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A series of cationic surfactants, di-chained esterquat surfactants, was synthesized from triethanolamine, stearic acid and various alkylation agents by two step processes. The quaterisation was carried out with diethyl sulphate, benzyl chloride, 1-chloro-2,4,6-trinitrobenzene, benzoyl chloride. The synthesized surfactants were confirmed by IR spectra. Surface properties, wetting time, softness and antibacterial activity of the synthesized surfactants were investigated. The results showed that the synthesized esterquats exhibit high surface activities, better wetting times and very good softening properties. A synthesized cationic surfactant was further prepared for formulation of hair conditioning and body care. This product can be used in formulations of shampoo, fabric softener and liquid soaps and also it does not have any harmful impact to aquatic life. Further, the synthesized surfactant, prepared from 1-Chloro-2,4,6-trinitrobenzene, exhibit a better antibacterial activity against E. coli and S. aureus. It was found that the alkylation agent and hydrocarbon chain length affected the results.

Esterquat cationic softener is basically the class of surface active quaternary ammonium compounds. Esterquat compounds were synthesized and their surface behavior, antibacterial activity and Textile softening properties were investigated. Easily found cheap material was used to synthesize cationic fabric softeners. This fabric softener will be a good for commercially and industrially important because their emulsify activity, rewettability dispersing power and softness. Free fatty acids were derived from tallow oil and were treated with triethanolamine and mono-ethanolamine at 140°C. This diester was quaternaries with dimethyl sulphate and benzyl chloride. The synthesized esterquat compounds were characterized by its cationic content, 1H NMR and FT-IR analysis. In addition to the cationic content, surface tension, CMC (critical micelle concentration), rewettability, fabric softening, emulsification and dispersing power were determined as their surface-active properties. The fabric softening activity of esterquat and esteramide prepared from DMS was better softening activity of fabrics compared to untreated cotton and polyester fabrics cloth. The presented result shows that the esterquat made from BCl exhibit the best dispersing power. The esterquat made from DMS both in TEA and MEA shows good rewettability was determined.

Cationic surfactants are mainly used for fabric softening in laundry applications. Esterquats are one class of cationic surfactants and are superseding other existing cationic surfactants on account of their excellent biodegradability. However, indigenous and cost-effective production of esterquats poses new challenges for the researchers. The availability of rice bran fatty acids and its price structure in Indian scenario makes this fatty feedstock quite lucrative for cost-effective synthesis of cationic surfactants. In the present study, esterquats based on rice bran fatty acids (RBFAs) were synthesized by using different alkanolamines i. e. diethanolamine (DEA) and triethanolamine (TEA) and dimethyl sulphate (DMS) for obtaining cationic surfactants which was used as active softener ingredient. For this purpose, esterquats have been synthesized by esterification of RBFAs and alkanolamines to recover diesters followed by the subsequent quaternization of diesters by DMS. It was found that the optimum reaction conditions for esterification of RBFAs and DEA was 140 °C and 3 h of duration. However, for RBFAs and TEA, it was found to be 140 °C and 4 h of duration. The chemical structures of diesters and esterquats were confirmed by FT-IR and NMR spectra. Studies of surface active and performance properties of these surfactants showed that esterquats based on TEA had better surface active and performance properties as compared to DEA based esterquats. The synthesized cationic surfactants when mixed with nonionic surfactant showed better performance properties as compared to the nonionic surfactant alone.

