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以辛烯基琥珀酸淀粉钠和油酸甲酯分别为替代乳化剂和溶剂,采用浓缩乳化法制备了高度稳定的2.5％高效氯氟氰菊酯水乳剂,通过测定乳液油滴粒径分布,结合乳液外观研究了乳化方法、预处理液中辛烯基琥珀酸淀粉钠质量分数、转速和剪切时间等工艺条件对乳液稳定性的影响.研究结果表明,辛烯基琥珀酸淀粉钠对油酸甲酯具有较好乳化效果,以其为乳化剂可制备高度稳定的2.5％高效氯氟氰菊酯水乳剂,油滴平均粒径在1.2 μm左右,且加速试验[即(54±2)℃密封14 d]和常温储存6个月后平均粒径仅增长了0.1～0.3μm,外观无变化;采用浓缩乳化法且预处理液中辛烯基琥珀酸淀粉钠质量分数在15％～25％时乳液稳定性较好,提高转速可降低油滴平均粒径,但对乳液均一性无显著影响,延长剪切时间对油滴平均粒径影响不大,但有利于提高乳液均一性;辛烯基琥珀酸淀粉钠为乳化剂制备的高效氯氟氰菊酯水乳剂稳定性优于常规水乳剂. 相似文献
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建立了田水、土壤、水稻植株、水稻稻壳和糙米中氰氟草酯及代谢产物氰氟草酸的残留分析方法。前处理方法利用乙腈为提取剂,N-丙基乙二胺(PSA)、石墨化碳黑(GCB)和C18为分散净化剂的QuEChERS方法,并利用超高效液相色谱-串联质谱(UPLC-MS/MS)在多反应离子监测模式(MRN)下进行检测,外标法定量。结果表明:氰氟草酯和氰氟草酸在0. 01～1. 0 mg·L~(-1)浓度范围内均具有良好的线性关系(R~2≥0. 997);在0. 05～1. 00 mg·kg~(-1)添加水平范围内平均回收率为70. 6%～105. 8%;相对标准偏差(RSD,n=5)为0. 3%～7. 9%;氰氟草酯和氰氟草酸的方法检出限(LOD)为0. 11和0. 16μg·kg~(-1);定量限为0. 37和0. 54μg·kg~(-1)。该方法分析速度快、灵敏度高、重现性好,适用于多种基质上氰氟草酯和氰氟草酸的快速检测和确证。 相似文献
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采用乙腈提取,NH2固相萃取柱净化,GC/MS测定,建立了大米中精噁唑禾草灵和氰氟草酯残留量的测定方法.添加精噁唑禾草灵质量分数为0.02,0.2,0.5mg/kg,平均回收率分别为82.3％,88.8％和90.7％,相对标准偏差分别为6.8％,8.2％和3.7％,检出限为0.02 mg/kg;添加氰氟草酯质量分数为0.02,0.2,0.5mg/kg,平均回收率分别为87.7％,94.2％和92.3％,相对标准偏差分别为8.6％,5.6％和7.3％,检出限为0.02mg/kg. 相似文献
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首次研究了二氟烯醇硅醚1与β,γ-不饱和酮酸酯2的反应.发现不论使用叔胺或叔胺-氢键给体双功能催化剂,均专一地发生Mukaiyama-aldol反应生成相应的叔醇3.利用手性氢化奎宁衍生的双功能脲催化剂11高对映选择性地实现了这一反应,为合成α-二氟烷基取代的手性叔醇提供了一种新方法.不同芳基取代的二氟烯醇硅醚以及γ位不同芳基取代的酮酸酯化合物均反应良好.在所考察的15个例子中,反应产率中等到良好(44%～81%),对映选择性中等到优秀(72%～96%).反应产物可方便转化为二氟烷基取代的手性二醇或三醇化合物. 相似文献
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《应用化学》2013,30(09):1048
Abstract: To replace the common emulsifiers and solvents, the mix-emulsifier of benzyl starch ether in combination with alkyl polyglycoside and solvent of methyl oleate were used in preparation of 10% cyhalofop-butyl aqueous emulsions. The structure of benzyl starch ether was characterized by FTIR and UV spectroscopies in case of benzyl carboxymethy. The effects of different processing parameters, including the concentration of benzyl starch ether and alkyl polyglycoside in pretreatment fluid, rotation speed and shearing time on the stability of emulsion were studied by measuring oil droplet diameter distribution and using the orthogonal experimental design. The results demonstrate that benzyl starch ether compared with pristine starch has absorption peak of benzyl carboxymethyl. High stable emulsions can be prepared with benzyl starch ether and alkyl polyglycoside complex in 3∶2 molar ratio as emulsifier and 9% methyl oleate as solvent. The mean droplet diameter of emulsions is about 1.02 μm and is increased by only 0.1~0.6 μm after storing at 25 ℃ for 6 months or at (54±2) ℃ for 14 days and the water separating proportion is only 2.7%. Cyhalofop-butyl oil-in-water emulsion prepared with benzyl starch ether, alkyl polyglycoside and methyl oleate has a better stability than the conventional emulsions. The results of this study show that benzyl starch compounding with alkyl polyglycosid and methyl oleate can be used as an alternative emulsifier and solvent for the environmentally friendly oil-in-water emulsion formulations. 相似文献
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《应用化学》2012,29(01):113-117
In order to provide a reference for octenyl succinic anhydride(OSA)-modified starch and methyl oleate used in green pesticide preparations, the formulation of the lambda-cyhalothrin oil-in-water emulsion with OSA-modified starch and methyl oleate as emulsifier and solvent was studied. Furthermore, the effects of different processing parameters, including the concentration of pretreating fluid of OSA-modified starch, rotational speed and shearing time on the stability of emulsion were studied by measuring oil droplet diameter distribution. Results demonstrated that OSA-modified starch had excellent emulsification ability to methyl oleate. High stable emulsions(2.5%) could be prepared with OSA-modified starch. The mean droplet diameters of emulsion were about 1.2 μm, and increased by only 0.1~0.3 μm after storing at 25 ℃ for 6 months or at (54±2) ℃ for 14 days, and approximately 100% of the oil remained stable in the emulsion. Higher stable emulsions could be prepared by