Refractive index of alcohol nonionics

Refractive index is a rapid and consistent method of analysis for alcohols and nonionics from normal alcohols and ethylene oxide. Correlations of refractive index with hydroxyl number of alcohols and nonionics are excellent and measurement error is considerably lower for refractive index. Refractive index affords a measurement of the amount of ethylene oxide in nonionics and can be used as a replacement for the 1% cloud point analysis. The ethylene oxide adduct distribution has no effect on refractive index. Specific adducts, a narrow range of adducts made by acid catalyzed ethoxylation and a broad range of adducts made by base catalyzed ethoxylation give the same refractive index value for any given ethylene oxide content. Applications for the refractive index method for the laboratory and plant are: alcohol blending control, calculation of ethylene oxide requirements for ethoxylation, nonionic control analysis, calculations of hydroxyl number for sulfations. Also, refractive index can help identify laboratory samples, indicate the 1% cloud point and predict the phase character of nonionics.     

A method for the quantitative determination of ethylene oxide adducts in their aqueous solutions or dispersions

Summary A method for quantitative determination of ethylene oxide adducts is described. By precipitation in hydrochloric acid solution with a known quantity of ferrocyanic acid, filtration, and titration with zinc sulfate, the consumption of ferrocyanic acid can be determined. From the results a m.d. of less than 8% was calculated, the corresponding figure for adducts containing more than 9 ethylene oxide units does not surpass 5%. The reaction takes place on the ethylene oxide chain in the compound. To precipitate an adduct containing 6 units ethylene oxide approximately one mole of ferrocyanic acid is necessary.     

Polarity index of surface-active ethylene oxide adducts

The polarity indexes of surface-active ethylene oxide adducts with varying lipophilic parts and varying content of ethylene oxide have been studied. An interesting relationship has been found between the fraction of ether groups and polarity index, which gives a polarity index line for every type of ethylene oxide adduct. It permits the calculation of polarity indexes of all ethylene oxide adducts of known composition with known polarity index of the lipophilic part. It also gives valuable information for evaluating different lipophilic substances as raw materials for ethylene oxide adducts.     

Die chromatographische Zerlegung der Äthylenoxid-Addukte in ihre Homologen und deren quantitative Bestimmung

Chromatographic Resolution of Ethylene Oxide Adducts into their Homologues and their Quantitative Determination The separation of ethylene oxide condensates in their polymeric homologues by gas-chromatograpy is not satisfactory owing to the limited volatility of the components having a large number of ethylene oxide groups. Against that, the column chromatography with silica gel as adsorbent and butanone as eluting medium enables a fractionation of such adducts upto 14–16 membered homologues of the series. This separation occurs solely according to the length of the ethylene oxide chain. The eluted substances are determined in the fractions and the components present in each fraction identified by thin-layer chromatography using test substances. In twocomponent mixtures, the amounts of individual substances are estimated by comparing the intensity of the spots. Finally the possibility of simplifying the apparatus involved in the above procedure is mentioned.     

Determination of oxyethylene distribution in condensates of primary alcohols with ethylene oxide

A new method has been developed that makes possible determination of the oxyethylene distribution of the condensates of mixed carbon number detergent-range, primary alcohols with ethylene oxide over a wide range. Circular thin layer chromatography of the 3,5-dinitrobenzoate ester derivatives is used to separate the condensates into a series of groups, each group containing all of the compounds present having the same number of oxyethylene units. These groups of esters are recovered and determined by a spectrophotometric procedure. Distribution curves are obtained that cover the range of added oxyethylene units from 0 to as high as 18. Higher adducts are recovered and determined as a group. Presented at the AOCS Meeting in New York, October, 1968.     

Ethylene oxide oligomer distribution in nonionic surfactants via high performance liquid chromatography (HPLC)

A high performance liquid chromatography (HPLC) method using adsorption columns combined with linear gradient elution has been developed for the determination of ethylene oxide (EO) distribution in nonionic surfactants. The quantitative ethoxylate adduct distribution in single-carbon-number and mixed-carbon-number primary alcohol-based samples can be obtained. The HPLC method is also applicable for determining the molar EO distributions in diverse ethylene oxide adduct compounds such as alkylphenol ethoxylates, branched alcohol ethoxylates and secondary alcohol ethoxylates. Nonionic surfactant samples containing adducts up to 25 mol have been successfully separated and the individual adducts quantitated.     

