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A novel betaine type asphalt emulsifier 3-(N,N,N-dimethyl acetoxy ammonium chloride)-2-hydroxypropyl laurate was synthesized after three steps by the reaction of lauric acid, epichlorohydrin, dimethylamine and sodium chloroacetate. The optimum reaction conditions were obtained for the synthesis of the first step of 3-chloro-2-hydroxypropyl laurate. The esterification yield reaches 97.1% at the optimum conditions of reaction temperature 80ºC, reaction time 6 h, feedstock mole ratio of epichlorohydrin to lauric acid 1.5, mass ratio of catalyst to lauric acid 2%. The chemical structure of the product was characterized by FTIR and 1H NMR. The first synthesis step of 3-chloro-2-hydroxypropyl laurate was monitored by online FTIR technique. The by-product was detected by the online FTIR analysis. Based upon the experimental data, a plausible reaction mechanism was proposed for the reaction. The CMC of the objective product has a lower value of 7.4×10-4 mol/L. The surface tension at CMC is 30.85 mN/m. The emulsifier is a rapid-set asphalt emulsifier.

A new sodium chlorite--iodide--acetylacetone chemical oscillatory reaction has been studied by the UV-Vis spectrophotometric method. The initial concentrations of acetylacetone, sodium chlorite, iodide, and sulfuric acid and the pH value have great influence on the oscillation observed at a wavelength of 570 nm for the starch-triiodide complex. There is a pre-oscillatory or induction stage and the amplitude and number of oscillations depend on the initial concentration of the reactants. Equations for the starch-triiodide complex reaction rate change with reaction time and the initial concentrations in the oscillation stage were obtained. The induction time decreases linearly with the initial concentration of acetylacetone or sodium chlorite but increases linearly with the initial concentration of sulfuric acid. The oscillation reaction can be accelerated by increasing the reaction temperature. The apparent activation energies at the induction stage and the oscillation stage were 61.02 and 61.36 kJ/mol, respectively, indicating that the two stages have similar reaction mechanisms. Generating the enol isomer by keto-enol tautomerism is an important step to constrain the time of the induction period. Key words: sodium chlorite, oscillation reaction, UV-Vis spectrophotometry, apparent activation energy, acetylacetone. Nous avons etudie une nouvelle reaction chimique oscillante faisant intervenir le chlorite de sodium--iodure acetylacetone par une methode spectrophotometrique UV-Vis. Les concentrations initiales d'acetylacetone, de chlorite de sodium, d'iodure et d'acide sulfurique et les valeurs du pH ont une importante influence sur l'oscillation observee a une longueur d'onde de 570 nm dans des complexes d'amidon et de triiodure. On observe d'abord un stade pre-oscillatoire, ou une periode d'induction, puis l'amplitude et le nombre d'oscillations depend de la concentration initiale des reactifs. Nous avons etabli les equations decrivant la variation de la vitesse de reaction du complexe amidon-triiodure en fonction du temps de reaction et des concentrations initiales au stade d'oscillation. La periode d'induction decroit de facon lineaire avec la concentration initiale d'acetylacetone ou de chlorite de sodium, mais croit, de facon lineaire aussi, avec la concentration initiale d'acide sulfurique. La reaction oscillante peut etre acceleree en augmentant la temperature. Les energies d'activation apparentes aux stades d'induction et d'oscillation etaient de 61,02 et de 61,36 kJ/mol, respectivement, indiquant que des mecanismes de reaction semblables operent aux deux stades. La generation de l'isomere enolique par tautomerisme ceto-enolique est une etape importante pour reduire la periode d'induction. [Traduit par la Redaction] Mots-cles: chlorite de sodium, reaction oscillante, spectrophotometrie UV-Vis, energie d'activation apparente, acetylacetone., Introduction Chemical oscillations are systems of chemicals that exhibit time-based fluctuations when they are far from equilibrium. Chlorite and chlorine dioxide based chemical oscillations play an important role in 'nonlinear [...]

