皂荚素的表面活性及其二元体系的热力学研究

通过表面张力的测定研究了皂荚素(GS)的表面活性及其热力学性质随温度的变化.测定了皂荚素分别与十二烷基磺酸钠、十二烷基聚氧乙烯醚硫酸钠、全氟辛酸钠、十二烷基脂肪醇聚氧乙烯(9)醚、辛基酚聚氧乙烯(10)醚及十六烷基三甲基溴化铵等复配的表面张力-浓度对数关系(γ～lgc)曲线,并用二维晶格模型及正规溶液理论计算了含皂荚素的二元表面活性剂溶液表面吸附层的组成、分子相互作用参数及分子交换能.结果表明,皂荚素主要呈现非离子表面活性剂的性质,与阳离子表面活性剂复配呈微弱的离子性.复配后分子交换能均小于零,复配增效.增效顺序为GS/阳离子>GS/非离子>GS/阴离子(表面活性剂复配体系).     

聚醚中氧化烯烃的裂解色谱快速分析

聚氧乙烯聚氧丙烯醚类表面活性剂,其性能随聚氧乙烯(POE)、聚氧丙烯(POP)含量不同而变化很大。为了有效地研究其聚合工艺和控制产品质量,必须建立一套快速而准确的测定POE和POP的分析方法。为此,曾提出过多种方法。核磁共振法虽好,但设备难得。直接热裂解气相色谱法虽简便,但重复性差。用某些试剂使醚链断裂,而后用气相色谱     

PEP型嵌段共聚醚非离子表面活性剂的研究

以聚乙二醇和环氧丙烷为原料，用常压法合成了一系列氧丙烯—氧乙烯—氧丙烯嵌段共聚醚，对合成产物进行了结构表征，并对产物的浊点、泡沫稳定性、临界胶束浓度、乳化性能等进行了测定。研究结果表明，氧丙烯—氧乙烯—氧丙烯嵌段共聚醚作为非离子表面活性剂，其性能与嵌段序列长度和含量密切相关。     

用双表面活性剂为共模板合成中孔分子筛MCM-48

利用水热法以非离子表面活性剂聚乙二醇辛基苯基醚和阳离子表面活性剂十六烷基三甲基溴化铵为共模板合成了中孔分子筛MCM-48.实验中发现利用较强的范德华力和氢键,聚乙二醇辛基苯基醚可在很大程度上降低合成MCM-48所需阳离子表面活性剂的用量,且利于制备有序性好、骨架聚合度高、稳定性好的MCM-48.通过调节聚乙二醇辛基苯基醚与十六烷基三甲基溴化铵的比例,可得到不同物相结构的分子筛.     

用MnO_4~-淬灭H_2QS-OP荧光体系测定中草药微量锰

本文报道使用非离子表面活性剂——聚乙二醇辛基苯基醚(OP乳化剂)对8-羟基喹啉-5-磺酸荧光体系的增敏增稳作用,进行中草药微量锰的淬灭测定,在最佳优选的实验条件下,重现性和灵敏度均有提高,取得了良好的效果。     

云南沱茶自水溶液中对铈(Ⅳ)离子的富集作用

研究了云南沱茶在不同浓度、温度、pH条件下, 自水溶液中吸附Ce(Ⅳ) 离子的特性, 并分别讨论了阴离子表面活性剂十二烷基硫酸钠(SDS), 阳离子表面活性剂氯代十六烷基吡啶(CPC) 和非离子表面活性剂聚乙二醇辛基苯基醚(OP) 对沱茶吸附Ce(Ⅳ) 离子的影响, 结果表明, 在一定条件下, 沱茶对铈(Ⅳ) 的吸附量可达7.95 mg*g-1, 吸附规律符合Langmuir等温方程, 计算了吸附热, 对沱茶吸附Ce(Ⅳ) 离子的机理进行了讨论.     

烷基酚阴离子表面活性剂的合成与应用进展

将本实验室最新研究成果与相关文献报导相结合,介绍了目前以烷基酚为原料合成阴-非离子表面活性剂、Extended表面活性剂和Gemini表面活性剂的最新动态,特别注重它们在三次采油等非直接环境排放型应用场合的高效合理利用。指出深入开发区域选择性硫酸化/磺化、硫酸酯盐转磺酸盐、羟基直接氧化合成羧酸盐以及烷基酚偶联合成Gemini骨架等技术对于合理和高效利用烷基酚具有重要意义。     

单一及复合表面活性剂对联苯菊酯微乳液的影响

通过对单一及复合型表面活性剂水溶液临界胶束浓度(CMC)和表面张力(γcmc)的测定分析,研究了表面活性剂对以水为介质、环己酮为溶剂形成的联苯菊酯质量分数为2.5%微乳液相行为及稳定性的影响.结果表明,在几种单一非离子表面活性剂中,苯乙烯基苯酚聚氧乙烯聚氧丙烯醚嵌段型非离子表面活性剂EPE的γcmc最低,为28.18 mN/m;按m(EPE):m(SDBS)=2∶1形成的复合型表面活性剂水溶液的γcmc更低,为27.60 mN/m,有利于O/W型微乳液的形成,当其质量分数为10%时,配制联苯菊酯质量分数为2.5%微乳液的有效成分热贮分解率为2.35%.     

