Nonionic detergent degradation. II. Thin-layer chromatography and foaming properties of alkyl phenol polyethoxylates

In Part I of this series (1) a study of the degradation of a number of commercially available alcohol polyethoxylates is described. This paper describes the application of the same procedures to the less degradable class of alkyl phenol polyethoxylates. It appears that, for these materials, the rate and extent of degradation is dependent on the environment in which the degradation occurs. Experiments are described that were carried out under neutral and high pH conditions, but it may well be that other variations in the environment could influence the degradation rate. Slow degradation was observed under conditions comparable with those used for the alcohol polyethoxylates, for example, a common alkyl phenol 9-ethoxylate initially at a concentration of 5 mg per liter showed approximately 50% loss after six weeks. No degradation residues of the polyethylene glycol type and no additional acid degradation products of the types derived from the alcohol ethoxylates were observed. The only visual evidence of degradation was a retardation of the spots on the thin-layer plates, and it was most readily observed on chromatograms prepared so that they showed a resolved series of spots. In the course of some of the degradation experiments using sewage effluent as the medium, an increase in pH value was observed. Under these conditions the degradation of the alkyl phenol ethoxylate was much more rapid and complete than usual, and the resolved trace on the thin-layer plate showed a predominance of ethoxy groups near the top of the chromatogram. In this series of experiments, as in those described in Part I, the foaming capacity during degradation could be closely correlated with the results obtained by using the thin-layer chromatographic procedure.     

Detergents in the arab world

The Arab world is increasing its consumption and production capacity of household detergents and its raw materials. The consumption of detergents, now about 400,000 tons annually, is expected to reach 900,000 tons in 1990. Detergent formulations follow European patterns and are primarily of the heavy duty foam type. Some international brands are produced under license, and more international brands are expected to be produced in the future. Most raw materials have been imported, but new plants are being built to produce LAB, sodium tripolyphosphate and sodium sulfate. Formerly with Egyptian Starch, Yeast & Detergents Co., Alexandria, Egypt; paper presented at the CESIO Congress in Munich in May 1984.     

Application of infrared spectroscopy to surfactant degradation studies

Several IR spectroscopic methods are described for the determination and analysis of detergent actives in sewage, ground water and finished detergents. The methods include the determination of the ratio of straight-chain to tetrapropylene chain alkylbenzene sulfonate (ABS), the determination of level and polyethoxy chain length of alkyl and alkylphenyl ethers of polyethylene oxide condensates, and the type of alkyl group in detergent actives isolated from formulated detergents. Specific applications of these methods to study of the degradation of alkylbenzene sulfonate in sewage from controlled use areas, and in studies of the rate and mechanism of degradation of the alkylphenyl ethers and alkyl ethers are discussed.     

Foaming properties of nonionic detergents

The foam formation and foam stability of aqueous solutions of polyoxyethylene tridecanols, t-octylphenols, nonylphenols, n-dodecanols, and n-octadecanols have been determined as a function of ethylene oxide chain length. In general nonionic detergents form unstable foams; the most stable foams formed by nonionic detergents are comparable to that of sodium dodecylbenzene sulfonate in the absence of foam promoters. In each homologous series of a nonionic detergent the foam formation and foam stability pass through a max at a critical hydrophilic-hydrophobic balance (CHHB). It is shown that the CHHB corresponds to conditions of minimum foam drainage and max resistance to film rupture. Paper presented in part at the 34th National Colloid Symposium, Lehigh University, Bethlehem, Pa., 1960.     

Thermal degradation of polyethylene in a nitrogen atmosphere of low oxygen content. III. Structural changes occuring in low-density polyethylene at oxygen contents below 1.2%

Samples of low-density polyethylene, free from additives, were kept at temperatures between 284° and 355°C under nitrogen containing 1.16% oxygen or less. Changes in molecular weight distribution (MWD) and degree of long-chain branching (LCB) were followed by gel chromatography (GPC) and viscosity measurements. Other structural changes were investigated by infrared spectroscopy and differential scanning calorimetry (DSC). Both chain scission and molecular enlargement occur simultaneously. Chain scission accounts for the formation of low molecular weight material and volatiles. Molecular enlargement reactions cause an increase in LCB and ultimately the formation of insoluble material. At lower temperatures (284°C) an increase in the high molecular weight end of the MWD is observed. The amount of olefinic unsaturation, carbonyl, and ether groups increase with degradation. Conjugated systems are formed. The formation of thin discolored and insoluble surface layers indicate that the attack of oxygen is diffusion controlled. The DSC thermograms undergo large changes at 333° and 355°C, increasing with time and oxygen content. A reaction scheme for the thermo-oxidative degradation of polyethylene is discussed. Both inter- and intramolecular hydrogen abstractions by peroxy radicals are suggested to occur. Thus, the formation of trans-vinylene and ether groups results from intramolecular abstraction, while internal carbonyl groups are formed by intermolecular abstraction. Chain scission will be accomplished by both routes and together with “back-biting” is suggested to accoun for the formation of volatiles. The formation of conjugated sequences causing discoloration is correlated with the formation of trans-vinylene groups. Because of the restricted accessability of oxygen under our conditions, the reactions discussed previously for pure thermal degradation¹ are also considered to be important. The molecular enlargement observed is thus proposed to be mainly due to the combination of alkyl radicals even when oxygen is present.     

