Environment-friendly fluorine-containing surfactant as well as preparation method and application thereof

Abstract

The invention discloses an environment-friendly fluorine-containing surfactant, a preparation method and application, the environment-friendly fluorine-containing surfactant has a structure as shown in a formula (I), R1 is selected from one or more of H and C2-C4 hydroxyalkyl, and R2 is selected from one or more of C2-C4 alkylene. A fluorine-containing monomer with a non-limited high-activity special structure is used as a raw material, different molecular structure types on two sides are designed according to the activity difference of acyl fluoride and sulfonyl fluoride at two ends, a double-end difference type surfactant compound is synthesized, and the surfactant has the advantages of a nonionic surfactant and an ionic surfactant at the same time. The water-oil compatibility is more excellent, the yield can reach 95% or above, and the water-oil compatibility is suitable for various industrial fields such as the coating industry, the cleaning industry, the protection field and the antifouling field. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the field of surfactant preparation, and in particular to an environmentally friendly fluorine-containing surfactant, a preparation method and application thereof. Background Art

[0002] Environmentally friendly fluorine-containing surfactants (fluorine containing surfactant) fluorinated surfactants (fluorinated surfactant) are a kind of surfactants with superior performance. This type of surfactant has mild performance and good cleaning, foaming and emulsification and stable chemical properties, so it has broad application prospects and development potential in the fields of daily chemical industry, textile printing and dyeing, electroplating and corrosion protection. In recent years, the research on environmentally friendly fluorine-containing surfactants has gradually become one of the most active research fields and development focuses in surfactants.

[0003] The hydrophobic group of ordinary surfactants is a long-chain alkane composed of hydrocarbon chains. Fluorocarbon surfactants are formed by replacing the hydrogen atoms of the hydrocarbon chains in ordinary surfactant molecules with fluorine atoms. The hydrophilic group of environmentally friendly fluorinated surfactants is the same as that of ordinary surfactants, so they can also be classified into anionic environmentally friendly fluorinated surfactants, cationic environmentally friendly fluorinated surfactants, nonionic environmentally friendly fluorinated surfactants and amphoteric environmentally friendly fluorinated surfactants. The unique fluorocarbon chain structure of environmentally friendly fluorinated surfactants gives them characteristics that non-environmentally friendly fluorinated surfactants are difficult to possess: ① It can significantly reduce the surface tension of aqueous solutions at extremely low addition concentrations; ② Extremely high surface activity; ③ High thermal stability and chemical stability; ④ Good compatibility: ⑤ It can dissolve oily substances and has good detergency, etc.

[0004] Currently, perfluorooctane sulfonic acid and its salts (PFOS) are widely used and paid attention to in the market because of their irreplaceable role in the application of fluorine-containing materials, fabric finishing agents, coatings, pigments, additives and other industries. However, recent studies have found that PFOS is difficult to degrade in the natural environment and has a high bioaccumulation. It is easy to accumulate in human and animal tissues and cause toxicity. It has been banned or restricted by countries around the world (including the European Union, the United States, Canada and other countries). Therefore, it is urgent to develop new fluorocarbon surfactants that meet environmental protection requirements to replace PFOS. This trend is becoming more and more severe under the modern green industrial situation.

[0005] Patent document CN104874328A discloses a hexafluoropropylene oligomer and hexafluoropropylene oxide oligomer type surfactant, which is a non-ionic environmentally friendly fluorinated surfactant produced by the reaction of an oxygen-containing compound with an active fluorinated chain segment. It has good hydrophilicity and low surface tension, but its yield is not high and requires a separation step, and the resulting fluorinated waste liquid is difficult to treat.

[0006] Patent CN 102784586 A discloses an environmentally friendly fluorinated surfactant, N-propyl-N-hydroxyethyl perfluorohexyl sulfonamide, the preparation method of which is as follows: alkylamine, triethylamine and isopropyl ether are mixed, perfluorohexyl sulfonyl fluoride is added in an ice bath, and heated to obtain N-propyl perfluorohexyl sulfonamide; N-propyl perfluorohexyl sulfonamide is dissolved in ethanol and potassium hydroxide is added, reacted for 1-3 hours, and then 2-chloroethanol is added, and heated to react for 12-24 hours to obtain the target product. The degree of surface tension reduction of the water system is not enough, which limits its application scope, and a large amount of wastewater is generated during the production process, which contains organic solvents and fluorides, etc., and is difficult to handle.

