肉桂酸苄酯定香剂的合成

本文报导了以肉桂酸或肉桂酸钠与苄酯或氯苄为原料，采用直接酯化法．氯苄与肉桂酸盐的取代。相转移催化法合成肉桂酸肉酯的研究结果．讨论了三种实验方法中，不同反应条件对产率的影响，并找到了提高肉桂酸苄酯产率的最佳途径。     

肉桂酸胆甾醇酯光二聚体液晶的制备及其性能的研究

首先合成了光二聚型肉桂酸胆甾醇酯，通过光二聚法制备了含强刚性结构的二苯基环丁烷二羧酸二胆甾醇酯液晶分子。研究发现：通过骤冷可得到玻璃态胆甾相液晶，并可以反复熔融和冷却实现可逆的彩色显示。     

琥珀酸二异辛酯磺酸钠的合成与新应用

针对琥珀酸二异辛酯磺酸钠的工业生产技术,从提高琥珀酸二异辛酯磺酸钠产品的纯度出发,概括和总结了琥珀酸二异辛酯磺酸钠的酯化和磺化合成技术,及合成工艺中催化剂、温度、助剂和体系真空度等主要影响因素,简要介绍了该表面活性剂在反胶束制备纳米材料等方面的应用新进展,指出了目前琥珀酸二异辛酯磺酸钠生产工艺中存在的不足,展望了琥珀酸二异辛酯磺酸钠系列表面活性剂的发展方向和应用前景.     

新型肉桂基咪唑啉缓蚀剂的合成及其对盐酸介质中Q235钢的缓蚀性能

目前,有关用肉桂酸和有机胺合成咪唑啉衍生物及其合成产物的缓蚀性能与机理研究未见介绍。利用肉桂酸和二乙烯三胺脱水反应生成咪唑啉衍生物,采用失重法、电化学方法、量子化学计算研究了合成缓蚀剂对Q235钢的缓蚀性能和机理。结果表明,新型肉桂基咪唑啉的缓蚀率随缓蚀剂浓度的增大而升高,＂-31mol／LHCl中缓蚀剂浓度为800m...     

马来酸酐在聚羧酸盐减水剂合成中的应用

随着聚羧酸盐减水剂的不断发展,马来酸酐在其合成中的应用也越来越多.根据马来酸酐与丙烯酸(以及甲基丙烯酸)各自的特性和聚羧酸盐减水剂合成的技术要求,分析了它们在合成过程中的作用和主要差别,并概述了马来酸酐在合成中的应用情况,最后提出了马来酸酐在合成中应用的几点建议.马来酸酐及其酯的分子结构和化学活性独特,应用于聚羧酸盐减水剂的合成必将有广阔的前景.     

新型聚丙烯酸酯的制备与非线性光学性能

设计合成了一种含偶氮苯和取代苯乙炔基长共轭生色团的丙烯酸酯,并采用溶液聚合法合成了功能化的聚丙烯酸酯,利用FTIR、NMR等对化合物的结构进行了表征,证实得到了指定结构的化合物.利用z-scan技术对合成的聚丙烯酸酯的非线性光学性能进行了表征,对聚合物的非线性吸收进行拟合,计算得到非线性吸收系数β和三阶非线性系数x(3).     

叔碳酸乙烯酯(VeoVaTM10)的研究进展与应用情况

叙述了叔碳酸乙烯酯(VeoVaTM10)以及共聚物涂层的优良特性,综合分析了各种叔碳酸乙烯酯合成技术的特点和进展,介绍了叔碳酸乙烯酯的应用情况,指明了行业方展中应注意的问题。     

沸石咪唑酯骨架材料-8的合成及其膜的制备研究进展

ZIF-8作为一种典型的沸石咪唑酯骨架材料,在气体储存、吸附/分离、催化和传感领域内有着广泛的应用。综述了ZIF-8的合成方法,如溶剂热法、微波合成、室温合成、微流控合成。阐述了各种合成方法的特点;分析了室温合成ZIF-8的策略;强调了微流控技术在连续、快速和可控制备ZIF-8方面的潜力。同时也简要综述了ZIF-8薄膜的制备方法,包括直接合成、二次生长法、表面功能化、特殊播种法以及逆扩散法。     

聚丁二酸丁二醇酯的研究进展

对聚丁二酸丁二醇酯(PBS)的合成、改性及应用进行了综述,讨论了合成过程中的影响因素以及合成工艺对材料性能的影响.     

