CN114195962B - Amphiphilic fluorine-containing block polymer and preparation method and application thereof - Google Patents

Abstract

The invention discloses a synthesis method of an amphiphilic fluorine-containing block polymer, which comprises the following steps: adding a first fluorine-free solvent, a RAFT reagent and a first initiator, carrying out mixed polymerization reaction on styrene and maleic anhydride, adding a solvent to dissolve a reaction product after the reaction, adding an alcohol solvent to precipitate, filtering the precipitate and drying to obtain a solid which is a macromolecular chain transfer agent; and B, adding the macromolecular chain transfer agent obtained in the step A, a second initiator and tridecafluorooctyl acrylate into a second non-fluorine-containing solvent, and reacting to obtain a transparent solution containing the polymer. In the polymer, the repeatability of the macromolecular segment of the styrene maleic anhydride is an integer between 5 and 30, and the repeatability of the tridecyl acrylate fluorooctyl unit is an integer between 5 and 30. The polymer disclosed by the invention has the advantages of good solubility in a fluorine-free solvent, high surface activity, few synthesis steps, low toxicity in the environment, easiness in degradation and good application prospect.

Description

Amphiphilic fluorine-containing block polymer and its preparation method and application

technical field

The invention relates to the field of new fluorine-containing materials, in particular to an amphiphilic fluorine-containing block polymer and its preparation method and application.

Background technique

Fluorosurfactants are usually composed of full fluorocarbon chains or partly fluorocarbon chains and hydrophilic groups, and have the characteristics of high activity, high heat resistance stability and high chemical stability. Among the fluorosurfactants, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) are the most widely used, but they are difficult to degrade and toxic in the environment, and are banned by most countries in the world.

Therefore, the development of a new degradable fluorosurfactant to fully replace the existing PFOS/PFOA fluorocarbon surfactant has received great attention from the scientific and industrial circles of various countries. The research and development orientation of alternatives can be roughly divided into two categories: (1) reducing the length of the perfluorocarbon chain; (2) introducing heteroatoms such as N, O, and methylene or methine into the fluorocarbon chain. However, the above orientations have the following problems: when the length of the perfluorocarbon chain decreases, its surface activity cannot meet the requirements in many fields; after introducing heteroatoms into the fluorocarbon chain, its crystallinity is significantly reduced, resulting in a decrease in its surface activity. Therefore, it is necessary to develop new short carbon chain fluorosurfactants to meet the requirements of the industry.

Gemini (Gemini) and Hetero-gemini (Hetero-gemini) surfactants refer to active agent monomers containing two hydrophobic groups (or three hydrophobic groups) and two hydrophilic groups. The surfactants obtained by linking groups at the groups were first synthesized by Zana (Langmuir 1991, 7, 1072.) and Jaeger (Langmuir 1996, 12, 4314) in the 1990s. Since the two hydrophilic head groups in the gemini surfactant molecule are connected by chemical bonds, stronger hydrophobic interactions are likely to occur between the alkyl chains, and the repulsion between the hydrophilic head groups is greatly weakened due to the effect of chemical bonds, which can be more tightly bonded. lined up. The interfacial properties of such surfactants in aqueous media are one to several orders of magnitude higher than those of traditional surfactants. However, such structures usually have many and complicated synthesis steps in the preparation process, and there is still a certain distance from the application.

Fluoropolymers, especially the polymerization of trifluorooctyl acrylate, usually need to be synthesized in a special fluorine-containing solvent, such as benzotrifluoride, to obtain a transparent solution. In ordinary solvents, it tends to precipitate out. For example, Yuan Jinying et al. (Macromolecular Rapid Communications, 2018: 1700840) showed that poly(dimethylaminoethyl methacrylate) was used as a macromolecular chain transfer agent to initiate the polymerization of trifluorooctyl acrylate. , the resulting blocks are insoluble in isopropanol, toluene, dioxane, and dimethylformamide, which is unfavorable for practical applications.

Contents of the invention

The object of the present invention is to develop an environment-friendly fluorine-containing surfactant in order to solve the replacement problem of fluorine-containing surfactant, that is, to develop a simple synthesis method of a gemini-like fluorine-containing surfactant.

Another object of the present invention is to invent a method for synthesizing a fluorine-containing block polymer with good solubility in an environment-friendly solvent.

The present invention solves its technical problems by adopting the following technical solutions.