Thermal degradation of polyethylene in a nitrogen atmosphere of low oxygen content. III. Structural changes occurring in low-density polyethylene at oxygen contents below 1.2%

Samples of low-density polyethylene, free from additives, were kept at temperatures between 284° and 355°C under nitrogen containing 1.16% oxygen or less. Changes in molecular weight distribution (MWD) and degree of long-chain branching (LCB) were followed by gel chromatography (GPC) and viscosity measurements. Other structural changes were investigated by infrared spectroscopy and differential scanning calorimetry (DSC). Both chain scission and molecular enlargement occur simultaneously. Chain scission accounts for the formation of low molecular weight material and volatiles. Molecular enlargement reactions cause an increase in LCB and ultimately the formation of insoluble material. At lower temperatures (284°C) an increase in the high molecular weight end of the MWD is observed. The amount of olefinic unsaturation, carbonyl, and ether groups increase with degradation. Conjugated systems are formed. The formation of thin discolored and insoluble surface layers indicate that the attack of oxygen is diffusion controlled. The DSC thermograms undergo large changes at 3333° and 355°C, increasing with time and oxygen content. A reaction scheme for the thermo-oxidative degradation of polyethylene is discussed. Both inter- and intramolecular hydrogen abstractions by peroxy radicals are suggested to occur. Thus, the formation of trans-vinylene and ether groups results from intramolecular abstraction, while internal carbonyl groups are formed by intermolecular abstraction. Chain scission will be accomplished by both routes and together with “back-biting” is suggested to account for the formation of volatiles. The formation of conjugated sequences causing discoloration is correlated with the formation of trans-vinylene groups. Because of the restricted accessability of oxygen under our conditions, the reactions discussed previously for pure thermal degradation¹ are also considered to be important. The molecular enlargement observed is thus proposed to be mainly due to the combination of alkyl radicals even when oxygen is present.     

Hydrotrope Substanzen für die Herstellung flüssiger Waschmittel

Hydrotropic Substances for the Preparation of Liquid Washing Agents The hydrotropic action of short chain alkyl benzenesulfonates was investigated on anion active and non-ionic raw materials for detergents as well as on their combinations containing either or no inorganic salts. In the combinations studied it was found that alkali salts of cumol sulfonate were the best hydrotropic agents. The solubility of the raw materials for washing agents could be improved such that concentrated charges with satisfactory clear-melting point could be prepared. The salting out effect of inorganic salts on aqueous solutions of raw materials for detergents is prevented by alkali-cumol sulfonate.     

Über den biologischen Abbau nichtionogener Waschmittel unter aeroben Bedingungen

The Biological Degradability of Non-ionic Detergents under Aerobic Conditions The relation between the structure and the biological degradability of non-ionic detergents was studied by determining the non-volatile organic matter after a fixed degradation time. It was found that benzene rings, branched alkyl chains and long ethylene oxide chains influence the degradation adversely.     

The photocatalytic activity and kinetics of the degradation of an anionic azo-dye in a UV irradiated porous titania foam

A porous organic–inorganic hybrid titania foam, prepared from a long chain organic surfactant, hexadecylamine (HDA) and a semiconductor powder was characterized by microscopic and spectroscopic techniques and photocatalytically evaluated for the solution phase decomposition of methyl orange under alkaline conditions. Kinetic data obtained indicate conformity with Langmuir–Hinshelwood kinetic model at the initial stages of the degradation reaction. An attempt was made to study the effect of experimental parameters including catalyst loading and dye concentration on photocatalytic degradation of MO. Results indicate that the rate of reaction is governed by adsorption of azo-dye into the surface of the photocatalyst materials and suggests an optimum catalyst load and dye concentration for the degradation reaction. Light absorption and scattering within the substrate reaction zone and arising from differences in optical properties of catalyst material, made it impossible to interpret entire kinetic data on the basis of a simple Langmuir–Hinshelwood kinetics. However, kinetic data obtained at the initial stages of the reaction suggest conformity with first-order kinetics. The foam promises to be a versatile material in that it can be used for the treatment of low concentrations of pollutants of biological, organic and inorganic origins in water and air.     

