不同方法测定两种表面活性剂的临界胶束浓度

采用电导法及表面张力法分别测定了十二烷基硫酸钠(阴离子表面活性剂)和十二烷基三甲基氯化铵(阳离子表面活性剂)的临界胶束浓度,两种实验方法测得十二烷基硫酸钠的临界胶束浓度约为7.0×10-3mol·dm-3,十二烷基三甲基氯化铵的临界胶束浓度约为1.60×10-2mol·dm-3,两种方法所得结果一致。     

月桂酸酯季铵盐阳离子表面活性剂的合成与表征

以十二烷基二甲基叔胺、环氧氯丙烷为原料,合成了中间体DMAC〔(2,3-环氧丙基)十二烷基二甲基氯化铵〕,再与月桂酸反应,生成月桂酸酯季铵盐阳离子表面活性剂HDAC〔(2-羟基-3-月桂酰氧基丙基)十二烷基二甲基氯化铵〕。通过正交实验确定了最佳合成条件:以异丙醇为溶剂,n(DMAC)∶n(LAC)=1∶1.2,反应时间6 h,反应温度50℃,产率大于90%,Krafft点-4.52℃。通过元素分析、傅立叶变换红外光谱、飞行时间质谱(TOF-MS)、1HNMR,确证了目的产物的结构。测定产物的临界胶束浓度CMC为8.91×10-4mol/L,γCMC为34.12 mN/m。表明所合成的月桂酸酯季铵盐阳离子表面活性剂具有较高的表面活性。     

N-烷基苯并咪唑阳离子表面活性剂的合成及性能

以苯并咪唑、不同链长的卤代烷烃、硫酸二甲酯为原料,合成了几种烷基苯并咪唑阳离子表面活性剂。通过IR1、HNMR对产物结构进行表征,测定了所得产物的表面活性和发泡性能,并计算出产物的饱和吸附量及饱和吸附面积。结果表明,合成的N-辛基、癸基、十二烷基、十四烷基苯并咪唑阳离子表面活性剂的最低表面张力随烷基链增长而降低,但N-十六烷基苯并咪唑阳离子表面活性剂的最低表面张力却高于十四烷基苯并咪唑阳离子表面活性剂;合成的表面活性剂中,十二烷基苯并咪唑阳离子表面活性剂的发泡性能较佳,但所有的表面活性剂的泡沫稳定性均较差。     

新型双子表面活性剂的合成与性能测定

利用十四烷基二甲基叔胺、无水乙醇及1,4-二溴丁烷等原料,通过一步法合成了十四烷基阳离子双子新型表面活性剂。表面张力的测定结果表明,该新型表面活性剂具有较小的表面张力和较低的临界胶束浓度;界面张力的测定结果表明,该新型表面活性剂与大庆油田采油二厂原油之间的油/水界面张力最低可降至1×10~(-3)m N/m;另外,该新型表面活性剂还具有稳定的乳化性能和泡沫性能,并与普通表面活性剂有良好的协同作用。     

N-烷基苯并三氮唑阳离子表面活性剂的合成及性能

以苯并三氮唑、不同链长的卤代烷烃、硫酸二甲酯为原料合成了几种N-烷基苯并三氮唑阳离子表面活性剂,通过IR1、HNMR对中间产物进行结构表征,并对最终产物进行定性分析。测定了所得产物的表面活性和发泡性能,结果表明,合成的N-丁基、辛基、十二烷基、十六烷基苯并三氮唑阳离子表面活性剂最低表面张力分别为:51.0 mN/m、36.5 mN/m、33.4 mN/m、35.4 mN/m;临界胶束浓度分别为:9.0×10-2mol/L、4.8×10-2mol/L、3.0×10-3mol/L、9.7×10-3mol/L。N-丁基、辛基、十二烷基苯并三氮唑阳离子表面活性剂最低表面张力随烷基链增长而降低,但N-十六烷基苯并三氮唑阳离子表面活性剂的最低表面张力却高于N-十二烷基苯并三氮唑阳离子表面活性剂的最低表面张力。合成的表面活性剂中,N-十二烷基苯并三氮唑阳离子表面活性剂的发泡性能最佳,而所有的泡沫稳定性均较差。     