[0007] Patent CN 116286030 A discloses a low-foam, low-surface-tension environmentally friendly perfluoropolyether surfactant, which is prepared by mixing perfluoropolyether carboxylic acid ammonium anionic surfactant and defoamer at a mass ratio of 100:0.5-5. The low-foam, low-surface-tension perfluoropolyether surfactant has a good defoaming effect, but the defoamer in its formula contains inert perfluoropolyether oil, which will cause phase separation after being added to a fluorine-free system for a long time, thereby affecting product performance and greatly reducing the long-term defoaming effect.

[0008] Judging from the research and development technology in recent years, the existing preparation technologies of various types of environmentally friendly fluorinated surfactants that meet the PFOA / PFOS restriction requirements mostly have problems such as low reaction selectivity, low yield, difficult purification, and environmentally unfriendly production process. In addition, the resulting product is a single type of surfactant, which limits its application range in various fields. Summary of the invention

[0009] In order to overcome the problems existing in the prior art, the present invention provides an environmentally friendly fluorinated surfactant and a preparation method and application thereof. The environmentally friendly fluorinated surfactant compound is a hybrid dual-end surfactant, which has the advantages of both non-ionic and ionic surfactants, has mild and controllable preparation conditions, high selectivity, high yield, and an environmentally friendly process, and can replace perfluorooctanoic acid products in multiple industries.

[0010] The first aspect of the present invention provides an environmentally friendly fluorinated surfactant having a structure as shown in formula (I):

[0011]

[0012] Among them, R 1 One or more selected from H, C2-C4 hydroxyl groups, R 2 One or more selected from C2 to C4 alkylene groups.

[0013] More preferably, R 1 One or both selected from H or hydroxyethyl, R 2 One or more selected from ethylene, propylene or isopropylene.

[0014] The environmentally friendly fluorinated surfactant of the present invention is a hybrid dual-terminal surfactant, which has the advantages of both nonionic and ionic surfactants, has better water-oil compatibility, and can replace perfluorooctanoic acid products in various industries such as coatings and cleaning.

[0015] The second aspect of the present invention provides a method for preparing the above-mentioned environmentally friendly fluorinated surfactant, comprising the following steps:

[0016] Step 1, adding a fluorinated ether structure active monomer into a reaction kettle, adding a catalyst, dropping an alkyl alcohol amine at below 5°C, dispersing, and then heating to react to obtain an intermediate product;

[0017] Step 2, adding an ammonia solution to the intermediate product at a temperature below 5°C, dispersing it, then heating it to react, and filtering it after the reaction is completed to obtain a crude product of an environmentally friendly fluorinated surfactant;

[0018] Step 3, adjusting the pH of the crude environmentally friendly fluorinated surfactant to 8-10 to obtain the environmentally friendly fluorinated surfactant;

[0019] The structure of the fluorinated ether structure active monomer is shown in formula (II):

[0020]

[0021] Here, n is an integer from 2 to 8.

[0022] In the present invention, the fluorine-containing polyether active monomer reacts with an alkyl alcohol amine at low temperature and under the action of a catalyst, and then reacts with an ammonia solution, and after adjusting the pH, the environmentally friendly fluorine-containing surfactant is obtained. The fluorine-containing ether structure active monomer of the present invention has a double-end differentially active acyl fluoride end group, i.e., a carbonyl fluoride end group and a sulfonyl fluoride end group, the carbonyl fluoride activity is greater than the sulfonyl fluoride activity, and it has a significant difference when reacting with an amine-containing compound. Based on this activity difference effect, a double-end surfactant with different terminal properties can be prepared by controlling the synthesis process and the equivalent of the amine.

