Formulating characteristics of high and low 2-phenyl linear alkylbenzene sulfonates in liquid detergents

Detergent range linear alkylbenzene (LAB) currently is manufactured by two different processes, using either aluminum chloride or hydrogen fluoride as the alkylation catalyst. The alkylates from the two processes are not exactly the same. Furthermore, the properties of the linear alkylbenzene sulfonate (LAS) surfactants made by sulfonation of the LABs also differ. Because LAS is used in most types of detergent products, it is important to known how the properties of each type of LAS differ. This paper compares the formulating characteristics (such as viscosity, solubility and foaming) of high and low 2-phenyl LAS in some typical household cleaning product formulations. It is concluded that the two types of LAS should not be used interchangeably without first checking carefully all the physical properties required in a product. Presented at the AOCS meeting in Honolulu, Hawaii in May 1986.     

Interactions between linear alkylbenzene sulfonates and water hardness ions. I. Effect of calcium ion on surfactant solubility and implications for detergency performance

This paper examines the interactions of linear alkylbenzene sulfonate (LAS) surfactants with calcium ions. Calcium sulfonate precipitation boundary diagrams are given which provide a convenient way to study these interactions over a wide range of surfactant and hardness ion levels. Some implications of these interactions for detergency performance are discussed. Presented at AOCS meeting in Philadelphia, May 1985.     

Precipitation of anionic surfactants in the presence of sodium oleate and calcium ions

Precipitation of anionic surfactants, linear alkylbenzene sulfonate (LAS) and alpha olefin sulfonate (AOS), by calcium ions was studied in the presence of sodium oleate. Lather stability was determined by the Ross-Miles method, precipitation was followed by measuring the optical density (OD), and equilibrium surface tension (EST) and Fourier transform infrared (FTIR) spectroscopy were used to characterize the nature of the precipitate formed. For the 5 mM LAS-0.7 mM oleate system, lather was unstable, and the OD was high in the 2–5°FH region of calcium hardness, while at higher calcium hardness levels, lather was stable and the turbidity of solutions decreased. On the other hand, in the 5 mM AOS-0.7 mM oleate system, lather was unstable throughout the calcium hardness region studied (0–20°FH). Also, the turbidity build-up was much higher in the AOS system than in the LAS system. Analysis of the precipitates formed in these systems by FTIR spectroscopy indicated that the precipitate from the AOS system had an additional band at 1190 cm⁻¹, corresponding to the sulfonate group. These results, together with the EST data, confirm that the precipitate formed in the LAS system between 2–5°FH calcium is calcium oleate, and that formed in the AOS system is likely to be calcium (AOS) oleate. It is tempting to hypothesize that the similarity of AOS and oleate in chainlength could be responsible for the coprecipitation of AOS and oleate with calcium, whereas LAS, which has a larger headgroup with a benzene ring and two smaller chains (average length is C8) is unlikely to precipitate with the oleate.     

The impact of biodegradable surfactants on water quality

The purpose of this paper is to review some of the recent contributions of the detergent industry to the national effort for cleaner water. Probably the single most important achievement to date has been the industry’s voluntary conversion from the use of alkyl benzene sulfonate (ABS) to linear alkylate sulfonate (LAS) and other biodegradable surfactants. This changeover was completed in mid-1965 at a cost that has been estimated to exceed $150,000,000. Since LAS was the surfactant of primary interest, the bulk of the pre- and postconversion research, in terms of water-pollution control, has been with that material. This paper concerns itself mainly with the over-all impact of the conversion to LAS on water quality. Data from pilot and full-scale sewage-treatment plants throughout the country are included, which clearly demonstrate the effectiveness of the conversion in terms of significantly lower surfactant residue levels.     

酶与表面活性剂的协同去污机理研究

研究了两种碱性蛋白酶（Ｓａｖｉｎａｓｅ,Ｅｓｐｅｒｓｅ）与三种表面活性剂（ＬＡＳ、ＡＥＳ、ＴＸ １０）对普通炭黑污垢、酪蛋白污垢及复合污垢的去污性能,发现酶与ＴＸ １０、ＡＥＳ配伍有增效去污作用,而与ＬＡＳ配伍有消减去污作用。酶与ＬＡＳ配伍使用时,洗涤１０ｍｉｎ后酶的相对活性降至８％;而加入稳定剂的对比实验,洗涤４０ｍｉｎ后仍能保持５２％～６２％的相对活性,相应对酪蛋白污垢的去除率从原来的８１％提高到９５％,表明加入稳定剂可以使酶与ＬＡＳ的配伍变为增效去污作用。提出了两者之间的协同增效去污机理模型。     

