Surfactants and precursors with minimized 1,4-dioxane formation

Abstract

The present disclosure relates to alcohol ether sulfate (AES) precursors that avoid 1,4-dioxane formation during sulfation. By using ethoxylates with only one ethyleneoxy group, the invention ensures that no appreciable 1,4-dioxane is formed under acidic conditions. Methods include producing a pure, homogeneous one-mole ethoxylate product through routes independent of ethoxylation or by distillation.

Description

Attorney Docket No. IVOX-6-PCT SURFACTANTS AND PRECURSORS WITH MINIMIZED 1,4-DIOXANE FORMATION CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 696,204, filed September 18, 2024, which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present disclosure relates to alcohol ether sulfate (AES) precursors that avoid 1,4- dioxane formation during sulfation. More particularly, the present disclosure relates to ethoxylates with one ethyleneoxy group that when subjected to acidic conditions as in sulfation, phosphation, esterification, and in low pH formulations, do not form 1,4-dioxane to any appreciable degree. BACKGROUND

[0003] Consumer products have been particularly scrutinized for 1,4-dioxane content due to its adverse health effects. As a result, 1,4-dioxane content in products must be severely limited (to about 1 ppm) in certain jurisdictions, especially in New York and California. AES manufacturers have taken the decision to comply with the 1 ppm maximum 1,4-dioxane in many regions including the U.S. Continued scrutiny may cause even lower 1,4-dioxane content requirements.

[0004] It is well known that 1,4-dioxane is formed to a significant (unacceptably large) extent when ethoxylates containing two or more ethyleneoxy unit chains are subjected to acidic conditions. Acids may include Lewis or protic acids. 1,4-dioxane may also form at elevated temperature at initially neutral or acidic conditions. Stability for two years is the recognized requirement. So called drift is when 1,4-dioxane content increases with time.

[0005] Formation of 1,4-dioxane may occur when molecules containing two or longer oxyethylene chains are subjected to acidic conditions. For example, this occurs during their conversion to sulfates or phosphates, [Levinson 2009], production of fatty acid methyl ester ethoxylates with acidic catalysts, and formulations containing ethoxylates at lower pH. Thermal decomposition is another process that might cause formation of 1,4-dioxane.Attorney Docket No. IVOX-6-PCT

[0006] It may be theorized that 1,4-dioxane forms by intramolecular cleavage of two adjacent oxyethylene groups in a poly(oxyethylene) chain. Thus, any molecules containing two or more oxyethylene linkages are subject to 1,4-dioxane formation.

[0007] Alcohol ethoxylate (AE) products made by catalytic ethoxylation invariably contain ethoxylates of various length, including molecules with two or more oxyethylene unit chains. For example, even when alcohols are reacted with EO in a 1:1 molar ratio, molecules with more than one oxyethylene chain form. Some refer to AE with an average of one mole as one mole ethoxylates but they contain molecules with two or more oxyethylene unit chains. Products that are oligomeric may also be termed polydisperse.. Compounds with no oligomers present are termed monodiperse. If made with an alkyl, aryl, or alkylaryl group, ethylene glycol ethers most likely to be a product used in industry and perhaps most importantly as a sulfate precursor.

[0008] 1,4-Dioxane may also be formed in an ethoxylation process when there is water or hydroxide present. Water content of the ethoxylate precursor is carefully controlled and limited to a very small amount to consequently minimize polyethylene glycol (PEG). Therefore, since the ethoxylate contains only a small amount of PEG, about 2 mole% or less, more preferably 1 mole% or less, it is possible only a minor amount of 1,4-dioxane would be formed by this route.

[0009] AE are particularly important products. Low mole AE (those containing an average of about one to four ethyleneoxy units) made by existing ethoxylation processes are used as precursors to AES, surfactants that are widely used in consumer and other products. Low mole ethoxylates contain a distribution of molecules containing different ethyleneoxy chain lengths including those with a length of two or more. Noteworthy is the presence of significant amounts of unreacted alcohol in low mole ethoxylates that is not subject to 1,4-dioxane formation. When these alcohols are sulfated, they yield alkyl sulfates. The importance of AES over alkyl sulfates has increased due to their more desirable properties. Hence the importance of AES. Alcohol ethoxylates with longer ethyleneoxy chains find wide use as nonionic surfactants. Additionally, diethylene glycol ethers may be used in formulation.

[0010] Selectivity to a one mole ethoxylate product obtained by base-catalyzed ethoxylation occurs when the starting material contains a proton that is more labile than the OH group in ethoxylated molecules. Herein we use the term one-mole indicating pure material with only one ethyleneoxy unit regardless whether obtained by separation of a product of an ethoxylation process or by other routes.) An example of selectivity to a true one mole during ethoxylation is alkylphenol. Phenolic protons are more labile than their corresponding ethoxylates. Even where the ethoxylation is selective for formation of the one mole adduct, products with moreAttorney Docket No. IVOX-6-PCT than one mole of EO added, except for phenoxyethanol, are usually desirable in many applications and as such pose the same dilemma of oligomer distribution. Alkylphenol ethoxylates and their sulfates are rarely used in consumer products. However, phenoxyethanol is used in formulations.

[0011] Several approaches have been undertaken to minimize 1,4-dioxane content in AES, such as appropriate sulfation conditions [Matheson et al. 2009]. However, even though 1,4- dioxane may be minimized, current requirements for 1,4-dioxane content are difficult or impossible to meet without further processing.1,4-Dioxane is often removed in a post sulfation stripping step. However, all methodologies are deficient due to increased process complexity and cost. It is highly desirable that manufacturers of AES precursors (such as AE) provide a product that does not form 1,4-dioxane.

[0012] One approach is to provide a pure, monodisperse one mole ethoxylate. In another, the one mole product may contain components that do not form 1,4-dioxane such as alcohols.

[0013] Several methods might be employed to separate a one mole ethoxylate from polydisperse products. Distillation [Weimer & Cooper (1966)] and phase separation [Gerhardt et al. (1974)] are two examples. Other methods that may be effective are flash or wiped film evaporation, centrifugal molecular distillation, column chromatography, flash chromatography, preparative liquid chromatography, and fractional crystallization.

[0014] Preparation of one mole products may be achieved by means other than ethoxylation, and often employ the use of ethylene glycol as a reagent. Included are alkylation with an alkyl halide, alcohol or olefin [Ku et al.2024], and reductive alkylation with an aldehyde [Tulchinsky et al. 2014], or other compounds with a -CO- moiety. These reactions require excess ethylene glycol to selectively produce monodisperse one mole product and avoid appreciable amounts of dialkylate. Unfortunately, when the reaction partner is nonpolar (e.g. the number of carbons in the R group is about six or more), EG is present in a reaction mixture as a second phase and inhibits efficient preparation of desired product. Separation of the excess glycol is also required once the desired product is formed. Most of the excess EG may be taken as a separate phase when a relatively nonpolar product is made. Further processing, such as filtration, distillation or liquid-liquid extraction, is likely necessary to remove any remaining reagents (such as EG or alkylating agent) catalyst, solvent, or byproduct(s). However, it should be noted that purification of the crude monodisperse one mole product may be easier than isolation of monodisperse one mole product from an ethoxylate.

[0015] A variety of other approaches have been investigated. They include alkylation of protected ethylene chlorohydrin with alcohol (and presumably alkyl halide) [Sallay et al.2002]Attorney Docket No. IVOX-6-PCT and hydrogenation of a 2-hydroxyethyl ester (difficult due to the high tendency to cleave and make alcohol instead of ether). Examples cited are not intended to represent all routes. SUMMARY

[0016] The present invention differs from other approaches for producing low-dioxane ethoxylate products in several key structural and synthetic aspects. Some methods focus on using olefins as starting materials with ethylene glycol under specific catalytic conditions to produce dialkyl ether structures having two alkyl groups (R^-O-CH^CH^-O-R^). The present invention provides alternative routes that produce monoalkyl ether structures having a single alkyl group with a terminal hydroxyl or sulfate group (R-O-CH^CH^-OH or R-O-CH^CH^- OSO^M). The first route involves purification of existing ethoxylate mixtures through distillation to remove compounds having n^2, allowing manufacturers to utilize current commercial ethoxylate streams and existing infrastructure. The second route involves direct synthesis through alkylation reactions using alkyl halides with ethylene glycol in the presence of strong bases and polar aprotic solvents such as N-methylpyrrolidinone. Each route can be implemented independently based on manufacturing preferences, available feedstocks, and process economics. Both routes achieve the same beneficial result of producing compositions that minimize or avoid formation of 1,4-dioxane under acidic conditions, while providing structural flexibility through the terminal hydroxyl functionality that is absent in dialkyl ether approaches.

[0017] One can envision a process whereby alcohol and monodisperse one mole ethoxylate are distilled from an oligomeric product. Then the monodisperse one mole product might be used as an AES precursor, alcohol could be recycled to ethoxylation, and the material containing more than one oxyethylene group may be mixed with other ethoxylate products or used as a new product. The advantage of a product containing little or no alcohol in the one mole ethoxylate may be in applications where their presence is detrimental (such as decreased foaming, odor, solubility, etc). Alternatively, the alcohol obtained in the separation process could be mixed with the one mole product and used as sulfation precursor. Currently, AES contain products made by sulfation of a conventional alcohol ethoxylate which contains unreacted alcohol and alcohol ethoxylates with various length oxyethylene chains.