Finding suitable precursor molecules that extend the lifetime of perfumes by decomposing and releasing fragrant chemicals under relatively mild, ambient conditions remains a significant challenge. Although the majority of effort in this regard has been directed toward using hydrolysis reactions as the release event, autoxidation and subsequent fragmentation reactions also would appear to be well suited for this purpose given the constant exposure of deposited perfumes to atmospheric oxygen. Divinyl ethers, prepared from enolizable perfume aldehydes, have two olefin functions adjacent to the ether oxygen and were found to provide prolonged release of fragrant carbonyl compounds by an autoxidative fragmentation process. After deposition onto cotton terry cloth from a liquid fabric softener, dynamic headspace analysis showed the liberation of the parent aldehyde along with a one-carbon smaller carbonyl compound and the enol formate ester of the parent aldehyde. Depending on the structure of the divinyl ether both liberated carbonyl compounds can be perfumery materials and both always were released from the cotton at significantly higher levels than the unmodified parent aldehydes used to prepare reference samples. Autoxidation of the divinyl ethers initiated by peroxy-radical addition to alkene functions would account for the oxidative cleavage reactions yielding the smaller carbonyl compounds and the enol formates. Hydrolysis of the enol formate could generate the parent aldehyde. The liberation of volatile carbonyl compounds from divinyl ethers demonstrates the potential usefulness of autoxidation as a trigger for the sustained release of fragrant compounds from suitably designed precursors. Copyright © 2014 John Wiley & Sons, Ltd.

Dynamic mixtures of aminals generated by reversible reaction of diamines with volatile aldehydes and ketones are suitable delivery systems to increase the long-lastingness of fragrance perception in functional perfumery applications. N-Heteroarylmethyl-substituted secondary diamines of 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopropane or 2-(aminomethyl)piperidine were prepared by reaction with furan-, 1H-pyrrole-, thiophene- or pyridine-2-carbaldehyde and reduction of the intermediate imines with NaBH4. The performance of the delivery system was evaluated in a fabric softener application in the presence and absence of a diamine by following the evaporation of a mixture of 18 fragrance aldehydes and ketones on dry cotton using dynamic headspace analysis. Equilibration of the mixture in the presence of a diamine simultaneously increased the headspace concentrations of several fragrance raw materials above the cotton surface as compared to a reference sample without diamine. Equilibrated dynamic mixtures of diamines were found to be suitable delivery systems to prolong the evaporation of fragrance aldehydes and ketones in practical applications of functional perfumery. Copyright © 2013 John Wiley & Sons, Ltd.

In this study, an attempt has been made to synthesize esterquat by esterification of stearic acid and 3-dimethylamino-1,2-propanediol (DMAPD) followed by quaternization with dimethyl sulfate, resulted in new quaternary useful as biodegradable fabric softener (2,3-bis(stearoloxy)-propyltrimethylamine [DMAPDEQDMS]). The softening property, biodegradation of DMAPDEQDMS were investigated, and compared with distearyl dimethylammonium chloride (D1821) and other ester quaternary. The results showed that DMAPDEQDMS's biodegradation was better than that of D1821, and its softening property was comparable with D1821. It is a new style softener with excellent properties, which can replace D1821.

Cationic surfactant is a chemical substance used in hair conditioner, fabric softener and other household products. By investigating the relationship between the aquatic toxicity and the chemical structures of two types of mono alkyl cationic surfactants, alkyl trimethylammonium salts and alkyl dimethylamine salts, we have found that the C22 alkyl chain length is effective to reduce the toxicity. Besides, we have recognized that the amidopropyl functional group contributes to the enhanced biodegradability by investigating the biodegradation trend of (alkylamidopropyl)dimethylamine salt (alkyl chain length: C18). Based on these findings, we have developed mono alkyl cationic surfactant called APA-22, N-[3-(dimethylamino)propyl]docosanamide salt. APA-22 is formed by the C22 alkyl chain, amidopropyl functional group and di-methyltertiary amine group. We evaluated the aerobic and anaerobic biodegradability of APA-22 by two standard methods (OECD Test Guideline 301B and ECETOC technical document No.28) and found that this substance was degraded rapidly in both conditions. The toxicity to algae, invertebrate and fish of this substance are evaluated by using OECD Test Guideline 201, 202 and 203, respectively. All acute toxicity values are >1 mg/L, which indicates that environmental toxicity of this substance is relatively less toxic to aquatic organism. In addition, we estimated the biodegradation pathway of APA-22 and observed the complete disappearance of APA-22 and its intermediates during the test periods. Based on the environmental data provided above, we concluded that APA22 is more compatible with the aquatic environment compared to other cationic surfactants with mono long alkyl chain.

