Furan surfactant compositions and methods

Abstract

Chemical compositions and related methods for synthesizing furans (e.g., oil furans, surfactants) include calcium, magnesium, ammonium, and / or lithium cations and one of several furan derivatives. Methods for synthesizing such furan surfactants containing calcium, magnesium, ammonium, and / or lithium cations can include chemical reagents and purification processes to produce furan surfactants containing calcium, magnesium, ammonium, and / or lithium cations. These furan surfactant compositions can be free of dioxane and ethoxylates.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to U.S. Provisional Patent Application No. 63 / 019,485, filed May 4, 2020. Technical Field

[0003] This disclosure generally relates to surfactant compositions and related methods for synthesizing such surfactants. In particular, the examples disclosed herein include dioxane-free furan surfactant compositions and methods for synthesizing dioxane-free furan surfactants. Background Technology

[0004] Surfactants are chemical compounds with a wide range of applications. These applications can include household cleaners and detergents, public and industrial cleaning products, agricultural chemicals such as spray coating auxiliaries, oilfield applications, and various coating additives. A surfactant is a chemical compound consisting of a hydrophilic portion that attracts water and a hydrophobic portion that attracts oil and dirt. The amphoteric structure of surfactant molecules allows them to suspend dirt, emulsify, and modify the surface properties of materials. Variations in the chemical structure of surfactant molecules can achieve tunable properties such as emulsifying ability (hydrophilic / lipophilic balance), oil / dirt suspending ability (critical micelle concentration), cold water performance (Krafft point), foaming, and biodegradability.

[0005] Surfactants are typically synthesized from petrochemical feedstocks, such as long-chain alkanes / olefins and ethylene oxide. However, surfactants synthesized from petrochemical feedstocks can present several problems. On the one hand, such surfactants may contain chemicals that are harmful to the environment. Furthermore, such surfactants may not perform as intended in certain applications. For example, despite decades of development, these various surfactant structures face a common problem: the presence of hard water (e.g., containing calcium, magnesium, iron, etc.) deactivates these surfactants. When deactivation occurs, this causes the surfactant to form solid precipitates and essentially lose its intended functionality.

[0006] To address some of the problems associated with surfactants synthesized from petrochemical feedstocks, surfactants began to be derived from natural sources, such as oils and sugars. Development has primarily focused on replacing petrochemical surfactants with bio-based analogs that have the same chemical structure. The result is surfactants that are more environmentally friendly than petrochemical surfactants.

[0007] However, both current production of petrochemical surfactants and the recently developed bio-based analogs typically involve the large-scale production of sodium lauryl ether sulfate (SLES) surfactants. A byproduct of SLES surfactant production is 1,4-dioxane, which has been the target of several recent regulatory developments because, according to the U.S. Environmental Protection Agency, 1,4-dioxane is a likely human carcinogen and not easily biodegradable. Therefore, emissions from industrial and consumer products (e.g., detergents, cosmetics, shampoos) can expose the general population to 1,4-dioxane via drinking water. In fact, elevated levels of 1,4-dioxane have been detected in drinking water across the U.S., prompting regulations to set limits on its presence in consumer products. Limitations on 1,4-dioxane pose a problem for surfactant manufacturers because major product brands contain orders of magnitude higher than the set limits. Therefore, affected products will need to be withdrawn from the market or comply with new contaminant limits, meaning manufacturers will need to redesign current formulations with reduced-dioxin versions or dioxane-free alternatives. Because the costly and difficult nature of suppressing 1,4-dioxane formulations during current manufacturing processes is attributable to limitations in available technologies, this may not enable cost-effective compliant solutions.

[0008] To further complicate the issues facing current surfactant producers, restrictions on ethylene oxide emissions are proposed, as the chemical building blocks of SLES are considered carcinogenic gases. Such restrictions, aimed at reducing ethylene oxide emissions from surfactant production facilities, would require extensive and costly equipment modifications, potentially limiting the production capacity of mainstream products. Summary of the Invention

[0009] In light of the aforementioned challenges, there is a need to introduce dioxane- and ethoxylate-free alternatives to SLES. The embodiments disclosed herein provide surfactant compositions (e.g., oil-furan surfactants) free of the problematic dioxane and ethoxylates, thereby offering alternatives to address the current challenges associated with SLES and other surfactants on the market. Notably, the embodiments disclosed herein also provide these alternative surfactant compositions with similar properties to SLES surfactants, but produced from renewable resources.

