Bio-based surfactant, fluorinated acrylate polymer and preparation method

Abstract

The present invention relates to the field of surfactant technology, specifically to a bio-based surfactant, a fluorinated acrylate polymer, and a preparation method. The bio-based surfactant has the following structural formula: Cyclosporine A, isopropyl alcohol, a sodium bisulfite solution, an organic base, and an initiator are mixed in a constant temperature oil bath and reacted at 39-42°C for 18-25 hours. The bio-based surfactant of the present invention is not only non-toxic and degradable, but also has excellent emulsification ability and the ability to reduce water surface energy.

Description

Technical Field

[0001] The present invention relates to the technical field of surfactants, and in particular to a bio-based surfactant, a fluorine-containing acrylate polymer and a preparation method thereof. Background Art

[0002] PFAS (per- and polyfluoroalkyl substances) are widely used in the preparation of fluorine-containing rubber, fire protection, pesticides, mineral processing, papermaking, leather and other fields, such as the most common perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS).

[0003] Because the environmental concerns of PFOS-based fluorocarbon surfactants stem from their long fluorocarbon chains, which are difficult to degrade in nature and organisms, current global PFOS alternative research and development strategies primarily focus on reducing the toxicity of the fluorocarbon chains. These include reducing the fluorocarbon chain length (e.g., PFHS with a hydrophobic fluorocarbon chain length of 6 carbon atoms and PFBS with a 4 carbon atoms), introducing more easily degradable weak sites in the fluorocarbon chain (e.g., the methylene group in vinylidene fluoride oligomers and the ether bond in hexafluoropropylene oxide oligomers), branching the fluorocarbon chains (e.g., hexafluoropropylene oligomers), and constructing novel fluorocarbon surfactant structures (e.g., gemini surfactants and heterogemini surfactants). For example, the surfactant constructed in CN 118955321 A circumvents the PFAS ban by reducing the total number of fluorinated carbon atoms, while CN 117903346 A introduces oxygen heteroatoms to increase the chain's weak points, thereby achieving the preparation of degradable surfactants. However, neither of these approaches fundamentally addresses the toxicity and potential bioaccumulation of fluorinated compounds.

[0004] All of these methods target the modification of fluorinated chains, achieving biodegradability by shortening them or increasing weak points in the chain, thereby circumventing PFAS regulations. However, these surfactants are still bioaccumulative and harmful to humans. Furthermore, the synthesis of most surfactants is complex and involves numerous steps. With the continuous improvement of environmental awareness, these compounds are being gradually regulated and banned, and cannot be used as emulsifiers in rubber emulsion polymerization. Summary of the Invention

[0005] The object of the present invention is to provide a bio-based surfactant and a preparation method thereof, wherein the bio-based surfactant is not only non-toxic and degradable but also has excellent emulsification ability and the ability to reduce water surface energy.

[0006] In addition, the present invention also provides a fluorine-containing acrylic polymer prepared from the above-mentioned bio-based surfactant and a preparation method thereof; the bio-based surfactant exhibits excellent emulsification effect in the emulsion polymerization of fluorine-containing monomers, and the obtained emulsion has high stability.

[0007] The present invention is achieved through the following technical solutions:

[0008] Bio-based surfactant, its structural formula is as follows:

[0009]

[0010] The bio-based surfactant of the present invention is a non-fluorine surfactant. The bio-based surfactant is not only non-toxic and degradable, but also has excellent emulsification ability and the ability to reduce water surface energy.

[0011] A method for preparing a bio-based surfactant comprises placing cyclosporine A, isopropyl alcohol, a sodium bisulfite solution, an organic base and an initiator in a constant temperature oil bath, mixing the mixture and reacting the mixture at 39-42° C. for 18-25 hours.

[0012] In a preferred embodiment, the organic base includes at least one of triethylamine, diisopropylamine and tetramethylethylenediamine.

[0013] In a preferred embodiment, the initiator includes at least one of tert-butyl perbenzoate, benzoyl peroxide and tert-butyl hydroperoxide.

[0014] In a preferred embodiment, based on the molar ratio of cyclosporin A, the sodium bisulfite is 2-5%; the organic base is 2-8%; and based on the mass of cyclosporin, the initiator is 2-15%.

[0015] The invention discloses an application of a bio-based surfactant as an emulsifier in the preparation of rubber latex.