[0018] In some examples, a composition is provided. The composition comprises a compound of having the general formula R[O-(CH2CH2O)n-X]m, where R may be a hydrocarbyl group that is, in some examples, aliphatic (which may be a saturated linear or branched alkyl), cycloaliphatic, or their olefinic derivatives; alkylaryl or their olefinic derivatives; alkylcarbonyl (R = R’-CO-), or a hydrogen atom; n is 0 or more; m is about 1-4. Ethoxylates may be definedAttorney Docket No. IVOX-6-PCT where n is one or more, and alcohols when n is zero. When R = H, n is one or more. In some examples, R is an aliphatic hydrocarbyl group, X is a substituent, n is an integer great than or equal to 0, and m is an integer equal to 1. In some examples, R is a linear aliphatic carbon chain, X is a substituent, n is an integer greater than or equal to 0, and m is an integer equal to 1.

[0019] In some examples, the composition may include one or more of the following features. R may be a linear aliphatic carbon chain selected from the group consisting of hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl groups. R may be an unsaturated derivative of a linear alkyl, such as oleyl, linoleyl, or linolenyl. R may be selected from the group consisting of dodecyl and tetradecyl groups. R groups may be different, such as a mixture of decyl, dodecyl, tetradecyl. and octadecyl. The composition may further comprise a compound of the general formula, wherein n is an integer equal to 0. The composition may comprise 95 mol% of the general formula, wherein R is a linear aliphatic carbon chain, n is an integer equal to 1, and x is an integer equal to 1. The composition may include a compound where n is an integer equal to 2, R is CyH2y+1, and y is an integer from 8 to 18. X may be a substituent selected from the group consisting of a hydrogen (H), a sulfonic acid group (SO3H), and a neutralized sulfonic acid group SO3M (e.g., sulfonate), where M is a cation selected from the group consisting of alkali metals, alkaline earth metals (NH4), ammonium (NH4), and organic ammonium cations. Examples of suitable alkali metals include sodium (Na), potassium (K). Examples of suitable alkaline earth metals include calcium (Ca), magnesium (Mg), strontium (Sr), and barium (Ba). Other alkali metals and alkaline earth metals may be suitable.

[0020] In some examples, a process of producing a composition is provided. The process comprises preparing a mixture of a first compound and a second compound, the first compound and the second compound each having the general formula, wherein R is a linear aliphatic carbon chain, X is a substituent, n is an integer greater than or equal to 0, and x is an integer equal to 1, wherein n is an integer equal to 1 for the first compound and n is an integer greater than or equal 2. The process further comprises distilling the mixture to remove the second compound from the mixture to produce the composition.

[0021] In some examples, the process may include one or more of the following features. The composition may be at least 95 mol% of the first compound. The composition may be at least 99 mol% of the first compound. The composition may further comprise a third compound having the general formula, wherein R is a linear aliphatic carbon chain, X is a substituent, n is an integer equal to 0, and x is an integer equal to 1. The composition may comprise less than 1 ppm of 1,4-dioxane. In some cases, X may be a substituent selected from the group consistingAttorney Docket No. IVOX-6-PCT of a hydrogen atom and a sulfonate group SO3M, where M is a cation selected from the group consisting of sodium (Na), potassium (K) and ammonium (NH4).

[0022] In some examples, a process of producing a composition is provided. The process comprises alkylating ethylene glycol with an alkyl halide in the presence of N- methylpyrrolidinone and a base, the base having a pH of at least 12 when in an aqueous solution with a concentration of at least 0.1M.

[0023] In some examples, the process may include one or more of the following features. The base may comprise NaOH. The base may comprise KOH. The base may comprise NaOMe. The base may comprise KOMe. The base may comprise NaOtBu. The base may comprise KOtBu.

[0024] The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The disclosure can be understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings.

[0026] FIG. 1 is a conceptual diagram illustrating an example method for producing a final composition by distilling a mixture, according to aspects of the present disclosure.

[0027] FIG. 2 is a conceptual diagram illustrating an example method for producing a composition through an alkylation reaction, according to an embodiment.

[0028] FIG.3 is a conceptual diagram illustrating an example distillation system. DETAILED DESCRIPTION

[0029] For purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nonetheless be understood that no limitation of the scope of the disclosure is intended by the illustration and description of certain embodiments of the disclosure. In addition, any alterations and / or modifications of the illustrated and / or described embodiment(s) are contemplated as being within the scope of the present disclosure. Further, any other applications of the principles of the disclosure, as illustrated and / or described herein, as would normally occur to one skilled in the art to which the disclosure pertains, are contemplated as being within the scope of the present disclosure.Attorney Docket No. IVOX-6-PCT

[0030] The terms “R,” “R1,” “R’,” and “R2” as used herein may refer to hydrocarbon or hydrocarbyl groups that can be linear, branched, or cyclic. These groups may be saturated or unsaturated and may contain from 1 to about 30 carbon atoms, or in some aspects from 6 to about 20 carbon atoms. The term "alkyl" specifically refers to saturated hydrocarbon groups within this broader definition. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, isodecyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl groups. Cyclic structures may include cycloalkyl groups, which are saturated hydrocarbon rings containing from 3 to about 10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. In some aspects, R, R1, and R2 may also contain one or more heteroatoms, such as oxygen, nitrogen, or sulfur, within the hydrocarbon structure.

[0031] In the general formula R[O-(CH^CH^O)^-X]^, the oxygen atom is typically attached to a primary carbon of the R group, forming a -CH^-O- linkage. This primary attachment is characteristic of ethoxylates derived from primary alcohols, which are the most common starting materials for commercial surfactant production. Primary alcohols such as dodecanol, tetradecanol, and hexadecanol provide the R groups with primary carbon attachment points. The invention may also encompass compounds where the oxygen is attached to a secondary carbon of the R group, forming a -CH(-O-)- linkage, as the fundamental principle of preventing 1,4-dioxane formation through controlled ethylene oxide distribution (n=0 or 1) applies regardless of the attachment point. However, the examples and preferred embodiments focus on primary carbon attachment points due to their commercial prevalence and established performance characteristics.

[0032] The present disclosure provides compositions and methods for producing surfactants and surfactant precursors with minimized 1,4-dioxane formation. More specifically, the disclosure relates to the production of pure “one mole” ethoxylates, which contain only a single ethyleneoxy unit. These ethoxylates are used as precursors for the production of alcohol ether sulfate (AES) surfactants. Notably, these one mole ethoxylates do not form 1,4-dioxane during sulfation or under acidic conditions, addressing a significant concern in the surfactant industry.

[0033] The disclosure further provides methods for producing these pure one mole ethoxylates. One such method involves the alkylation of ethylene glycol with alkyl halides in the presence of a strong base and N-methylpyrrolidinone solvent. Another method involves continuous or batch distillation using suitable unit operations and, optionally, under vacuum or deep vacuum, or alternatively using wiper film evaporators, and / or with a feed of at least lauryl alcoholAttorney Docket No. IVOX-6-PCT ethoxylates and myristyl alcohol ethoxylates to produce a distillate including pure one mole product.

[0034] The resulting AES surfactants derived from these pure one mole ethoxylates exhibit extremely low levels of 1,4-dioxane, meeting stringent regulatory requirements. Additionally, these surfactants may demonstrate improved stability and properties compared to those derived from conventional ethoxylates.

[0035] In some embodiments, the one mole ethoxylates and the resulting AES surfactants can be produced with various alkyl chain lengths, allowing for the optimization of surfactant properties for different applications. This flexibility opens up opportunities in various sectors, including personal care, household cleaning, and industrial applications.

[0036] In summary, the present disclosure provides a solution for producing AES surfactants with improved stability and properties while avoiding the formation of the potentially harmful 1,4-dioxane byproduct. In some examples, the AES surfactants are substantially free of 1,4- dioxane. As used herein, the term “substantially free” may refer to a composition, substance, or product that contains only trace amounts or is completely devoid of a particular component, impurity, or contaminant. In quantitative terms, substantially free may indicate that the composition contains less than about 1 mol%, less than about 0.5 mol%, less than about 0.1 mol%, less than about 0.01 mol%, or less than about 0.001 mol% of the specified component. Low-dioxane products may refer to those conforming to current requirements by containing about 1 ppm or less of 1,4-dioxane. In some cases, substantially free may mean that the amount of the specified component is below the detection limit of standard analytical techniques used in the field. The term may also imply that any presence of the specified component does not materially affect the basic and novel characteristics of the composition or its intended function

[0037] Referring to FIG. 1, a method 100 for producing a final composition by distilling a mixture of two compounds is illustrated. In step 102, where a mixture is prepared containing a first compound and a second compound. Both compounds conform to the general formula: R[O-(CH2CH2O)n-X]m, where R may be a hydrocarbyl or a hydrocarbon group that is, for example, aliphatic (saturated linear or branched alkyl), cycloaliphatic, or their olefinic derivatives; alkylaryl or their olefinic derivatives; alkylcarbonyl (R = R’-CO-), or a hydrogen atom. The integer n is 0 or more, and m is about 1-4. Ethoxylates may be defined where n is one or more, and alcohols when n is zero. When R is hydrogen, n is one or more. In some cases, R is a linear or branched aliphatic carbon chain, n is an integer greater than or equal to 0, and m is an integer equal to 1. R may be mixtures of aliphatic carbon chains. In the context of this method, n is an integer equal to 1Attorney Docket No. IVOX-6-PCT for the first compound and n is an integer greater than or equal to 2 for the second compound. This step sets the initial composition for further processing. In some examples, the mixture may include more than two compounds, for example, different ethoxylate or different alcohol ethoxylate. In some examples, the mixture may include synthetic alcohol ethoxylates. In some examples, the mixture may be provided from a commercially available source, such as the NEODOL® line of alcohol ethoxylates available from Shell plc, London, United Kingdom, or ALFONIC® brand of alcohol ethoxylates available from Sasol Ltd, Johannesburg, South Africa.

[0038] In step 104, which involves distilling the mixture. The purpose of step 104 is to remove the second compound from the mixture, thereby producing the final composition predominantly consisting of the first compound. The distillation process may be carried out under vacuum or at atmospheric pressure, depending on the boiling points of the compounds and the desired purity of the final composition.