12-3-12型Gemini阳离子表面活性剂的合成及性能研究

以十二叔胺与环氧氯丙烷为主要原料,在实验室合成12-3-12型Gemini阳离子表面活性剂,终产物用傅立叶红外变换仪和元素分析仪进行定性分析,并对表面活性剂的性能进行了详细讨论.实验合成的12-3-12型Gemini阳离子表面活性剂cmc为7.28×10-4 mol/L,表面张力γ cmc=39.53 mN/m;乳化力、增溶作用、发泡性及稳泡性均较十八烷基三甲基氯化铵(S 1831)、十六烷基三甲基氯化铵(S 1631)好,但发泡性及稳泡性不及十二烷基硫酸钠(SDS).     

含酯基不对称双季铵盐表面活性剂的合成

以长链烷基叔胺、盐酸、环氧氯丙烷为原料,合成了N (3 氯 2 羟丙基) N,N 二甲基长链烷基氯化铵,研究了其合成工艺,优化反应条件为:n(长链烷基叔胺)∶n(盐酸)∶n(环氧氯丙烷)=1∶1∶1 1,反应温度为40℃,体系pH=6～7。以月桂酸及2 二甲氨基乙醇为原料,酯化得到二甲基月桂酸乙基叔胺(Ⅲ),利用其与N (3 氯 2 羟丙基) N,N 二甲基长链烷基氯化铵季铵化得到含酯基不对称双季铵盐阳离子表面活性剂〔长链烷基分别为(Ⅰ)C12H25和(Ⅱ)C14H29〕。经测定,产物的临界胶束浓度CMC分别为6 61×10-3、8 31×10-3mol·L-1,γCMC分别为37 6、39 2mN·m-1,证明所合成的含酯基不对称双季铵盐阳离子表面活性剂具有较高的表面活性。     

非对称双子季铵盐阳离子表面活性剂的合成及性能

以十二烷基二甲基叔胺、盐酸、环氧氯丙烷为原料,合成了中间体N-(3-氯-2-羟丙基)-N,N-二甲基十二烷基氯化铵,后与3种不同烷基链长的长链烷基叔胺反应,得到3种非对称Gemini季铵盐阳离子表面活性剂(Ⅰ～Ⅲ)。通过IR光谱,1HNMR确证了中间体及目的产物的结构。测定了产物的临界胶束浓度cmc及γcmc。cmc分别为1 07×10-3mol·dm-3、1 99×10-3mol·dm-3和9 55×10-3mol·dm-3,γcmc分别为40 9mN·m-1、48 0mN·m-1和50 9mN·m-1。结果表明:所合成的非对称Gemini季铵盐阳离子表面活性剂具有较高的表面活性。     

新型阳离子表面活性剂的合成及性能研究

本文研究了利用３－氯－１，２－丙二醇和二甲基十二烷基胺合成新型阳离子表面活性剂二（羟基）丙基二甲基十二烷基氯化铵的合成工艺，并研究了其溶液性能。     

烷基酰胺基丙基—N,N—二甲基—2,3—二羟丙基氯化铵的合成

合成了新型阳离子表面活性剂－烷基酰胺基丙基－Ｎ，Ｎ－二甲基－２，３－二羟丙基氯化铵，研究了其最佳合成工艺条件。初步的应用实验表明，该类化合物在与阴离子表面活性剂复配时，表面出很好的相容性。     

几种醇溶液表面张力的测定与分析

采用圆环法对不同浓度的甲醇溶液、乙醇溶液、正丙醇溶液、正丁醇溶液的表面张力进行测定,并通过对溶液密度、铂丝半径和铂丝环半径的修正,研究几种醇溶液表面张力与浓度及烷基链长的变化情况,从而分析醇溶液表面张力变化情况与溶度和烷基键长的关系。     

Correlations between alkyl side chain length and dynamic mechanical properties of poly(n-alkyl acrylates) and poly(n-alkyl methacrylates)