[0016] A fluorinated acrylate polymer is obtained by carrying out a polymerization reaction using a fluorinated acrylate as a raw material and a bio-based surfactant as an emulsifier; the fluorinated acrylate includes at least one of hexafluorobutyl acrylate, tridecafluorooctyl acrylate and hexafluorobutyl methacrylate.

[0017] A method for preparing a fluorinated acrylic polymer comprises the following steps:

[0018] S1, mixing a fluorinated acrylate, a bio-based surfactant, and a solvent to obtain a pre-emulsion;

[0019] S2. In the presence of an initiator, mixing the pre-emulsion in step S1 with a solvent and initiating a reaction to obtain a reaction solution;

[0020] S3. Mix the pre-emulsion in step S1, the initiator, and the reaction solution prepared in step S2, and perform a polymerization reaction to obtain a fluorine-containing acrylate polymer.

[0021] In a preferred embodiment, the initiator in step S2 and step S3 is potassium persulfate.

[0022] In a preferred embodiment, the solvent in step S1 and step S2 includes water.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] 1. The bio-based surfactant synthesized by the present invention is non-toxic, biodegradable, ecologically safe and has high surface activity. At the same time, the preparation method of the bio-based surfactant of the present invention is most effective for the addition of double bonds by using a catalytic system composed of an organic base and an organic peroxide. The reaction conditions are simple and easy to operate, and it is suitable for industrial production. It has the advantages of short synthesis steps and simple actual operation. At the same time, it shows a good emulsifying effect in the polymerization of fluorinated acrylate monomers, the reaction time is short, and the obtained emulsion is stable, which can greatly improve the reaction efficiency.

[0025] 2. The raw material of the bio-based surfactant obtained in the present invention is cyclosporine A obtained by fungal fermentation. The source of the raw material complies with green chemistry and there is no environmental pollution problem during the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0027] Figure 1 This is the infrared spectrum of the bio-based surfactant prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the examples. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention. The embodiments described below are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details are not necessarily required to practice the present invention. In other examples, well-known structures, materials, or methods are not specifically described to avoid obscuring the present invention. The materials, instruments, and reagents used in the following examples, unless otherwise specified, are commercially available. The techniques used in the examples, unless otherwise specified, are conventional techniques well known to those skilled in the art.

[0030] In order to solve the problems of toxicity and complex synthesis process of existing non-fluorinated surfactants, this embodiment provides a bio-based surfactant, the structural formula of which is as follows:

[0031]

[0032] The preparation method of the bio-based surfactant comprises placing cyclosporine A, isopropyl alcohol, sodium bisulfite solution, organic base and initiator in a constant temperature oil bath, mixing them, and reacting them at 39-42° C. for 18-25 hours.

[0033] The synthesis pathway of the above bio-based surfactants is as follows:

[0034]

[0035] This example uses cyclosporin A, a cyclic peptide molecule composed of 11 amino acids. By utilizing the double bond of the active functional group on the cyclosporin A and reacting with sodium bisulfite, a novel bio-based cyclosporin A sodium sulfonate non-fluorinated surfactant can be constructed through a series of optimized conditions. The initiator is tert-butyl peroxybenzoate (TBPB), benzoyl peroxide (BPO), or tert-butyl hydroperoxide (TBHP). X is a raw material mass percentage of 2, 4, 6, 10, 12, or 15. Y is a raw material molar ratio of 2, 3, 4, or 5. Base is an organic base such as triethylamine, diisopropylamine, or tetramethylethylenediamine. Z is a raw material molar ratio of 2, 4, or 8.

[0036] The raw material of the bio-based surfactant of this embodiment is cyclosporin A obtained by fungal fermentation. The raw material source conforms to green chemistry and there is no environmental pollution problem during the production process. In addition, this embodiment uses a catalytic system combining an organic base and an organic peroxide to achieve the most effective addition of double bonds. The reaction conditions are simple and easy to operate, suitable for industrial production. The prepared bio-based surfactant can effectively reduce the surface tension of the aqueous solution, has good solubility, low foaming, fine foam, and excellent surfactant performance.

[0037] The bio-based surfactant can be used as an emulsifier in the preparation of rubber latex, specifically, in the preparation of fluorine-containing acrylic polymers.