[0039] In some cases, the distillation process may be performed in a single stage or multiple stages, depending on the complexity of the mixture and the desired purity of the final composition. The distillation process may also be carried out in a continuous or batch mode, depending on the scale of the operation and the specific requirements of the process.

[0040] In some aspects, the method 100 may further include a purification step after distillation to further enhance the purity of the final composition. This purification step may involve techniques such as recrystallization, chromatography, or additional distillation steps.

[0041] In some cases, the method 100 may also include a characterization step after the distillation process to confirm the identity and purity of the final composition. This characterization step may involve techniques such as gas chromatography, nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, or infrared (IR) spectroscopy.

[0042] In some aspects, the method 100 may be used to produce a variety of compositions by varying the R group in the general formula. For example, R may be a linear or branched group, such as a hexyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, or octadecyl group, as well as their branched isomers, allowing for the production of a range of one mole ethoxylates with different hydrophobic properties.

[0043] In some embodiments, the process for producing the composition may involve a reaction using two main reactants. In some aspects, the reaction can be generally represented by the formula: R1Y1+ R2Y2^ Products,Attorney Docket No. IVOX-6-PCT where R1 and R2 represent hydrocarbon groups that may be linear, branched, or cyclic, and may contain one or more heteroatoms or hydroxyl groups, and Y1 and Y2 each independently represent either a hydroxyl group (OH) or a halide (X, where X is typically Cl, Br, or I).

[0044] In some embodiments, the process for producing the composition may involve an alkylation reaction using two main reactants. In some aspects, one reactant may contain only hydroxyl groups (or one OH group), such as ethylene glycol or other polyols. The other reactant may have a halogen, typically an alkyl halide. This specification of reactants ensures the selective formation of the desired ethoxylate product.

[0045] For example, the reaction may proceed as follows: R1-(OH)n+ R2-X ^ R1-O-R2+ HX where: represents a hydrocarbon group that may be linear, branched, or cyclic, and may contain one or more heteroatoms, (OH)nrepresents one or more hydroxyl groups, where n is an integer ^ 1, R2 represents a linear or branched aliphatic carbon chain, and X represents a halogen (typically Cl, Br, or I).

[0046] The first reactant may contain only hydroxyl groups, and the second reactant may contain a halogen.

[0047] This reaction may lead to the formation of compounds represented by the general formula R[O-(CH2CH2O)n-X]m, where R is a linear or branched aliphatic carbon chain, X is a substituent, n is an integer greater than or equal to 0, and m is an integer equal to 1. The progression from the initial reaction to the final product may occur through several steps:

[0048] In some cases, when R1 is HOCH2CH2OH (ethylene glycol) and R2 is a hydrocarbyl group, such as a linear aliphatic chain, the initial reaction may produce: HOCH2CH2OH + R2-X ^ HOCH2CH2O-R2+ HX

[0049] If multiple hydroxyl groups are present on R1(n > 1), or if excess ethylene glycol is available, the reaction may repeat: HOCH2CH2O-R2 + HOCH2CH2OH ^ HOCH2CH2O-CH2CH2O-R2 + H2O

[0050] This process may continue, potentially forming a chain of ethylene oxide unit: R2-O-(CH2CH2O)n-H

[0051] The terminal hydroxyl group may react again with R2-X (present in the initial step or added separately): R2-O-(CH2CH2O)n-H + R2-X^ R2-O-(CH2CH2O)n- R2 + HX

[0052] The likelihood of progressing from the initial reaction to the final product may depend on various factors, including reaction conditions, reactant ratios, and the presence of catalysts.Attorney Docket No. IVOX-6-PCT In some cases, the reaction may be driven towards the desired product by controlling these factors. For example, using an excess of ethylene glycol may improve selectivity, while careful control of temperature and pH may influence the substitution of the terminal hydroxyl group with the alkyl halide.

[0053] The distribution of n values in the final product may be influenced by reaction time, temperature, and the ratio of reactants. In some cases, additional purification steps may be employed to isolate specific n values or ranges of n values.

[0054] It should be noted that while this reaction pathway describes one possible route to the desired product, other reaction pathways or modifications to this process may also lead to the formation of compounds represented by the general formula R[O-(CH2CH2O)n-X]m. The specific reaction conditions and methodologies may be optimized based on the desired product characteristics and process efficiency considerations.

[0055] In some cases, the molar ratio of the hydroxyl-containing compound (e.g., ethylene glycol) to the halogen-containing compound (e.g., alkyl halide) in the alkylation reaction mixture may vary depending on the desired product characteristics and reaction efficiency. The ratio may be adjusted to drive the selectivity towards the formation of the one mole product. In some aspects, an excess of the hydroxyl-containing compound may be used to promote the formation of the desired product. In some cases, the molar ratio of the hydroxyl-containing compound (e.g., ethylene glycol) to the halogen-containing compound (e.g., alkyl halide) in the alkylation reaction mixture may range from about 5:1 to about 15:1. For example, the molar ratio may be about 7:1, or about 10:1, or any ratio within this range. This ratio may drive the selectivity towards the formation of the one mole product. The specific ratio may be adjusted based on the particular reactants used and the desired product characteristics. This ratio may drive the selectivity towards the formation of the one mole product.

[0056] In some aspects, a strong base as used in the alkylation reaction may be defined as a base that, when in an aqueous solution with a concentration of at least 0.1M, has a pH of at least 12. The strong base used in the reaction may be derived from sodium hydroxide (NaOH), potassium hydroxide (KOH), sodium methoxide (NaOMe), potassium methoxide (KOMe), sodium t-butoxide (NaOtBu), or potassium t-butoxide (KOtBu). These bases, when dissolved in water at the specified concentration, typically produce solutions with pH values of 12 or higher. The choice of base may affect the reaction kinetics, yield, and ease of product isolation. In some cases, bases with higher pH values or higher concentrations may be used to further promote the reaction.Attorney Docket No. IVOX-6-PCT

[0057] The use of these specific solvents and reactants, combined with the optimized reaction conditions, may result in improved reaction rates and higher yields of the desired one mole ethoxylate product. This approach addresses the challenge of producing high-quality surfactant precursors with extremely low levels of 1,4-dioxane, meeting stringent regulatory requirements for various applications in personal care, household cleaning, and industrial products.

[0058] Referring to FIG. 2, a method 200 for producing a composition through an alkylation reaction is illustrated. In step 202, where ethylene glycol, an alkyl halide, N- methylpyrrolidinone, and a base are provided. In some aspects, the base may have a pH of at least 12 when in an aqueous solution with a concentration of at least 0.1M. The alkyl halide may be selected from a group consisting of bromodecane, 1-bromododecane, 1- bromotetradecane, or 1-bromohexadecane. In some cases, corresponding chloroalkanes or iodoalkanes may be used instead of alkyl halide (e.g., alkyl bromide).

[0059] Following the provision of materials, in step 204, which involves combining the ethylene glycol, alkyl halide, N-methylpyrrolidinone, and base. This step prepares the reaction mixture for the subsequent alkylation process. The use of N-methylpyrrolidinone as a solvent in this step may improve the reaction efficiency by mitigating the slow reaction of a two (or more) phase mixture.

[0060] In some cases, the molar ratio of ethylene glycol to alkyl halide in the reaction mixture may be at least 7:1. This ratio may drive the selectivity towards the formation of the one mole product. The strong base used in the reaction may be derived from sodium hydroxide (NaOH), potassium hydroxide (KOH), sodium methoxide (NaOMe), potassium methoxide (KOMe), sodium t-butoxide (NaOtBu), or potassium t-butoxide (KOtBu). The choice of base may affect the reaction kinetics, yield, and ease of product isolation.

[0061] In some aspects, the method 200 may be used to produce a variety of compositions by varying the alkyl chain in the alkyl halide. For example, the alkyl chain may be an octyl, decyl, dodecyl, tetradecyl, hexadecyl, or octadecyl group, allowing for the production of a range of one mole ethoxylates with different hydrophobic properties.

[0062] Continuing with the description of FIG. 2, in step 206, where the alkylation reaction between ethylene glycol and the alkyl halide is performed in the presence of N- methylpyrrolidinone and the base. This step represents the core chemical reaction of the method. The base used in this reaction may have a pH of at least 12 when in an aqueous solution with a concentration of at least 0.1M. This high pH condition ensures that the base is sufficiently strong to facilitate the alkylation reaction.Attorney Docket No. IVOX-6-PCT

[0063] In some aspects, the base used in the alkylation reaction may be derived from sodium hydroxide (NaOH). Sodium hydroxide is a strong base that can effectively deprotonate ethylene glycol, enabling the nucleophilic attack on the alkyl halide.

[0064] In other cases, the base used in the alkylation reaction may be derived from potassium hydroxide (KOH). Like sodium hydroxide, potassium hydroxide is a strong base that can facilitate the alkylation reaction. The choice between sodium hydroxide and potassium hydroxide may depend on factors such as availability, cost, and the specific requirements of the reaction.

[0065] In some embodiments, the base used in the alkylation reaction may be derived from sodium methoxide (NaOMe). Sodium methoxide is a strong base that can also effectively deprotonate ethylene glycol, facilitating the nucleophilic attack on the alkyl halide.

[0066] In other embodiments, the base used in the alkylation reaction may be derived from potassium methoxide (KOMe). Like sodium methoxide, potassium methoxide is a strong base that can facilitate the alkylation reaction.

[0067] In some aspects, distillation of methanol before alkylation when using NaOMe or KOMe avoids competing alkylation by methanol. That is, when using methoxide bases (NaOMe or KOMe), the methanol byproduct is distilled off before adding the alkyl halide to prevent competing side reactions and improve product selectivity.