介质阻挡放电协同复合碳材料去除VOCs

挥发性有机物（VOCs）是常见的空气污染物,实验研究低温等离子体催化技术去除以甲苯为代表的VOCs。采用炭粉末、酚醛树脂和致孔有机高分子聚合物的有机溶剂混合物作为前驱物,经过炭化、水汽活化和负载锰催化剂,制备一种基于发泡金属的复合碳材料。采用扫描电子显微镜、XRD、全自动比表面积及微孔孔隙分析仪对材料进行表征。两段式介质阻挡放电反应器结合复合碳材料降解甲苯,前段介质阻挡放电初步降解甲苯,后段复合碳材料利用介质阻挡放电产生的长寿命活性物种和臭氧进一步去除甲苯。输入电压为10 kV时,甲苯去除率约99.4％,CO₂选择性达72.2%,并且有效控制了副产物臭氧。实验结果表明,复合碳材料有望应用于如臭氧和VOCs等的污染控制。     

The status of biodegradability testing of nonionic surfactants

A wide range of nonionic surfactants was studied in an extensive inter-laboratory biodegradability testing program carried out by member companies of The Soap and Detergent Association over a three year period. The objectives were to determine the biodegradability of a variety of nonionic surfactants, and to develop a reliable laboratory scale test method which could be used to evaluate the biodegradability of new candidate materials. The results of this research and testing confirm that the primary and secondary alcohol ethoxylates, the alkyl alkanolamides, and the alkyl amine oxides are all highly biodegradable. These materials represent the important classes of nonionics used in household and institutional synthetic detergents. The removal of these materials under conditions of normal secondary wastewater treatment can be anticipated. The diversity of structures represented in the complete nonionic surfactant spectrum, and the problems of residue analysis imposed serious obstacles in the development of a single standard laboratory procedure which will correlate well with the limited field data presently available. The objective of establishing a standard test for all nonionics was not achieved. Residues of nonionic surfactants from household and institutional synthetic detergents do not appear to contribute to esthetic water pollution or to interfere with waste treatment processes. A variety of biodegradability assessment procedures, applicable to specific nonionics or nonionic groups are currently available and should assure that their residues will not adversely affect the quality of receiving waters. The Subcommittee plans to maintain a program for continued research in nonionic biodegradability testing. Prepared under the auspices of The Subcommittee on Biodegradation Test Methods of The Soap and Detergent Association.     

On the thermal degradation of poly(vinyl chloride). II. The effect of atmosphere

The early stages of the thermal degradation of PVC were studied. Two commercial, suspension-polymerized resins were thermally treated at different temperatures and oxygen contents. Dehydrochlorination kinetics were followed by conductometric measurements and the formation of polyene sequences by ultraviolet-visible spectroscopy. Crosslinking and chain scission were followed by gel chromatography (GPC) and viscometry. No chain scission was observed in nitrogen atmosphere and no crosslinking in oxygen. Degradation in air proceeded by both reactions. The rate of dehydrochlorination for one of the investigated polymers increased linearly with the logarithm of the oxygen pressure. In nitrogen, an increasing degradation temperature was found to give both an increasing crosslinking and less discoloration. In oxygen, chain scission reactions showed a slight temperature dependence. The temperature effect on the discolorations was similar to that in nitrogen. The main difference between the investigated resins was the amount of internal doubled bonds in the original polymers, the ratio being 2:1. The higher amount resulted in a higher rate of dehydrochlorination, a larger extent of chain scission in oxygen, and a lower extent of crosslinking in nitrogen. Both in oxygen and nitrogen, the obtained results are consistent with allylic mechanisms. In nitrogen, the polyene formation supposedly proceeds by a unimolecular reaction and crosslinking by an intermolecular nonradical dehydrochlorination. In oxygen, radical reactions are superposed and may lead to chain rupture via β-scissions of alkoxy radicals.     