The action of various lime soap dispersants

The course of the lime soap-dispersing action of various surfactants has been examined by use of a titrimetric method. Two types of dispersants can be distinguished. With the addition of a surfactant of the first type, the concentration of the dispersed fatty acid increases gradually. If a surfactant of the second type is used, a definite increase of the fatty acid concentration first occurs after the addition of considerable amounts of the dispersant. Ethylene oxide adducts and sodium triethylene glycol monolauryl ether sulfate behave like dispersants of the first type whereas sodium dodecylbenzenesulphonate and sodium lauryl sulfate belong to those of the second type. The dispersing action of both types of surfactants is discussed.     

Preparation of detergents from formaldehyde

A process was developed for condensing different mol ratios of dodecanol, formaldehyde and ethylene oxide to form a series of adducts with useful detergent properties. These products are analogous to the commercially important class of nonionic surfactants produced by treating fatty alcohols with ethylene oxide to produce a homologous series of adducts. The structures were shown to be represented by RO[(CH₂O)_x(CH₂CH₂O)_y]R where R is either dodecyl or hydrogen, x and y are integers (including zero), and it is understood that the oxymethylene and oxyethylene groups are intermingled in the ether chains. Unfortunately, we were unable to produce commercially viable detergent compositions. For these, our calculations indicate that a dodecanol:HCHO:EO mol ratio between 1:3:4 and 1:5:2 would be necessary both for good detergency and good economics. With acidic catalysts such as BF₃, the condensation is facile and product with desired overall mol ratios can be produced. However, much of the formaldehyde and ethylene oxide are incorporated into by-products that either detract from the detergency properties (e.g., terminal ethers where both R groups are dodecyl) or make the mixtures unacceptable as detergents (e.g., 1,4-dioxane). Because of the presence of terminal ethers, the detergent properties are similar to those of propylene oxide adducts rather than ethylene oxide adducts. With selected basic catalysts most of the harmful by-products can be eliminated, but the reaction rates and conversions are unsatisfactory. Basic catalysts that give high reaction rates convert most of the formaldehyde fed to methyl formate.     

Development of screening tests for hard surface cleaners: I. Artificial soil removal from linoleum surfaces

A quantitative method for evaluating performance of hard surface cleaners has been developed based on a series of modifications of previously proposed tests. The principle involves the mechanical cleaning of artificially soiled linoleum with a Gardner Straight Line Washability Machine. A quantitative estimation of the relative cleaning efficiency is determined photometrically and results are expressed as per cent return to original whiteness. Statistical evaluations have shown the method to be reproducible and applicable for discerning differences in formulations, concentration and surfactant structure. The test method details are described and experimental results showing ethylene oxide content optimization of commercial linear primary alcohol-based nonionics, as well as builder effects, are presented. Presented at the AOCS Meeting, New York, October, 1968.     

Optimization of nonionic surfactants for hard-surface cleaning

The hard-surface cleaning performance of various nonionic homologs was evaluated as a function of carbon chain length, ethylene oxide (EO) content, blending and concentration. Results show carbon chain length to be very important to hard-surface cleaning. Performance significantly increases as carbon-chain length decreases, probably as a result of an increase in solvency properties as carbon chain length is decreased. EO content is also important, particularly if nonionics with longer carbon chain lengths are used. Surfactant concentration (dilution) has little effect on the optimum ethylene oxide content but significantly affects the optimum carbon chain length of the hydrophobe. With 5% homolog solutions, the optimally performing nonionic contains a C6 hydrophobe, but with 0.2% solutions, the optimal carbon chain length is shifted to the C8–C10 range. This is thought to result from a trade-off between the surfactant and solvent properties of the nonionic. Overall results show the optimal nonionic for hard-surface cleaning to consist of a blend of C6, C8 and C10 alcohols ethoxylated to a 50% EO level. Commonly used surfactant systems, e.g., alkylphenol ethoxylates and alkylphenol ethoxylate (APE)-butyl cellosolve (BC) blends, were also examined. Results show that alkylphenol ethoxylates give relatively poor performance compared with lower molecular weight linear nonionics because of the large size of their hydrophobe. Under concentrated use, a synergism does exist between APE and BC, but under dilute conditions, the addition of BC is ineffective. BC does not help the performance of low molecular weight nonionics. Surfactant-soil diffusion studies indicate that surfactant penetration of the soil may be the primary mechanism involved in the hard-surface cleaning of solid soils. Presented May 10, 1983, at the 74th Annual Meeting of the AOCS, Chicago, IL.     