[0068] In some aspects, the formation of alcohols from alkyl halides during the alkylation reaction may occur as a side reaction but does not interfere with the desired product formation. Alcohol formation can result from hydrolysis of the alkyl halide in the presence of water or hydroxide ions. While this side reaction consumes some of the alkyl halide starting material, the resulting alcohols (having n=0 in the general formula) can be beneficial components of the final composition since they cannot form 1,4-dioxane. To minimize alcohol formation when pure one mole ethoxylate is desired, the reaction may be conducted under anhydrous conditions with careful exclusion of water. However, in many applications, the presence of both alcohols (n=0) and one mole ethoxylates (n=1) in the final composition may be acceptable and may even be advantageous for certain surfactant applications.

[0069] In some aspects, the base used in the alkylation reaction may be derived from sodium t-butoxide (NaOtBu). Sodium t-butoxide is a strong base that can effectively deprotonate ethylene glycol, enabling the nucleophilic attack on the alkyl halide. The t-BuOH formed is not subject to alkylation due to steric hindrance. Therefore, its removal is not required before alkylation, although its removal may be performed to optimize reaction conditions.Attorney Docket No. IVOX-6-PCT

[0070] In other cases, the base used in the alkylation reaction may be derived from potassium t-butoxide (KOtBu). Like sodium t-butoxide, potassium t-butoxide is a strong base that can facilitate the alkylation reaction. The tBuOH formed is not subject to alkylation due to steric hindrance. Therefore, its removal is not required before alkylation, although its removal may be performed to optimize reaction conditions.

[0071] The choice of base may affect the reaction kinetics, yield, and ease of product isolation. Therefore, the selection of the appropriate base is an important aspect of the alkylation reaction process.

[0072] Continuing with the description of FIG. 2, in step 206, where the alkylation reaction between ethylene glycol and the alkyl halide is performed in the presence of N- methylpyrrolidinone and the base. In some aspects, the base used in this reaction may be derived from sodium t-butoxide (NaOtBu). Sodium t-butoxide is a strong base that can effectively deprotonate ethylene glycol, enabling the nucleophilic attack on the alkyl halide.

[0073] In other cases, the base used in the alkylation reaction may be derived from potassium t-butoxide (KOtBu). Like sodium t-butoxide, potassium t-butoxide is a strong base that can facilitate the alkylation reaction. The choice of base may affect the reaction kinetics, yield, and ease of product isolation. Therefore, the selection of the appropriate base is an important aspect of the alkylation reaction process.

[0074] For alkylation reactions, the reactants may include an ethylene glycol (EG), a strong base, and NMP solvent. Alternative reactants include: 1-bromodecane, 1-bromododecane, 1- bromotetradecane, or 1-bromohexadecane. Corresponding chloroalkanes or iodoalkanes may be used. Strong base may include sodium or potassium hydroxide or sodium or potassium alkoxide. Alkoxides include 1 to 6 carbon alkoxides.

[0075] For sulfation reactions, the reactant is a pure one mole material such as 2-hexyloxy-, 2- octyloxy-, 2-decyloxy-, 2-dodecyloy-, 2-tetradecyloxy-, 2-hexadecyloxy-, or 2-octadecyloxy- ethanol or their mixtures. They may alternatively contain corresponding alkanols.

[0076] These examples demonstrate the synthesis and characterization of pure one mole ethoxylates through alkylation reactions, including reaction conditions, gas chromatography data showing conversion rates over time, and base content measurements indicating reaction progress. The key ranges for optimal product formation and minimal byproduct generation are highlighted, providing valuable insights for the efficient production of these surfactant precursors.

[0077] While distillation could occur after some form of alkylation or ethoxylation, the specific alkylation process described in FIG.2 is not necessarily preceded by the distillation process ofAttorney Docket No. IVOX-6-PCT FIG.1. The distillation process and alkylation process may be used as alternative methods for achieving the desired product, rather than sequential steps in a single process. The distillation process may be employed separately or after the alkylation process to further purify the product.

[0078] In some aspects, the alkylation process may produce a sufficiently pure one mole ethoxylate product that does not require subsequent purification. Alternatively, in cases where the alkylation process results in a mixture of products, a distillation process may be used to isolate the desired one mole ethoxylate. The flexibility to use these processes independently or in combination allows for optimization of the production method based on specific reactants, desired purity levels, and process efficiency considerations.The alkylation process may be further optimized through careful control of reaction parameters. The reaction temperature may be maintained between 50°C and 120°C, with temperatures of 60°C to 100°C being preferred for balancing reaction rate and selectivity. The molar ratio of ethylene glycol to alkyl halide may range from 5:1 to 15:1, with ratios of 7:1 to 10:1 being particularly effective for achieving high conversion while minimizing side reactions. The base concentration may be maintained at stoichiometric to slight excess relative to the alkyl halide, typically 1.0 to 1.2 equivalents, to ensure complete conversion while avoiding excessive base-catalyzed side reactions. The reaction progress may be monitored by measuring the base content of the reaction mixture, with base values decreasing from initial levels of about 0.5-1.0 meq / g to final levels of less than 0.02 meq / g indicating near-complete conversion. Gas chromatography analysis may be used to confirm product formation and purity, with conversion rates typically exceeding 90% under optimized conditions.

[0079] In some aspects, the distillation process may be optimized through control of various parameters to achieve high purity separation of the one mole ethoxylate product. The distillation may be conducted under reduced pressure, typically less than 10 torr, more preferably less than 5 torr, and most preferably less than 1 torr, to minimize thermal degradation and reduce operating temperatures. The distillation temperature may range from about 100°C to about 200°C depending on the pressure and the specific alkyl chain length of the ethoxylate. The use of structured packing or theoretical plates may enhance separation efficiency, with at least 5 theoretical plates, preferably at least 10 theoretical plates, being beneficial for achieving high purity products. Reflux ratios may be optimized based on the desired purity and throughput requirements, typically ranging from 2:1 to 10:1. The distillation may be conducted in batch or continuous mode, with continuous operation being preferred for large-scale commercial production.Attorney Docket No. IVOX-6-PCT

[0080] Referring to FIG.3, distillation system 300 is illustrated that may be used to implement the distillation processes described herein for producing purified one mole ethoxylate compositions. Distillation system 300 can include a bottom flask or reboiler 302 that serves as the primary vessel for containing the ethoxylate mixture to be separated. Bottom flask 302 may have a capacity ranging from 100 mL for laboratory-scale operations to several thousand liters for plant scale commercial production, with typical pilot-scale operations using vessels of 1 to 50 liters capacity. Heater 304, such as a reboiler, is positioned adjacent to or integrated with bottom flask 302 to provide the thermal energy necessary for vaporization of the ethoxylate components. Heater 304 may include an electric heating mantle, steam jacket, thermal fluid circulation system, or direct flame heating, with electric heating mantles being preferred for precise temperature control and safety considerations. Plant scale system may use alternative heaters as known in the art.

[0081] Temperature monitoring throughout distillation system 300 can be accomplished using multiple temperature sensors positioned at strategic locations. First temperature sensor 306 may be positioned at or near bottom flask 302 to monitor the temperature of the liquid mixture being heated. Additional temperature sensors 310 may be positioned at various points along the distillation column to monitor temperature profiles and ensure proper separation efficiency. Temperature sensors 310 may be positioned at the bottom, middle, and top sections of the column, or at regular intervals for columns with multiple theoretical stages. Second temperature sensor 314 is positioned at or near condenser 312 to monitor the overhead vapor temperature, which provides critical information about the composition of the distilling vapors.

[0082] Distillation system 300 includes a distillation column, which in the illustrated embodiment includes a spinning band column 308. Spinning band column 308 provides high separation efficiency through the use of a rotating helical band that creates intimate contact between ascending vapors and descending liquid, resulting in multiple theoretical stages of separation within a compact column design. Spinning band column 308 may provide approximately 50 theoretical stages at atmospheric pressure, with proportionally higher separation efficiency under the vacuum conditions typically employed for ethoxylate separations. Spinning band column 308 may operate at rotational speeds of 500 to 3000 rpm, preferably 1000 to 2000 rpm, with higher speeds providing increased separation efficiency at the cost of higher power consumption. Alternative column designs may include packed columns using structured packing materials such as metal mesh, ceramic rings, or plastic packing elements, random packing materials such as Raschig rings or Berl saddles, plateAttorney Docket No. IVOX-6-PCT columns with sieve trays, bubble cap trays, or valve trays, short path distillation columns for heat-sensitive materials, or wiped film evaporators which provide short residence times and can be particularly suitable for heat-sensitive ethoxylate materials or high-viscosity feedstocks. The choice of column type may depend on factors such as the required separation efficiency, throughput requirements, pressure drop considerations, and cost constraints.

[0083] Condenser 312 can be positioned at or near the top of spinning band column 308 to condense the ascending vapors back to liquid form. Condenser 312 may include a water- cooled condenser, air-cooled condenser, or refrigerated condenser depending on the operating temperature and cooling requirements. For ethoxylate separations, water-cooled condensers are typically sufficient, with cooling water temperatures of 10°C to 25°C providing adequate condensation efficiency. Condenser 312 can include a cooling system 330 that provides controlled cooling fluid circulation. Cooling system 330 may include cooling water inlet and outlet connections, flow control valves, and temperature monitoring to maintain optimal condensation conditions throughout the distillation process.

[0084] Distillation system 300 can include receiver 316 positioned downstream of condenser 312 to collect the condensed distillate. Receiver 316 may include a single collection vessel or multiple receivers that can be switched during operation to collect different fractions. For the separation of ethoxylate mixtures, multiple receivers may be used to separately collect unreacted alcohols, one mole ethoxylates, and heavier ethoxylate fractions. Receiver 316 may be equipped with level indicators, sampling ports, and temperature monitoring to track the collection process and enable real-time analysis of the distillate composition.