[0010] This disclosure describes examples of chemical compositions and examples of methods for synthesizing furan surfactants containing calcium, magnesium, ammonium, and / or lithium cations and one of several furan derivatives. Examples of methods for synthesizing furan surfactants containing calcium, magnesium, ammonium, and / or lithium cations may include novel chemical reagents and purification processes to prepare furan surfactants containing calcium, magnesium, ammonium, and / or lithium cations.

[0011] The furan surfactant examples containing calcium, magnesium, ammonium, and / or lithium cations disclosed herein offer several useful, improved associated properties, for example, compared to sodium cationic surfactants. In particular, the furan (e.g., oleofuran) surfactant composition examples disclosed herein are useful because these furan surfactant compositions can have dissimilar physical and surfactant properties arising from the calcium, magnesium, ammonium, and / or lithium cations included in the furan (oleofuran) surfactant composition examples. For example, furan (e.g., oleofuran) surfactant composition examples containing calcium, magnesium, ammonium, and / or lithium cations can offer one or more improved properties, including solubility, Kraft characteristics, critical micelle concentration, surface tension, fabric wetting kinetics, foam formation, and foam stability. Therefore, the furan (e.g., oleofuran) surfactant compositions disclosed herein can be tailored to suit a wider range of everyday surfactant applications.

[0012] Specific embodiments disclosed herein include a class of oil-furan sulfonate surfactant (OFS) molecules and methods for tuning desired properties, such as foaming and critical micelle concentration. More particularly, embodiments disclosed herein include a subgroup of methyl-substituted oil-furan surfactants that can possess beneficial performance properties (e.g., modified critical micelle concentration). As described herein, some embodiments can neutralize oil-furan sulfonate surfactants with cations other than sodium (e.g., with calcium cations), thus imparting unique foaming properties and significant improvements in critical micelle concentration (CMC), surface tension at CMC, wetting behavior (e.g., Drave's wetting time), and function under hard water conditions. By combining, the methyl-substituted and calcium-neutralized oleuron sulfonate surfactant examples disclosed herein can possess unique performance properties that mimic (and in some cases surpass) those of ether sulfate surfactants (e.g., SLES). However, it is noteworthy that, in the absence of both the 1,4-dioxane byproduct and the ethylene oxide subunit, it is generally necessary to achieve the level of performance provided by the examples disclosed herein. Therefore, the surfactant examples disclosed herein can have properties similar to or superior to those of the commercial surfactant sodium lauryl ether sulfate, SLES, while avoiding the production of the carcinogenic compound 1,4-dioxane as an unavoidable sodium lauryl ether sulfate byproduct by other methods. Thus, the surfactant examples disclosed herein can provide a high-performance, biorenewable, and dioxane-free alternative to SLES surfactants.

[0013] Typically, anionic surfactants are neutralized with basic sodium salts because this provides the desired functionality and acceptable solubility of sodium surfactants in water-based applications. For example, sodium dodecyl sulfate and sodium dodecylbenzene sulfonate (two common anionic surfactants used in cleaning products) have solubilities of 0.2 and 0.25 g / mL, respectively. Conversely, while the calcium forms of these surfactants offer some advantageous properties compared to their sodium forms, they have much lower solubility in water at ℃, making their use in water-based applications more challenging. Although direct measurement of the solubility of calcium surfactants can be difficult due to their extremely low solubility, the Krafft characteristic of calcium dodecyl sulfate is approximately 29℃, and the solubility of calcium dodecylbenzene sulfonate is estimated to be less than 0.01 g / mL even at higher temperatures of 50℃, indicating that both calcium surfactants have negligible solubility in solutions at room temperature and even slightly higher temperatures. It is worth noting that the embodiments disclosed herein, such as the calcium-form surfactants seen in structure A of the following general structure 1, demonstrate improvements over the sodium form in the useful surfactant properties seen in Table 2 below, while maintaining higher solubility (e.g., 0.35 g / mL) than the common sodium surfactants mentioned above. This benefit in this application can be threefold: the calcium-form surfactant embodiments may not be derived from calcium (e.g., from hard water), as common sodium surfactants are deactivated, and the calcium-form surfactant embodiments can be derived from calcium... 2+ The functional improvements provided by the cation are due to the higher solubility of the calcium-form surfactants compared to the most common sodium surfactants, which are still formulated at higher concentrations.

