Co-sulfonation process of dodecylbenzene and glycerol binary system, product prepared by co-sulfonation process and application of product

Abstract

The invention discloses a co-sulfonation process of a dodecylbenzene and glycerol binary system, a product prepared by the co-sulfonation process and application of the product, and belongs to the technical field of fine chemical engineering. The co-sulfonation process comprises the following steps: by taking a mixture of glycerol and dodecylbenzene as a raw material and SO3 as a sulfonating agent, carrying out a co-sulfonation reaction in a falling-film sulfonation device to prepare a co-sulfonated substance; and adding an alkali solution into the co-sulfonated substance for neutralization to prepare the surfactant. The product prepared by the co-sulfonation process has excellent wettability and decontamination ability, so that the product is more suitable for household and industrial detergents, wetting agents and other products.

Description

Technical Field

[0001] The present invention belongs to the technical field of fine chemicals, and in particular relates to a co-sulfonation process of a binary system of dodecylbenzene and glycerol, and products prepared therefrom and applications thereof. Background Art

[0002] Sodium dodecylbenzenesulfonate (LAS) is the most widely used anionic surfactant worldwide. According to statistics, LAS accounts for over 60% of the world's total consumption of synthetic surfactants, exceeding 3 million tons annually. Over 70% of this is used in household and industrial detergents such as laundry detergents, dishwashing liquids, and liquid detergents. However, dodecylbenzene, the main component of synthetic sodium dodecylbenzenesulfonate, is derived from non-renewable petroleum resources. With dwindling petroleum reserves and fluctuating market prices, its long-term supply faces certain uncertainties. Over-reliance on petrochemicals also poses environmental sustainability challenges. Furthermore, the performance of single sulfonated compounds needs to be improved.

[0003] Therefore, finding renewable raw materials to build high-performance surfactant systems has become a key focus of the current industry. Summary of the Invention

[0004] To address the above technical issues, the present invention proposes a co-sulfonation process for a binary system of dodecylbenzene and glycerol, as well as the products and applications thereof. The products produced by the co-sulfonation process have excellent wettability and detergency, making them more suitable for use in household and industrial detergents, wetting agents, and other products.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention:

[0007] A co-sulfonation process of a binary system of dodecylbenzene and glycerol comprises the following steps:

[0008] A co-sulfonated product is prepared by using a mixture of glycerol and dodecylbenzene as raw materials and SO3 as a sulfonating agent to carry out a co-sulfonation reaction.

[0009] An alkaline solution is added to the co-sulfonated product for neutralization to prepare a surfactant.

[0010] Beneficial effects: Glycerol, as a natural polyol molecule, is widely available, inexpensive, and biodegradable. It has three hydroxyl sites and can participate in a variety of functionalization modification reactions. The present invention can construct a composite hydrophilic structure molecule of "sulfonic acid group + polyhydroxyl group" by mixing glycerol with dodecylbenzene and then sulfonating it, which significantly improves the polarity matching and interface rearrangement ability of the molecule in the aqueous phase, helps to quickly reduce surface tension and enhance the adsorption and encapsulation of hydrophobic pollutants. In addition, the co-sulfonation of glycerol and dodecylbenzene in the present invention can not only optimize product performance, but also improve sustainability, which is in line with the current trend of green chemistry and environmental protection development.

[0011] Optionally, the blend is obtained by uniformly mixing glycerol and dodecylbenzene, wherein the mass concentration of glycerol is 5% to 15%.

[0012] Furthermore, the feed temperature of the blend is 20-30°C.

[0013] Optionally, the SO3 is a gas with a concentration of 5 to 7 vol%, and the remainder is dry air.

[0014] Furthermore, the inlet temperature of the SO3 is 45-55°C.

[0015] Optionally, the molar ratio of the blend (i.e. the sum of the total amount of glycerol and dodecylbenzene) to the SO3 is 1:1.15-1.25.

[0016] Beneficial Effects: In the co-sulfonation reaction, the SO3 supply rate and concentration are key factors influencing the experimental results. If the SO3 supply rate is too fast, it may lead to localized oversulfonation, forming disulfonic acid byproducts or even charred products, darkening the product color and affecting quality. However, if the supply rate is too low, sulfonation will be incomplete, resulting in unreacted glycerol and dodecylbenzene, and reducing the surface activity of the product. Therefore, the SO3 concentration is controlled at 5-7% (volume fraction), and the molar ratio of SO3 to raw materials (dodecylbenzene + glycerol) is maintained at 1.15-1.25:1 to ensure sufficient but not excessive sulfonation.