[0085] Cold trap 318 can be positioned between receiver 316 and the vacuum system to protect the vacuum pump from condensable vapors and to recover any volatile components that may pass through primary condenser 312. Cold trap 318 may be cooled using dry ice, liquid nitrogen, or mechanical refrigeration, with dry ice cooling being commonly used for ethoxylate distillations. Cold trap 318 serves the dual purpose of protecting vacuum pump 320 from contamination and recovering valuable product that might otherwise be lost to the vacuum system.

[0086] The vacuum system may include vacuum pump 320 that creates the reduced pressure conditions necessary for low-temperature distillation of the ethoxylate mixture. Vacuum pump 320 may include a rotary vane pump, diaphragm pump, or liquid ring pump, with rotary vane pumps being preferred for their ability to achieve deep vacuum conditions. Vacuum pump 320 may be capable of achieving pressures of 0.1 torr to 50 torr, with the specific pressure depending on the boiling points of the components being separated and theAttorney Docket No. IVOX-6-PCT desired operating temperature. Outlet flow 338 from vacuum pump 320 allows for venting of non-condensable gases and maintaining proper vacuum operation throughout the distillation process.

[0087] Pressure monitoring and control can be accomplished using pressure sensor 322 positioned in the vacuum line between the distillation system and vacuum pump 320. Pressure sensor 322 may provide real-time pressure measurement that can be used for manual monitoring or automatic pressure control. Pressure sensor 322 may include a mechanical gauge, electronic pressure transducer, or capacitance manometer, with electronic transducers being preferred for their accuracy and ability to interface with automated control systems.

[0088] Distillation system 300 can include multiple control valves for regulating various process parameters. First control valve 324 may be positioned to control air flow from air inlet 336, allowing for controlled introduction of atmospheric air for pressure regulation or vacuum breaking. Second control valve 326 may be positioned to control nitrogen flow from nitrogen inlet 332, regulating the introduction of inert gas for pressure control, atmosphere protection, or vacuum breaking operations. Third control valve 328 may be positioned in the main vacuum line between cold trap 318 and vacuum pump 320 to control the system pressure by regulating the vacuum level throughout the distillation system. Fourth control valve 334 may be positioned to control a secondary vacuum or venting line, providing additional pressure control capabilities or serving as a bypass for system pressure regulation.

[0089] Nitrogen inlet 332 can provide the capability to introduce inert gas into distillation system 300 for various purposes. Nitrogen inlet 332 may be used to break vacuum at the end of a distillation run, to provide an inert atmosphere during operation, or to control system pressure in combination with the vacuum system. The nitrogen flow may be controlled using control valve 326 and may include flow measurement and pressure regulation capabilities. Air inlet 336 may be provided to introduce atmospheric air for pressure control, system purging, or to break vacuum conditions at the end of a distillation run.

[0090] Distillation system 300 may be operated in various modes depending on the specific separation requirements. For batch distillation, the entire ethoxylate mixture is charged to bottom flask 302 at the beginning of the operation, and different fractions are collected sequentially as the distillation progresses. For continuous distillation, fresh feed is continuously added to the system while product streams are continuously withdrawn, allowing for steady-state operation and higher throughput. Semi-batch operations may also be employed, where feed is added periodically while maintaining continuous product withdrawal.Attorney Docket No. IVOX-6-PCT

[0091] Distillation system 300 can be particularly well-suited for implementing the two-pass distillation strategy described in the present disclosure. In the first distillation pass, the system can operate to remove the majority of unreacted alcohols (n=0 compounds) from the ethoxylate mixture. The first pass may be conducted at a vacuum of approximately 10 torr with a reflux ratio of 5:1, conditions that provide effective separation while minimizing thermal degradation. The intermediate product from the first pass typically contains a concentrated mixture of one mole ethoxylates and reduced alcohol content, providing an optimal feedstock for the second distillation pass. The second distillation pass can utilize the same distillation system 300 or the same configuration but may operate under conditions optimized for separating the purified one mole ethoxylate product from heavier ethoxylates having n^2. The final purified composition obtained from the two-pass process may contain approximately 50% unreacted alcohols and 50% pure one mole ethoxylates, providing a composition that is substantially free of compounds capable of forming 1,4-dioxane under acidic conditions.

[0092] Distillation system 300 may be equipped with various analytical and monitoring capabilities to ensure optimal separation performance. Online gas chromatography sampling systems may be connected to sample ports on the receiver 316 or other locations to provide real-time composition analysis. Refractive index monitors may be used to track changes in product composition, while density meters can provide additional compositional information. Temperature and pressure data logging systems may record process parameters for optimization and quality assurance purposes.

[0093] Distillation system 300 may be automated using programmable logic controllers (PLCs) or distributed control systems (DCS) to maintain consistent operating conditions and optimize separation performance. Automated systems may control temperature setpoints, pressure regulation, reflux ratio, and fraction collection based on predetermined parameters or real-time analytical feedback. Safety systems may include temperature and pressure alarms, emergency shutdown capabilities, and fire suppression systems appropriate for the materials being processed.

[0094] Distillation system 300 is particularly well-suited for the separation of ethoxylate mixtures to produce pure one mole ethoxylates as described in the present disclosure. The system can effectively separate unreacted alcohols (n=0), one mole ethoxylates (n=1), and higher ethoxylates (n^2) based on their different boiling points. The resulting purified one mole ethoxylate product contains minimal amounts of compounds capable of forming 1,4- dioxane, thereby addressing the regulatory and performance concerns associated withAttorney Docket No. IVOX-6-PCT conventional ethoxylate products. The flexibility of distillation system 300 can allow for processing of various alkyl chain lengths and ethoxylate distributions, making it suitable for producing a wide range of low-dioxane surfactant precursors for different commercial applications.

[0095] In some aspects, the composition may include a compound having the general formula, where R is a linear or branched aliphatic carbon chain, X is a substituent, n is an integer greater than or equal to 0, and m is an integer equal to 1. The linear or branched aliphatic carbon chain, represented by R, may be selected from a group that includes hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl groups, as well as their branched isomers. These groups represent different lengths and structures of the carbon chain, providing a range of hydrophobic properties for the resulting ethoxylate and the derived AES surfactant.

[0096] The compound of the general formula may represent a class of compounds known as monoethoxylated aliphatic ethers or “one mole” ethoxylates. These compounds may consist of an alkyl chain (R) of 6 to 18 carbon atoms connected to a single ethylene oxide unit (- (CH2CH2O)-) and terminated by a substituent group (X).

[0097] In some cases, these compounds may exhibit surfactant properties due to their hydrophobic alkyl chain and hydrophilic ethoxy group. The precise ethoxylation, with n = 1, ensures these are specifically monoethoxylated compounds, containing exactly one ethylene oxide unit. In some cases, these compounds may exhibit hydrotropic properties which would make formulation more efficient or effective.

[0098] The nature of the substituent X may allow for various derivatives. For example, when X is a hydrogen atom, the compound may be classified as an ethoxylated alcohol. In other aspects, X may be a different substituent, such as a sulfate group (SO3Na), resulting in an ethoxylated alcohol derivative.

[0099] The different alkyl chain lengths represented by R (from hexyl to octadecyl) may allow for tuning of the hydrophobic properties of the compound. This flexibility in the alkyl chain length may provide opportunities to optimize the compound’s performance for various applications.

[0100] These compounds may be particularly significant in the context of minimizing or eliminating 1,4-dioxane formation, which can be a concern with conventional ethoxylated compounds that have longer ethylene oxide chains. The single ethylene oxide unit in these compounds may contribute to their potential for reduced 1,4-dioxane formation under various conditions.Attorney Docket No. IVOX-6-PCT

[0101] In some cases, R may be specifically selected from the group that includes linear or branched dodecyl and tetradecyl groups. These particular chain lengths and structures may offer a balance between hydrophobicity and solubility, making them suitable for a wide range of surfactant applications.

[0102] In some embodiments, the composition may include a compound of the general formula, where n is an integer equal to 2, R is CyH2y+1, and y is an integer from 8 to 18. This represents a specific subset of the one mole ethoxylates, where the ethyleneoxy unit is directly attached to a linear or branched alkyl chain of varying length. The length and structure of the alkyl chain, represented by y, can be adjusted to optimize the hydrophobic-hydrophilic balance of the resulting surfactant.

[0103] In some aspects, X in the general formula may be a substituent selected from the group consisting of a hydrogen atom and a sulfonic acid group, where X = H, or neutralized sulfonic acid group SO3M, where M is a cation selected from the group consisting of sodium (Na), potassium (K), and ammonium (NH4). The choice of substituent can affect the properties of the resulting surfactant, with the sulfonic acid group providing hydrophilic properties and the hydrogen atom providing a nonionic character. The cation M in the sulfonic acid group can be selected to optimize the solubility and performance of the resulting AES surfactant in different applications and conditions.

[0104] In some aspects, the final composition obtained from the distillation process may contain a compound of the general formula, wherein n is an integer equal to 0. This compound (e.g., alcohols, sulfates) may be present in the final composition due to incomplete reaction or separation during the distillation process.

[0105] In some aspects, the composition may include varying amounts of the compound (e.g., the first compound) of the general formula. For example, the composition may include at least 90 mol% of the compound of the general formula. In certain embodiments, the composition may include between 85 mol% and 99 mol% (99 mol%) of the compound of the general formula.

[0106] Some variations of the composition may contain from 92 mol% to 98 mol% of the compound of the general formula. In particular embodiments, the composition may include at least 95 mol% of the compound of the general formula. Highly purified compositions may contain greater than 97 mol% of the compound of the general formula.

[0107] In some cases, the composition may include from 80 mol% to 99.9 mol% of the compound of the general formula. Certain embodiments may feature a composition containingAttorney Docket No. IVOX-6-PCT 94 mol% to 96 mol% of the compound of the general formula. The composition may, in some instances, include at least 99 mol% of the compound of the general formula.