[0014] Another advantage of the surfactant examples disclosed herein is their inherent stability, particularly in their acidic form prior to neutralization (oleo-furan sulfonic acid). As mentioned elsewhere herein, structural stability is a problem in the production of common anionic surfactants SLES, leading to occasional ring closure of unstable ethoxy chains during ethoxylation and sulfation steps, which can cause the formation of carcinogenic byproducts (e.g., 1,4-dioxins). In contrast, oleo-furan sulfonic acid has shown negligible degradation or byproduct formation in 8-week time-course studies at both room temperature and high temperature (42°C) using high-purity liquid chromatography.

[0015] Critical micelle concentration (CMC) is a fundamental surfactant characteristic and consistently has economic implications because it affects the amount of surfactant required to impart the desired effect in an application. The embodiments disclosed herein include structural modifications, including shorter alkyl chains on the furan ring and changes in the sulfonation position on the furan ring. This structural change, and the corresponding change in surfactant properties, can be seen in Table 3 below. In particular, for the two surfactant structural embodiments with and without the listed methyl group, depending on the exact structure of the hydrophilic head group, the presence of the methyl group and the shift of the sulfonation position can result in a 34% or 15% reduction in the CMC. In some applications, this can result in the same percentage reduction in surfactant loading, thus making the addition of shorter alkyl chains on the furan ring a significant cost benefit and an improvement over the previous structure.

[0016] Generally, the various exemplary embodiments disclosed herein include methods for neutralizing surfactants. In one example, the surfactant may be a proton monoanion or diproton dianionite surfactant. In this method embodiment, a mixture of salts or alkaline metal salts containing at least one cation including calcium carbonate (including, but not limited to, mixtures of calcium carbonate and sodium carbonate) is added by volume to a surfactant solution consisting of a mixture of water and an organic solvent, wherein the organic solvent includes acetonitrile. The result is a surfactant salt having the selected cation in the solution, which is subsequently reduced to a solid by heating at a temperature ranging from 25 to 80°C while optionally applying a vacuum at a pressure ranging from 0.001 to 0.99 atm. Residual sulfates or carbonates in the product mixture can be removed by dissolving the solid in water and adding sufficient organic solvent (including, but not limited to, acetone) to prepare a 1:1 aqueous solution and organic solvent solution by volume, the amount of which may vary depending on the selected sulfonation conditions and the neutralization of the alkaline salt. This solution can be mixed and then stored at a temperature between 0 and 15°C for a period of time from 1 to 48 hours. Solid salts can then be removed by filtration, and liquids can be removed by heating in the temperature range of 25 to 80°C while optionally applying a vacuum in the pressure range of 0.001 to 0.99 atm. If unsulfonated organics or sulfation byproducts remain in the product mixture, they can be removed by recrystallization in an organic solvent, including but not limited to isopropanol, ethanol, methanol, acetonitrile, acetone, or mixtures of the foregoing.

[0017] An exemplary embodiment includes a compound having formula (1):

[0018]

[0019] In the embodiment of formula (1), each numbered position (1 to 4) indicates a functional group, such as -H, -CH3, -CH2CH3, or C4 to C4 which may or may not contain a ketone functional group. 28 Long alkyl chains and -SO3; this structure must contain at least C4 to C3 atoms with ketone functional groups. 28 It has a long alkyl chain and a -SO3 functional group. A complete list of possible substituents for formula (1) is included in Table 1 below. Formula (1) may contain one or more alkyl furan sulfonates, one or more alkyl furan disulfonates, or any combination of both; these anions may react with Na+, Na+, or other alkyl furan sulfonates. + or NH4 + One or more monovalent cations, including Mg 2+ or Ca 2+ One or more divalent cations or any combination of monovalent and divalent cations as described herein. Although the preferred repetition of formula (1) includes one monoanion oil furan sulfonate anion for each valent cation or two monoanion oil furan sulfonate anions or one dianion oil furan disulfonate for each divalent cation, some repetitions may not follow this ratio, especially in repetitions in which a mixed cation basic salt is used for neutralization.

[0020] Another exemplary embodiment includes a compound having formula (2):

[0021]

[0022] For compounds having the above formula (2), M can be freely selected from the group consisting of: NH4 + Li + Ca 2+ Na + and Mg 2+ R can be freely selected from the following group: CH3 and other alkyl substituents; y can be freely selected from the following group: 1, 2 and non-integer values ​​between 1 and 2; and n can be an alkyl chain with a length of 4 to 28 carbon atoms.