Imidazoline derivatives, a class of novel cationic surfactants are presently gaining importance in global detergent market due to their wide range of applications. These are extensively used mainly as fabric softeners and antistatic agents. The present communication reviews the preparation, reaction scheme, reaction rates and properties of imidazoline derivatives. The analysis of imidazoline derivatives, its mode of action, their biodegradation and various applications have also been discussed.

Imidazoline surfactants belong to the category of cationic surfactants. Cationic surfactants are often quaternary nitrogen salts and are widely used both in non aqueous systems and in applications such as textile softeners, dispersants and emulsifiers. In the class of imidazoline compounds there is a presence of a pendant group, an imidazoline head group and a hydrocarbon tail. This paper reviews the imidazoline and its salts as an emerging class of cationic surfactants. It deals with the synthesis, various properties that prove its use in laundry detergent applications like good detergency, resiliency, foaming property, softening property, rewettability, good storage stability and less irritating property. In addition the film forming and corrosion inhibition properties tend them to varied and numerous industrial applications.

Headspace solid-phase microextraction (HS-SPME) has been successfully applied to the determination of perfume components in scented candle wax, liquid laundry detergent, and fabric softener. Different fiber coatings (100 μm polydimethylsiloxane, 50/30 μm divinylbenzene/Carboxen/polydimethylsiloxane, 70 μm Carbowax/divinylbenzene, and 85 μm polyacrylate) were tested and the extraction conditions were optimized. For most compounds extraction efficiency, reproducibility, and long-term stability were highest for polydimethylsiloxane. The compatibility of SPME with fast gas chromatographic separation was investigated. The speed of conventional gas chromatography was increased by a factor of 2.5, without loss of separation efficiency, simply by reducing the column length and inner diameter and adjusting the separation conditions by use of method translation software. It was demonstrated that SPME is a suitable sample-introduction technique for fast GC if split injection is used.

Triethanolamine (TEA)-based esterquat has been the primary ingredient in European fabric softeners for several years and is becoming the global molecule of choice. Although it has an excellent environmental profile, TEA esterquat has been plagued by mediocre performance compared to historical molecules such as dihydrogenated tallow dimethyl ammonium chloride and ditallow imidazoline quat. In this study, the chain lengths, the level of unsaturation, and the source of the raw material (tallow or palm stearine) were varied to better understand their effect on softening and dispersion viscosity. Palm stearine derivatives generally soften as well as tallow derivatives despite the lower C18 content of palm. Various additives were examined to improve dispersibility and other properties such as dye transfer inhibition (DTI) and ease of ironing. DTI is normally accomplished in the wash cycle by additives to the laundry detergent such as polyvinylpyrrolidone. In this study, we found that fabric softener molecules themselves provide some color care, or DTI. Certain additives to fabric softeners, such as monoalkylquats, greatly enhance the color care of the fabric. DTI treatment in the rinse cycle of the washing sequence makes more sense scientifically and to the consumers, since fabric softeners are designed to coat the textile. Because no competing detergency operations are occurring during the rinse cycle, color care works well in the fabric softener cycle. Addition of organosilicones to fabric softeners reduces wrinkling of fabrics and makes them easier to iron. Softening increases slightly.

A number of new diesterquats and anidoester quats were synthesized and tested for biodegradation and softening. Methyldiethanolamine, 3-methoxylpropylamine, diethanolaminopropylamine, aminoethylethanolamine, dimethylethanolamine, and diethanolamine were reacted, either “as is” or after alkoxylation, with tallow fatty acid and further converted into dialkyl quats. The diesterquat from diethanolisopropanolamine was by far the best of the ester quats synthesized in overall biodegradation, softening, and cost/ease of manufacture. It appears that two ester groups are needed for ready biodegradation as opposed to an amide-ester combination. Increasing unsaturation of the alkyl chains within a molecule increases its rate of biodegradation slightly.