非离子表面活性剂——水杨基萤光酮分光光度法测定微量钛

近年来,表面活性剂的应用使得微量钛的光度法测定得到了较大的进展。据文献报道,在多数方法中,均采用阳离子表面活性剂。不久前,王淑仁等曾经用非离子表面活性剂(OP-10)-苯基萤光酮分光光变法测定钛。方法灵敏度较使用阳离子表面活性剂要高。鉴于水杨基萤光酮比苯基萤光酮具有更好的分沂     

矿石中微量铍的测定——铬天青S-聚乙二醇辛基苯基醚分光光度法

近年来应用表面活性剂,提高铬天青S(CAS)光度法测定铍的灵敏度的报道日益增多,但多数是应用阳离子表面活性剂作增感剂。本文应用非离子表面活性剂-聚乙二醇辛基苯基醚(乳化剂OP),在溶液pH4.0～6.0的条件下,铍与CAS及OP生成三元络合物,最大吸收峰在620毫微米处,摩尔吸收系数ε=8.75×10~4。采用EDTA作掩蔽剂消除干扰离子的影响。本法可不经分离直接用于矿石中微量铍的测定,结果良好。     

Poly[(2-chloroethyl)oxirane], poly[(3-chloropropyl)-oxirane] and poly[(4-chlorobutyl)oxirane]: New polyether elastomers of improved chemical reactivity

(2-Chloroethyl)oxirane, (3-chloropropyl)oxirane, and (4-chlorobutyl)oxirane were prepared from the corresponding alkenols and polymerized using a triethylaluminum-water-acetylacetone initiator system. Copolymerizations with propylene oxide and epichlorohydrin were also accomplished; the copolymerization activities of the (chloroalkyl)oxiranes were similar to the activity of epichlorohydrin. Poly[(2-chloroethyl)oxirane], poly[(3-chloropropyl)oxirane], and poly[(4-chlorobutyl)oxirane] exhibit elastomeric properties and are highly reactive in nucleophilic substitution reactions.     

Poly[(3-hydroxypropyl) oxirane] and poly[(4-hydroxybutyl)oxirane]: New hydrophilic polyether elastomers

Preparations of poly[(3-hydroxypropyl)oxirane] and poly[(4-hydroxybutyl)oxirane] are described. Three routes to poly[(3-hydroxypropyl)oxirane] are discussed, each of which involves the methanolysis of a polymeric ester. (3-Acetoxypropyl)oxirane, [3-(m-chlorobenzoyloxy)propyl]oxirane, and (3-chloropropyl)oxirane were polymerized using the AIEt₃/H₂O/AcAc initiator system. Poly[(3-acetoxypropyl)oxirane] and poly{[3-(m-chlorobenzoyloxy)propyl]oxirane} were converted directly to poly[(3-hydroxypropyl)oxirane] by methanolysis, the former under either acidic or basic conditions only. Poly[(3-chloropropyl)oxirane] was first converted to poly[(3-benzoyloxypropyl)oxirane] by treatment with tetrabutylammonium benzoate; subsequent basic methanolysis then afforded poly[(3-hydroxypropyl)oxirane]. Poly[(3-hydroxypropyl)oxirane] is a colorless elastomer which can be cast into tough, clear films from water or methanol. Poly[(4-hydroxybutyl)oxirane] was prepared from poly[(4-chlorobutyl)oxirane] by benzoyloxylation and subsequent methanolysis. Poly[(4-hydroxybutyl)oxirane] is insoluble in water, but is hydrophilic and can be cast into tough films from methanol or dimethylsulfoxide.     

Photoinitiated cationic polymerization of oxetane formulated with oxirane

Photoinitiated cationic polymerization of oxetane, oxirane (epoxide), and a formulation of both was carried out and their reactivity compared. To investigate a formulated system of oxetane and oxirane in photoinitiated cationic polymerization, computational and experimental methods were used. In the computational study, we employed a semiempirical molecular orbital method (AM1). On the other hand, the reactivities of each system were evaluated and compared experimentally by a real-time FT-IR method. The computational study reveals that oxetane seems to polymerize in S_N2 mechanism, but two possibilities, of S_N1 mechanism through the α-cleavage and of S_N2 mechanism through β-cleavage, are implied for oxirane. Using the real-time FT-IR method, the formulation of oxetane and oxirane was proved to possess rather high reactivities of oxetane toward photoinitiated cationic polymerization. The formulated system exhibited slightly lower number-average molecular weight than oxetane but higher than oxirane. These experimental observations are well explained in terms of the calculated reaction paths. © 1995 John Wiley & Sons, Inc.     