[0023] In another embodiment of the compound having formula (2), the alkyl chain may include a ketone functional group α of the furan ring. In another embodiment of the compound having formula (2), R may be CH3. In another embodiment of the compound having formula (2), M may be Na. + And y can be 1. In another embodiment of the compound having formula (2), M can be NH4. + And y can be 1. In another embodiment of the compound having formula (2), M can be Li + And y can be 1. In another embodiment of the compound having formula (2), M can be Ca. 2+And y can be 2. In another embodiment of the compound having formula (2), M can be Mg. 2+ And y can be 2. In another embodiment of the compound having formula (2), M can be Na. + and Ca 2+ A mixture, where y can be a non-integer value between 1 and 2. In another embodiment of the compound having formula (2), M can be Na. + and Li + A mixture, and y can be 1. In another embodiment of the compound having formula (2), M can be Na. + and NH4 + A mixture, and y can be 1. In another embodiment of a compound having formula (2), M can be Na. + and Mg 2+ The mixture, where y can be a non-integer value between 1 and 2. In another embodiment of the compound having formula (2), n can be 4, and the alkyl chain has a total of 10 carbon atoms. In another embodiment of the compound having formula (2), n can be 5, and the alkyl chain has a total of 12 carbon atoms.

[0024] In one embodiment, a compound having formula (2) can be as follows:

[0025]

[0026] Another specific embodiment of formula (2) immediately following the above compound examples can be as follows:

[0027]

[0028] In another embodiment, the compound having formula (2) can be as follows:

[0029]

[0030] As an example, another specific embodiment of formula (2) immediately following the above compound examples may include n equal to 5.

[0031] In yet another embodiment, the compound having formula (1) is as follows:

[0032]

[0033] As an example, another specific embodiment of formula (2) immediately following the above compound examples may include n equal to 4.

[0034] An exemplary embodiment of neutralizing acidic oil furan sulfonate (OFS) molecules with a Ca, Mg, or NH4 cationic base, such as CaCO3, to form Ca, Mg, or NH4 of formula (1) is as shown in process 1 below:

[0035] Detailed Implementation

[0036] The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. In fact, the following description provides some practical illustrations for carrying out exemplary embodiments of the invention. Examples of elements, materials, compositions, and / or steps are provided below. Those skilled in the art will recognize that many of the mentioned examples have various suitable alternatives that are also within the scope of this disclosure.

[0037] The embodiments described herein relate to surfactant compositions and related methods for synthesizing such surfactants. In particular, embodiments herein disclose surfactant compositions that do not contain dioxanes and ethoxylates produced from renewable sources, while providing similar performance compared to SLES surfactants.

[0038] Sulfonation and sulfation reactions are typically final process steps in the manufacture of commercial surfactants. Alkyl furan sulfonates, alkyl difuran sulfonates, and SLES are products of sulfonation and sulfation reactions. From a chemical point of view, sulfonation describes the reaction of an organic surfactant precursor, such as alkylbenzene or the oleofuran surfactant examples disclosed herein, with sulfur trioxide (SO3) to form stable sulfur-carbon bonds in the acid surfactant product (alkylbenzene sulfonic acid, the oleofuran sulfonic acid examples disclosed herein). Due to the stability of the sulfur-carbon bonds, sulfonic acids can generally be isolated, stored, and transported in their pure acid form. On the other hand, sulfation involves the reaction between an organic alcohol surfactant precursor, such as ethoxylated lauryl alcohol, and SO3 to form hydrolyzable unstable carbon-oxygen-sulfur bonds in the surfactant product (SLES). To avoid the rapid decomposition of this unstable acid form, immediate neutralization and dilution of the sulfation product may be required, resulting in high transportation costs for diluted surfactant solutions (30 to 70% active surfactant). Therefore, a useful advantage of the oil furan surfactant examples disclosed herein is that they are sulfonates, and thus can provide stable concentrated acid forms, thereby reducing transportation costs and the possibility of on-site neutralization for surfactant consumers.

[0039] Commercially, various technologies exist for producing a range of detergent sulfonates and sulfates. For all of them, the main challenges are heat removal and controlling the molar concentration of SO3 to the organic precursor ratio, determining two process factors: the extent of side reactions and the amount of byproducts resulting from the highly exothermic nature of the reaction. In the past, this challenge has been addressed by diluting or complexing the SO3 precursor and reducing the rate of sulfonation or sulfation.