[0023] In the fluorinated ether structure active monomer of the present invention, n is an integer of 2 to 8. If n is too large, that is, the fluorinated ether chain is too long, the compatibility with water and oil may be deteriorated. If n is too large, the viscosity of the reaction system is too large and cannot be fully dispersed, and local overheating and incomplete reaction may occur when the alkyl alcohol amine is added dropwise. If n is too small, the surface tension increases due to the amplification of the tail effect, and the unique properties of the environmentally friendly fluorinated surfactant cannot be highlighted. Further preferably, n is an integer of 2 to 8. More preferably, n is an integer of 3 to 4.

[0024] Preferably, the catalyst is an acid-binding catalyst, including triethylamine, tripropylamine, tributylamine, potassium carbonate or a core-shell type acid-binding catalyst.

[0025] Preferably, the mass ratio of the added amount of the catalyst to the active monomer containing a fluorinated ether structure is 0.03-2.5:1.

[0026] More preferably, the acid-binding catalyst is a core-shell acid-binding catalyst, and the preparation method of the core-shell acid-binding catalyst is:

[0027] (1) adding nano-fumed silica, tetramethyldivinylsilazane, vinylalkoxysilane and water to an organic solvent A, stirring, reacting, and performing reduced pressure distillation after the reaction is completed to obtain an active nano-silica precursor;

[0028] (2) adding an organic solvent B, an active nano-silica precursor, styrene, fluorinated styrene and vinyl imidazole into a reactor, stirring, adding an initiator, and reacting. After the reaction is completed, spray drying the obtained product to obtain the core-shell acid-binding catalyst.

[0029] The core-shell acid-binding catalyst of the present invention is a multi-microporous acid-binding catalyst with nano silicon balls as the core and a polymer base as the shell. The surface of nano gas-phase silica is rich in silanol groups, and vinyl alkoxysilane and tetramethyl divinyl silazane are chemically bonded to the surface to obtain an active nano silica precursor, and then the active nano silica precursor is subjected to surface copolymerization reaction with unsaturated fluorinated styrene, styrene and vinyl imidazole to obtain a similar encapsulated shell. The vinyl monomer of the shell contains a large number of benzene rings, and the silazane in the precursor synergistically plays a skeleton support role, and after spray drying, it is shaped into a multi-microporous spherical particle.

[0030] The nano silicon spheres composed of the nano fumed silica core can absorb trace moisture in the first step of the reaction of the present invention, reduce the side reactions caused by the presence of water, and improve the conversion rate and selectivity of the reaction. The polymer-based shell has a relatively high compatibility with the fluorine-containing ether structure active monomer reaction system, improves the adsorption capacity of fluorine ions and hydrogen ions at the reaction site, has the effect of synergistically accelerating the reaction and improving the selectivity to avoid side reactions, promotes the reaction to proceed to the right, and further improves the conversion rate and selectivity of the reaction.

[0031] Preferably, the organic solvent A includes N,N-dimethylformamide or N,N-dimethylacetamide.

[0032] Preferably, the particle size of the nano-fumed silica is 50-80 nm. The present invention controls the particle size of the nano-fumed silica to 50-80 nm, which ensures that the catalyst has sufficient specific surface area and sufficient hydroxyl groups. Too small a particle size may cause subsequent filtration difficulties, and the removal of water during recycling is also relatively difficult.

[0033] Preferably, the vinyl alkoxysilane is one or both of vinyl ethoxysilane and vinyl diethoxysilane.

[0034] Preferably, the mass ratio of the organic solvent A, nano-fumed silica, tetramethyldivinylsilazane, vinylalkoxysilane and water is 20-50:15-25:0.2-0.5:0.4-0.8:0.01-0.05.

[0035] In the present invention, adding too much tetramethyldivinylsilazane will affect the number of hydroxyl groups, and because it contains more double bonds, the outer benzene ring structure may be too dense and the gaps may become smaller. Adding too little will result in too many residual hydroxyl groups and too few divinyl groups, resulting in insufficient strength of the particles.

[0036] Preferably, in step (1), the reaction temperature is 45-60° C. and the reaction time is 60-120 min.

[0037] Preferably, the organic solvent B is tetrahydrofuran or 2-methyltetrahydrofuran.