[0038] The preparation method of the fluorinated acrylic polymer comprises the following steps:

[0039] S1, mixing a fluorinated acrylate, a bio-based surfactant, and a solvent to obtain a pre-emulsion;

[0040] S2. In the presence of an initiator, mixing the pre-emulsion in step S1 with a solvent and initiating a reaction to obtain a reaction solution;

[0041] S3. Mix the pre-emulsion in step S1, the initiator, and the reaction solution prepared in step S2, and perform a polymerization reaction to obtain a fluorine-containing acrylate polymer.

[0042] The initiator in step S2 and step S3 is potassium persulfate, which is preferably used in the form of an aqueous solution.

[0043] The solvent in step S1 and step S2 includes water, such as distilled water.

[0044] The raw materials of the above-mentioned fluorinated acrylic polymer are as follows:

[0045]

[0046] Wherein, Formula I is an emulsifier (bio-based surfactant); R in Formula II 1 H or Me, R 2 is perfluorohexylethyl or hexafluoropropylmethyl; Formula II specifically represents that the fluorinated acrylate includes at least one of hexafluorobutyl acrylate, tridecafluorooctyl acrylate and hexafluorobutyl methacrylate.

[0047] The weight portion of the compound represented by formula II is 0.1 to 10 parts, preferably 1 to 7 parts; the weight portion of the compound represented by formula I is 0.01 to 1.0 parts, preferably 0.02 to 0.07 parts, for example 0.03 parts.

[0048] In order to better illustrate the technology of this embodiment, the following specific case is used for illustration:

[0049] Example 1:

[0050] A method for preparing a bio-based surfactant:

[0051] To a 250 mL three-necked round-bottom flask, cyclosporine A (12.02 g, 0.01 mol), isopropyl alcohol (10 mL), sodium bisulfite (4.16 g, 0.4 mol), triethylamine (0.3 g, 2.0% molar ratio relative to cyclosporine A), and TBPB (0.60 g, 5.0% mass ratio relative to cyclosporine A) were added sequentially (the molar ratio of sodium bisulfite to cyclosporine A was 4). The mixture was placed in a thermostatic oil bath, stirred thoroughly, and reacted at (40 ± 0.5)°C for 20 h. After completion of the reaction, petroleum ether and distilled water were added for extraction. The aqueous phase was collected and desalted with anhydrous ethanol. After filtration, the solvent was removed by rotary evaporation, and the product was washed with water to obtain a white powder with a yield of 80%.

[0052] The infrared spectrum of the bio-based surfactant prepared in this example is as follows Figure 1 As shown: Through the infrared data, it can be seen that at 1695cm -1 -1630cm -1 No stretching vibration peaks of olefins were observed, so the double bond had been reacted.

[0053] Example 2:

[0054] A method for preparing a bio-based surfactant:

[0055] To a 250 mL three-necked round-bottom flask, cyclosporine A (12.02 g, 0.01 mol), isopropyl alcohol (10 mL), sodium bisulfite (4.16 g, 0.4 mol), diisopropylamine (0.2 g, 2.0% molar ratio relative to cyclosporine A), and dibenzoyl peroxide (BPO) (0.60 g, 5.0% mass ratio relative to cyclosporine A) were added sequentially. The molar ratio of sodium bisulfite to cyclosporine A was 4. The mixture was placed in a thermostatic oil bath, stirred thoroughly, and reacted at (40 ± 0.5)°C for 20 h. After completion of the reaction, petroleum ether and distilled water were added for extraction. The aqueous phase was collected and desalted with anhydrous ethanol. After filtration, the solvent was removed by rotary evaporation, and the product was washed with water to obtain a white powder with a yield of 75%.

[0056] Example 3:

[0057] A method for preparing a bio-based surfactant:

[0058] To a 250 mL three-necked round-bottom flask, cyclosporine A (12.02 g, 0.01 mol), isopropyl alcohol (10 mL), sodium bisulfite (4.16 g, 0.4 mol), tetramethylethylenediamine (0.2 g, 2.0% molar ratio relative to cyclosporine A), and tert-butyl hydroperoxide (TBHP) (0.60 g, 5.0% mass ratio relative to cyclosporine A) were added sequentially. The molar ratio of sodium bisulfite to cyclosporine A was 4. The mixture was placed in a thermostatic oil bath, stirred thoroughly, and reacted at (40 ± 0.5)°C for 20 h. After completion of the reaction, petroleum ether and distilled water were added for extraction. The aqueous phase was collected and desalted with anhydrous ethanol. After filtration, the solvent was removed by rotary evaporation, and the product was washed with water to obtain a white powder with a yield of 77%.