[0040] Commercially, the following types of diluting / complexing SO3 reactants are used (increasing in the order presented): aminosulfonic acid < chlorosulfonic acid < fuming sulfuric acid < air / SO3. Aminosulfonic acid is used with sulfated alcohols and ethoxylated alcohols, such as SLES, and directly forms ammonium-neutralized salts. It is one of the mildest and most selective sulfation agents that does not react with aromatic rings of, for example, alkylbenzenes or the proposed oil furan surfactants, and tends to be economically useful only for small-batch processes due to the high cost of SO3 precursor salts. Chlorosulfonic acid is also specifically used with sulfated alcohols and ethoxylated alcohols, and reacts rapidly and stoichiometrically with the sulfation products, requiring immediate neutralization upon completion of the reaction. Fuming sulfuric acid (SO3·H2SO4), on the other hand, is primarily used for the sulfonation of aromatic hydrocarbons such as alkylbenzenes and can be used in the examples disclosed herein, with the advantage of low raw material and capital equipment costs. A disadvantage of this technique is that sulfonation with fuming sulfuric acid is an equilibrium process, leaving a large amount of unreacted sulfuric acid that cannot be completely separated, resulting in approximately 8% sodium sulfate in the neutralized product. Finally, the SO3 / air process is the most commonly used and has been a stable replacement for the fuming sulfuric acid process. The SO3 / air process is capable of sulfonating and sulfonating a wide range of organic feedstocks. Generally, the process is rapid and stoichiometric, producing high-quality products under tightly controlled reaction conditions, and is best suited for large-scale continuous production. For example, organic feedstocks such as aromatic hydrocarbons, alcohols, or ethoxylated alcohols (i.e., SLES) react with a mixture of SO3 gas (usually derived from sulfur) and extremely dry air. The resulting sulfonic acid or sulfuric acid is then combined with a neutralizing agent (usually 50% sodium hydroxide), water as a diluent, and possibly additives to produce a solution of a neutral active surfactant (slurry or paste) with the desired composition and pH. Although immediate neutralization of SLES is unavoidable to prevent decomposition, it is noteworthy that the stability of oil furan sulfonic acids allows for the omission of neutralization and dilution after SO3 / air sulfonation, resulting in the described benefits of reduced transportation costs and on-site neutralization by the formulation manufacturer.

[0041] The feedstock for this process may also include solvents from surfactant sulfonation processes or any other residual reactants or byproducts, thus neutralization can be applied directly to the sulfonation effluent stream. Preferably, the feedstock stream will contain only the acidic form of oleofuranyl sulfonate in the absence of solvent (solvent-free).

[0042] The raw materials used in the process may include, but are not limited to, alkyl furan sulfonates and alkyl difuran sulfonates, wherein the carbon chain length can be saturated or unsaturated (mono, di, or tri) (C4 to C5). 28 (Changes). The alkyl furan sulfonate structure in the raw material may partially include a furan moiety or furan derivatives, such as methyl furan, ethyl furan, or furfural.

[0043] The following provides a general description of an exemplary neutralization process. Generally, the neutralization of a proton monoanion or diproton dianionon surfactant can be achieved by adding (e.g., relatively slowly) an alkaline salt containing, but not limited to, a selected cation including, calcium carbonate, or a mixture of alkaline metal salts including but not limited to a mixture of calcium carbonate and sodium carbonate, to a surfactant solution consisting of a mixture of water and an organic solvent, wherein the organic solvent is present in a volume ratio of 0 to 50%, and the organic solvent includes, but is not limited to, acetonitrile. This process produces a surfactant salt having the selected cation in solution, which is subsequently reduced to a solid by heating at a temperature ranging from 25 to 80°C and optionally by applying a vacuum in a pressure range ranging from 0.001 to 0.99 atm. Residual sulfates or carbonates in the product mixture can be removed by dissolving the solid in a minimal amount of water and adding a sufficient amount of organic solvent, including but not limited to acetone, to prepare a 1:1 aqueous solution versus organic solvent solution by volume. The amount of residual sulfates or carbonates present can vary depending on the selected sulfonation conditions and the neutralization of the alkaline salt. This solution is thoroughly mixed and then stored at a temperature between 0 and 15°C for a period of 1 to 48 hours. Solid salts are then removed by filtration, and liquids are removed by heating in the temperature range of 25 to 80°C while optionally applying a vacuum in the pressure range of 0.001 to 0.99 atm. If unsulfonated organics or sulfation byproducts remain in the product mixture, they can be removed by recrystallization in an organic solvent, including but not limited to isopropanol, ethanol, methanol, acetonitrile, acetone, or mixtures thereof.

[0044] An exemplary embodiment of the neutralization process is described below as process 1, and an exemplary embodiment of the composition formed from process 1 is described below as general structure 1.