The global textile industry has an ongoing need for improved softening products. Current materials systems, including those with siloxane polymers, exhibit certain limitations such as yellowing, high cost, and low softening efficiency. Investigations into fabric softening mechanisms invoke molecular modeling tools to simulate siloxane polymer and cotton fiber interactions at the molecular level. This research describes how certain polymer types exhibit fundamentally enhanced siloxane and fiber interactions within particular pH ranges. Molecular modeling results are also correlated with empirical findings. The output of this research adds insight into efforts to understand fabric softening phenomena. Siloxanes have low surface energy, excellent lubricity, heat stability, and limited solubility in organics, coupled with water insolubility. At the molecular level, the fabric softening properties of siloxanes are believed to be derived from the flexibility of the siloxane backbone [12] that results from the freedom of rotations about the Si-O-Si linkages and the low interaction energies of the methyl groups. At room temperature, there is virtually no energy barrier to prevent molecular flexing [12, 13]. Consequently, siloxanes act as highly effective lubricants in reducing fiber-on-fiber friction. Siloxane functional groups provide strong attractive interactions between the fabric softener and the cotton surface, without which the softener would wash off over time. To enhance interactions between siloxanes and textile materials to increase durability during processes such as washing, reactive siloxanes and modified, nonfunctional siloxane structures are used [19]. Indeed, modifying nonfunctional siloxane structures by replacing pendant or terminal methyl groups with various organic functional groups brings a wide range of physical properties to the siloxane polymers. Amino functional groups play an important role in providing enhanced softening properties to organosilicone compounds [8]. In practice, amino functional silicones are widely used in the textile industry as premium-grade fabric softeners [9, 18, 1]. Because of the interactions of amino groups with textile materials, amino functional siloxanes are physically adsorbed onto fiber surfaces. This adsorption feature improves the durability of amino functional siloxane fabric softeners during the washing process. The amino groups become cationic (-NH3 +) at acidic conditions,and the ionization provides strong

Both alkylketene dimer (AKD) and alkenyl succinic anhydride (ASA) are widely used neutral papermaking sizing agents. However, AKD has the issue of sizing hysteresis, while ASA requires on-site emulsification. In addition, both reagents are readily hydrolyzed. Di-(stearylamidoethyl) epoxypropyl ammonium chloride (DSEAC) has been applied as a fabric softener, but it is a potential sizing agent which leads to good sizing without sizing hysteresis. It could be synthesized by a two-step process starting from stearic acid and diethylenetriamine. During the process, the stearamide structure obtained from the first step plays a key role in the second process as well as sizing. This paper focuses on the impact of the synthetic process of the first step on the structure and sizing properties of DSEAC. Single factor experimental results demonstrated that the optimal temperature should be 160 °C while the optimal reaction time should be less than 3.5 hours. Orthogonal analysis experiments indicated that the optimal synthetic process was maintaining 100 °C for 30 min, and then increasing the temperature to 160 °C for 3.5 hours. Dosages of the catalysis and antioxidant were 0.5% and 0.6% of stearic acid, respectively.

In this study, polyurethane-urea microcapsules containing fabric softener fragrance (TeddysoftTM, by EPS) as active agents were produced by interfacial polymerization. Size, shape and morphology of the microcapsules were studied by using an optical microscope and scanning electron microscope. The effectiveness of the fragrance containing microcapsules was tested by washing hand towels in a commercial washing machine. Textile impregnation and the durability of the fragrance impregnation effect were evaluated qualitatively by perfumers, and by headspace GC analysis. Optical and scanning electron microscopic results indicated that increasing the stirring rate during the emulsion step results in microcapsules with smaller particle size, but at some point morphologies were adversely affected. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Current approaches for identifying and quantitating surfactants in various product matrices require the use of wet chemical, chromatographic, and spectroscopic techniques. The primary objective of this work is to replace current multiple-technique approaches for identifying surfactants and quantitating their homologue distribution with a single rapid technique. To meet this objective, a simple preparation procedure has been developed to prepare consumer product samples for subsequent analysis by ion-spray mass spectrometry. Quantitation of linear alkylbenzene sulfonates in detergents with this technique is demonstrated.