Studies on replacement of phosphate builders in laundry detergents using radiolabeled soils

The fabric detergency performance of systems containing different types of surfactants and several builders of reduced phosphate content has been compared using a radiolabeled sebum-clay soil. Use of this soil allows quantitative measurement of both sebum and clay removal from soiled swatches, generally cotton and permanent press Dacron-cotton. One study compared alkylbenzene sulfonate (LAS), alcohol sulfate (AS), alcohol ethoxysulfate (AEOS) and alcohol ethoxylate (AEO) as surfactants in formulations containing from 0–45% sodium tripolyphosphate (STPP). Especially under hard water conditions, the AEO and AEOS considerably out-perform the LAS and AS at equal use concentrations and are less sensitive to phosphate reduction. Tests with cotton swatches soiled with five different carbon black-oil mixtures generally rank the surfactants in the same order, although individual responses of the cloths vary considerably. A further study compares the effect of replacing STPP with sodium nitrilotriacetate (NTA) in formulations containing varying amounts of AEO or LAS. Detergency improves significantly with increasing surfactant concentration, particularly with AEO, and declines as builder strength is reduced. AEO exceeds LAS considerably in performance under the test conditions even at relatively high concentrations of LAS. Another study compares the performance of AEO and LAS at equal concentrations in formulations containing a variety of builders. AEO is generally superior to LAS in removing both sebum and clay soils and is less sensitive to builders and water hardness. The builders generally rank in this order: STPP > NTA = citrate > carbonate > sulfate. Presented at the AOCS Short Course, “Update on Detergents and Raw Materials,” Lake Placid, N.Y., June 1971.     

直链烷基苯磺酸异丙胺盐的性能及其在餐具洗涤剂中的应用研究

对直链烷基苯磺酸异丙胺盐(HIPN)的表面张力、润湿力、乳化力、发泡能力等基本性能进行研究,并与洗涤剂常用阴离子表面活性剂直链烷基苯磺酸钠(LAS)、脂肪醇聚氧乙烯醚硫酸钠(AES)和α-烯基磺酸钠(AOS)进行了对比,研究了HIPN在手洗餐具洗涤剂配方中的表现。结果表明,在餐具洗涤剂中HIPN具有优异的增稠性能,能全部代替或者部分代替LAS和AES,实现和AOS复配的低成本无二烷配方。     

两种油溶性磺酸盐与重烷基苯磺酸盐复配体系的界面性能

以十二烷为油相,比较了二烷基苯磺酸盐（DAS）与α-烯烃磺酸钠（C2024AOS）两种不同结构的油溶性表面活性剂与重烷基苯磺酸盐（HABS）复配体系的界面张力.结果表明,具有苯环结构的DAS和直链型C2024AOS本身界面张力均较高.但与HABS/LAS二元体系复配之后,DAS与HABS之间在降低界面张力方面存在明显的协同效应（固定HABS与DAS质量比为3∶1,LAS含量为20％时,DAS/HABS/LAS三元体系界面张力可以达到3.28×10-3 mN/m;固定LAS含量为30％,DAS与HABS质量比为1∶1时,界面张力可以达到1.85×10-3 mN/m）,而C2024AOS与HABS之间不存在明显的协同效应.     

Protease stabilization by highly concentrated anionic surfactant mixtures

We have found that anionic surfactants such as linear alkylbenzene sulfonate (LAS) can solubilize proteases in a substantially nonaqueous environment without loss of proteolytic activity. Moreover, in mixtures of anionic and nonionic surfactants with a moderate amount of water (water less than 30 wt%), controlled levels of LAS and water solubilize proteases; yet, in these concentrated surfactant mixtures, enzymes maintain their activity for extended periods. Experimental design techniques have been used to delineate the relationship between protease stability and the water, pH and anionic surfactant levels in these surfactant concentrates. As the sum of water and LAS levels is increased, maximum enzyme stability is observed, after which stability falls off. At low water and LAS levels (sum of both <20%), protease solubility is low, while at high levels of water and LAS (sum of LAS and water >45%), denaturation predominates. Additionally, we have developed a new and simple method to predict protease stability by which a synthetic peptide is used to measure protease activity directly in the surfactant concentrate. From the application of this new technique to our system and to commercial liquid detergent formulations, it is apparent that water facilitates the loss of activity of proteases in surfactant concentrates by increasing the rate of autolysis.     