Headspace solid‐phase microextraction with gas chromatography/mass spectrometry reveals a correlation between the degradation product pattern and changes in the mechanical properties during the thermooxidation of in‐plant recycled polyamide 6,6

The increased susceptibility of in‐plant recycled polyamide 6,6 toward thermooxidation was shown by headspace solid‐phase microextraction with gas chromatography/mass spectrometry (HS‐SPME/GC‐MS), tensile testing, differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). A correlation between the deterioration in mechanical properties and the formation of degradation products due to thermooxidation was found, and the most prominent decrease in mechanical properties coincided with the largest increase in the abundance of degradation products. The recycled materials had a shorter induction period toward oxidation, and their mechanical properties deteriorated faster than the mechanical properties of virgin material. The same trend was observed with HS‐SPME/GC‐MS because degradation products were found for recycled materials after oxidation times shorter than those for virgin material. Furthermore, larger amounts of degradation products were formed in the recycled materials. The high sensitivity of HS‐SPME/GC‐MS as an analytical tool was demonstrated because it was able to detect changes caused by oxidation considerably earlier than the other methods. Unlike DSC and FTIR, it could also show differences between samples recycled for different times. Four groups of degradation products—cyclic imides, pyridines, chain fragments, and cyclopentanones—were identified in thermooxidized polyamide 6,6. After 1200 h of thermooxidation, 1‐pentyl‐2,5‐pyrrolidinedione was the most abundant degradation product. Approximately four times more 1‐pentyl‐2,5‐pyrrolidinedione was formed in polyamide recycled three times than in virgin polyamide. Pyridines and chain fragments behaved toward oxidation and repeated processing like cyclic imides; that is, their amounts increased during oxidation, and larger amounts were formed in recycled materials than in virgin material. The cyclopentanone derivatives were present already in unaged material, and their amounts decreased during oxidation. Cyclopentanones were not formed because of the thermooxidation of polyamide 6,6. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3396–3407, 2002     

Sugar-based surfactants for consumer products and technical applications

Sugar-based surfactants, such as sorbitan esters, sucrose esters, alkyl polyglycosides, and fatty acid glucamides gain increasing attention due to advantages with regard to performance, health of consumers, and environmental compatibility compared to some standard products. Sorbitan esters are well established products, which are mainly used as leather and textile auxiliaries or as emulsifiers for food at a volume of approx. 20,000 t/a. Sucrose esters are relatively hydrophobic products. The actual market size is estimated to be < 4,000 t/a – the main application being emulsifiers for food and cosmetics. Their use is still limited. Alkyl polyglycosides and fatty acid glucamides represent a perfect amphiphilic structure with excellent surface activity as well as solubility due to highly selective syntheses. For alkyl polyglycosides industrial processes have been developed in the past couple of years and a total capacity of ca. 80,000 t/a has been established. They are mainly used for cosmetic, manual dishwashing, and detergent applications. Fatty acid glucamides to date are exclusively used by one company in liquid and powdered detergents. The estimated production capacity is approx. 40,000 t/a. Comparable in their performance profile as co-surfactants, both products differ in their raw material base: whereas in the case of the fatty acid glucamides methylamine is incorporated in the product, alkyl polyglycosides are completely based on renewable resources. This, combined with very good performance and mildness, could be one reason why alkyl polyglycosides are the most successful sugar-based surfactants nowadays. Research to develop derivatives on this basis is still ongoing.     

Characterization of adsorbent materials supported on polyurethane foams by nitrogen and toluene adsorption

Different composite adsorbent materials were obtained by supporting three activated carbons, one zeolite and one pillared clay, in a polyurethane foam. Adsorption isotherms of nitrogen and toluene were determined to evaluate the influence of the supporting process in the adsorption capacity of the different adsorbent materials. The results indicate that the activated carbons in form of pellets presented the best results with a decrease of about 20% in the nitrogen adsorption capacity but maintaining the same toluene adsorption capacity. The inorganic adsorbents presented a decrease of about 73% for the zeolite and 97% for the pillared clay in the nitrogen adsorption capacity and also a pronounced decrease in the toluene adsorption capacity. Two materials, one activated carbon and one zeolite, with different particle sizes were supported in the polyurethane foam. The decrease in the adsorption capacity of nitrogen and toluene was more pronounced when solids with smaller particles were used. This was an indication that the decrease in the adsorption capacity is related to the impregnation of the surface of the solid particles by the polyurethane during the synthesis of the composite material, which was observed by scanning electron microscopy. Nevertheless, the supporting method, in a one step procedure, presented itself with good possibilities for applications with activated carbons in the form of pellets.     