In the present paper, dynamic mechanical properties of poly(n-alkyl acrylates) (PnAA) and poly(n-alkyl methacrylates) (PnAMA) with different alkyl side chain length were studied. The results show that with the increase of alkyl side chain length, the storage modulus changes more steadily, and the loss modulus peak and the tanδ peak become broader for PnAA and PnAMA. At the same time, the tanδ peak is more and more apart from the loss modulus peak and the point where the storage modulus begins to drop. For quantitative discussion, three variables, the steepness index (S), the transition wideness (W) of storage modulus and the integration area (A) of tanδ were defined to investigate the potential correlation between the dynamic mechanical properties and alkyl side chain length. It can be observed that S decreases while W and A increase with increasing alkyl side chain length. Moreover, the relaxation spectra of the two series of polymers are calculated from the corresponding mechanical spectra. The shapes of the relaxation spectra are broader and broader with the increase of the alkyl side chain length. These phenomena are interpreted by the perspective of fragility, molecular packing efficiency and intermolecular coupling.     

A study of the surface activity of tertiary alcohol sulfates

A number of tertiary alcohols were prepared by the action of a series of Grignard reagents on ethyl oleate. The tertiary alcohols were converted to alkyl sulfates by reaction with sodium chlorosulfonate. The surface active properties of the prepared sodium alkyl sulfates were studied in relation to the length of the branched chain and the bulkiness of the charged head of the surfactants.     

The chemistry of alkyl dihalides in zeolite NaX at room temperature

Alkyl dihalides adsorbed in NaX zeolite undergo room temperature, substitutional dehalogenation, single dehydrohalogenation, combined dehalogenation–dehydrohalogenation, or two consecutive dehydrohalogenations. The preference for a particular reaction depends on the nature and relative positions of the halogens, and on alkyl chain length. Nuclear magnetic resonance chemical shifts and mass spectrometric assignments to the reagents and products indicate the particular reactions taking place.All of the alkyl dihalides containing the iodo group (diiodoalkanes) studied (αα, αβ, α,γ) undergo only substitutional dehalogenation to form zeolite bound iodoalkoxy. The same chemistry was observed with both short and long chain diiodoalkanes. The dichloroalkane and dibromoalkane chemistry is dependent on the relative halogen positions and the alkyl chain length. The α, α dichloroalkanes and dibromoalkanes examined by us undergo single dehydrohalogenation, with the exception of 2,2-dichloropropane, which forms a mixture of dehydrohalogenation and substitutional dehalogenation products. The chemistry of α, β alkyl dihalides (Cl, Br) in NaX is dependent on the carbon chain length. The dihaloethanes (Cl, Br) undergo both substitutional dehalogenation and dehydrohalogenation. As the chain length increases to three carbon atoms or more, only dehydrohalogenation reactions take place. No alkyne products were observed with α, β dichloroalkanes and dibromoalkanes, an indication that NaX is too weak a base to initiate sequential dehydrohalogenations. The chemistry of α, γ dichloroalkanes and dibromoalkanes were also dependent on the chain length. The α, γ dihalopropanes (Cl, Br) in NaX form a propene-framework bound product, associated with dehydrohalogenation and subsequent substitutional dehalogenation. The α, γ dihalobutanes (Cl, Br) undergo two consecutive dehydrohalogenations to form dienes.     

磷酸酯在化纤油剂中的应用和性能研究

对磷酸酯在化纤油剂中的应用和性能要求进行阐述，研究了不同碳链的烷基磷酸酯钾盐在不同温、湿度条件下的纤维应用性能，主要包括吸湿性能、抗静电性能和摩擦特性。     

Comparison of Antioxidant Capacities of Rosmarinate Alkyl Esters in Riboflavin Photosensitized Oil-in-Water Emulsions

Effects of the alkyl chain length of rosmarinate alkyl esters on the oxidative stability in photosensitized oil-in-water (O/W) emulsions were determined by lipid hydroperoxides and headspace volatile analyses. Antioxidant capacities of 20 μM rosmarinate esters with alkyl chain length of 0, 4, 8, 12, 18, and 20 were tested in O/W emulsion containing stripped soybean oil, Tween 20 as an emulsifier, and riboflavin as a photosensitizer. Synergistic or antagonistic effects of 20 μM α-tocopherol in the presence of rosmarinate alkyl esters were also determined. Samples containing rosmarinate with 4 and 8 alkyl esters showed lower lipid hydroperoxides and headspace volatiles than those without rosmarinate and those with 0, 12, 18, and 20 alkyl esters, which indicates that phenolic free radical scavengers showed antioxidant capacities non-linearly in riboflavin photosensitized O/W emulsions. Antagonistic rather than synergistic effects were observed in all rosmarinate alkyl esters with α-tocopherol in current conditions although rosmarinates with 4, 8, and 12 alkyl esters showed better antioxidant capacities than those with other alkyl chain length. The results of this study clearly showed that rosmarinates need the proper length of non-polar groups to show optimum antioxidant capacities in O/W emulsions with Tween 20 as an emulsifier under riboflavin photosensitization.     