SYNTHESIS,STRUCTURE AND THERMOLYSIS OF PENTACOORDINATE 1,2-OXASTIBETANES

Pentacoordinate 1,2-oxastibetanes have been synthesized and characterized by x-ray crystallographic analysis and NMR spectroscopy. Thermolyses of a pentacoordinate 1,2-oxastibetane were carried out under various conditions to give the corresponding oxirane with retention of configuration, the oxirane with inversion of configuration and the olefin respectively.     

Synthesis and Properties of Novel Cationic Triazolium Gemini Surfactants

New type of triazolium Gemini surfactants were synthesized by reaction of epichlorohydrine with long-chain fatty alcohols namely cetyl alcohol and oleyl alcohol furnishing product 2-(alkoxymethyl)oxirane followed by the their subsequent treatment with triazole resulting in the formation of 1-(1,2,4-triazole)-3-alokoxypropane-2-ol which on reaction with 1,6-dibromohexane resulted in the formation of triazolium-based cationic Gemini surfactant. Their formation was confirmed by IR spectroscopy. Surface tension values were used to determine the critical micelle concentration (CMC), minimum area per molecule (A_min) at air?water interface, Gibbs free energy of adsorption (ΔG_ads), the maximum surface excess concentration (Γ_max), and other parameters. The inhibition behavior of dimeric surfactant on the corrosion of carbon steel (CS) in 1 N H₂SO₄ aqueous medium was studied at 30°C. Performance tests like dispersion capability, foaming power and stability, emulsifying power, and wetting ability were determined. The obtained results show that dispersion capability, foaming power, foaming stability, and emulsifying ability are very good. The wetting power of synthesized surfactants is quite better.     

Reactive Polymers and Oligomers from Cyclic Ethers and Cyclic Sulfides

(2-Bromoethyl)oxirane is converted in 39% yield to poly-[(2-bromoethyl)oxirane] of inherent viscosity 1.99 dL/g. The AlEt₃/H₂O/AcAc system is a very effective initiator for the polymerization of (2-bromoethyl)oxirane. Poly[(2-bromoethyl)-oxirane] is a white elastomer, soluble in CHCl₃ and insoluble in CH₃OH. Polyether-urethane hydrogels are prepared by the room temperature crosslinking of poly[(3-hydroxypropyl)oxirane] with aliphatic or aromatic diisocyanates. These networks absorb 100–200% of their weights in water, and can be prepared in transparent form with potential application as biomaterials or contact lenses.     

Obtention d'un oxiranne far actiom de l'ozone sur un vinylsulfure

Ozone reacts with one vinyl sulphide and gives an oxirane, this fact confirms that oxirane is probably an intermediate in course of reactions of ozone with vinyl derivatives which give products containing unmodified hydrocarbon chains.     

Rearrangement reactions of the molecular ions of some substituted aliphatic oxiranes

The fragmentation reactions of glycidic methyl ester (1) and of its derivatives (2–6) substituted by one, two and three methyl groups, respectively, at the oxirane ring, of the corresponding glycidols (7–12), and of the glycidyl ethers (13–16) in the 70 eV mass spectra have been studied using isotopic labelling and mass-analysed ion kinetic energy spectrometry. It is shown that the typical reaction of these aliphatic oxirane radical cations carrying a nucleophilic methoxy group and hydroxy group, respectively, at the side chain corresponds under high-energy conditions to a rearrangement by a methoxy group or a hydroxy group migration to the β-carbon atom of the oxirane moiety. This rearrangement is very likely mediated by the isomerization of the molecular ions into distonic ions via C? C bond cleavage within the oxirane ring.     

Synthesis, structure, and thermolysis of a pentacoordinate 1,2-oxastibetane

Isomeric pentacoordinate 1,2-oxastibetanes bearing the Martin ligand have been synthesized by the reactions of bromo(2-hydroxyalkyl)stiboranes with sodium hydride of which one of the isomers was characterized by X-ray crystallographic analysis and NMR spectroscopy. Thermolysis of the isomer shown (CD3CN, 140 degrees C) afforded the oxirane with retention of configuration, while its thermolyses in the presence of lithium bromide and LiBPh4.3DME provided the oxirane with inversion of configuration and the olefin. The addition of the salts in the thermolyses of this pentacoordinate 1,2-oxastibetane controls both the stereochemistry of the oxirane formed and the ratios of the three main products.     

Kinetics of Hydroxyethylation of Dimethylamine

The kinetics of hydroxyethylation of dimethylamine with oxirane was studied in the temperature interval 20-50°C at the oxirane : dimethylamine molar ratio of 1 : 3. The influence exerted on the reaction rate by the reaction product, dimethylethanolamine, was examined.