[0108] In certain aspects, the remainder of the composition not accounted for by the compound of the general formula may include unreacted starting materials, byproducts, or other compounds of similar structure but with different values of n or x. The composition may in some embodiments contain less than 5 mol% of compounds where n is greater than 1.

[0109] The purity of the composition may be influenced by the synthesis method and purification techniques employed. For instance, compositions obtained through distillation may achieve higher purities compared to those obtained directly from the reaction mixture. The specific purity achieved may depend on factors such as distillation temperature, pressure, and the number of theoretical plates in the distillation column.

[0110] In some embodiments, the composition may be further purified using techniques such as recrystallization, chromatography, or selective precipitation. These additional purification steps may allow for the production of compositions with even higher percentages of the compound of the general formula.

[0111] The high purity of these compositions with respect to the compound of the general formula may contribute to their effectiveness in minimizing 1,4-dioxane formation in subsequent reactions or applications. This may be particularly advantageous in the production of surfactants or other products where low levels of 1,4-dioxane are desired or required by regulations.

[0112] In some cases, the final composition may comprise 95 mol% of a compound of the general formula, wherein R is a linear aliphatic carbon chain, n is an integer equal to 1, and x is an integer equal to 1. This indicates a high purity level of the one mole ethoxylate in the final composition, which is desirable for minimizing 1,4-dioxane formation in subsequent sulfation processes.

[0113] In some embodiments, the composition produced by the distillation method may comprise at least 95 mol% of the first compound, which is the one mole ethoxylate. This high purity level can be achieved through careful control of the distillation conditions, such as temperature and pressure, as well as the use of appropriate distillation equipment.

[0114] In other embodiments, the composition produced by the distillation method may comprise at least 99 mol% of the first compound. This represents an even higher level of purity, which may be necessary for certain applications where extremely low levels of 1,4-dioxane are required.Attorney Docket No. IVOX-6-PCT

[0115] In some aspects, the composition produced by the distillation method may further comprise a third compound having the general formula, wherein n is an integer equal to 0. This compound may be present in the final composition due to incomplete reaction or separation during the distillation process. Despite its presence, the overall composition still exhibits extremely low levels of 1,4-dioxane due to the very low or complete absence of ethoxylates where n is an integer greater than 1.

[0116] In some aspects, the alkylation reaction process may be optimized to produce a composition that comprises less than 1 ppm of 1,4-dioxane. This low level of 1,4-dioxane is achieved by using pure one mole ethoxylates as precursors, which do not form 1,4-dioxane during sulfation or under acidic conditions.

[0117] In some aspects, the alkylation reaction process may be optimized by using specific solvents to improve reaction rate.

[0118] The use of N-methylpyrrolidinone (NMP) as a solvent in the alkylation reaction may enhance the reaction efficiency and minimize the formation of byproducts, including 1,4- dioxane. NMP’s ability to dissolve both polar and non-polar compounds helps create a more homogeneous reaction environment, facilitating the interaction between the reactants.

[0119] N-methylpyrrolidinone (NMP) is a polar aprotic solvent used in the alkylation reaction process described in this invention. NMP can help improve the reaction efficiency by mitigating the slow reaction rates typically observed in two-phase mixtures. NMP's ability to dissolve both polar and non-polar compounds helps create a more homogeneous reaction environment, facilitating the interaction between ethylene glycol and the alkyl halide. This solvent choice is particularly beneficial for the synthesis of pure one mole ethoxylates, as it enhances the selectivity towards the desired product while minimizing the formation of unwanted byproducts, including 1,4-dioxane. The use of NMP contributes to the overall goal of producing high-quality surfactant precursors with extremely low levels of 1,4-dioxane, meeting stringent regulatory requirements for various applications in personal care, household cleaning, and industrial products.

[0120] In some embodiments, other polar aprotic solvents may be used in addition to or instead of NMP to improve reaction rates. Experimental evaluation has demonstrated that N- methylpyrrolidinone (NMP) provides effective results in the alkylation of ethylene glycol with alkyl halides, while other polar aprotic solvents such as hexamethyl phosphoramide (HMPA) and dimethylformamide (DMF) were found to be less effective under similar reaction conditions. Additional solvents that may be suitable include ethylene glycol, diethylene glycol or longer chain poly(ethylene glycol) dialkyl ethers; anisole, cresol, or otherAttorney Docket No. IVOX-6-PCT poly(methoxy)benzene compounds; pyrrolidinone and N-alkylpyrrolidinones; formyl or acetyl morpholine; N-methylmorpholine oxide; dimethylacetamide (DMAC); dimethyl sulfoxide (DMSO), or sulfolane. The choice of solvent may depend on factors such as reactant solubility, reaction temperature requirements, desired reaction rate, ease of product separation, and overall process economics.

[0121] In some cases, the substituent X in the general formula may be selected from a group consisting of a hydrogen atom, a sulfonic acid group (e.g., X=H), a sulfonic acid salt (e.g., SO3M), etc., where M is a cation selected from the group consisting of sodium (Na), potassium (K), and ammonium (NH4). The choice of substituent can affect the properties of the resulting surfactant, with the sulfonic acid group providing hydrophilic properties and the hydrogen atom providing a hydrophobic character. The cation M in the sulfonic acid group can be selected to optimize the solubility and performance of the resulting AES surfactant in different applications and conditions.

[0122] In some embodiments, the molar ratio of ethylene glycol to alkyl halide in the alkylation reaction may be at least 7:1. This ratio may drive the selectivity towards the formation of the mono alkyl ether product. The strong base used in the reaction may be derived from sodium hydroxide (NaOH), potassium hydroxide (KOH), sodium methoxide (NaOMe), potassium methoxide (KOMe), sodium t-butoxide (NaOtBu), or potassium t-butoxide (KOtBu). The choice of base may affect the reaction kinetics, yield, and ease of product isolation.

[0123] In some aspects, alternative purification methods may be employed to isolate the pure one mole ethoxylate product from the reaction mixture. For instance, fractional crystallization at different temperatures may be used to separate the one mole ethoxylate based on its different solubility at various temperatures. This method can provide a high purity product without the need for additional distillation steps.

[0124] In some aspects, alternative purification methods may be employed to isolate the pure one mole ethoxylate product from the reaction mixture. For instance, molecular distillation may be used as an alternative purification method. Molecular distillation operates under a high vacuum, reducing the boiling point of the components and minimizing thermal degradation. This method can be particularly effective for separating components with close boiling points or for removing small amounts of impurities from a product.

[0125] In other cases, column chromatography using various stationary phases may be used to separate the one mole ethoxylate based on its different interactions with the stationary phase. This method can provide a high degree of separation and purity and can be easily scaled up for industrial production.Attorney Docket No. IVOX-6-PCT

[0126] In other cases, membrane separation techniques may be used as an alternative purification method. Membrane separation techniques, such as ultrafiltration, nanofiltration, or reverse osmosis, can separate components based on their size or chemical properties. These techniques can be particularly useful for removing small amounts of impurities or for concentrating a product.

[0127] In some cases, phase separation techniques may be used such as liquid-liquid separation, extraction, or filtration.

[0128] In summary, the present disclosure provides methods for producing pure one mole ethoxylates and their derived AES surfactants with minimized 1,4-dioxane formation. These methods involve optimized alkylation reactions and alternative purification techniques, offering a solution for producing high-quality surfactants while meeting stringent regulatory requirements for 1,4-dioxane content.

[0129] The examples demonstrate that sulfation of a monodisperse one-mole product was found not to produce 1,4-dioxane. Stability is being tested. Improved conditions to make a one-mole product from excess EG and alkyl halide is being investigated.

[0130] Alkylation of Ethylene Glycol (EG) with Alkyl Halide

[0131] In some aspects, R may represent a mixture of different aliphatic hydrocarbyl groups within a single composition, reflecting the reality of commercial surfactant production. Commercial alcohol feedstocks typically contain distributions of different chain lengths rather than single pure compounds. For example, a typical commercial composition may contain compounds where R includes a mixture of decyl, dodecyl, tetradecyl, and hexadecyl groups in various proportions. Such mixtures are commonly characterized by their average carbon number and distribution range. The specific distribution of R groups may be selected to optimize surfactant properties such as solubility, surface tension reduction, foaming characteristics, and performance in specific end-use applications. The inventive concept of controlling ethylene oxide distribution to minimize 1,4-dioxane formation applies equally to compositions containing single R groups or mixtures of different R groups, providing flexibility for commercial manufacturing and product optimization.

[0132] Reactions require at least a stoichiometric amount of base and extent of reaction can be indicated by measuring the base number of the reaction mixture. Otherwise, the product and alkyl halide can be determined by gas chromatography (GC) to indicate the extent of reaction as the alkyl halide content decreases relative to product. Alternatively, GC analysis can be made of an extract of the sample with a relatively nonpolar solvent. Water can be added to the sample if advantageous. Conversion is measured by subtracting the percentage of alkyl halideAttorney Docket No. IVOX-6-PCT relative to the total of alkyl halide, product and byproducts peaks from 100. Examples showing the requirement of long reaction time for a two phase reaction.

[0133] Example 1:

[0134] A mixture of 620.74 g (10.00 mol) ethylene glycol and 103.42 g (1.000 mol NaOMe as 30% sodium methylate) was heated under nitrogen purge to 80°C for three hours. The temperature was increased to 90°C over a one hour period to allow distillation of methanol into a Dean-Stark trap.1-Bromododecane (249.24 g, 1.00 mol) was then added over 35 minutes as the temperature was raised to 100°C. Two liquid phases were present. Reaction was continued at 100°C for about 42h and was followed by GC analysis of an ethyl acetate extract of a reactor sample mixed with DI water. The reaction was further continued for another five days. Analysis of the reaction mixture indicated a conversion of about 70% with a selectivity to product of 90%.