纤维状甲基丙烯酸正丁酯／甲基丙烯酸β羟乙酯共聚树脂的性能

采用悬浮聚合法合成了甲基丙烯酸正丁酯、甲基丙烯酸β羟乙酯二元共聚树脂,并用冻胶纺丝技术制备了纤维状共聚物树脂.研究了甲基丙烯酸β羟乙酯含量对树脂饱和吸油率以及充分溶胀后树脂剩余率的影响,分别利用傅立叶变换红外光谱(FT-IR)和动态热机械分析仪(DMA)对树脂的化学结构和动态力学性能进行了分析和讨论.     

Long-Term Permeation Kinetics of Estradiol: (III) Kinetic Analyses of the Simultaneous Skin Permeation and Bioconversion of Estradiol Esters

Abstract

The skin permeation system developed earlier in this laboratory was utilized to study the kinetics of the simultaneous skin permeation and bioconversion of 5 estradiol esters. The equilibrium solubility of estradiol esters in the lipophilic silicone fluid and in hydrophilic PEG 400/saline solution was found to be dependent upon the alkyl chain length of the esters. Estradiol-3,17-diacetate had a greater solubility in silicone fluid and a lower solubility in PEG 400/saline solution than estradiol-17-acetate. The (skin/silicone fluid) partition coefficients were observed to decrease as the alkyl chain increased in length. During the course of skin permeation, the estradiol esters were metabolized by esterase to regenerate estradiol. The rate of appearance of estradiol from the estradiol esters was observed to be dependent upon the ester concentration on stratum corneum surface and to follow the order of: diacetate > valerate > heptanoate > cypionate > acetate. From the dermal uptake and metabolism studies of estradiol esters the first-order rate constants for the metabolism of estradiol esters were determined. The rate constant for the metabolism of estradiol-3,17-diacetate to form estradiol acetate was observed to be about 22 times faster than the rate constant for the metabolism of estradiol acetate to generate estradiol. The enzymatic hydrolysis of the ester group at 17th position was found also to follow a first-order kinetic process and the rate constants varied with the variation in alkyl chain length.     

The Solubilities of Esters of 4-Hydroxybenzoic Acid,Determined Separately and Together,in Aqueous Solutions of 2-Hydroxypropyl-β-cyclodextrin

Abstract

The solubilities of four esters of 4-hydroxybenzoic acid have been investigated singly and together in water and in aqueous solutions of 2-hydroxypropyl-β-cyclodextrin (HPCD). Values obtained for the solubilities of methyl (MP), ethyl (EP), propyl (PP), and butyl (BP) esters in water agreed welt with literature values, when determined separately. When measured together the solubilities of the methyl and butyl esters increased slightly, that of the ethyl ester decreased slightly, and the solubility of the propyl ester decreased by approximately 50%. Association constants for complexes of esters and HPCD determined separately in water agreed well with literature values, declining from methyl to ethyl and then increasing through propyl to butyl. When the association constants were determined for the esters together in solutions of HPCD the same pattern was noted, but the large decreases in association constants may indicate some other process in addition to competition between the esters for the HPCD molecules.     

Dynamic microwave-assisted extraction coupled on-line with solid-phase extraction and large-volume injection gas chromatography: determination of organophosphate esters in air samples

An on-line method was developed for the extraction, cleanup, and analysis of airborne organophosphate esters collected on glass fiber filters. The extraction and cleanup step was performed by conducting the dynamic microwave-assisted extraction (DMAE) coupled to solid-phase extraction (SPE). This system was further connected to include large-volume injection gas chromatography. The Injection interface was a programmable temperature vaporizer. The system performance test was investigated using spiked glass fiber filters. The DMAE-SPE recovery of the organophosphate esters was found to be greater than 97%. The repeatability of the uncorrected peak areas and the retention times was determined to be 4.2-8.0 and 0.03% relative standard deviation, respectively, and limits of detection were in the range 61-186.2 pg/m3. The method was tested in a newly restored office, in which several of the targeted organophosphate esters were detected. The total sampling and analysis time was less than 1.5 h.     

固相萃取-高效液相色谱法测定地表水中邻苯二甲酸酯

建立了固相萃取-高效液相色谱法分析8种邻苯二甲酸酯类物质,并对实际水样进行了测定。8种邻苯二甲酸酯类化合物的线性回归相关系数均大于0.999,检出限为0.11-0.19μg/L,保留时间和峰面积相对标准偏差分别为0.09-0.19%、0.25-0.56%,回收率为76.2-96.4%。     