[0038] Preferably, the fluorinated styrene is at least one of 4-trifluoromethylstyrene, pentafluorostyrene, 2-trifluoromethylstyrene and 3-trifluoromethylstyrene. The fluorinated part of the fluorinated styrene has a relatively high compatibility with the reactive monomer reaction system containing a fluorinated ether structure on the surface, improves the adsorption capacity of fluoride ions and hydrogen ions at the reaction site, and has the effect of synergistically accelerating the reaction and improving the selectivity to avoid side reactions.

[0039] Preferably, the vinyl imidazole is one or both of 1-vinylimidazole and 2-methylvinylimidazole. Imidazole is a weakly alkaline compound, and the unsaturated vinyl group is copolymerized to form a part of the shell, which can adsorb fluoride ions and hydrogen ions to form an ionic liquid salt, promoting the reaction to the right, thereby improving the conversion rate and selectivity.

[0040] Preferably, the initiator includes azobisisobutyronitrile, azobisisovaleronitrile, benzoyl peroxide or diisopropyl peroxydicarbonate.

[0041] Preferably, the mass ratio of the organic solvent B, the active nano-silica precursor, styrene, fluorinated styrene, vinyl imidazole and the initiator is 40-60:5-20:0.1-0.5:0.3-0.5:0.2-0.8:0.05-0.3.

[0042] Preferably, in step (2), the reaction temperature is 50-75°C and the reaction time is 2-4h.

[0043] Preferably, the mass ratio of the core-shell type acid-binding catalyst to the fluorine-containing ether structure active monomer is 0.05-2:1.

[0044] Preferably, in step 1, the alkyl alcoholamine is at least one of ethanolamine, ethylene glycolamine, isopropanolamine or 3-aminopropanol. The fluorine-containing ether structure active monomer has two active end groups, carbonyl fluoride and sulfonyl fluoride. Carbonyl fluoride is more active than sulfonyl fluoride. Sulfonyl fluoride hardly reacts at low temperatures, while carbonyl fluoride reacts as soon as it comes into contact. After the alkyl alcoholamine is added dropwise, the alkyl alcoholamine first reacts with the carbonyl fluoride end group. By controlling the amount of the alkyl alcoholamine, the structure of the reaction product can be accurately controlled.

[0045] Preferably, in step 1, the molar ratio of the alkyl alcohol amine to the fluorine-containing ether structure active monomer is 0.95-1.1:1.

[0046] Preferably, in step 1, the dispersion time is 0.5-1 h, and then the temperature is raised to 10-60° C. and reacted for 1-4 h.

[0047] Preferably, in step 2, the ammonia solution is aqueous ammonia, and the molar ratio of aqueous ammonia to the active monomer containing a fluorine-containing ether structure is 1.05-1.2:1.

[0048] Preferably, in step 2, the dispersion time is 0.5-3h, and then the temperature is raised to 30-70°C for reaction for 1-6h.

[0049] Preferably, after step 2, calcium oxide is added to the reaction kettle to absorb excess F ions, thereby improving the purity and quality of the product.

[0050] The third aspect of the present invention provides the use of the above-mentioned environmentally friendly fluorinated surfactant in the fields of coatings, electroplating, cleaning, pesticides, protection, antifouling, etc. The environmentally friendly fluorinated surfactant of the present invention is a hybrid dual-terminal surfactant, which has the advantages of both nonionic and ionic surfactants, has excellent water-oil compatibility, and has broad application prospects in the fields of coatings, electroplating, cleaning, pesticides, protection, antifouling, etc.

[0051] Compared with the prior art, the present invention has at least the following beneficial effects:

[0052] (1) The present invention uses a new type of non-restricted high-activity special structure fluorine-containing monomer as a raw material, designs different molecular structure types on both sides through the activity difference of the double-ended acyl fluoride and sulfonyl fluoride, and synthesizes a double-ended differential surfactant compound, which is a hybrid new structure surfactant product. This surfactant has the advantages of both non-ionic and ionic surfactants and has better water-oil compatibility.

[0053] (2) The present invention designs a core-shell acid-binding catalyst for the reaction, which greatly improves the conversion rate, selectivity and product yield of the reaction, so that the conversion rate of the final product can exceed 98%, the selectivity exceeds 97% and the yield exceeds 95%.

