可裂解的表面活性剂（英）（续完）

１ ３缩酮与图１和图２所示制备缩醛的反应相类似 ,含缩酮键的表面活性剂可由长链酮和二醇反应制备。近期 ,一类由长链羰基化合物（酮或醛）与甘油乙氧基化物制备的非离子表面活性剂已商品化。这类表面活性剂既可以是环缩醛 ,也可以是环缩酮。这些酸不稳定性表面活性剂已被用于微乳液中六氯苯的还原。脱卤以后 ,溶液的 ｐＨ值降到３以下 ,表面活性剂水解使溶液失去表面活性 ,可以从溶液中直接回收电解产品。用酮酸酯也可以制备二氧戊环类缩酮表面活性剂 ,收率较高 ,如图７所示。其降解速度与脂肪链长密切相关。可裂解表面活性剂比Ｋ１２ 的…     

化学降解表面活性剂的开发

表面活性剂在洗涤剂、涂料、盥洗用品和医药方面得到了广泛应用。化学降解型表面活性剂在履行完其固有机能后可转化为没有表面活性的化合物,在表面化学领域受到了极大关注。1-O-烷基甘油可以合成含1,3-二氧杂环烷的酸降解性羧酸盐表面活性剂和酯基化学降解表面活性剂,合成时无需使用特殊装置和试剂。这些化学降解表面活性剂都具有良好的表面活性,且生物降解性均优于月桂酸钠。本文还讨论了它们在洗涤剂和乳化聚合等方面的应用。     

表面活性剂生物降解的标准与法规

表面活性剂对环境的影响引起了各国和地区的关注，纷纷建立标准与法规，引导表面活性剂向着正确的方向发展。表面活性剂对环境的影响主要表现为其生物降解性。简要概述了各组织建立的表面活性剂生物降解测试方法、降解性能要求及各国为表面活性剂建立的一些法规。阐述了我国表面活性剂生物降解标准的现状及发展趋势。     

可生物降解——表面活性剂发展的瓶颈与机遇

介绍了表面活性剂生物降解的定义、分类及其重要性.详述了表面活性剂生物降解的实验方法、表面活性剂结构与生物降解之间的关系和国内外有关表面活性剂生物降解标准与法规的现状及发展趋势.分析了表面活性剂行业面临的问题,提出了促进可持续发展的建议.     

脂肪酸甲酯制备表面活性剂的研究与生产现状

生物柴油的迅猛发展使得脂肪酸甲酯作为重要化工原材料引起了广泛关注,并为其进一步开发应用提供了良好的机会和广阔的发展空间。本文论述了以脂肪酸甲酯为原料生产的各类可生物降解的表面活性剂,并对环氧乙烷加成物、脂肪酸甲酯α-磺酸钠、脂肪酸蔗糖酯等产品的性能、研究现状及目前企业生产概况等进行了重点介绍。     

表面活性剂生物降解性能的研究进展

对表面活性剂的生物降解性能进行了全面概述。着重讨论了表面活性剂的降解性能测试方法、生物降解机理、降解动力学及用于量化分析可生物降解的同位素标记反应运移模型,并对各类表面活性剂结构与降解能力作了评价。最后,指出了我国表面活性剂生物降解度研究的发展方向。     

含链烯基或烷基羧基磺酸盐的非离子型液体洗涤剂

含链烯基或烷基羧基磺酸盐的非离子型液体洗涤剂本文提供的是一种以非离子表面活性剂为主的液体洗涤剂。它具有稳定、均匀、可生物降解和低泡等性能，其主要组成为：（ａ）２０％～３０％非离子表面活性剂，如脂肪醇聚氧乙烯醚表面活性剂和烷基酚聚氧乙烯酸表面活性剂，其...     

醇醚羧酸盐在日化产品中的应用性能研究

考察了脂肪醇聚氧乙烯醚乙酸钠(AE9C Na)的生物降解性和酸、碱水解稳定性,研究了AE9C Na在洗衣粉、肥皂及香波中的应用性能。结果表明,AE9C Na易生物降解,在整个pH值范围内具有良好的酸、碱水解稳定性;在普通肥皂中添加AE9C Na作钙皂分散剂,大大提高了其去污力、抗硬水性,在冷水中的溶解性及织物洗后纤维表面的光滑柔软性;与洗衣粉各助剂及常用各类型表面活性剂配伍性能良好,特别在高硬度水中显示出强大的去污力和钙皂分散能力;在香波中表现出强的起泡、稳泡能力和良好的增调作用。     

表面活性剂生物降解和光降解技术研究进展

表面活性剂的生物降解和光降解技术正受到越来越多的关注。介绍了该两项技术在国内外的研究现状；讨论了表面活性剂生物降解和光降解的研究成果；并对近几年发展起来的表面活性剂光催化降解的催化剂、工艺组合作了简要介绍。提出了表面活性剂生物降解和光降解的今后研究方向。     