Mixed matrix membrane materials with glassy polymers. Part 2

Analysis presented in Part 1 of this paper indicated the importance of optimization of the transport properties of the interfacial region to achieve ideal mixed matrix materials. This insight is used in this paper to guide mixed matrix material formation with more conventional gas separation polymers. Conventional gas separation materials are rigid, and, as seen earlier, lead to the formation of an undesirable interphase under conventional casting techniques. We show in this study that if flexibility can be maintained during membrane formation with a polymer that interacts favorably with the sieve, successful mixed matrix materials result, even with rigid polymeric materials. Flexibility during membrane formation can be achieved by formation of films at temperatures close to the glass transition temperature of the polymer. Moreover, combination of chemical coupling and flexibility during membrane formation produces even more significant improvements in membrane performance. This approach leads to the formation of mixed matrix material with transport properties exceeding the upper bound currently achieved by conventional membrane materials. Another approach to form successful mixed matrix materials involves tailoring the interface by use of integral chemical linkages that are intrinsically part of the chain backbone. Such linkages appear to tighten the interface sufficiently to prevent “nonselective leakage” along the interface. This approach is demonstrated by directly bonding a reactive polymer onto the sieve surface under proper processing conditions.     

Isomeric Detergent Comparison for Membrane Protein Stability: Importance of Inter‐Alkyl‐Chain Distance and Alkyl Chain Length

Membrane proteins encapsulated by detergent micelles are widely used for structural study. Because of their amphipathic property, detergents have the ability to maintain protein solubility and stability in an aqueous medium. However, conventional detergents have serious limitations in their scope and utility, particularly for eukaryotic membrane proteins and membrane protein complexes. Thus, a number of new agents have been devised; some have made significant contributions to membrane protein structural studies. However, few detergent design principles are available. In this study, we prepared meta and ortho isomers of the previously reported para‐substituted xylene‐linked maltoside amphiphiles (XMAs), along with alkyl chain‐length variation. The isomeric XMAs were assessed with three membrane proteins, and the meta isomer with a C₁₂ alkyl chain was most effective at maintaining solubility/stability of the membrane proteins. We propose that interplay between the hydrophile–lipophile balance (HLB) and alkyl chain length is of central importance for high detergent efficacy. In addition, differences in inter‐alkyl‐chain distance between the isomers influence the ability of the detergents to stabilise membrane proteins.     

次磷酸铝添加量对碱木质素基聚氨酯 泡沫阻燃性能的影响

利用精制后的碱木质素部分代替聚醚多元醇制备碱木质素基聚氨酯泡沫材料(PUF/木质素)。将次磷酸铝(AHP)作为阻燃剂添加到材料中制备PUF/木质素/AHP材料。通过极限氧指数(LOI)测试PUF/木质素/AHP材料的阻燃性能,通过热重分析(TG)研究了材料的热降解行为和成炭性能,通过锥形量热(CONE)测试和扫描电子显微镜(SEM)分别研究了PUF/木质素/AHP材料的燃烧行为和残炭的表面形貌。结果表明：当碱木质素添加量为聚醚多元醇的5%、AHP的添加量为30%时,PUF/5%木质素/30%AHP材料的LOI值达到了25.6%,同时降低了材料的热分解速率和热释放量,促进了材料的成炭。当AHP受热分解时,产生的PO自由基会捕捉材料燃烧时产生的氢氧自由基,从而抑制燃烧反应,同时产生磷酸铝和焦磷酸铝,形成致密的炭层阻隔物质和能量的传递,阻止材料进一步燃烧,从而提高材料的阻燃性能。     

高皂基及低皂基主洗液在洗衣房布草洗涤中的应用

本研究设计了高皂基、低皂基两种主洗液,考察了水质对主洗液去污性能的影响,并对体系的控泡性能进行了测定.结果表明,水质在洗衣房布草清洗中起着至关重要的作用,洗涤化料对于蛋白污垢和皮脂污垢的去除能力随着水硬度的上升而快速下降.此外,高皂基主洗液和低皂基主洗液在同等硬水条件下去污能力相差并不是很大,但其泡沫表现差别巨大.     

Nonionic detergent degradation: III. Initial mechanism of the degradation

In Parts I and II of this series (1,2), degradation and foaming experiments on a number of commercially available alcohol polyethoxylates and alkyl phenol polyethoxylates are described. This paper describes an extension of the thin layer chromatographic work on which the experiments described earlier were based, supplemented by a variety of other chemical and physical tests to provide some insight into the initial mechanism of degradation of these materials before they disappear by the established oxidation and hydrolytic routes. In the case of the readily degradable alcohol ethoxylates, two distinct mechanisms are shown to proceed simultaneously: a fission of the molecule into hydrophobic and hydrophilic entities, and a rapid oxidation of the hydrophobic group. No fission occurs in the case of the alkyl phenol ethoxylates, the more usual route of degradation being slow oxidation and hydrolysis of the alkyl groups, the aromatic ring and the ethoxy chain simultaneously; occasionally, and at higher pH, the hydrolysis of the ethoxy chain proceeds at a considerably increased rate.