[0054] (3) The core-shell acid-binding catalyst of the present invention can be used repeatedly, and the conversion rate and selectivity in the preparation of the environmentally friendly fluorinated surfactant compound of the present invention will not be significantly reduced after being used for more than 15 times, thereby saving costs and having obvious advantages in scale-up production.

[0055] (4) The environmentally friendly fluorinated surfactant prepared by the present invention has good stability, good compatibility and solubility with water and oil systems, and is suitable for various industrial fields, such as the coating industry, cleaning industry, protection, anti-fouling and other fields.

[0056] (5) The novel environmentally friendly fluorinated surfactant compound prepared by the present invention belongs to a new generation of degradable fluorinated compounds, is not within the scope of PFOA / PFOS restrictions, and does not have long-term environmental hazards.

[0057] (6) The synthesis process and conditions of the present invention are relatively mild, and do not involve high temperature and high pressure processes. The entire process does not generate waste gas, and the generated waste solids and waste liquids can also be easily disposed of, which is in line with the concept of modern industrial development and has the environmentally friendly advantage of scaled-up production. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is the infrared spectrum of the environmentally friendly fluorinated surfactant prepared in Example 1;

[0059] Figure 2This is the H-NMR spectrum of the environmentally friendly fluorinated surfactant prepared in Example 1. DETAILED DESCRIPTION

[0060] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0061] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0062] The present invention will be described in detail below by way of examples, but the protection scope of the present invention is not limited thereto. The experimental materials used in the following examples, unless otherwise specified, can be purchased from a biochemical reagent store.

[0063] The fluorinated ether structure active monomer used in the embodiment of the present invention is prepared by KF catalytic isomerization / addition under the conditions of solvent and auxiliary agent with tetrafluorosulfone and hexafluoropropylene oxide as raw materials. For details, reference can be made to the preparation of the intermediate pure product in step 1) of the preparation method in patent CN202210499054.1. This fluorinated ether structure active monomer has a structure with hexafluoropropoxy repeating chain segments, which has obvious degradability advantages compared to long-chain fluoroalkyl groups and is not included in the PFOA / PFOS restricted list.

[0064] Preparation of the core-shell acid-binding catalyst in the embodiment of the present invention:

[0065] SC-1: by weight: 15 parts of nanometer fumed silica (particle size = 60nm), 0.2 parts of tetramethyldivinylsilazane, 0.4 parts of vinylethoxysilane, 0.05 parts of water were added to 20 parts of N,N-dimethylformamide, the mixture was heated to 45°C and stirred for 60min, and then the active nanometer silica precursor was obtained by reduced pressure distillation; 60 parts of tetrahydrofuran, 5 parts of the aforementioned active nanometer silica precursor, 0.5 parts of styrene, 0.3 parts of 4-trifluoromethylstyrene, and 0.2 parts of 1-vinylimidazole were added to a closed autoclave, and the mixture was stirred and heated to 50°C after dehydration and deoxygenation, and 0.05 parts of azobisisobutyronitrile (30% concentration dissolved in chloroform) was added, the temperature was maintained for reaction for 4h, the mixture was cooled and discharged, and then the core-shell acid-binding catalyst of the present invention was obtained by spray drying.

[0066] SC-2: by weight: add 20 parts of nanometer fumed silica (particle size = 50nm), 0.35 parts of tetramethyldivinylsilazane, 0.5 parts of vinylethoxysilane, and 0.03 parts of water to 40 parts of N,N-dimethylformamide, heat to 50°C and stir for 90min, and then distill under reduced pressure to obtain an active nanometer silica precursor; add 50 parts of tetrahydrofuran, 15 parts of the aforementioned active nanometer silica precursor, 0.25 parts of styrene, 0.4 parts of pentafluorostyrene, and 0.6 parts of 2-methylvinylimidazole to a closed autoclave, remove water and oxygen, stir and heat to 65°C, add 0.1 parts of azobisisobutyronitrile (30% concentration dissolved in chloroform), maintain the temperature for reaction for 3h, cool down and discharge, and then spray dry to obtain the core-shell acid-binding catalyst of the present invention.