[0045]

[0046] Procedure 1 describes the exemplary neutralization of an acidic oil furan sulfonate (OFS) molecule with a Ca, Mg, NH4, or Li cationic base (e.g., CaCO3) to form a Ca, Mg, NH4, or Li salt of general structure 1, wherein each numbered position (1 to 4) indicates a functional group, such as -H, -CH3, -CH2CH3, or C4 to C4, which may or may not contain a ketone functional group. 28 The structure contains at least one long alkyl chain with a ketone functional group (C4 to C5). 28 Chain length, and one -SO3 functional group. A complete list of possible substituents for general structure 1 is included in Table 1 below. General structure 1 may contain one or more alkyl furan sulfonates, one or more alkyl furan disulfonates, or any combination thereof; these anions may react with Na+, Na+, or other substituents. +NH4 + Or Li + One or more monovalent cations, including Mg 2+ or Ca 2+ One or more divalent cations or any combination of the aforementioned monovalent and divalent cations are charged and balanced. Although the preferred repeat of general structure 1 will contain one monoanion oil furan sulfonate anion for each valent cation or two monoanion oil furan sulfonate anions or one dianion oil furan disulfonate for each divalent cation, some repeats may not follow this ratio, especially in repeats in which a mixed cationic basic salt is used for neutralization.

[0047] Table 1 lists examples of substituents for furan surfactants of general structure 1.

[0048]

[0049] Table 1

[0050] The preparation of the bianionic calcium, magnesium, ammonium, and lithium surfactants of general structure 1 is described below and can be prepared from the corresponding acid forms according to procedures 2 and 3, respectively.

[0051] An exemplary embodiment for the preparation of calcium, magnesium, ammonium, and lithium cationic dianionic oil furan surfactants with tailed alkyl chains is described below as process 2.

[0052]

[0053] An exemplary embodiment for the preparation of calcium, magnesium, ammonium, and lithium cationic dianionic oil furan surfactants with bridging alkyl chains is described below as process 3.

[0054]

[0055] In another embodiment of processes 1, 2 and 3 described above, for example, an alkaline calcium salt of calcium hydroxide can be used to neutralize acidic surfactants.

[0056] An exemplary embodiment of using an alkaline salt to neutralize the acidic surfactant of process 1 is described below as process 4.

[0057]

[0058] Process 4 demonstrates the preparation of surfactants from protonated monoanionic oil furan sulfonates containing tailed alkyl chains. The structures shown in Process 4 have C-type structures derived from lauric acid. 12Alkyl saturated carbon chain. Alternatively, surfactants can also be derived from the distribution of fatty acids with different alkyl chain lengths, and can use different degrees of unsaturation, such as those obtained from soybean oil, to produce surfactant mixtures with different alkyl chain lengths, the final product of which may or may not contain chain unsaturation.

[0059] An exemplary embodiment of using an alkaline salt to neutralize the acidic surfactant in process 2 is described below as process 5.

[0060]

[0061] Process 5 demonstrates the preparation of surfactants from protonated bianionic oil furan sulfonates containing tailed alkyl chains.

[0062] An exemplary embodiment of using an alkaline salt to neutralize the acidic surfactant in process 3 is described below as process 6.

[0063]

[0064] Process 6 demonstrates the preparation of surfactants from protonated bianionic oil furan sulfonates containing bridging alkyl chains.

[0065] Examples of surfactant structures described below may be generated, for example, by the process examples described herein (e.g., neutralization process examples). The surfactant structure examples described below are based on the general structure 1 provided above. These surfactant structure examples may be portions of a class of calcium, magnesium, ammonium, and lithium cationic oil furan surfactants, for example, one or both furan portions acting as hydrophilic head portions, and hydrophobic alkyl chains acting as bridging or terminal carbon chains.

[0066] In each of these other surfactant structural embodiments based on Universal Structure 1, the alkyl chain length at the end of the furan moiety (e.g., as seen in structures A and B of Universal Structure 1) or between furan molecules (e.g., as seen in structure C of Universal Structure 1) can be, for example, C4 to C5. 28 Or from C4 to C 18 Within the alkyl chain range or from C6 to C6 18 Within the alkyl chain range or from C8 to C9 14 The alkyl chain length varies within a range. The length of the alkyl chain can be an important structural feature of surfactants and can significantly alter surfactant properties, including factors affecting performance in applications such as laundry detergent performance. For these reasons, an alkyl chain length within one range (e.g., C1 to C3) is considered as producing surfactants with properties different from those within another range (e.g., C4 to C5). 28 Surfactants with significantly different application properties due to the alkyl chain length within the group.

[0067] Returning to the general structure 1, the functional group indicated by the numbered positions (1 to 4) may be -H, -CH3, -CH2CH3, long alkyl chain, -OH, polyglycoside, polyethoxylated, sulfate, sulfonate or any other functional group listed in Table 1 above.

