级反应，２２．５℃和４０℃时的反应速率常数分别为０．４６４３（ｍｏｌ／ｌ）＾－１ｈｒ＾－１和２．８３３０（ｍｏｌ／ｌ）＾－１ｈｒ＾－１；提高反应秀初始浓度及反应温度有利于反应的进行。     

对硝基苯甲酸催化加氢本征动力学

用活性炭载钯催化剂,在排除扩散影响的条件下,研究了对硝基苯甲酸加氢的动力学。实验测定了氢气压力、温度、催化剂浓度等因素对反应速率的影响。研究结果表明：对硝基苯甲酸催化加氢反应为一级反应,表面化学反应活化能Ｅ＝２５．９１０ｋＪ／ｍｏｌ,原子氢吸附热ＱＨ＝３８．４８７ｋＪ／ｍｏｌ,其总括动力学方程为ｒ＝Ｋｃ２ＴＫＨαＰＨ（１＋ＫＨα·ＰＨ）２·ｃＡ其中：ｃ２ＴＫ＝４．０３５×１０３ｅｘｐ［－２５９０９．４９／ＲＴ］,ｍｉｎ－１αＫＨ＝５．０１３×１０－６ｅｘｐ（３８４８６．９３／ＲＴ）,ＭＰ     

癸二酸二辛酯非酸催化合成反应动力学研究

研究了采用改进的非酸性催化剂铝酸盐，合成癸二酸二辛酯反应过程的动力学，结果表明，该非酸催化反应的速率方程为－ｄｃＡ／ｄｔ＝ｋｃＡ，反应表观活化能Ｅａ＝５６．６８ｋＪ／ｍｏｌ，反应速率常数ｋ／ｍｉｎ－１＝４．１４×１０４ｅｘｐ（－６８１８ＫＴ）。     

1,3—二氯丙烯水解反应动力学

本文研究了顺及反—１,３—二氯丙烯混合物水解反应过程的动力学。结果表明,利用１０％ＮａＯＨ水溶液,在６５～８０℃的条件下,顺及反—１,３—二氯丙烯的水解反应均为二级反应,顺、反异构体的表观活化能分别为８７５１ＫＪ·ｍｏｌ－１和１１３６０ＫＪ·ｍｏｌ－１,反应速率常数ｋ顺＝２６２×１０１０ｅｘｐ（－１０５２５６／Ｔ）,ｋ反＝１０９×１０１４ｅｘｐ（－１３６６３１／Ｔ）。     

乙二醛溶液体系中乙酸络合萃取的动力学研究

采用恒界面池法研究了乙酸在乙二醛溶液中的萃取动力学，实验结果表明：萃取速率由界面化学反应所控制，且表观反应速率方程为：ｒ＝ｋｓＣＨＡｃ１．３６４１，在２５℃时的反应速率常数ｋｓ＝１．８２×１０－２ｍｏｌ／ｃｍ２·ｓ。此外，还研究了温度对反应速率的影响，求取了表观反应的活化能Ｅａ＝２３．２８３３ｋＪ／ｍｏｌ，从而进一步说明了萃取速率控制步骤为界面化学反应所控制。     

Effect of ultrasound on micromixing

It is well known that the apparent reaction rate constant is increased by exposing the reactor to ultrasound. The authors reveal in this paper that another effect of ultrasound, that is, the decrease of the segregation of points in the sense of Danckwerts, also appears and that this effect is probably due to some hammering action caused by the collapse of cavities. The saponification of ethyl acetate in a continuous stirred tank reactor is chosen for the experimental work.     

Stimuli‐sensitive behaviour of novel betaine‐type polyampholytes

Novel linear and crosslinked polyampholytes of betaine structure based on acrylic acid and ethyl 3‐aminocrotonate (ethyl ester of 3‐amino‐2‐butenoic acid) have been synthesized by Michael addition reaction followed by radical copolymerization. The mechanism of formation of monomer and polymer betaines is discussed. The linear polyampholyte has been characterized by potentiometric titration, IR, NMR and GPC. Crosslinked polymeric betaines were synthesized in the presence of N,N′‐methylenebisacrylamide. The stimuli‐sensitive properties of amphoteric gels have been studied as a function of pH, ionic strength, water–organic mixture composition, electric, and combined electric and magnetic fields. The isoelectric points of linear and crosslinked polymeric betaines correspond to pH 2.0–2.1. The effect of ionic strength on the solution and gel properties of polybetaine has been interpreted on the basis of destruction of inter‐chain, intra‐chain and intra‐group salt bonds. Water–acetone, water–ethanol or water–DMF mixtures cause the shrinking of amphoteric gel due to change of the dielectric constant of the medium and decrease of the osmotic pressure. Electrocollapse is observed under the action of DC electric field. Simultaneously cross action of electric and magnetic fields enhances the collapsing rate. Appearance of pH gradient within the volume of polyampholyte gel under the externally imposed DC electric field has been observed. Copyright © 2003 Society of Chemical Industry     

电场强化乙酸乙酯自然对流和沸腾换热的实验研究

对沉浸于强极性有机液体工质乙酸乙酯中的平板表面上的自然对流和沸腾换热的外加电场强化进行了实验,得出了自然对流和沸腾换热的表面传热系数、强化效果与电场电压、热通量的关系.实验数据表明,外加电场对平板表面自然对流换热的强化效果好于对沸腾换热的强化效果.实验条件下,当施加外电场时,平板表面的自然对流换热的传热系数最大可达到无外电场时的6～7倍,沸腾换热的传热系数最大可达到无外电场时的4～5倍.     