[0059] Comparative Example 1:

[0060] A method for preparing a bio-based surfactant:

[0061] To a 250 mL three-necked round-bottom flask were added cyclosporine A (12.02 g, 0.01 mol), isopropyl alcohol (10 mL), sodium bisulfite (4.16 g, 0.4 mol) dissolved in distilled water (10 mL), and tetramethylethylenediamine (0.2 g, 2.0% molar ratio relative to cyclosporine A substrate) in sequence. The mixture was placed in a thermostatic oil bath, stirred thoroughly, and reacted at (40 ± 0.5)°C for 20 h. Upon completion of the reaction, TLC monitoring indicated that the starting material had not reacted, and no corresponding product was obtained.

[0062] Comparative Example 2:

[0063] A method for preparing a bio-based surfactant:

[0064] To a 250 mL three-necked round-bottom flask were added cyclosporine A (12.02 g, 0.01 mol), isopropanol (10 mL), sodium bisulfite (4.16 g, 0.4 mol) dissolved in distilled water (10 mL), K2CO3 (0.2 g, 2.0% molar ratio relative to the substrate cyclosporine A), and TBPB (0.60 g, 5.0% mass ratio relative to the substrate cyclosporine A). The mixture was placed in a thermostatic oil bath, stirred thoroughly, and reacted at (40±0.5)°C for 20 h. Upon completion of the reaction, TLC monitoring indicated that the starting material had not reacted, and no corresponding product was obtained.

[0065] Example 4:

[0066] A method for preparing a fluorinated acrylic polymer:

[0067] Dissolve 0.3 g of formula INFS in 10 g of ultrapure water to obtain a clear, transparent solution. Add 10 g of a mixture of hexafluorobutyl acrylate and tridecafluorooctyl acrylate (7:3) while stirring. After stirring at room temperature for 30 minutes, add 10 g of a 0.03% wt aqueous solution of KPS (potassium persulfate). After stirring at room temperature for 10 minutes, displace the nitrogen and heat to 70°C for 6 hours. After the reaction, pour into saturated brine to break the emulsion. Wash and dry to obtain 9.78 g of fluoropolymer.

[0068] Example 5:

[0069] A method for preparing a fluorinated acrylic polymer:

[0070] Dissolve 0.3 g of Formula I NFS in 10 g of ultrapure water to obtain a clear, transparent solution. Add 10 g of tridecafluorooctyl acrylate while stirring. After stirring at room temperature for 30 minutes, add 10 g of a 0.03% wt aqueous solution of KPS. After stirring at room temperature for 10 minutes, displace the nitrogen and heat to 70°C for 6 hours. After the reaction, pour the mixture into saturated brine to break the emulsion. Wash and dry the mixture to obtain 9.18 g of a fluoropolymer.

[0071] Example 6:

[0072] A method for preparing a fluorinated acrylic polymer:

[0073] Dissolve 0.3 g of Formula I NFS in 10 g of ultrapure water to obtain a clear, transparent solution. Add 10 g of hexafluorobutyl acrylate while stirring. After stirring at room temperature for 30 minutes, add 10 g of a 0.03% wt aqueous solution of KPS. After stirring at room temperature for 10 minutes, displace the nitrogen and heat to 70°C for 6 hours. After the reaction, pour into saturated brine to break the emulsion. Wash and dry to obtain 9.55 g of a fluoropolymer.

[0074] Example 7:

[0075] A method for preparing a fluorinated acrylic polymer:

[0076] Dissolve 0.3 g of Formula I NFS in 10 g of ultrapure water to obtain a clear, transparent solution. Add 10 g of a mixture of hexafluorobutyl acrylate and tridecafluorooctyl acrylate (6:4) with stirring. After stirring at room temperature for 30 minutes, add 10 g of a 0.03% wt aqueous solution of KPS. After stirring at room temperature for 10 minutes, displace the nitrogen and heat to 70°C for 6 hours. After the reaction, pour the mixture into saturated brine to break the emulsion. Wash and dry the mixture to obtain 9.23 g of a fluoropolymer.