[0017] In order to accurately control the SO3 addition rate, a mass flow meter or pressure sensor can be used to monitor the gas flow in real time to ensure the stability and consistency of the reaction.

[0018] Optionally, the co-sulfonation reaction is carried out in a falling film sulfonation unit.

[0019] Optionally, the conditions during the co-sulfonation reaction are:

[0020] The co-sulfonation temperature is 45-55°C; after the raw materials and SO3 are introduced, the reaction products will flow into the collection tank. The acid value of the product in the test tank is tested. When the theoretical acid value is reached, the reaction is confirmed to be complete; then the next stage is entered.

[0021] The theoretical acid value is the acid value that the reaction product should have, calculated based on stoichiometry. The acid value is usually defined as the number of milligrams of potassium hydroxide (KOH) required to neutralize 1 gram of sample.

[0022] Optionally, the alkaline solution is a sodium hydroxide aqueous solution with a concentration of 20-30%.

[0023] Optionally, the conditions during the neutralization process are:

[0024] The neutralization temperature is 25-35°C, and the neutralization pH value is 7-8.

[0025] The second technical solution of the present invention:

[0026] A surfactant is prepared by the above co-sulfonation process.

[0027] The third technical solution of the present invention:

[0028] The above surfactants are used in the fields of household and industrial detergents and wetting agents.

[0029] Compared with the existing single sulfonated products, the co-sulfonated products prepared by the process of the present invention have the following advantages:

[0030] 1) Enhanced Wettability: The trihydroxy structure in the glycerol molecule imparts multi-site hydrogen bonding capability, enabling synergistic interactions with polar functional groups at the liquid-solid interface, enhancing the adsorption and spreading of droplets on solid surfaces. Furthermore, the sulfonated glycerol product possesses a complex hydrophilic structure composed of sulfonic acid groups and residual hydroxyl groups, enhancing the interfacial adaptability and polarity compatibility of surface molecules.

[0031] 2) Improve the detergency of the product: The polyhydroxy structure in the glycerol compound system is highly polar and can be reconstructed through a rapid hydrogen bond network to accelerate the molecular diffusion rate. At the same time, the dynamic surface tension of the compounded system decreases faster than LAS, which can significantly increase the surface tension gradient in the initial stage of decontamination, promoting the infiltration and removal of water into stains.

[0032] 3) Reduce environmental pollution and improve eco-friendliness: Glycerol is biodegradable, which can improve the environmental friendliness of the final product and conform to the trend of green production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0034] Figure 1This is the ESI-MS spectrum of the co-sulfonation product (b) of LAS (a) and Example 3 (15% glycerol). DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0036] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0037] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0038] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0039] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0040] The embodiment of the present invention discloses a co-sulfonation process of a binary system of dodecylbenzene and glycerol, comprising the following steps:

[0041] The first step is to mix dodecylbenzene and glycerin and stir evenly;

[0042] The second step is to sulfonate the mixed solution of dodecylbenzene and glycerol with SO3 gas in a falling film sulfonation device to obtain a co-sulfonated product. Specifically, the mixed solution of dodecylbenzene and glycerol is poured into the raw material barrel. The mixed solution is then pumped through the organic feed port into the reaction tube, where it forms a thin organic liquid film on the inner wall of the tube. It then flows downward from the top of the tube and rapidly reacts with the SO3 dilution gas entering from the SO3 gas nozzle at the top of the reactor.

[0043] The third step is to add a certain concentration of sodium hydroxide solution dropwise to the co-sulfonated product at a specific temperature until the pH value of the solution stabilizes at 7-8.

[0044] The present invention adopts the above method to regulate the temperature range of the sulfonation reaction tube, the gas concentration of SO3, and the molar ratio of the mixed raw material to SO3, thereby improving the reaction completion and reducing the occurrence of side reactions during the oversulfonation reaction, reducing the residual amount of glycerol and dodecylbenzene, and improving the purity of the acid ester after sulfonation (i.e., the active matter content).

[0045] In some optional embodiments, during the mixing in the first step, 5% to 15% of glycerol is added, and the remainder is dodecylbenzene, and the mixture is stirred at 20 to 30° C. for 20 to 30 minutes at a stirring rate of 250-300 rpm.

[0046] In some optional embodiments, in the second step, the molar ratio of the raw material mixture to SO3 is 1:1.15-1.25.

[0047] In some optional embodiments, in the second step, the sulfonation temperature is set to 45-55°C.

[0048] In some optional embodiments, in the second step, the volume concentration of SO3 is 5-7%.

[0049] In some optional embodiments, in the second step, the inlet temperature of SO3 is 45-55°C.