Saponification value determination of difficultly saponifiable drying oil products

Conclusions The use of n-butyl alcohol as a solvent for saponification of a representative series of drying oils has been studied. It appears from this work that n-butyl alcoholic potassium hydroxide reagent, containing 5% of water added to the reaction mixture, gives very acceptable results based upon calculated saponification values. With the exception of maleic-modified oils of certain types, the solvent system of ethyl alcohol-pyridine exhibits excellent results based upon calculated values. However it has the disadvantages that it is a two-solvent system, and the pyridine must be of reagent grade to avoid end-point difficulties. The end-point in the butyl alcohol system is not as sharp as the normal saponification end-point in ethyl alcohol. This may be caused by the two-phase nature of the titration mixture. Addition of ethyl alcohol to the n-butyl alcoholic saponification reaction mixture gives improvement, although the end-point is not as sharp as in the regular ethyl alcohol system. Work is continuing on methods for improvement of the end-point.     

Determination of Kinetic and Energetic Parameters of Chemical Reactions in a Heterogeneous Liquid/Liquid System

A global method is proposed for estimating the kinetic and energetic parameters of chemical reactions taking place in the continuous phase of a heterogeneous liquid/liquid system. This method, based on energy and mass balances, uses the thermal power freed or absorbed by the reaction mass. It is only applicable to systems with sufficient thermal effects. Knowledge of the mass flow exchanged between the dispersed and continuous phases is needed to establish the mass balance. It is determined thanks to a model based on the double film theory. The model was applied to the saponification of pure ethyl acetate in an aqueous reaction mass. It was possible to determine simultaneously the velocity constant and the reaction enthalpy, as well as the apparent overall mass transfer constant.     

Data acquisition system for chemical kinetic studies

A microcomputer-interfaced data acquisition system for chemical kinetics (interfacing with laboratory analogue instruments) has been developed. Analogue signals from instruments used in kinetics experiments are amplifed by a wide-range adjustable high-gain operational amplifier and smoothed by an op-based filter, and then digitized at rates of up to 10⁴ samples per channel by an ADC 0816 digitizer. The ADC data transfer and manipulation routine was written in Assembler code and in high-level language; the graphics package and data treatment package is in Basic. For the various sampling speeds, all of the program can be written using Basic-Assembler or completely in Assembler if a high sampling rate is needed. Several numerical treatment methods for chemical kinetics have been utilized to smooth the data from experiments.The computer-interfaced system for second-order chemical kinetic studies was applied to the determination of the rate constant of the saponification of ethyl acetate at 35°C. For this specific problem, an averaging treatment was used which can be called an interval method. The use of this method avoids the diffcully of measuring the starting time of the reaction. Two groups of experimental data and results were used to evaluate the systems performance. All of the results obtained are in agreement with the reference value.     

流速对磁场阻垢效果的影响

利用双道的实时监测系统,通过监测碳酸钙过饱和溶液中的pH和Ca2 浓度在析晶过程中的变化,系统的研究了不同流速下磁场的阻垢效果.准确、可重复的试验数据表明,磁场对碳酸钙过饱和溶液有阻垢效果,并且不同流速下磁场的阻垢效果不同.同时试验结果还表明在磁处理时间恒定的条件下,在0～6 m/s的流速范围内,溶液通过磁场的流速越高磁处理的阻垢效果越强.     

L-苯丙氨酸手性固定相的制备

L-苯丙氨酸和硬酯酰氯经酯化、酰胺化、皂化和酰氯化反应得到新型手性固定相,用FTIR、1HNMR和元素分析对手性固定相(CSP)进行了表征。将制得的手性固定相按m(CSP)∶m(硅胶)=3∶1制备薄层色谱板,采用V(乙醇)∶V(乙酸乙酯)∶V(三乙胺)=11∶5∶1作为展开体系,对手性药物度洛西汀进行拆分,其中右旋度洛西汀Rf1=0.87,左旋度洛西汀Rf2=0.75。     

Preparation of monodisperse poly(vinyl alcohol) microspheres by heterogeneous surface saponification and iodine complex formation

Monodisperse poly(vinyl acetate) (PVAc) microspheres with high molecular weight obtained by suspension polymerization of vinyl acetate were saponified in alkaline aqueous solution to keep their spherical structure. The saponification was restricted on the surface of the PVAc microspheres and obtained particles had skin/core structure. Various poly(vinyl alcohol) (PVA) microspheres with different diameters and degrees of saponification (DSs) were obtained. The conversion of PVAc to PVA during the heterogeneous surface saponification time were examined by nuclear magnetic resonance spectroscopy and after 72 h hydrogel type PVA microspheres completely saponified were obtained. The crystal melting temperatures of the microspheres obtained by the saponification were measured a constant value of 238°C irrespective of varying DS, and the peaks became enlarged as reaction time. Iodine complexes were formed in saponified microspheres with DS of 41% and 99% by immersing them in I₂/KI aqueous solution and decomposed by the reduction of I₂ in the complexes to 2I^? using sodium sulfite to confirm whether the skin formed through the saponification was composed of PVA with high VA content. Obviously, characteristic blue color developments owing to I₅^?‐PVA complexes were observed in both saponified regions and a red in the PVAc core. Consequently, it was concluded that the PVA skins formed by heterogeneous surface saponification had high DSs. Such complexes endowed polymeric microspheres a good radiopacity which would be useful in clinical treatment of vascular diseases and were examined by X‐ray irradiation image. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

富反式菊酸的制备工艺

研究了菊酸乙酯顺反异构、皂化制富反式菊酸的工艺条件。将菊酸乙酯顺反异构后,产物不经分离直接进行皂化制富反式菊酸。研究了反应温度、反应时间、甲醇钠用量、溶剂量对异构效果和收率的影响,确定了优化工艺条件。