[0135] After cooling, 100 g DI water and 100 ml of ethyl acetate were added to the reactor. The top layer was washed three times with DI water. Rotary evaporation of the organic layer gave 65.0 g of liquid product.

[0136] Example 2:

[0137] Sodium t-butoxide (96.1g, 1.00 mol) was dissolved with caution in 434.4 g (7.00 mol) EG. The mixture was brought to 100°C and t-butanol was allowed to distill through a short path head into an ice-cooled receiver. Then 2849.2 g (1.00 mol) 1-bromododecane was added over 43 minutes. The resulting two-phase mixture with an orange top layer was further reacted at 100°C. Extent of reaction was estimated by GC analysis of the top layer, the results shown in Table 1. An unknown material was observed which was found to have coincident retention in a GC chromatogram of 1-dodecene and reaction sample mixture.Attorney Docket No. IVOX-6-PCT Table 1

[0138] The top layer was separated in a warm separatory funnel and subsequently dissolved in 300 ml ethyl acetate. This material and the original bottom layer were treated with extractive workup using ethyl acetate and DI water or NaCl (aq). Salt was added at times to facilitate separation. The crude product was subjected to fractional crystallization at about -4°C. Decantation was used to isolate crystalline solid as they tend to dissolve at room temperature. After evaporation of the fractions the following were obtained as shown in Table 2: Table 2

[0139] Example 3

[0140] A similar reaction of EG with 1-bromododecane using sodium t-butoxide base was conducted with the same molar amounts. However, this time tetrabutylammonium bromide (0.050 mol) was added as a phase transfer catalyst. The reaction was followed by GC and gave the following results as shown in Table 3:Attorney Docket No. IVOX-6-PCT Table 3

[0141] Extractive workup provided product as 198.2 g (th. 230.4) of orange liquid that solidified on cooling.

[0142] Example 4

[0143] A 1L round-bottomed flask equipped with gas sparge tube, mechanical stirrer, and thermocouple-controlled heating mantle was charged with 86.92 g (1.400 mol) EG and 156.02 g N-methyl-2-pyrrolidinone (NMP). After mixing, 19.24 g (0.200 mol) sodium t-butoxide was charged in portions with stirring. The apparatus was fitted with a short path distillation head to ice-cooled receiver. Removal of t-butanol was done by heating the reactor to 110 °C under nitrogen sparge and holding at that temperature until no more distillate was being collected. The pot was sampled and found to have a base value of 0.772 meq / g. The distillation section was replaced by a gas outlet adapter and 49.71 g 1-bromododecane (0.199 mol) was added with nitrogen sparge and stirring at 63°C over about 27 minutes. Reaction continued at 60°C, and the pot was sampled periodically for base content. Reaction was interrupted to cool overnight and reheated the next day. After reaction at 60°C for about nine hours a sample was taken, shaken with water and allowed to separate. The top layer was taken for GC and showed a 1- bromododecane to product ratio of 0.048. Reaction was continued another hour then cooled overnight. The next day, the reactor was brought to 100°C and an additional 0.40 g sodium t- butoxide was added and reaction continued another two hours. The cold reaction mixture contained some gel-like material. It was heated to about 50°C and sampled for base content which was used to calculate the appropriate amount of 50% sulfuric acid to add to neutralize the now completely liquid reaction mixture. Base values found during the reaction are tabulated below in Table 4.Attorney Docket No. IVOX-6-PCT Table 4

[0144] Then 100 ml DIW was added, the mixture stirred for a short time and taken to a pre- warmed separatory funnel. Removal of the top layer gave 46.7 g of an amber liquid. GC analysis indicated 4.74 unknown, 1.37 EG, 10.47 NMP and 81.78 A% product. The bottom layer was found to have a pH of 6.0-6.5. Attempted extraction with ethyl acetate was unsuccessful. Therefore, the bottom layer was extracted three times with 50 ml hexane. The combined extracts were treated with anhydrous sodium sulfate, filtered and allowed to evaporate in a fume hood for a few days, then in an 80°C oven for about two hours to provide 1.69 g of light-yellow liquid.

[0145] This example shows the reaction is faster than the simple two-phase reaction or when phase transfer is used even when conducted at lower temperature.

[0146] Another reaction was conducted using NMP solvent at a 7 to 1 molar ratio of EG to 1- bromododecane. From 1.00 mol 1-bromododecane, 330.2 g of crude product was obtained.

[0147] Distillation of 2-dodecyloxyethanol (one mole product)

[0148] Example 5

[0149] Vacuum distillation of crude product obtained from the reaction in the presence of NMP was conducted through a 12 cm vacuum-jacketed three-stage perforated plate column. It was carried out at the lowest pressure possible. Although the pressure was not measured, it was believed to be less than 1 torr. From 183.8 g of crude product, 78.4 g of a colorless liquid of 100% pure 2-dodecyloxyethanol was obtained at 130-135°C. A forerun of 32.9 g of 99.1% pure material was also obtained.

[0150] Alcohol Ether Sulfate

[0151] Example 6Attorney Docket No. IVOX-6-PCT

[0152] SURFONIC® L24-1 surfactant (a commercial alcohol ethoxylate with an average degree of ethoxylation of about 1) and pure 2-dodecyloxyethanol (dodecanol one mole) obtained by vacuum distillation of product obtained by alkylation of EG were independently sulfated in a 7 x 730 mm glass falling film reactor. SO3 diluted to ca. 3% in nitrogen was contacted with alcohol ethoxylate in a 1.0 mole ratio at 45°C. The sulfate was immediately neutralized with aqueous NaOH to give a 26-28% product active content.

[0153] 1,4-Dioxane content was measured using headspace GC-MS and found to be 13 ppm in the L24-1 sulfate and none was detected in the 2-dodexyloxyethanol sulfate. A sample of the latter was acidified to pH 4 with citric acid. After one week 1,4-dioxane was still below detection.

[0154] The following clauses illustrated example subject matter described herein.

[0155] Clause 1. A composition comprising a compound of general formula: R[O- (CH2CH2O)n-X]m, wherein R is an aliphatic hydrocarbyl group selected from the group consisting of hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl groups; n is an integer equal to 1; X is H; and m is an integer equal to 1.

[0156] Clause 2. The composition of clause 1, wherein R is selected from the group consisting of dodecyl and tetradecyl groups.

[0157] Clause 3. The composition of clauses 1 or 2, further comprising a compound of the general formula wherein n is an integer equal to 0.

[0158] Clause 4. The composition of any one of clauses 1 through 3, wherein the composition comprises at least 95 mol% of the compound of the general formula.

[0159] Clause 5. The composition of any one of clauses 1 through 4, further comprising a compound of the general formula, wherein R is CyH2y+1, X is H, n and m are each an integer equal to 1, and y is an integer from 6 to 18.

[0160] Clause 6. The composition of clause 5, wherein y is 12 or 14.

[0161] Clause 7. The composition of any one of clauses 1 through 6, further comprising a compound of the general formula: wherein y is an integer from 8 to 18, R is CyH2y+1, y is 6 to 18, X is SO3M, and M is selected from the group consisting of H, an alkaline earth metal, Na, K, and NH4.

[0162] Clause 8. A method of producing an alcohol ether sulfate (AES) surfactant, comprising: producing a compound of general formula: R[O-(CH2CH2O)n-X]m,wherein R is a linear aliphatic carbon chain selected from the group consisting of hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl groups; n is an integer equal to 1; and m is an integer equal to 1, with a sulfating agent to form an AES surfactant of the general formula, wherein R isAttorney Docket No. IVOX-6-PCT CyH2y+1, X is SO3M, m and n are each an integer equal to 1, y is an integer from 6 to 18; and M is selected from the group consisting of H, Na, K, and NH4.

[0163] Clause 9. The method of clause 8, wherein R is a linear aliphatic carbon chain having 6 to 18 carbon atoms.

[0164] Clause 10. The method of clauses 8 or 9, wherein R is selected from the group consisting of dodecyl and tetradecyl groups.

[0165] Clause 11. The method of any one of clauses 8 through 10, wherein the sulfating agent is SO3 diluted in nitrogen gas.

[0166] Clause 12. The method of clause 11, wherein the SO3 is present at a concentration of about 3% in the nitrogen gas.

[0167] Clause 13. The method of any one of clauses 1 through 12, further comprising neutralizing the AES surfactant with an aqueous base to form a neutralized AES surfactant solution.

[0168] Clause 14. The method of clause 13, wherein the aqueous base is sodium hydroxide and the neutralized AES surfactant solution has an active content of 26% to 28%.

[0169] Clause 15. A surfactant composition comprising a compound of general formula: R[O- (CH2CH2O)n-X]m, wherein R is CyH2y+1, X is SO3M, m and n are each an integer equal to 1, y is an integer from 6 to 18; M is selected from the group consisting of H, Na, K, and NH4; and CyH2y+1is a linear alkyl chain with y carbon atoms, wherein the surfactant composition contains less than 1 ppm of 1,4-dioxane.

[0170] Clause 16. The surfactant composition of clause 15, wherein y is an integer from 10 to 16.

[0171] Clause 17. The surfactant composition of clauses 15 or 16, wherein y is 12 or 14.

[0172] Clause 18. The surfactant composition of any one of clauses 15 through 17, wherein M is Na.

[0173] Clause 19. The surfactant composition of any one of clauses 15 through 18, further comprising a compound of the general formula, wherein R is a linear aliphatic carbon chain selected from the group consisting of octyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl groups; X is H, and n is an integer equal to 1.

[0174] Clause 20. The surfactant composition of clause 19, wherein R in the compound of the general formula has the same number of carbon atoms as CyH2y+1 in the compound of the general formula.