The hydrolysis kinetics of monobasic and dibasic aminoalkyl esters of ketorolac

Six aminoethyl and aminobutyl esters of ketorolac containing 1-methylpiperazine (MPE and MPB), N-acetylpiperazine (APE and APB) or morpholine (ME and MB), were synthesized and their hydrolysis kinetics were studied. The hydrolysis was studied at pH 1 to 9 (for MPE, APE and ME) and pH 1 to 8 (for MPB, APB and MB) in aqueous phosphate buffer (0.16?M) with ionic strength (0.5?M) at 37°C. Calculation of k_obs, construction of the pH-rate profiles and determination of the rate equations were performed using KaleidaGraph^® 4.1. The hydrolysis displays pseudo-first order kinetics and the pH-rate profiles shows that the aminobutyl esters, MPE, APB and MB, are the most stable. The hydrolysis of the ethyl esters MPE, APE and ME, depending on the pH, is either fast and catalyzed by the hydroxide anion or slow and uncatalyzed for the diprotonated, monoprotonated and nonprotonated forms. The hydrolysis of the butyl esters showed a similar profile, albeit it was also catalyzed by hydronium cation. In addition, the hydroxide anion is 105 more effective in catalyzing the hydrolysis than the hydronium cation. The hydrolysis pattern of the aminoethyl esters is affected by the number and pKa of its basic nitrogen atoms. The monobasic APE and ME, show a similar hydrolysis pattern that is different than the dibasic MPE. The length of the side chain and the pKa of the basic nitrogen atoms in the aminoethyl moiety affect the mechanism of hydrolysis as the extent of protonation at a given pH is directly related to the pKa.     

Density of <Emphasis Type="Italic">Jatropha curcas</Emphasis> Seed Oil and its Methyl Esters: Measurement and Estimations

Density data as a function of temperature have been measured for Jatropha curcas seed oil, as well as biodiesel jatropha methyl esters at temperatures from above their melting points to 90 ^° C. The data obtained were used to validate the method proposed by Spencer and Danner using a modified Rackett equation. The experimental and estimated density values using the modified Rackett equation gave almost identical values with average absolute percent deviations less than 0.03% for the jatropha oil and 0.04% for the jatropha methyl esters. The Janarthanan empirical equation was also employed to predict jatropha biodiesel densities. This equation performed equally well with average absolute percent deviations within 0.05%. Two simple linear equations for densities of jatropha oil and its methyl esters are also proposed in this study.     

分散液液微萃取--气相色谱法测定海水中的邻苯二甲酸酯

本文以分散液液微萃取作为样品的前处理技术,建立了气相色谱-氢火焰离子化检测器分析海水中邻苯二甲酸酯的新方法。优化了分散液液微萃取的萃取条件,6种邻苯二甲酸酯线性范围在1.0-50.0μg/mL之间,R≥0.9953,回收率在92.5%~106.4%之间,最低检测限为0.15μg/mL。将方法应用于海水中邻苯二甲酸酯类的检测,易于操作,分析结果可靠。     

Some Aspects of the Antimicrobial and Chemical Properties of Phenyl Boronate Esters of Chloramphenicol

Substituted phenyl boronate esters of chloramphenicol have significant antimicrobial potency against common pathogens. The isosteric 1,3-dioxanes in which the boron atom has been replaced by a methine group are inactive under the conditions of test. The boronate esters are regarded as having the same conformation as the parent antibiotic. Photochemical degradation of these esters by simulated sunlight proceeds much faster than it does with chloramphenicol.     

Some Aspects of the Antimicrobial and Chemical Properties of Phenyl Boronate Esters of Chloramphenicol

Substituted phenyl boronate esters of chloramphenicol have significant antimicrobial potency against common pathogens. The isosteric 1,3-dioxanes in which the boron atom has been replaced by a methine group are inactive under the conditions of test, The coronate esters are regarded as having the same conformation as the parent antibiotic; Photochemical degradation of these esters by simulated sunlight proceeds much faster than it does with chloramphenicol.     

Esr study of the migration of paramagnetic additives from rigid PVC to pure or mixed fatty esters used as food simulators

The ESR study presented here provides an insight into the behaviour of paramagnetic additives in rigid PVC before, during and after contact with methyl fatty esters and their migration from the plastic material. Before contact, diffusion processes took place in rigid PVC. The mobility of the NO group of the paramagnetic additives is directly linked to the displacement of the whole molecule. Methyl fatty esters plasticize the PVC matrix, increase the mobility of the additive in the material and enhance their migration. The increased lability is due to methyl ester penetration into the polymeric network. Penetration was greatest with short chain esters and probe migration was greater when more penetrating simulators were used. If a fast migration test is required, methyl oleate could be an interesting approach. Results describing the behaviour of binary mixtures as simulators are very complex, probably because they depend to a large extent on the type of paramagnetic additive.