金属焊接防溅渣附着剂

非离子表面活性剂在酸、碱、盐溶液中比较稳定,具有低泡,无毒,防锈,易生物降解,亲水基和疏水基的数量可以根据产品的要求调整,复配方便等优点,且用量少,收效大,被广泛应用于各工业部门。我们和冶金部第十三冶金公司协作,参考国外有关     

Cleavable surfactants

Cleavable surfactants are of interest for several reasons. Above all, the development of surfactants with weak bonds deliberately built into the structure is driven by the need for improved biodegradability of amphiphiles. The breakdown may be catalyzed by enzymes, and biodegradation would be the normal mechanism in sewage plants. Alternatively, the surfactant may degrade by chemical means, e.g., induced by acid, alkali, ultraviolet (UV) light, heat, or ozone. Acid- and alkali-labile surfactants have attracted particular attention, and there is often a compromise between required stability at one stage and ease of breakdown at a subsequent stage. The paper reviews the main routes used to prepare cleavable surfactants and points out advantages and disadvantages of the different approaches. Emphasis is placed on the development during recent years. Cyclic and acyclic acetals, ketals, and ortho esters are the most important types of bonds for the preparation of acid-labile surfactants, whereas alkali-labile amphiphiles usually are based on ester bonds. The ester bond approach has been particularly important for cationic surfactants, and so-called ester quats have rapidly taken a large share of the traditional market for quats. Betaine esters constitute a special class of ester with very pronounced pH dependence. UV-labile surfactants based, for instance, on an azo bond, offer promise for the future.     

Ester-based surfactants: Are they stable enough?

Surfactants with an ester bond connecting the polar headgroup and the hydrophobic tail are common. They are easy to synthesize, they can often be made from natural raw materials and their biodegradation profile is generally good, partly due to lipase or esterase catalyzed breakdown of the ester bond in sewage plants. A labile ester bond in the molecule may cause problems, however. Surfactants are often formulated at relatively high pH and it is important that they remain intact for a given period of time. In this article we discuss alkaline hydrolysis of different types of ester-based surfactants—cationic, anionic and nonionic—and also of surfactant mixtures. We show that the ester bond in a surfactant has a different hydrolysis pattern than ester bonds in non-surface active uncharged molecules. Cationic ester-based surfactants are hydrolyzed rapidly while anionic and also nonionic ester-containing surfactants are relatively resistant to hydrolysis.     

Cleavable Surfactants: A Comparison between Ester,Amide, and Carbonate as the Weak Bond

Cleavable surfactants, i.e., surfactants in which a weak bond has deliberately been inserted into the molecule, are of interest when remaining surface-active material at a surface can cause problems. Ester and amide bonds are established as week linkages in surfactants but these generate an acid when they hydrolyze. For some applications, acidic degradation products are unwanted. Surfactants with a carbonate bond between the polar headgroup and the hydrophobic tail are of interest for such purposes. In this article, we compare the physical–chemical properties of nonionic carbonate surfactants with those of the corresponding ester and amide surfactants. The half-lives of the different cleavable surfactants are also compared and it was found that a carbonate bond is slightly more stable to alkaline hydrolysis than an ester bond when present in otherwise identical structures. A nonionic Gemini surfactant with a carbonate bond in the spacer, which on hydrolysis decomposes into two identical single-tailed nonionic amphiphiles, is also presented. The hydrolysis kinetics for this surfactant was studied in some detail and it was found that it degrades much faster at low temperature than at higher temperature. This anti-Arrhenius type of hydrolysis kinetics is proposed to be due to the reverse solubility versus temperature behavior of ethoxylated surfactants.     

Sugar fatty acid ester surfactants: Structure and ultimate aerobic biodegradability

Ultimate aerobic biodegradabilities of an array of sugar ester surfactants were determined by International Standards Organisation method 7827, “Water Quality—Evaluation in an Aqueous Medium of the Aerobic Biodegradability of Organic Compounds, Method by Dissolved Organic Carbon” (1984). The surfactants were nonionic sugar esters with different-sized sugar head groups (formed from glucose, sucrose, or raffinose) and different lengths and numbers of alkyl chains [formed from lauric (C₁₂) or palmitic (C₁₆) acid]. Analogous anionic sugar ester surfactants, formed by attaching an α-sulfonyl group adjacent to the ester bond, and sugar esters with α-alkyl substituents were also studied. It was found that variations in sugar head group size or in alkyl chain length and number do not significantly affect biodegradability. In contrast, the biodegradation rate of sugar esters with α-sulfonyl or α-alkyl groups, although sufficient for them to be classified as readily biodegradable, was dramatically reduced compared to that of the unsubstituted sugar esters. An understanding of the relationship between structure and biodegradability provided by the results of this study will aid the targeted design of readily biodegradable sugar ester surfactants for use in consumer products.     