[0068] An embodiment of the surfactant structure based on general structure 1 is described below as structure A of general structure 1.

[0069]

[0070] Another embodiment of the surfactant structure based on general structure 1 is described below as structure B of general structure 1.

[0071]

[0072] Another embodiment of the surfactant structure based on general structure 1 is described below as structure C of general structure 1.

[0073]

[0074] Example

[0075] The following provides illustrative, non-limiting experimental examples of methods for synthesizing and related synthetic structures.

[0076] The monoanionic oil furan surfactant of structure A according to general structure 1 is prepared from the corresponding oil furan sulfonic acid as outlined in process 4, and this calcium oil furan surfactant is shown below as experimental structure 1.

[0077]

[0078] Referring to Experimental Structure 1, neutralization of oleofuranyl sulfonic acid was performed by dissolving the acid in a 1:1 melt (v / v) of water and acetonitrile, followed by the addition of calcium carbonate (>99%, standard deviation), which induced the release of CO2 gas. Calcium salt was continuously added until gas formation ceased and insoluble salts were observed. The pH of the melt was measured, and the mixture was allowed to be stirred until the pH was at least 6 or approximately 12 hours. The mixture was then filtered to remove excess carbonate and reduced to a solid at 50°C on a hot plate. Further salt removal was achieved by dissolving the carbonate in a 1:1 solution of water and acetone, freezing it at 4°C for 4 hours, and then filtering. After drying the filtrate to a solid at 50°C on a hot plate, recrystallization in a 1:1 solution of isopropanol and acetone produced a grayish-white solid product.

[0079] Table 2 below provides the physical properties and performance metrics of the selected surfactants relative to SLES.

[0080] Table 2

[0081]

[0082] 1 Critical micelle concentration

[0083] 2 Surface tension at critical micelle concentration

[0084] 3 The height of the foam immediately after formation and 5 minutes later shall be determined according to ASTM D1173. 4 The height of the foam in the distilled water melt immediately after foam formation and 5 minutes later was determined according to ASTM D319-88 using a mixing rate of 13,700 rpm and a surfactant concentration of 0.1 wt%.

[0085] 5 When the same test is run in 100ppm hard water melt, the percentage of high shear foam height lost is... 6 While maintaining the concentration of the precipitate, the expression of Ca from the CaCl2 source salt is noted. 2+ ppm 7 According to ASTM D2281, the wetting of cotton nylon at 30°C (Testfabrics)

[0086] 8 Solubility in deionized water at 20℃

[0087] 9 The height of the foam increases with the addition of hard water.

[0088] *Record the saturated surfactant melt at 20°C

[0089] Sodium lauryl ether sulfate surfactant with 3 ethoxylate (Stepan STEOL CS 330) was used as a comparison.

[0090] The tests included synthetic surfactants with the structures depicted in Experimental Structure 1, as well as corresponding Na, Li, NH4, and Mg surfactants, to determine surfactant properties. These included the time required for the surfactant melt to wet cotton fabric, the amount of foam generated by the surfactant during stirring, the surfactant's performance in hard water, its tolerance to calcium ions in solution, and the temperature below which the surfactant forms a solid precipitate, known as the Kraft characteristic.

[0091] The results are listed in Table 2 above. These results demonstrate significant differences in performance depending on the cation. In particular, surface tension, critical micelle concentration, and wetting kinetics were observed with calcium cationic surfactants compared to sodium surfactants prepared in the prior art. Both calcium and magnesium monoanionic surfactants were observed to exhibit high foaming and foam stability, which is attractive for several applications, including household cleaning, personal care, detergents, cosmetics, ore flotation, and oil recovery. Compared to common industrial surfactants SLES, despite the presence of the carcinogenic byproduct 1,4-dioxane, which is known for its widespread use across a large number of household and personal care products, calcium surfactants exhibit very similar performance metrics and even demonstrate improvements in critical micelle concentration, foaming, and high shear foam stability in hard water. The stability of oleofuran surfactants, particularly the acidic form of the precursors of calcium and other cationic surfactants, was measured over an eight-week time series at room temperature and high temperature, and the results are shown in Figure 2. Figure 2 is depicted below and illustrates the stability tracking of the oleofuran sulfonic acid surfactant precursors.

[0092] Figure 2

[0093]

[0094] In addition to having a unique cation derived from previous oil-based furan surfactants, the compositions disclosed herein may contain an additional short alkyl chain on the furan ring. Although this structural change can be minimal, its impact on the properties of the resulting surfactant is significant and unpredictable.