emulsification at high viscosity with mass fraction of pretreating fluid of OSA-modified starch in the range of 15%~25%. Smaller oil droplet diameters were obtained when the rotational speed was increased, which had no significant effect on homogeneity of emulsions. On the other hand, an increase of the shearing time reduced the span of oil droplet diameter distribution, but had no significant impact on the mean oil droplet diameter. Lambda-cyhalothrin oil-in-water emulsion prepared with OSA-modified starch had a better stability than the conventional emulsions. The results of this study show that OSA-modified starch and methyl oleate can be used as an effective emulsifier and solvent for the environment-friendly lambda-cyhalothrin oil-in-water emulsion formulations. 相似文献
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绿色表面活性剂烷基糖苷的合成方法评述 总被引：12，自引：0，他引：12
烷基葡萄糖苷是一类重要的非离子表面活性剂,性能良好,应用日益广泛,目前一些发达国家已经开始了初具规模的工业化生产.作者简要评述了烷剂糖苷的合成历史、合成方法和催化剂选择. 相似文献
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Yan‐Ping Chu Lan Luo Guang‐Yu Chen Xue‐Song Fu Lin Wang 《Journal of Dispersion Science and Technology》2013,34(2):315-322
Experimental studies are conducted in order to elucidate the mechanisms responsible for synergism/antagonism for lowering interfacial tension in alkyl benzene sulfonate/brine/methyl oleate model oil and alkyl benzene sulfonate/alkali/methyl oleate model oil systems. We found that different mechanisms exist in above two systems. In alkyl benzene sulfonate/brine/methyl oleate model oil systems, methyl oleate influences the partition of added surfactants between oil and aqueous phase by changing equivalent alkane carbon number (EACN) value of model oil. In alkyl benzene sulfonate/alkali/methyl oleate model oil systems, methyl oleate in oil phase has two functions: on the one hand, it influences the partition of surfactant between oil and aqueous phase; on the other hand, it directly affects IFT by displacing surfactant molecule or forming mixed film with surfactant molecule at the interface. 相似文献
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Preparation and characterization of microemulsions consisting of a plant-derived alkyl polyglycoside (APG) surfactant and the essential oil of Melaleuca alternifolia (tea tree) was studied. This nonionic APG surfactant used was Triton CG-110 with a CMC at 1748 ppm at 25 °C. Tea tree oil (TTO) was extracted from tea tree leaves by Triton CG-110-assisted hydrodistillation method. The preparation of the microemulsion was aided by the construction of pseudo-ternary phase diagrams, which were investigated at the different weight ratios of surfactant mixtures (Smix = Triton CG-110/PPG) as 0.6:1, 1.8:1, 1:0 with hydrodistilled and commercial TTO by water titration method at room temperature. Particularly, structure of microemulsion was identified by electrical conductivity and viscosity. Moreover, shelf stability of some microemulsion made of 1% TTO with various concentration of Triton CG-110/PPG (1.8:1 w/w) were monitored for over a two-month period with dynamic light scattering. These results showed that microemulsion made of 1% TTO, 9% Triton CG-110/PPG (1.8:1 w/w) was insensitive with time and temperature of storage. 相似文献
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J.I. Gutiérrez-Ortiz R. López-Fonseca C. González-Ortiz de Elguea M.P. González-Marcos J.R. González-Velasco 《Reaction Kinetics and Catalysis Letters》2000,70(2):341-348
A detailed mass transfer analysis was developed both theoretically and experimentally for the heterogeneously catalyzed hydrogenation of methyl oleate using a Ni/silica catalyst in a slurry reactor. The results indicate that, at the conditions studied, working with stirring rate between 1400 and 2000 rpm, catalyst particle size below 50 µm, and catalyst weight below 1.11 g assured the kinetic regime for the reaction. 相似文献
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Girdhar Joshi 《合成通讯》2013,43(5):720-728
The synthesis of benzyl alkyl ethers from benzyl bromides and alcohols using FeSO4 as a recoverable and reusable mediator has been described without use of base and cosolvent under mild conditions. 相似文献
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