Chlorine dioxide based chemical oscillating behavior was modeled by a simple scheme consisting of three component reactions. Furthermore, little is known about the influence of the pH value. In this study, four component reactions were used to model the chlorite--iodide--ethyl acetoacetate oscillating reaction by dynamic analysis software. The oscillatory phenomenon is observed for concentration changes of triiodide ion, chlorite ion, and hydrogen ion. The initial concentration of ethyl acetoacetate, chlorite ion, iodide ion, and hydrogen ion has great influence on oscillations. The amplitude and number of oscillations are associated with the initial reactant concentrations. The equation of the reaction rate of triiodide ion, chlorite ion, or hydrogen ion changing with reaction time and initial concentrations in the oscillation stage was obtained. The bifurcation surface between oscillatory and nonoscillatory behavior with different pH values was obtained. The spatial zone for the occurrence of oscillation is reduced with an increase in the pH value. The range of oscillation as concentrations of chlorine dioxide, iodine, and ethyl acetoacetate is well described by an equation. There is a lower limit on ethyl acetoacetate initial concentration for oscillation. However, there is a higher limit on chlorine dioxide and iodine concentration for oscillation. The concentrations of chlorine dioxide and iodine for oscillation decrease with an increase in the pH value. The results provide new theoretical evidence of the importance of pH value, which can affect the bifurcation surface between oscillatory and nonoscillatory behavior. Key words: chlorite, chemical oscillating reaction, simulation, ethyl acetoacetate. Les oscillations de reactions chimiques a base de dioxyde de chlore ont ete modelisees sous la forme d'un systeme simple de reactions a trois composants. En outre, on en sait peu sur l'influence du pH. Dans la presente etude, on a fait appel a des reactions a quatre composants pour modeliser la reaction oscillante chlorite--iodure--acetoacetate d'ethyle au moyen d'un logiciel d'analyse dynamique. Le phenomene d'oscillation est observe lors de changements de concentration des ions triodure, chlorite et hydrogene. La concentration initiale d'acetoacetate d'ethyle, d'ion chlorite, d'ion iodure et d'ion hydrogene influe beaucoup sur les oscillations. L'amplitude et le nombre des oscillations sont lies aux concentrations initiales des reactifs. On a obtenu l'equation du taux de reaction de l'ion triiodure, de l'ion chlorite ou de l'ion hydrogene, qui varie en fonction du temps de reaction et des concentrations initiales a l'etape d'oscillation. On a egalement obtenu la surface de bifurcation entre les comportements oscillatoire et non oscillatoire pour differents pH. La zone spatiale oU se produisent les oscillations se reduit lors le pH augmente. La variation des oscillations en fonction des concentrations de dioxyde de chlore, d'iode et d'acetoacetate d'ethyle est bien decrite a l'aide d'une equation. Il existe une limite inferieure de la concentration oscillatoire initiale d'acetoacetate d'ethyle. Il existe egalement une limite superieure des concentrations oscillatoires de dioxyde de chlore et d'iode. Les concentrations oscillatoires de dioxyde de chlore et d'iode diminuent lorsque le pH augmente. Les resultats mettent en evidence, par la theorie, l'importance du pH, qui influe sur la surface de bifurcation entre les comportements oscillatoire et non oscillatoire. [Traduit par la Redaction] Mots-cles: chlorite, reaction chimique oscillante, simulation, acetoacetate d'ethyle., Introduction Chemical oscillations are observed in systems of chemicals that exhibit time-based fluctuations when they are far from equilibrium. The most studied chemical oscillation is the Belousov-Zhabotinsky reaction, which is [...]

In order to study the chemical oscillatory behavior and mechanism of a new chlorine dioxide-iodide ion-methyl acetoacetate reaction system, a series of experiments were done by using UV-Vis and online FTIR spectrophotometric method. The initial concentrations of methyl acetoacetate, chlorine dioxide, potassium iodide, and sulfuric acid and the pH value have great influence on the oscillation observed at wavelength of 289 nm. There is a preoscillatory or induction period, and the amplitude and the number of oscillations are associated with the initial concentration of reactants. The equations for the triiodide ion reaction rate changing with reaction time and the initial concentrations in the oscillation stage were obtained. Oscillation reaction can be accelerated by increasing temperature. The apparent activation energies in terms of the induction period and the oscillation period were 26.02 KJ/mol and 17.65 KJ/mol, respectively. The intermediates were detected by the online FTIR analysis. Based upon the experimental data in this work and in the literature, a plausible reaction mechanism was proposed for the oscillation reaction.