Properties and uses of some unsaturated fatty alcohols and their derivatives

A number of unsaturated fatty alcohols are known, but only those of the C₁₆ and C₁₈ chain lengths are of much importance. In particular, oleyl alcohol., 9,10-octadecenol-1, is by far the most important. A variety of grades of oleyl alcohols is produced and used in the USA ranging from high purity material having iodine values (IV) of 90–95 to those having IV of 45–55, with the other components being primarily cetyl (hexadecanol-1) and stearyl (octadecanol-1) alcohols. This paper takes a brief look at the various grades of unsaturated alcohols used in the USA, methods of preparation, and the change in physical and chemical properties as the octadecanol-1 content and IV decline. Uses of these alcohols industrially and in cosmetic and pharmaceutical preparations are also discussed. Unsaturated alcohols are useful chemical intermediates since they have two reactive sites, the hydroxyl group and the carbon-carbon double bond. Particular attention is paid to the properties, uses and potential uses of some of their sulfates, ether sulfates, ethylene oxide adducts and ethylene/propylene oxide adducts as detergents and emulsifiers for ultimate use in cosmetics and light-duty and heavy-duty systems. Current estimated consumption of unsaturated alcohols in the USA is discussed.     

Rapid quantitative HPLC analysis of polyethoxylated nonionics

A rapid quantitative HPLC method for alkylethoxylate was studied. According to theoretical considerations based on the plate theory, it was expected that alkylethoxylate could be separated to give one chromatographic peak regardless of the carbon number distribution in hydrophobic moiety and adducted number of ethylene oxide by using a back flush technique. As expected, a single peak with good shape for quantitative use was obtained. Quantitative analytical methods were developed for (i) unconverted alkylethoxylate in alkylethoxysulfate, and (ii) alkylethoxylate nonionics formulated with anionics in detergents. As anionics generally were retained less than alkylethoxylates under the condition in which ODS-column and a methanolic aqueous eluent were used, a single peak for alkylethoxylates was obtained by back flushing after anionics were eluted from the column. In the case of a heavy duty detergent, an additional column was needed to remove the interferences owing to co-existing more retained species.     

Micelle formation of polyoxyethylene-polyoxypropylene surfactants

Contradictory literature references on their micelle formation led to an investigation of block copolymers of ethylene and propylene oxides. By means of differential absorbance measurements of the dye-surfactant complex, critical micelle concentrations (CMC’s) for these polyols were determined. CMC values for surfactants with a molecular weight range of 1,100 to over 15,000 varied from 3.0 to 11.1 μmoles per liter, which are much lower than for other nonionics normally encountered. Corroborative data were obtained by the surface tension depression method. An increase in temperature below the cloud point or the addition of sodium chloride resulted in an increase in the CMC, which is not usual for many nonionics. Presented at the AOCS meeting, Houston, April, 1965.     

Gas chromatographic analysis of nonionic surfactants by acid cleavage of ether linkages

The gas chromatographic analysis of various kinds of nonionic surfactants has been carried out after chemical decomposition using the mixed anhydride of acetic and p-toluene sulfonic acids which acts as a reagent for cleavage of ether linkages. The gas chromatographic peaks of the reaction products show the alkyl distributions of the hydrophobic groups of ethylene oxide adducts. The alkyl compositions closely agree with those of the starting materials. In this way, the hydrophobic groups of polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl amine, and polyoxyethylene alkyl thioether have been analyzed. At the same time, the hydrophilic group, namely polyoxyethylene group, can be identified in the form of ethylene glycol diacetate.     