Model investigations of physicochemical aspects of the substantivity of fragrance raw materials on laundered fabrics were performed. The overall process was divided into two consecutive steps, laundry and dryout, which were characterized by affinity and tenacity, respectively. The affinities of fifteen fragrance raw materials to cotton and polyacrylonitrile were measured in standard fabric softener and detergent solutions. Affinities correlated with the corresponding partition coefficient, P(o/w). To study the impact of parameters independent of the chemical structure of the fragrance molecules, 1-[3H]-3-methyl-5-phenylpentanol (phenylhexanol) was selected, and aqueous solutions of defined anionic, nonionic and cationic surfactants were used as model detergent and fabric softener media. A sequence of experiments, based on the fractional factorial design, was planted for quantifying the relative contribution on substantivity of a number of variables: the concentration of the fragrance chemical, the type and concentration of the surfactants, the type and weight of the fabrics (cotton or polyacrylonitrile) and the washing temperature in the case of cotton. The affinity that characterizes the washing process depends mainly on the type of fabric and the type of surfactant and, to a lesser extent, on the surfactant concentration and the temperature. Anionic and nonionic surfactants, the main components of detergent powders, behave similarly, whereas the combination of cationic surfactant with cotton markedly enhances the affinity. For phenylhexanol, the tenacity after dryout is largely controlled by the type of fabric. The role of fiber swelling is discussed. The substantivity, which represents the global effect of laundering and dryout, shows the same trend as the affinity. The complexity of the physicochemical phenomena involved is highlighted by the importance of the interactions between the main contributing factors.

The interaction of solid alkyldimethylamine oxide and ditallowdimethylammonium chloride (DTMAC) and ditallow dimethylammonium sulfate (DTMAS) quats in representative types of fabric softener systems was studied with particular focus on synergistic behavior. Softening, whiteness retention, wetting, static build-up and detersiveness were evaluated for laundry rinses, laundry detergents and dryer sheets. In laundry rinses, blends of amine oxide and DTMAC proved to be synergistic for improving the wetting of cotton towels. Although no synergism was observed in laundry detergents, formulations containing amine oxide gave better detersiveness than systems with DTMAC without the splotching associated with the quaternary salt. In dryer sheets, it was discovered that blends of amine oxide and DTMAS gave synergistic softening of cotton towels and were unexpectedly effective in preventing static charge build-up on polyester fabric.

From the practical standpoint of fabric softener formulation, a comparative study was made on adsorption behavior toward fabrics of binary systems consisting of di(hydrogenated tallow) dimethyl ammonium chloride (purified Arquad 2HT) and typical polyoxyethylenated nonionic surfactants which are commonly used as auxiliary agents for softeners.

Esterquats, which are quaternary ammonium compounds having two long (C(16)-C(18)) fatty acid chains with 2 weak ester linkages, represent a new generation of fabric softening agents, having replaced the dialkyldimethylammonium salts (e.g. DTDMAC and DSDMAC). The inclusion of ester linkages into the aliphatic chains has significantly improved the kinetics of biodegradation of the cationic surfactants, lowering the environmental exposure levels. This new generation of fabric softening agents combines a good environmental profile with the structural features required for an effective fabric conditioner. The present paper reviews the synthesis, types, actives combines a good environmental profile with the structural features required for a properties and applications of esterquats.