[0067] SC-3: by weight: add 25 parts of nanometer fumed silica (particle size = 80nm), 0.5 parts of tetramethyldivinylsilazane, 0.8 parts of vinyldiethoxysilane, and 0.01 parts of water to 50 parts of N,N-dimethylformamide, heat to 60°C and stir for 120min, and then distill under reduced pressure to obtain an active nanometer silica precursor; add 40 parts of tetrahydrofuran, 20 parts of the aforementioned active nanometer silica precursor, 0.1 parts of styrene, 0.5 parts of 3-trifluoromethylstyrene, and 0.8 parts of 2-methylvinylimidazole to a closed autoclave, remove water and oxygen, stir and heat to 75°C, add 0.3 parts of azobisisobutyronitrile (30% concentration dissolved in chloroform), maintain the temperature for reaction for 2h, cool down and discharge, and then spray dry to obtain the core-shell acid-binding catalyst of the present invention.

[0068] Comparative catalyst SC-04: tetramethyldivinylsilazane was not added, and the other components were the same as SC-01.

[0069] Comparative catalyst SC-05: no vinyl imidazole was added, and the rest was the same as SC-01.

[0070] Comparative catalyst SC-06: no fluorinated styrene was added, and the rest was the same as SC-01.

[0071] Preparation of environmentally friendly fluorinated surfactant compounds in Examples and Comparative Examples

[0072] Example 1

[0073] 1) Add 99.8 g of fluorinated ether structure active monomer (n=4) into a dehydrated and deoxygenated sealed reactor, add 9.98 g of SC-02 core-shell acid-binding catalyst to disperse, keep cold and slowly drop 6.1 g (0.1 mol) of ethanolamine and disperse for 1 hour, slowly heat to 40° C. and react for 2 hours to obtain an intermediate product;

[0074] 2) Cooling and keeping the synthesis kettle cold, dropping 11 g (0.11 mol) of 35% ammonia water into the kettle and dispersing for 1.5 hours, slowly heating to 50° C. to react for 3 hours, cooling and filtering to obtain the crude product of the environmentally friendly fluorinated surfactant compound of the present invention;

[0075] 3) Purification: Add 40 g of calcium oxide to the synthesis reactor, disperse at 30° C. for 2 h, adjust the pH to 9 with ammonia water, filter the material, and obtain the environmentally friendly surfactant compound.

[0076] Figure 1 and Figure 2 The infrared spectrum and nuclear magnetic hydrogen spectrum of the fluorinated surfactant of this embodiment are respectively. The structure of the main chain of the fluorinated surfactant of the present invention is a fluorinated ether structure active monomer. Since the reaction occurs at both ends of the fluorinated ether structure active monomer, the structures at both ends of the surfactant shown in the figure indicate that a surfactant with a structure of formula (III) is generated.

[0077]

[0078] Example 2

[0079] 1) Add 66.6 g of fluorinated ether structure active monomer (n=2) into a dehydrated and deoxygenated sealed reactor, add 3.33 g of SC-01 core-shell acid-binding catalyst to disperse, slowly add 8.3 g (0.11 mol) of isopropanolamine dropwise while keeping cold and disperse for 0.5 h, slowly heat to 10° C. and react for 1 h to obtain an intermediate product;

[0080] 2) cooling the synthesis kettle, dropping 13.1 g (0.105 mol) of 28% ammonia water into the kettle and dispersing for 3 hours, slowly heating to 30° C. to react for 6 hours, cooling and filtering to obtain the crude product of the environmentally friendly fluorinated surfactant compound of the present invention;

[0081] 3) Purification: adjusting the pH to 10 with aqueous ammonia, filtering the material to obtain the environmentally friendly surfactant compound.