[0050] In some optional embodiments, in the second step, the feed temperature of the raw material mixture is set to 20-30°C.

[0051] In some optional embodiments, in the third step, the temperature during neutralization is 25-35°C.

[0052] In some optional embodiments, in the third step, the concentration of the sodium hydroxide aqueous solution is 20-30 wt.%.

[0053] The raw materials used in the present invention were all purchased from the market. The falling film sulfonation device was purchased from China Daily Chemical Industry Research Institute, model FJEE.

[0054] The technical solution of the present invention is further described below through examples. The performance test standards are:

[0055] Test method for anionic active matter content: According to GB / T 5173-2018 Surfactants, detergents, determination of anionic active matter content: direct two-phase titration method, in a two-phase medium of water and chloroform, in the presence of an acidic mixed indicator solution, titrate with a cationic surfactant (benzylthionium chloride) to determine the anionic active matter.

[0056] Test method for inorganic sulfate content: According to GB / T 6366-2012 Determination of inorganic sulfate content of surfactants, the titration method uses disulfide as an indicator and uses lead nitrate standard solution to titrate the buffered acetone solution of the sample.

[0057] Determination of wetting properties: According to the immersion method for determination of the wetting power of surfactants in GB / T 11983-2008, the wetting properties of the co-sulfonated product were studied by using the length of time the canvas was wetted.

[0058] Determination of stain removal performance: According to GB / T 13174-2008 Determination of stain removal power and cyclic washing performance of detergents for clothing, the stain removal performance of artificial soiled cloth was determined in 250 mg / kg hard water using a vertical stain removal tester and a whiteness meter.

[0059] Example 1

[0060] Mix 475g of dodecylbenzene with 25g of glycerol, stir at 25°C at a stirring rate of 275rpm for 25 minutes, cool to 20°C, pour into a feed barrel at a temperature of 20°C, and carry out sulfonation reaction in a falling film sulfonation tube with a gas concentration of 6% SO3 according to the molar ratio of raw materials (total amount of dodecylbenzene and glycerol, the same applies to the following examples) to SO3 of 1:1.17, and control the sulfonation reaction temperature to be maintained at 45°C; obtain a co-sulfonate; place the obtained co-sulfonate in a water bath at 25°C, and add 20% sodium hydroxide aqueous solution dropwise to the co-sulfonate until the pH value of the solution stabilizes at 7-8.

[0061] After testing: the active matter content in the final product is 96.89%; the inorganic sulfate content is 0.7%; the decontamination ratio to JB-03 is 1.42; and the wetting time is 14.4s.

[0062] Example 2

[0063] Mix 450g of dodecylbenzene with 50g of glycerol, stir at 20°C at a stirring rate of 300rpm for 30 minutes, cool to 25°C, pour into a feed barrel at a temperature of 25°C, and carry out sulfonation reaction in a falling film sulfonation tube with a gas concentration of 7% SO3 at a molar ratio of raw materials to SO3 of 1:1.18, and control the sulfonation reaction temperature to be maintained at 50°C; obtain a co-sulfonate; place the obtained co-sulfonate in a water bath at 30°C, and add 25% sodium hydroxide aqueous solution dropwise to the co-sulfonate until the pH value of the solution stabilizes at 7-8.

[0064] After testing, the active matter content was 96.03%; the inorganic sulfate content was 0.80%; the decontamination ratio to JB-03 was 1.3; and the wetting time was 14s.

[0065] Example 3

[0066] 425g of dodecylbenzene and 75g of glycerol were mixed and stirred at 70°C at a stirring rate of 250 rpm for 20 minutes. After cooling to 30°C, the mixture was poured into a feed barrel at 30°C and sulfonated in a falling film sulfonation tube with a 7% SO3 gas concentration at a molar ratio of 1:1.19. The sulfonation temperature was maintained at 55°C to obtain a co-sulfonated product. The co-sulfonated product was placed in a 35°C water bath and 30% sodium hydroxide aqueous solution was added dropwise to the co-sulfonated product until the pH of the solution stabilized at 7-8.

[0067] After testing: the active matter content is 95.05%; the inorganic sulfate content is 0.86%; the decontamination ratio to JB-03 is 1.27; and the wetting time is 13.5s.