The commercial hair conditioners and fabric softeners were analyzed for the content of alkyltrimethylammonium compounds (ATMACs) by gas chromatography-mass spectrometry (GC-MS) with electron impact (EI) and low-pressure positive-ion chemical ionization (PICI) modes. The method involves mixed diluted samples (adjust pH to 10.0) with potassium iodide to enhance the extraction of iodide-ATMA+ ion pairs by direct liquid-liquid extraction. The iodide-ATMA+ pairs were then demethylated to their corresponding nonionic alkyldimethylamines (ADMAs) by thermal decomposition in a GC injection-port. A high abundance of ADMAs was detected at the temperature above 300 degrees C in the GC injection-port. The enhanced selectivity of quasi-molecular ion chromatograms of C12-C18-ADMA, obtained using methanol PICI-MS enables ADMAs to be identified. The accuracy and precision of the method was validated and was successfully applied to determine contents of ATMAC in commercial hair conditioners and fabric softeners. The contents of total measured ATMAC ranged from 0.4 to 6.9% for hair conditioners, and from 3.3 to 4.6% for fabric softeners.

The light-induced controlled release of fragrances from photolabile 2-oxo-(2-phenyl)acetates via Norrish Type II photofragmentation was evaluated by irradiation of the precursors in different solvents and on cotton in a typical fabric softener application. The desired photooxidation was found to work efficiently in water-based systems, and it tolerates the presence of oxygen. The formation of a certain amount of alcohol besides the desired aldehyde or ketone was attributed to further reaction of the photochemically released carbonyl compound, rather than to ester hydrolysis in an aqueous environment.

Improved catalyst systems have been developed for use in the glyoxal-glycol process under a wide variety of curing conditions. The mild cure process, now conducted with polyethylene as fabric softener in place of the reactive hydrophobic silicones formerly required, takes place at 120-125°C in 2 minutes by aluminum sulfate catalysis in the presence of tartaric acid. Minor amounts of phosphoric acid are added as needed to counteract fabric alkalinity. The medium cure process at 145-160°C occurs within 15 seconds with the same catalyst and activators in the presence of aluminum dihydroxy acetate as buffer. The high temperature process uses aluminum chlorhydroxide as catalyst in the presence of an α-hydroxy acid, and takes place at 170°C or higher. In all three systems, 1,6-hexanediol is the preferred glycol from the standpoint of durable press performance, fabric strength retention, and fabric whiteness.

The most difficult performance attribute to measure when evaluating a fabric softener has been static control. Several instrumental methods have been used in the past, all with limited success. The most frequently used method has been a subjective evaluation by an experienced operator, but this also has obvious short-comings. The topic method is based on a Faraday Cage. Test swatches are removed from the dryer and placed in an insulated stainless steel tank. As each swatch is removed, a corresponding charge is induced on the tank, which is measured by a high impedence volt meter.

Rinse cycle, wash cycle, and dryer type softeners are reviewed and their compositions discussed. Ashland’s conclusions are: (a) Rinse cycle softeners give the best performance from a softening and anti-static point of view. They are, however, less convenient to use since they must be introduced into the final rinse, (b) Wash cycle softeners are convenient to use, but higher use levels are necessary to impart adequate softening and anti-static properties making their use more expensive. They also tend to decrease the cleaning properties of the detergent used, (c) Dryer type softeners are convenient to use, but they impart less softening because of nonuniform deposition of softener on the fabric. The anti-static properties, on the other hand, imparted by these softeners are very good.

Cationic surfactants have a positively charged nitrogen atom and at least one hydrophobic, long-chain substituent in the molecule. Because of their fabric-softening and antistatic properties, they are used as active materials in fabric-softening agents. Suitable cationic surfactants are mostly quaternary ammonium salts, and to a lesser extent, imidazolinium salts with two long hydrophobic alkyl chains. Alkylated, partly ethoxylated polyamines, amine amides, ester amines and di-quaternary compounds also have recently been used or proposed. Fabric softeners generally are aqueous dispersions of distearyl dimethyl ammonium chloride or tallow alkylated imidazolinium derivatives in concentrations of 1–9%. Concentrated fabric softeners have recently been pushed into the market as double, triple or 10-fold concentrates. Fabric softeners used in the forms of acrosol sprays, pads or sheets, are not used in the washing machine but can be used in the laundry dryer. The combination of laundry detergent and fabric softener is a single product is impaired by anionic surfactants normally contained in laundry detergents because they react with the cationics to form neural salts. With the so-called soft detergents, one attempts to circumvent these difficulties by means of special formulations, e.g., with nonionics or by using definite physical-chemical mechanisms. They represent a compromise with regard to detergency performance and softening effect.