Oxidized rapeseed oil methyl ester as a bitumen flux: Structural changes in the ester during catalytic oxidation

Structural changes occurring in the rapeseed oil methyl ester upon catalytic oxidation at 200 °C were examined. Oxidative decomposition of fatty acid chains to lower molecular weight compounds and the formation of oligomers were the major oxidation pathways at 200 °C. FT-IR and ¹H NMR examinations, as well as the fall in iodine number, revealed the disappearance of double bonds. Quantitative analysis of the rapeseed oil methyl ester and the liquid products of its oxidation showed that oxidation of fatty acid methyl esters possessing three and two double bonds was practically complete whereas for structures possessing one double bond the loss of unsaturation amounted to 25% only. The decrease in iodine number from about 110 to about 65 and the 1.5-fold increase in molecular weight of the liquid products in the course of 25-h oxidation suggest that only a part of the unsaturated bonds in the fatty acid methyl ester was engaged in the formation of liquid oligomers and volatile oxidation products. The addition of dicumyl peroxide promoted the formation of organic peroxides during the initial stage of oxidation, which resulted in a higher molecular weight of the liquid products. The volatile oxidation products were found to contain lower molecular weight aldehydes, ketones, free fatty acids and their methyl esters, alkylfurans, lactones, n- and isoalkanes. The reaction schemes for their formation were presented. The results of the study are of importance to the optimization of the conditions for oxidation of the ester in order to obtain a quality ecological bitumen flux.     

Chemical reactions of fatty acids with special reference to the carboxyl group

Unsaturated fatty acids contain unsaturated centres and the carboxyl group both of which can be modified to give a range of interesting and useful compounds. The former have been discussed in detail in two recent references [8, 9] and therefore this paper will be concerned with the reactions of the carboxyl group and its derivatives. Attention is directed to the lactones, alcohols and their ethoxylates and sulfates, to the preparation of cleavable surfactants (acetals, ketals, ortho esters and ester quats), Guerbet alcohols and acids, alkyl polyglycosides and to amines and other nitrogencontaining compounds.     

异构酯类表面活性剂的性质及应用

介绍了新型表面活性剂异构酯类的性质及应用,发现具有比正构酯类更为优越的性能,用作日用化学品、树脂和润滑油等的添加剂,可提高产品的延展性、稳定性和润湿性等,已日益显示出良好的应用前景,引起了人们广泛关注。重点对异构酸季戊四醇酯、异构酸甘油酯及其他异构酸异构醇酯等几种新型异构酯的性质及应用研究进展作了概述。引用文献13篇。     

Sugar fatty acid ester surfactants: Biodegradation pathways

In previous work, we found that the presence of a sulfonyl or alkyl group adjacent to the ester bond of sugar ester surfactants is associated with a dramatic reduction in the rate of biodegradation relative to that of unsubstituted esters. In this study, we investigated the pathways followed during the biodegradation of sucrose laurate, sucrose α-sulfonyl laurate, and sucrose α-ethyl laurate to determine the reasons for their different biodegradation rates. Through the use of high-performance liquid chromatography and proton nuclear magnetic resonance spectroscopy, the nature of the intermediates formed during the biodegradation of these three key sugar esters was determined. It was found that sucrose laurate biodegradation occurs via initial ester hydrolysis. In contrast, sucrose α-sulfonyl laurate degrades by initial alkyl chain oxidation. This indicates that the ester hydrolysis pathway is blocked by the sulfonyl group adjacent to the ester bond so that biodegradation is forced to proceed via the slower alkyl chain oxidation pathway. Sucrose α-ethyl laurate was degraded at least in part by alkyl chain oxidation, indicating that ester hydrolysis was also inhibited by the presence of an ethyl group. It is therefore concluded that previously observed relationships between structure and biodegradability arise because of the influence that different structural elements have on the pathways followed during biodegradation.     

阳离子及脂肪胺类表面活性剂的展望(英文)

过去的几年间 ,减产、兼并及重组在表面活性剂行业屡见不鲜 ,但其中也不乏增长机会。目前市场上阳离子型表面活性剂的产量近 80 0 0 0 0t。近几年 ,以北美及欧洲地区的市场用量最大且较为活跃。尽管总体增长趋缓 ,产品间的微调却始终未断。而产品的新旧转换又进一步推进了市场的前进。随着东南亚经济的复苏 ,南美及亚洲市场呈现增长势头 ,预计全球的增长将主要来自亚洲。介绍了阳离子表面活性剂的技术及其主要应用范围与市场情况。此项技术还在继续发展中 ,比如一些市场已从烷基胺 (四基胺 )转变为酯类四基胺 ,亦描述了几个大市场的情况及潜在增长的可能性     

高压下CO2在几种物理吸收剂中的溶解度测定

为开发新型高效物理吸收溶剂,采用恒定溶剂法,测定了不同温度、压力条件下,CO2气体在酮、碳酸酯、乙酸酯、二酸酯、醚及醚酯化合物等不同纯溶剂中的溶解度,温度变化282.76-302.81 K,压力最高可达4 MPa.结果表明:在此测定条件下,CO2在物理溶剂中的溶解度符合亨利定律,溶解度随压力升高而增大,随温度升高而减小...