[0068] Figure 1 The ESI-MS spectrum of the co-sulfonation product (b) of LAS (a) and Example 3 (15% glycerol). Figure 1 As can be seen in (a), the main characteristic ion peak m / z = 325.18404 / 325.18410 was detected in the negative ion mode, corresponding to LAS (C 18 H 29 O3SNa, molecular weight 348.4760) [M-Na] - ion (theoretical value m / z = 325.4800). Figure 1 (b) also shows a new characteristic ion peak m / z = 170.9954, corresponding to the [M-Na] of monoglycerol sodium sulfate (C3H7O6SNa, molecular weight 194.1399). - ion (theoretical value m / z = 171.1501), proving the formation of sodium monoglyceride sulfate.

[0069] Comparative Example 1

[0070] 500 g of dodecylbenzene is poured into a feed barrel at a temperature of 25° C., and a sulfonation reaction is carried out in a falling film sulfonation tube with a gas concentration of 6% SO3 according to a molar ratio of raw material to SO3 of 1:1.02, and the sulfonation reaction temperature is controlled to be maintained at 45° C.; a sulfonate is obtained; the obtained sulfonate is placed in a water bath at 20° C., and a 20% sodium hydroxide aqueous solution is added dropwise to the co-sulfonate until the pH value of the solution stabilizes at 7-8.

[0071] After testing: the active matter content is 97%; the inorganic sulfate content is 1.02%; the decontamination ratio to JB-03 is 1.22; and the wetting time is 16s.

[0072] Comparative Example 2

[0073] The difference from Comparative Example 1 is that dodecylbenzene is replaced by glycerol of equal mass.

[0074] Sulfate Test Method: Weigh (2.5 ± 0.2) g of sample into a 250 mL round-bottom flask, add 25 mL of sulfuric acid solution, attach a condenser, and heat in a boiling water bath for 60 minutes. Remove from heat, cool, and rinse the condenser with 30 mL of anhydrous ethanol and then deionized water. Add a few drops of phenolphthalein indicator and titrate with a NaOH standard solution.

[0075] The sulfate content measured by the above method was 3.01%.

[0076] Comparative Example 3

[0077] The only difference from Example 1 is that the molar ratio of the raw material to SO3 is replaced with 1:1.14.

[0078] After testing: the active matter content is 82%; the inorganic sulfate content is 1.1%; the decontamination ratio to JB-03 is 1.22; and the wetting time is 14.9s.

[0079] Comparative Example 4

[0080] The only difference from Example 3 is that the molar ratio of the raw material to SO3 is replaced with 1:1.27.

[0081] After testing: the active matter content is 80%; the inorganic sulfate content is 1.2%; the decontamination ratio to JB-03 is 1.25; and the wetting time is 14.7s.

[0082] Summary: Comparing the products and performance data prepared in the above examples and comparative examples, it can be seen that the co-sulfonated product of the binary system of glycerol and dodecylbenzene in the present invention has superior detergency and wetting properties compared to sodium dodecylbenzene sulfonate.

[0083] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A co-sulfonation process of a binary system of dodecylbenzene and glycerol, characterized in that: The following steps are involved: A co-sulfonated product is prepared by using a mixture of glycerol and dodecylbenzene as raw materials and SO3 as a sulfonating agent to carry out a co-sulfonation reaction. An alkaline solution is added to the co-sulfonated product for neutralization to prepare a surfactant.

2. A co-sulfonation process for a binary system of dodecylbenzene and glycerol according to claim 1, characterized in that: The mass concentration of glycerol in the blend is 5% to 15%.

3. A co-sulfonation process for a binary system of dodecylbenzene and glycerol according to claim 1, characterized in that: The concentration of SO3 is 5-7 vol%.

4. A co-sulfonation process for a binary system of dodecylbenzene and glycerol according to claim 1, characterized in that: The molar ratio of the blend to the SO3 is 1:1.15-1.

25.

5. A co-sulfonation process of a binary system of dodecylbenzene and glycerol according to claim 1, characterized in that, The co-sulfonation reaction is carried out in a falling film sulfonation device.

6. A co-sulfonation process of a binary system of dodecylbenzene and glycerol according to claim 5, characterized in that, The conditions during the co-sulfonation reaction are: The co-sulfonation temperature is 45-55°C.

7. A co-sulfonation process of a binary system of dodecylbenzene and glycerol according to claim 1, characterized in that, The alkaline solution is a sodium hydroxide aqueous solution with a concentration of 20-30%.

8. The co-sulfonation process of a binary system of dodecylbenzene and glycerol according to claim 1, characterized in that: The conditions in the neutralization process are: The neutralization temperature is 25-35°C, and the neutralization pH value is 7-8.

9. A surfactant, characterized in that The product is prepared by the co-sulfonation process according to any one of claims 1 to 8.

10. Use of the surfactant according to claim 9 in the fields of household and industrial detergents and wetting agents.

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