Use of certain alcohol ethoxylates to maintain protease stability in the presence of anionic surfactants

Anionic surfactants, including linear alkylbenzene sulfonate (LAS), are known to decrease the stability of detergent proteases, possibly by hastening autoproteolytic processes. Thus, protease shelf life in enzyme-containing, heavy-duty liquid laundry detergents (HDL) is typically maintained by adding stabilizers, by limiting the level of interfering anionics, or by utilizing more compatible anionics, such as alcohol ethoxysulfates (AES). This study examines the stability of Savinase^® detergent protease in HDL formulations based on LAS and containing different alcohol ethoxylates (AE) for protection against protease inactivation. Dose response curves demonstrated that all commonly used anionic surfactants except AES promote loss of protease activity. In HDL formulations with equal percentage compositions of LAS and AE, the structure of the selected AE was found to have a profound influence on protease stability. Inclusion of AE with chain length ≥C₁₄ and ethoxylate levels >70% resulted in greater protease stability. HDL containing LAS and these protective AE could be formulated to achieve protease stability matching those of simulated commercial products. Unlike polyhydric stabilizers, the AE by themselves confer no additional stability to the protease. It is more likely that the stabilizing effect of the “protective” AE is due to decreased availability of LAS to the protease.     

Effect of temperature on the biodegradation of linear alkylbenzene sulfonate and alcohol ethoxylate

The effect of temperature on the biodegradation of linear alkylbenzene sulfonate (LAS) and alcohol ethoxylate (AE) was evaluated using method OECD 303 A, Confirmatory test (Husmann units). The experiments were performed using an initial surfactant concentration of 10 mg/L and working temperatures of 25, 15, and 9°C, keeping the biodegradation units inside a thermostatic chamber. In all cases, the removal of both surfactants tested, LAS and AE, was higher than 90%, regardless of the temperature used in the test. We observed that longer acclimation periods were needed by the microorganisms at lower temperatures.     

The influence of sodium tripolyphosphate and zeolites on detergency of linear alkylbenzene sulfonate in the presence of Mg++

The influence of sodium tripolyphosphate (STPP) and zeolites on the detergency performance of linear alkylbenzene sulfonate (LAS) has been evaluated at different water magnesium ion levels. This study demonstrates that LAS/STPP gives better results in the presence of calcium than in the presence of magnesium, whereas the LAS/zeolite mixture gives better results in the presence of magnesium than in the presence of calcium.     

椰子油脂乙氧基化物在餐具洗涤剂中的应用

通过对椰子油脂乙氧基化物（COE）与阴离子表面活性剂直链烷基苯磺酸钠（LAS）及脂肪醇聚氧乙烯醚硫酸钠（AES）等的复配实验,研究了复配体系的黏度、去污力和泡沫性能。实验结果表明,COE与AES、LAS有优异的协同效能,COE适合做餐具洗涤剂中的主表面活性剂。     

无机盐对表面活性剂去污力影响的研究

用去污实验机测定了直链烷基苯磺酸钠(LAS)、脂肪醇聚氧乙烯醚硫酸钠、α-烯基磺酸钠、脂肪酸甲酯磺酸钠等阴离子表面活性剂的去污力,考察了无机盐对去污力的影响。结果表明,三聚磷酸钠使这几种表面活性剂的去污值增加了29.11%~121.26%,磷酸三钠使LAS的去污值增加了128.25%;三聚磷酸钠、δ-层状结晶二硅酸钠、4A沸石等软水剂增强去污力的效果最好,碳酸钠和硅酸钠等碱性助剂次之;硫酸钠、氯化钠、磷酸二氢钠和十水四硼酸二钠不适合用作洗涤剂的助洗剂。     

New amphoteric surfactant containing a 2-hydroxyalkyl group: III. Performance of binary systems of amphoteric/anionic surfactants

The performance of new amphoteric surfactants, N-(2-hydroxyethyl)-N-(2-hydroxyalkyl)-β-alanines (HAA), and their oxyethylated derivatives (HAA-nEO) was studied in blends with conventional anionic surfactants. Viscosity, ultraviolet (UV) spectroscopy, surface tension, foaming power, dye solubilization and detergency were measured for the blends of various compositions. The interaction between HAA and sodium linear alkylbenzene sulfonate (LAS) was discussed with respect to the deviation of molar extinction coefficient in the UV spectra. A complex formation was assumed. A notable change in viscosity of 1.0% aqueous solutions was observed at pH 8.0 for the compositions of HAA/LAS (3:1) and HAA/sodium lauryl sulfate (4:1). The binary systems exhibited excellent detergency and other surface active properties, and indicated synergistic effects at a certain weight ratio. Human and rabbit skin irritation also was evaluated.     