Because earlier model detergency studies have shown that oil/water interfacial tension is critically important in oil removal processes, factors affecting the interfacial tension between detergent-range nonionic surfactant solutions and paraffin oil have been examined. For a given hydrophobe, equilibrium interfacial tension values increase with the length of the ethylene oxide chain in the hydrophile, because of the attendant decrease in overall surface activity. For a given degree of ethoxylation, commercial nonlphenol ethoxylates reduce interfacial tension more effectively than their secondary alcohol-based counterparts, and these in turn are more effective than commercial primary alcohol ethoxylates. Furthermore, monodisperse primary alcohol ethoxylates reduce interfacial tension more effectively than broad-range ethoxylates with similar cloud points. This observed order of effectiveness is attributed in part to variations in the extent of fractionation that occur as nonionic surfactants divide between the oil and water phases. Equilibrium interfacial tension values produced by commercial nonionic surfactants are significantly more dependent on concentration and temperature than those obtained with monodisperse ethoxylates. However, the time-course for lowering interfacial tension exhibited by monodisperse ethoxylates varies with concentration and temperature to a greater extent than that displayed by commercial products. These findings are accounted for by the combined effects of the changes in relative surface activity and partitioning that occur as the concentration and temperature are varied. An imidazoline-based quaternary fabric softener markedly increases the interfacial tension immediately following phase contact, whereas equilibrium values are only slightly higher in the presence of the softener. Appatently, preferential adsorption of the softener occurs at the interface, followed by adsorption of the nonionic surfactant at the new softener/water interface. Builders and electrolytes have no significant effect on the interfacial tension between aqueous nonionic surfactant solutions and paraffin oil. Terg-O-Tometer results demonstrate the correlation between oil/water interfacial tension and detergency.

The Waters and Kupfer disulfine blue method for cationic surfactants has been extensively modified in order to extend its applicability to the broad range of samples necessary for elucidating the removal and biodegradability of the cationic fabric softener distearyl dimethyl ammonium chloride (DSDMAC) during sewage treatment. In addition, these modifications have overcome the need for preconditioning anion-exchange resin columns and the instability of the disulfine blue-quaternary ion association compound, both recognized by the authors as problems associated with the Waters and Kupfer method. The addition of a thin layer chromatographic procedure has made possible the semiquantitative estimation of the DSDMA+ cation contribution to the measured level of disulfine blue active substances.

The choice of a cationic fabric softener for rinse, wash and dryer cycle applications is based upon an understanding of the physical and performance differences of the softeners. These differences are primarily governed by composition of fatty alkyl groups rather than differences in chemical types. In general, the more saturated alkyl fatty groups make softeners more difficult to handle and disperse but are the best for softening fabric. Unsaturation improves handling, rewet, and ease of formulation.

It has been determined that the incorporation of a highly active antibacterial agent, phenylmercuric propionate, into an aqueous solution of a fabric softener of the quaternary ammonium type results in a most effective antibacterial laundry rinse additive. The presence of the quaternary ammonium compound appears to enhance the antibacterial activity of the mercurial. When applied at a level of 63 parts of available mercurial to one million parts of fabric, the treated cloth is rendered bacteriostatic to several strains ofS. aureus and to ammonia-producing organisms of theProteus group, also mildewstatic toChaetomium globosum. The formulated antibacterial softener as well as the treated linens appear to be entirely safe to humans.