[0175] Clause 21. A composition represented by general formula: R[O-(CH2CH2O)n-H]m, wherein n=1 exclusively and R is a linear aliphatic carbon chain.Attorney Docket No. IVOX-6-PCT

[0176] Clause 22. The composition of clause 21, wherein x=1.

[0177] Clause 23. The composition of clauses 21 or 22 where R is an octyl, decyl, dodecyl, tetradecyl, hexadecyl or octadecyl group.

[0178] Clause 24. The composition of any one of clause 21 through 23 where R is a linear hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl or octadecyl group.

[0179] Clause 25. The composition of any one of clauses 21 through 24 where the purity is >95%.

[0180] Clause 26. A composition containing that of clause 24 which also contains molecules where x = 0, a linear alcohol.

[0181] Clause 27. The following composition: R[O-(CH2CH2O)n-X]m,wherein R is CyH2y+1, X is SO3M, m and n are each integers equal to 1, y is 6 to 18, and M is H, Na, K, or NH4which contains no more than 1 ppm of 1,4-dioxane.

[0182] Clause 28. A composition of clause 27, wherein CyH2y+1is a linear alkyl chain.

[0183] Clause 29. A composition containing a substance of clause 28 and also R[O- (CH2CH2O)n-X]m, wherein R is CyH2y+1, n is an integer equal to 0, m is an integer equal to 1, X is SO3M, and M is Na, K, or NH4and that contains no more than 1 ppm of 1,4-dioxane.

[0184] Clause 30. The following composition: R[O-(CH2CH2O)n-X]m, wherein R is CyH2y+1, X is H, n is only 2 or more, m is 1, and y is 8 to 18:

[0185] Clause 31. A process where an ethoxylate that contains ethyleneoxy chains with a length of 0 and 1 and also contains substances where ethyleneoxy chains with a length of 2 or more is distilled and provides a product where n is exclusively 1.

[0186] Clause 32. A process of clause 31 where the product has a purity of at least 95%.

[0187] Clause 33. A process of clauses 31 or 32 where the purity is at least 99%.

[0188] Clause 34. A process of any one of clauses 31 through 33 where the alcohol present is obtained along with product in which n is exclusively 1.

[0189] Clause 35. A process where EG is alkylated with an alkyl halide in the presence of a strong base and N-methylpyrrolidinone.

[0190] Clause 36. The process of clause 35 where the molar ratio of EG to alkyl halide is at least 7.

[0191] Clause 37. The process of clauses 34 or 35 where the strong base is derived from NaOH.

[0192] Clause 38. The process of clauses 34 or 35 where the strong base is derived from KOH.

[0193] Clause 39. The process of clauses 34 or 35 where the strong base is derived from NaOMe.

[0194] Clause 40. The process of clauses 34 or 35 where the strong base is derived from KOMe.

[0195] Clause 41. The process of clauses 34 or 35 where the strong base is derived from NaOtBu.Attorney Docket No. IVOX-6-PCT

[0196] Clause 42. The process of clauses 34 or 35 where the strong base is derived from KOtBu.

[0197] Clause 43. A process for producing a compound of general formula R[O-(CH2CH2O)n- X]m, wherein R is a hydrocarbon group that may be linear, branched, or cyclic; n is an integer equal to 1; m is an integer equal to 1; and X is a substituent, the process comprising: reacting a first reactant containing a hydroxyl group with a second reactant containing a halogen, wherein the first reactant is selected from the group consisting of ethylene glycol and compounds of the formula R-(OH)y, where R is as defined above and y is an integer ^ 1, and wherein the second reactant is of the formula R'-Z, where R' is a hydrocarbon group that may be linear, branched, or cyclic, and Z is a halogen.

[0198] Clause 44. The process of clause 43, wherein the first reactant is ethylene glycol.

[0199] Clause 45. The process of clauses 43 or 44, wherein the halogen in the second reactant is selected from the group consisting of chlorine, bromine, and iodine.

[0200] Clause 46. The process of any one of clauses 43 through 45, further comprising conducting the reaction in the presence of a solvent.

[0201] Clause 47. The process of any one of clauses 43 through 46, further comprising conducting the reaction in the presence of a solvent, wherein the solvent is N- methylpyrrolidone.

[0202] Clause 48. The process of any one of clauses 43 through 47, further comprising conducting the reaction in the presence of a base.

[0203] Clause 49. The process of any one of clauses 43 through 48, further comprising conducting the reaction in the presence of a base, wherein the base is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, sodium t-butoxide, and potassium t- butoxide.

[0204] Clause 50. The process of any one of clauses 43 through 49, wherein the reaction is conducted at a temperature between 50°C and 150°C.

[0205] Clause 51. The process of any one of clauses 43 through 50, further comprising purifying the compound of the general formula by distillation.

[0206] Clause 52. The process of any one of clauses 43 through 51, wherein R' in the second reactant is a linear aliphatic carbon chain selected from the group consisting of hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl groups.

[0207] Clause 53. The process of any one of clauses 43 through 52, wherein a molar ratio of the first reactant to the second reactant is at least 7:1.Attorney Docket No. IVOX-6-PCT

[0208] Clause 54. The process of any one of clauses 43 through 53, further comprising monitoring the progress of the reaction by measuring the base content of the reaction mixture.

[0209] Clause 55. The process of any one of clauses 43 through 54, wherein X in the compound of the general formula is a hydrogen atom.

[0210] Clause 56. The process of any one of clauses 43 through 55, further comprising reacting the compound of the general formula with sulfur trioxide to form an alcohol ether sulfate.

[0211] Clause 57. The process of any one of clauses 43 through 56, further comprising reacting the compound of the general formula with sulfur trioxide to form an alcohol ether sulfate, wherein the resulting alcohol ether sulfate contains less than 1 ppm of 1,4-dioxane.

[0212] Clause 58. The process of any one of clauses 43 through 57, wherein the compound of the general formula contains no detectable amount of 1,4-dioxane.

[0213] Clause 59. A composition comprising a compound of general formula R[O- (CH2CH2O)n-X]m, wherein R is a hydrocarbyl group selected from the group consisting of hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl groups; and n is an integer equal to 1.

[0214] While the disclosure has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore, it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the disclosure, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and / or “a portion” is used the item may include a portion and / or the entire item unless specifically stated to the contrary.

Claims

Attorney Docket No. IVOX-6-PCT CLAIMS What is claimed is:

1. A composition comprising compounds of general formula R[O-(CH2CH2O)n-X]m, wherein R is an aliphatic hydrocarbyl group; X is selected from H, SO3H, and SO3M, wherein M is a cation; and m is an integer from 1 to 4; and at least 95 mol% of the compounds have n equal 0 or 1 and up to 5 mol% of the compounds have n greater than or equal to 2. The composition of claim 1, wherein R is selected from a group consisting of octyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl groups.

3. The composition of claims 1 or 2, wherein R is selected from a group consisting of dodecyl and tetradecyl groups.

4. The composition of any one of claims 1 through 3, wherein at least 99 mol% of the compounds have n equal 0 or 1 and up to 1 mol% of the compounds have n greater than or equal to 2.

5. The composition of any one of claims 1 through 4, wherein m is an integer equal to 1, and at least 95 mol% of the compounds have n is an integer equal to 1.

6. The composition of any one of claims 1 through 5, wherein R is CyH2y+1, wherein y is an integer from 8 to 18, and up to 5 mol% of the compounds have n equal to 2.

7. The composition of any one of claims 1 through 6, wherein R is CyH2y+1, wherein y is an integer from 10 to 16.Attorney Docket No. IVOX-6-PCT 8. The composition of any one of claims 1 through 7, wherein R is CyH2y+1, wherein y is an integer from 12 to 14.

9. The composition of any one of claims 1 through 8, wherein R is CyH2y+1, wherein y is an integer equal to 12.

10. The composition of any of claims 1 through 9, wherein R is CyH2y+1, wherein y is an integer equal to 14.

11. The composition of any one of claims 1 through 10, wherein X is SO3M and M is a cation selected from a group consisting of alkali metals, alkaline earth metals, and ammonium (NH4).

12. A process comprising: preparing a mixture of a first compound and a second compound, the first compound and the second compound each having general formula: R[O-(CH2CH2O)n-X]m, wherein R is an aliphatic hydrocarbyl group; X is H; n is an integer greater than or equal to 0; and m is an integer from 1 to 4, wherein n is an integer equal to 1 for the first compound and n is an integer greater than or equal 2 for the second compound; and separating the mixture to remove the second compound from the mixture to provide a purified composition comprising at least 95 mol% of the first compound.Attorney Docket No. IVOX-6-PCT 13. The process of claim 12, wherein for the first compound, R is CyH2y+1, and y is an integer from 10 to 16.

14. The process of any one of claims 12 or 13, wherein separating the mixture comprises distilling the mixture.

15. The process of any one of claims 12 through 14, wherein the purified composition is at least 99 mol% of the first compound.

16. The process of any one of claims 12 through 15, wherein the mixture further comprises a third compound having the general formula, wherein R is an aliphatic hydrocarbyl group; n is an integer equal to 0; and m is an integer equal to 1.

17. The process of any one of claims 12 through 16, further comprising sulfating the purified composition to form a sulfated composition comprising alcohol ether sulfate surfactants having the general formula, wherein X is SO3M or SO3H and M is a cation selected from a group consisting of alkali metals, alkaline earth metals, and ammonium (NH4), and wherein the sulfated composition comprises less than 1 ppm of 1,4-dioxane.

18. The process of claim 17, further comprising neutralizing the sulfated composition.

19. A process comprising alkylating ethylene glycol with an alkyl halide with N- methylpyrrolidinone and a base, the base having a pH of at least 12 when in an aqueous solution with a concentration of at least 0.1M.Attorney Docket No. IVOX-6-PCT 20. The process of claim 19, wherein the base is selected from a group consisting of NaOH, KOH, NaOMe, KOMe, NaOtBu, and KOtBu.

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