[0082] Example 3

[0083] 1) Add 166.2 g of fluorinated ether structure active monomer (n=8) into a dehydrated and deoxygenated sealed reactor, add 33.24 g of SC-03 core-shell acid-binding catalyst to disperse, keep cold and slowly drop 5.8 g (0.095 mol) of ethanolamine and disperse for 1 h, slowly heat to 60° C. and react for 4 h to obtain an intermediate product;

[0084] 2) cooling the synthesis kettle, dropping 8.4 g (0.12 mol) of 50% ammonia water into the kettle and dispersing for 3 hours, slowly heating to 70° C. to react for 6 hours, cooling and filtering to obtain the crude product of the environmentally friendly fluorinated surfactant compound of the present invention;

[0085] 3) Purification: Add 100 g of calcium oxide to the synthesis reactor, disperse at 45° C. for 3 h, adjust the pH to 8 with ammonia water, filter the material, and obtain the environmentally friendly surfactant compound.

[0086] Recovery method of core-shell acid-binding catalyst: The core-shell acid-binding catalyst after the reaction in Example 3 is washed with 5 times the weight of 5% KOH, filtered, then washed twice with water and filtered, and dried in a vacuum oven for standby use, which is counted as one recovery.

[0087] Example 4: The core-shell acid-binding catalyst was replaced with a core-shell acid-binding catalyst recovered 14 times, and the rest was the same as Example 3.

[0088] Comparative Example 1: Triethylamine was used as the acid binding catalyst, and the rest was the same as Example 2.

[0089] Comparative Example 2: SC-04 was used instead of SC-01 as the acid binding catalyst, and the rest was the same as Example 2.

[0090] Comparative Example 3: SC-05 was used instead of SC-01 as the acid-binding catalyst, and the rest was the same as Example 2.

[0091] Comparative Example 4: SC-06 was used instead of SC-01 as the acid binding catalyst, and the rest was the same as Example 2.

[0092] Product Testing

[0093] The conversion rate and selectivity in the product detection method described in the present invention are the professional terms and general detection methods generally recognized by the chemical profession. The yield is defined as the ratio of the amount of the product obtained after step 3 described in the present invention to the theoretical yield * 100%, and the product grade is defined as follows: the yield exceeding 95% is grade A, 90%≤yield<95% is grade B, and the yield<90% is grade C.

[0094] According to the preparation methods of the environmentally friendly fluorinated surfactants of the embodiments and comparative examples of the present invention, the test results of the obtained products are shown in Table 1.

[0095] It can be seen from the table that the efficiency of the acid-bound catalyst used in the present invention does not deteriorate significantly when it is new and after being reused 15 times.

[0096] Comparative Example 1 uses triethylamine as the acid-binding catalyst, and its selectivity is significantly lower. Due to the dispersion of triethylamine, some reaction sites are too concentrated and some side reactions occur.

[0097] Compared with Example 2, in Comparative Example 2, no vinylsilazane is added, the hydroxyl sites in the inner core are not occupied, more residual hydroxyl groups are present, the micropores are larger, and the supporting strength of the outer shell is insufficient. The synergy between the components is poor, the specific surface area is reduced, the acid binding capacity is poor, and the conversion rate and selectivity are reduced.

[0098] Comparative Example 3 did not add vinyl imidazole, and its acid-binding catalytic effect was greatly reduced.

[0099] Comparative Example 4 did not add fluorinated styrene, resulting in poor compatibility of the acid-bound catalyst with the fluorine-containing phase, poor dispersion, and more prone to agglomeration, resulting in uneven reaction, poor conversion rate and selectivity.

[0100] Table 1

[0101] Example Conversion Rate % Selectivity% Yield % Product Grade Example 1 99.6 98.3 97.9 A Example 2 99.5 97.5 97.0 A Example 3 99.7 97.9 97.6 A Example 4 99.0 97.0 96.0 A Comparative Example 1 97.2 85.5 83.1 C Comparative Example 2 96.2 94.3 90.7 B Comparative Example 3 93.1 82.7 77.0 C Comparative Example 4 96.1 84.4 81.1 C

[0102] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An environmentally friendly fluorinated surfactant, characterized in that: It has a structure as shown in formula (I): Among them, R 1 One or more selected from H, C2-C4 hydroxyl groups, R 2 One or more selected from C2 to C4 alkylene groups.