A colorimetric method for the determination of parts/million of nonionic surfactants

A method for the determination of nonionics in low concn (0–20 ppm) has been developed. This method is based on the formation of a blue complex between ammonium cobaltothiocyanate reagent and a polyethoxylated compound. This complex is extracted into benzene from a saturated salt solution and measured with a spectrophotometer at 320 mμ. The absorbance reading is compared to a standard. The method requires only a single extraction and no preliminary concn step is necessary. It is sensitive to polyethoxylated compounds containing three or more moles of ethylene oxide. We have used this method to detect as little as 0.01 mg of nonionic in 100 ml of sample (0.1 ppm). Reaction conditions, sensitivity differences between compounds, interferences and suitability for use in biodegradation studies have been investigated. The accuracy and repeatability of this method is ±3% relative at 20 ppm concn.     

Effect of degree of ethoxilation on the viscosity depressancy properties of fatty acid ethoxilates used in PVC paste formulations

Plastisols of poly (vinylchloride) (PVC) are important commercial products. The rheological properties especially the viscosity of the paste plays an important role in PVC paste applications. Viscosity depressants are usually added to paste formulations in order to obtain desired paste viscosities. In this work, viscosity depressant effects of various fatty acid/ethylene oxide condensates containing 2 to 12 moles ethylene oxide per mole are investigated by Brookfield rotational viscometric method. The effectivenesses of the viscosity depressants are determined at 1.3 sec^?1 shear rates and a relationship between ethylene oxide content and viscosity reduction is found. This relationship between effectiveness and degree of ethoxilation gives way to prediction of viscosity reduction of paste by simply determining the ethylene oxide content. The effect on 24 h aging is also studied. The results showed improvements in short term aging properties of the PVC paste.     

New tertiary amine-based surface active polymers

Surface active polymers with molecular weight ranging from 5600 up to 30,000 were synthesized by the oxyethylation of polyoxpropylene glycol adducts of ethylene diamine, which range in molecular weight from 4750 up to 6750. The toxicological properties of some of these new nonionics indicated that they would be nontoxic when used in contact with the skin and scalp. Their typical physical properties such as wetting, emulsifying, foaming and thickening are reported. A variety of cosmetic formulations has been prepared utilizing these new nonionic surface active polymers. This illustrates their versatility when used in products as diverse as a floating bath oil, an antiperspirant gel, a cold cream and a sun screen lotion. Presented at the AOCS Meeting, Chicago, October 1967.     

Determination of cloud points of nonionic surfactants

By use of a specially adapted fluorometer attached to a strip chart recorder, a spectrum or cloud-o-gram can be obtained from various types of ethylene oxide condensates (nonionic surfactants). A cloud-point reproducible to ±0.2C can be determined from the cloud-o-gram. The cloud-o-gram is unique for each classification, and differences can be detected within classifications.     

测定2,6-双(苦氨基)-3,5-二硝基吡啶纯度的研究

用电位滴定法对２，６－双（苦氨基）－３，５－二硝基吡啶（ＰＹＸ）标准物质的纯度进行测定。ＰＹＸ用二甲基甲酰胺溶解，以四甲基氢氧化铵的二甲基酰胺溶液为滴定剂。该方法的回收率和变异系数分别为１００．０％和０．１３％。     

Analysis of surfactant mixtures. I

Summary Some data on the use of 93% phosphoric acid as a reagent for recovering the hydrophobic portion of surfactants are presented, and their application to the analysis of surfactant mixtures is discussed. Aromatic sulfonates, straight-chain alkyl sulfates, fatty acid amides, and fatty acid esters decomposed to give good yields of the starting hydrophobic materials. Dioctylsulfosuccinate gave a mixture of octyl alcohols and olefins while the ethylene oxide condensates of lauryl alcohol, tridecyl alcohol, and tertiary dodecyl mercaptan gave olefins derived from the starting hydrophobic materials. Diisobutylene phenol-ethylene oxide condensate decomposed to olefins, conjugated olefins, and alcohols formed by rupture of the aromatic ring. The products are characteristic of the hydrophobic oils, and in most cases products from mixtures of surfactants can be separated by known analytical methods.Alpha-sulfo fatty acids or alkane sulfonates do not give recoverable oils by this treatment.