[0077] Example 8:

[0078] A method for preparing a fluorinated acrylic polymer:

[0079] Dissolve 0.3 g of Formula I NFS in 10 g of ultrapure water to obtain a clear, transparent solution. Add 10 g of a 5:5 mixture of hexafluorobutyl acrylate and tridecafluorooctyl acrylate while stirring. After stirring at room temperature for 30 minutes, add 10 g of a 0.03% wt aqueous solution of KPS. After stirring at room temperature for 10 minutes, displace the nitrogen and heat to 70°C for 6 hours. After the reaction, pour the mixture into saturated saline to break the emulsion. Wash and dry the mixture to obtain 9.22 g of a fluoropolymer.

[0080] Bio-based surfactant performance test:

[0081] The comparison of the bio-based surfactant prepared in Example 1 and the commercially available sodium sulfonate surfactant in terms of emulsification ability, surface tension, demulsification time and total amount of agglomeration is shown in Table 1:

[0082] Table 1

[0083]

[0084]

[0085] Emulsifying ability: According to the industry standard emulsifying ability test method, measure 40mL of the sample aqueous solution and 40mL of edible oil in a stoppered graduated cylinder and shake vigorously ten times. Let it stand and observe the time required for 10mL of aqueous phase to precipitate.

[0086] Surface tension was measured using a Sigma-700 tester, using the Wilhelmy plate method according to GB / T 22237-2008. When a plate is inserted into a liquid, the interaction between the liquid and the plate generates an additional force. The surface tension of the liquid can be calculated using the Young-Laplace equation.

[0087] Demulsification time: Under the conditions of the above embodiment, the time required from the start of the reaction to the appearance of agglomerated products.

[0088] Total amount of agglomerates: under the conditions of the above embodiment, the total amount of agglomerates after the reaction is completed.

[0089] From Table 1 we can see that:

[0090] By comparing the emulsification ability, surface tension, demulsification time and total agglomeration amount of different commercially available sodium sulfonate surfactants, it can be clearly observed that the bio-based surfactant prepared by the present invention has excellent emulsification ability and the ability to reduce the surface energy of water. At the same time, it shows an excellent emulsification effect in the emulsion polymerization of fluorinated monomers, and the resulting emulsion is highly stable.

[0091] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A bio-based surfactant, characterized in that Its structural formula is as follows:

2. The method for preparing a bio-based surfactant according to claim 1, wherein: Place cyclosporine A, isopropyl alcohol, sodium bisulfite solution, organic base and initiator in a constant temperature oil bath and mix, and react at 39-42°C for 18-25 hours; The organic base comprises at least one of triethylamine, diisopropylamine and tetramethylethylenediamine; The initiator includes at least one of tert-butyl perbenzoate, benzoyl peroxide and tert-butyl hydroperoxide.

3. The preparation method according to claim 2, characterized in that Calculated by the molar ratio of the cyclosporin A, the sodium bisulfite is 2-5%; the organic base is 2-8%; and the initiator is 2-15% based on the mass of the cyclosporin.

4. The use of the bio-based surfactant as claimed in claim 1 as an emulsifier in the preparation of rubber emulsion, characterized in that: The rubber latex is a fluorine-containing polymer prepared by taking hexafluorobutyl acrylate and / or tridecafluorooctyl acrylate as raw materials.

5. Fluorinated acrylic polymer, characterized in that The fluorinated acrylate is obtained by polymerization reaction using fluorinated acrylate as raw material and the bio-based surfactant as claimed in claim 1 as emulsifier; the fluorinated acrylate is hexafluorobutyl acrylate or tridecafluorooctyl acrylate or a mixture of the two.

6. The method for preparing a fluorinated acrylic polymer according to claim 5, wherein: The following steps are involved: S1, mixing the fluorinated acrylate, the bio-based surfactant and a solvent to obtain a pre-emulsion; S2. In the presence of an initiator, mixing the pre-emulsion in step S1 with a solvent and initiating a reaction to obtain a reaction solution; S3, mixing the pre-emulsion and initiator in step S1 and the reaction solution prepared in step S2, and performing a polymerization reaction to obtain the fluorine-containing acrylate polymer; The initiator in step S2 and step S3 is potassium persulfate; The solvent in step S1 and step S2 includes water.

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