2. The method for preparing an environmentally friendly fluorinated surfactant according to claim 1, characterized in that: The following steps are involved: Step 1, adding a fluorinated ether structure active monomer into a reaction kettle, adding a catalyst, dropping an alkyl alcohol amine at below 5°C, dispersing, and then heating to react to obtain an intermediate product; Step 2, adding an ammonia solution to the intermediate product at a temperature below 5°C, dispersing it, then heating it to react, and filtering it after the reaction is completed to obtain a crude product of an environmentally friendly fluorinated surfactant; Step 3, adjusting the pH of the crude environmentally friendly fluorinated surfactant to 8-10 to obtain the environmentally friendly fluorinated surfactant; The structure of the fluorinated ether structure active monomer is shown in formula (II): Here, n is an integer from 2 to 8.

3. The preparation method according to claim 2, characterized in that: The catalyst is an acid-binding catalyst; the mass ratio of the acid-binding catalyst to the active monomer containing fluorine ether structure is 0.03-2.5:

1.

4. The preparation method according to claim 3, characterized in that: The acid-binding catalyst is a core-shell type acid-binding catalyst, and the preparation method of the core-shell type acid-binding catalyst is as follows: (1) adding nano-fumed silica, tetramethyldivinylsilazane, vinylalkoxysilane and water to an organic solvent A, stirring, reacting, and performing reduced pressure distillation after the reaction is completed to obtain an active nano-silica precursor; (2) adding an organic solvent B, an active nano-silica precursor, styrene, fluorinated styrene and vinyl imidazole into a reactor, stirring, adding an initiator, and reacting. After the reaction is completed, spray drying the obtained product to obtain the core-shell acid-binding catalyst.

5. The preparation method according to claim 4, characterized in that: The particle size of the nano-gas phase silicon dioxide is 50-80nm.

6. The preparation method according to claim 4, characterized in that: The vinyl alkoxysilane is one or both of vinyl ethoxysilane and vinyl diethoxysilane; And / or, the fluorinated styrene is at least one of 4-trifluoromethylstyrene, pentafluorostyrene, 2-trifluoromethylstyrene and 3-trifluoromethylstyrene; And / or, the vinyl imidazole is one or both of 1-vinylimidazole and 2-methylvinylimidazole.

7. The preparation method according to claim 4, characterized in that: In step (1), the mass ratio of the organic solvent A, nano-fumed silica, tetramethyldivinylsilazane, vinylalkoxysilane and water is 20-50:15-25:0.2-0.5:0.4-0.8:0.01-0.05; the reaction temperature is 45-60°C, and the reaction time is 60-120min.

8. The preparation method according to claim 4, characterized in that: In step (2), the mass ratio of the organic solvent B, active nano-silica precursor, styrene, fluorinated styrene, vinyl imidazole and initiator is 40-60:5-20:0.1-0.5:0.3-0.5:0.2-0.8:0.05-0.3; the reaction temperature is 50-75°C, and the reaction time is 2-4h.

9. The preparation method according to any one of claims 4 to 8, characterized in that: The mass ratio of the core-shell type acid-binding catalyst to the fluorine-containing ether structure active monomer is 0.05-2:

1.

10. The preparation method according to claim 2, characterized in that: In step 1, the alkyl alcohol amine is at least one of ethanolamine, ethylene glycol amine, isopropanolamine or 3-aminopropanol; and the molar ratio of the alkyl alcohol amine to the fluorine-containing ether structure active monomer is 0.95-1.1:

1.

11. The preparation method according to claim 2, characterized in that: In step 1, the dispersion time is 0.5-1h, and then the temperature is raised to 10-60°C for reaction for 1-4h.

12. The preparation method according to claim 2, characterized in that: In step 2, the ammonia solution is aqueous ammonia, and the molar ratio of aqueous ammonia to the fluorine-containing ether structure active monomer is 1.05-1.2:

1.

13. The preparation method according to claim 2, characterized in that: In step 2, the dispersion time is 0.5-3h, and then the temperature is raised to 30-70°C for reaction for 1-6h.

14. Use of the environmentally friendly fluorinated surfactant according to claim 1 in the fields of coatings, electroplating, cleaning, pesticides, protection or antifouling.

Images