Isolation and identification of soil bacteria resistant to surfactants in washing detergents

Linear alkylbenzene sulfonate (LAS) and polyoxyethylene lauryl ether (POLE) are the major surfactants in washing detergents. In the present study, we isolated surfactant-resistant bacteria from soil samples collected from a sports ground and a farm field. The samples were treated with 2.0% LAS or POLE at 25°C for 30 min and cultivated on agar plates at 25°C for several days, after which manifold bacterial colonies were isolated. Thereafter, we tested the ability of each bacterial isolate to resist the antibacterial activity of the surfactant. Ten LAS-resistant strains were isolated, and all were found to be Gram-negative bacteria such as Enterobacter and Pseudomonas. On the other hand, 18 POLE-resistant strains were isolated, of which 14 were Gram-positive bacteria including Bacillus and Microbacterium. Notably, one POLE-resistant strain was identified as Bacillus cereus, a potential causative agent for foodborne illness. The genera of LAS- and POLE-resistant bacteria did not overlap. Therefore, the combination of LAS and POLE could be more effective to eliminate soil bacteria from clothes and/or daily necessities.     

Study of the Effects of LAS and Zein Concentrations on Protein Solubilization

The effects of both linear alkylbenzene sulfonate (LAS) and zein protein concentrations on protein solubilization were investigated to better understand the influence of increasing concentration of the surfactant on protein denaturation and skin irritation. Different methods have been used for the determination of the amount of protein dissolved. A wide range of LAS concentrations and zein amounts were used. The results confirm that protein solubilization increases with LAS concentration increase and demonstrate that a minimum LAS/Zein ratio exists for all the zein to be dissolved.     

Evaluation of the rheological properties of sulfonic acids and sodium sulfonates

Sulfonic acids of linear alkylbenzene (LAB) are converted into the corresponding sodium salts to produce the most widely used anionic surfactant worldwide, linear alkylbenzene sulfonate (LAS). Used in many industrial applications and consumer products, the physical and mechanical properties of the sulfonates are strongly dependent on the LAB manufacturing process. Until recently, commercial alkylation of benzene has employed aluminum chloride or hydrogen fluoride catalysts, but a new fixed-bed alkylation process (DETAL) has been developed with improved 2-phenyl isomer selectivity and low tetralin concentration. In order to better understand the rheology of LAS in aqueous media, a comprehensive comparative evaluation of sulfonic acids and sodium sulfonates of the three LAB process derivatives has been done using dynamic mechanical rheometry, steady shear viscometry, and X-ray diffraction for phase identification. LAB sulfonic acids are Newtonian fluids in the temperature range of 20–60°C. The neat AlCl₃, HF, and DETAL sulfonic acids are Newtonian fluids within the temperature range of 20–60°C. At 30 wt%, all three sulfonates are Newtonian at 20–60°C, and the 40 wt% AlCl₃ sodium sulfonate remains in the Newtonian regime within this temperature range. Lamellar liquid crystalline phases have been identified for the sulfonates in the concentration range of 40–60 wt% in water at 20–60°C, and a hexagonal lattice phase also has been identified for DETAL sodium alkylbenzene sulfonate at 40 wt%, 60°C. The presence of anisotropic phases results in non-Newtonian pseudoplastic behavior with time-dependent viscosity functions.     

椰子油乙氧基化物与阴离子表面活性剂协同效应研究

摘要：对椰子油乙氧基化物-30EO（COE-30）与直链烷基苯磺酸（LAS）、脂肪醇聚氧乙烯醚硫酸钠（AES-2）及脂肪醇聚氧乙烯醚羧酸钠（AEC-5）复配的二元体系进行研究,运用非理想溶液理论计算混合胶束和混合吸附层的组成及二者在混合胶束和混合吸附层中协同作用参数。结果表明,复配体系在混合胶束和混合吸附层显示出较强的协同作用,混合胶束中作用参数|βm|= 2~6,混合吸附层中作用参数|βσ|= 2~6。三个复配体系在形成胶束能力和降低表面张力效率方面存在协同增效作用,同时COE-30/AES-2和COE-30/AEC-5体系在降低表面张力能力方面也存在协同增效作用。     

新型表面活性剂、助剂与碱性蛋白酶的相互作用

研究了洗涤剂组分中表面活性剂(MEE、AEC、甜菜碱、AEO9、AOS、LAS)溶液和助剂(高稳定层状二硅酸钠、3型AN助剂、亚微米4A沸石、4A沸石)溶液对碱性蛋白酶(黄海黄杆菌YS-9412-130低温碱性蛋白酶、Properase450E、Savinase4.0T)的影响作用。40min时表面活性剂溶液中酶的存活率在70%以上,助剂中酶的存活率在85%以上,并对以上结果提出可能的作用机理解释。