[0095] Table 3, described below, illustrates the physical properties and performance metrics of the selected surfactants with different surfactant structures.

[0096] Table 3

[0097]

[0098] 'R' indicates the position where the hydrophilic head group is attached to the long alkyl chain. All compounds compared here have alkyl chains of the same length.

[0099] 1 Critical micelle concentration

[0100] 2 Surface tension at critical micelle concentration

[0101] 3 The height of the foam immediately after formation and 5 minutes later shall be determined according to ASTM D1173. 4 While maintaining the concentration of the precipitate, the expression of Ca from the CaCl2 source salt is noted. 2+ ppm 5According to ASTM D2281, the wetting of cotton nylon at 30°C (Testfabrics)

[0102] 6 The height of the foam increases with the addition of hard water.

[0103] *Record the saturated surfactant melt at 20°C

[0104] Performed at 48°C to allow sufficient dissolution of solids and high-temperature characteristics. The experiment may not have been performed due to the high Cluff characteristics (low solubility) of the surfactant.

[0105] As can be seen in Table 3, adding a short methyl alkyl chain to the head group of the surfactant causes a change in the sulfonation position from being directly adjacent to the furan oxygen atom. This structural change has been observed to lead to a significant decrease in the critical micelle concentration. Furthermore, changes were observed in surface tension, foam height, foam stability, calcium tolerance, wetting time, and Krafft characteristics; in fact, the presence of the short alkyl chain on the furan ring altered each measured surfactant property. These surfactant properties are therefore relevant to performance in applications, and thus this modification to the surfactant structure is highly relevant to its intended use in everyday applications.

[0106] Table 4 shows the time taken to separate an emulsion containing equal volumes of 0.1 wt% surfactant melt and soybean oil. The length of time the surfactant melt can maintain the oil-water emulsion is relevant to any cleaning application, including detergents, personal care and industrial cleaning products, and oilfield applications. As seen for other surfactant properties, emulsion stability is significantly altered with the addition of a methyl group to the furan ring (an 18% increase). The effect of cationic selectivity on emulsion stability was also observed, with the calcium form of the methyl furan surfactant (OMFS-12-1 / 0) maintaining the emulsion for almost five times longer than the sodium form.

[0107] Table 4

[0108]

[0109] *Separation time indicates the time taken for the surfactant oil emulsion to separate and reach a specified volume. The surfactant concentration is 0.1 wt%, and the mixture consists of 20 mL each of surfactant melt and soybean oil.

[0110] Table 5 provides a comparison of the detergency of furan surfactant (OFS-12-1 / 0) against similar methylfuran surfactant (OMFS-12-1 / 0) on hard blood stains on cotton fabrics. The Stain Removal Index (SRI) is a measure of the amount of stain removed based on the change in RGB values ​​before and after washing, with a higher SRI indicating better detergency. The significant difference in SRI between furan and methylfuran surfactants observed when washing with 0.1 wt% surfactant in an aqueous solution provides further evidence that structural changes at the furan moiety cause performance differences that would not be apparent to those skilled in the art.

[0111] Table 5

[0112]

[0113] Washing conditions: The dyed fabric was purchased from Testfabrics Inc. (Item #2210026) and was washed by agitation for 1 minute in 0.2 L of a 0.1 wt% surfactant melt at 20°C, followed by rinsing in deionized water. The detergency index was calculated by irradiating the dyed fabric before and after washing with an Olympus E-M10 Mark II camera, followed by the method outlined in ASTM D2244.

[0114] Various examples have been described with reference to some of the disclosed embodiments. Examples are presented for illustrative purposes and not for limitation. Those skilled in the art will understand that various changes, adaptations, and modifications can be made without departing from the scope of the invention.

Claims

1. A compound having formula (1) （1） M is selected from the following groups: NH4 + Ca 2+ and Mg 2+ , Where R is CH3. Where y is 1 or 2, and Where n is the number of repeating ethylene units in equation (1), which is in the range of 3-8.

2. The compound according to claim 1, wherein M is NH4. + And y is 1.

3. The compound according to claim 1, wherein M is (i)Ca 2+ and (ii) Mg 2+ One of them, where y is 2.

4. The compound according to claim 1, wherein n is 4 and the alkyl chain has a total of 10 carbon atoms.

5. The compound according to claim 1, wherein n is 5 and the alkyl chain has a total of 12 carbon atoms.

6. The compound according to claim 1, wherein the compound is: 。

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