烷基碳链对N-烷基二甲基甜菜碱性能的影响

甜菜碱表面活性剂的烷基碳链的长度对其表面活性及其它性质有不同程度的影响。通过实验测定碳链长度对泡沫力、洗涤力等的影响情况,为不同使用目的选择合适长度碳链的烷基甜菜碱提供依据。结果表明:十四烷基甜菜碱的起泡力较强,十二烷基的次之;十四、十六烷基甜菜碱的洗涤力较强,十四烷基的洗涤力更强;相对碳链长的甜菜碱活性剂具有较好的加溶作用和钙皂分散力。     

Effect of Alkyl Chain Length on the Extraction of Copper(II) Complexes with 1‐Alkyl‐2‐Methylimidazoles

Abstract

By using the liquid‐liquid partition method, the formation of Cu(II) complexes with 1‐alkyl‐2‐methylimidazoles (where alkyl=isobutyl, pentyl, isopentyl, hexyl, octyl, decyl, and dodecyl) has been studied at 25°C and at fixed ionic strength of the aqueous phase (I=0.5; (HL)NO₃, KNO₃). The complexes were extracted with 2‐ethyl‐1‐hexanol, dichloromethane, trichloromethane and, in one system only, toluene. Stability constants of the complexes in aqueous solution as well as partition constants of the extractable species were determined. It has been shown that the stability constants are invariable and do not depend on the 1‐alkyl chain length. The constants were smaller than those of the previously studied Cu(II) – 1‐alkylimidazole complexes owing to the steric effect of the methyl group at position 2. The partition constants of the complexes incereased with increasing alkyl chain length. Branched 1‐alkyl substituents (isobutyl, isopentyl) suppressed both stability constants and the partition constants of the complexes.     

Influence of ionic surfactants on the hydrogen peroxide bleaching of wool fabric

We have studied the influence of ionic surfactants on the bleaching of wool with hydrogen peroxide under acidic and alkaline conditions, comparing anionic sodium alkyl sulphates with eight, 12 and 16 carbon atoms and the cationic surfactant dodecyltrimethylammonium bromide (DTAB). Addition of ionic surfactants to both acidic and alkaline bleaching baths improved the whiteness of wool, especially at above 0.01 mol/l. Anionic surfactants prevented fibre damage during bleaching of wool, whereas DTAB accelerated it. The fibre damage decreased with increasing concentration of alkyl sulphates and with increasing length of hydrocarbon chain.     

The Influence of the Alkyl Chain Length on Extraction Equilibrium of Cu(II) Complexes with 1‐Alkylimidazoles in Aqueous Solution/Organic Solvent Systems

Abstract

The partition of Cu(II) complexes with 1‐alkylimidazoles (with alkyl ranging from 1‐n‐butyl through 1‐n‐hexadecyl) between the aqueous ((0.5HL, K)NO₃) and organic phase has been studied at 25°C. The organic solvents used were toluene, p‐xylene, tetrahydronaphthalene, dichloromethane, 2‐ethyl‐1‐hexanol, and others. Extraction curves have been shown to be displaced towards lower pH values with increasing alkyl chain length of the alkyl substituent. Stability constants of the Cu(II) complexes with the 1‐alkylimidazoles have been determined in the aqueous phase as well as the number of compounds extractable into the organic solvent, and their partition ratios. Stability constants of the complexes did not depend on the alkyl chain length. One or two complexes were transferred to the organic phase. Partition ratios of these complexes, P ₁ and P ₂, increased rapidly with increasing alkyl chain length. They were higher in magnitude than those of their Co(II), Ni(II), and Zn(II) counterparts.