A kind of amphiphilic fluorine-containing block polymer, the structure of this polymer is shown in general formula (I):

In the general formula (I), R ₁ is the leaving group of the RAFT reagent, Z is the stabilizing group of the RAFT reagent, R ₂ is -(CF ₂ ) ₅ CF ₃ , wherein m is an integer between 5 and 30 , n is an integer between 5 and 30.

As a further improvement of the amphiphilic fluorine-containing block polymer of the present invention, the R ₁ is -C(CH ₃ ) ₂ -COOH, Z is CH ₃ (CH ₂ ) ₁₁ -S-(C=S)- S-.

As a further improvement of the amphiphilic fluorine-containing block polymer of the present invention, said m is an integer between 10-25, and n is an integer between 10-20.

The present invention also proposes a method for preparing the above-mentioned amphiphilic fluorine-containing block polymer, comprising the following steps:

A: Under the condition of adding the first fluorine-free solvent, RAFT reagent and the first initiator at the temperature of -20°C to 25°C, mix styrene and maleic anhydride in a molar ratio of 1 to 1.2:1, and the obtained The molar ratio of the maleic anhydride, the RAFT reagent and the first initiator is 5-30:1:0.01-0.2, the reaction environment is set to an oxygen-free environment, and then the temperature is raised to 50-90°C to carry out the polymerization reaction 8-24h, after the reaction, add a solvent (such as butanone, methyl isobutyl ketone, propylene glycol methyl ether acetate, etc.) to dissolve the reaction product, and then add another solvent (which can be an alcoholic solvent, such as methanol, or It is a non-alcoholic solvent, such as n-hexane, a solvent that can precipitate styrene-maleic anhydride macromolecular chains) to separate out the precipitate, filter the precipitate and dry to obtain a solid that is a macromolecular chain transfer agent;

B: the macromolecular chain transfer agent obtained in step A, the second initiator and trifluorooctyl acrylate are added in the second fluorine-free solvent, and the tridefluorooctyl acrylate, macromolecular chain transfer agent and The molar ratio of the second initiator is 5-30:1:0.1-0.5, the reaction is carried out at 60-100° C. for 8-24 hours, and a transparent solution containing the polymer is obtained through the reaction.

As a further improvement of the preparation method of the amphiphilic fluorine-containing block polymer of the present invention, the described RAFT agent is 2-(dodecyltrithiocarbonate)-2-methyl propionic acid; Both the first initiator and the second initiator are azobisisobutyronitrile.

As a further improvement of the preparation method of the amphiphilic fluorine-containing block polymer of the present invention, in step A, the first fluorine-free solvent is butanone, acetone, methyl isobutyl ketone and propylene glycol methyl ether acetic acid One of the esters.

As a further improvement of the preparation method of the amphiphilic fluorine-containing block polymer of the present invention, in step B, the second fluorine-free solvent is a mixture of butanone and butyl acetate according to a mass ratio of 1:0.5-2 solvent.

As a further improvement of the preparation method of the amphiphilic fluorine-containing block polymer of the present invention, in step A, styrene and maleic anhydride are mixed at a molar ratio of 1:1.

As a further improvement of the preparation method of the amphiphilic fluorine-containing block polymer of the present invention, in step A, the molar ratio of maleic anhydride and RAFT reagent is 10 to 25:1; The molar ratio of octyl ester to macromolecular chain transfer agent is 10-20:1.

The application of the above-mentioned amphiphilic fluorine-containing block polymers is that the polymers are used as surfactants in detergents and cosmetics.

The beneficial effects of the invention are: a simple synthesis method of a gemini-type fluorine-containing surfactant is developed, and an environment-friendly amphiphilic fluorine-containing block polymer is obtained. In the polymer, the repeating degree of styrene maleic anhydride macromolecular segment (indicated by m, hydrophilic group) is an integer between 5 and 30, and the repeating degree of trifluorooctyl acrylate unit (indicated by n , hydrophobic group) is an integer between 5 and 30. During synthesis, as the chain length of the polystyrene maleic anhydride macromolecular transfer agent increases, the activity of the obtained polymer gradually decreases, and the properties of the amphiphilic fluorine-containing block polymer are similar to that of the gemini-type fluorine-containing surfactant. Polymer fluorosurfactant transition. At the same time, the length of the macromolecular chain transfer agent has a significant impact on the solvability of the amphiphilic fluorine-containing block polymer. When the number of monomer units in the molecule is less than 5, the solubility in common solvents is significantly reduced. The surface activity of this amphiphilic fluorine-containing block polymer is also related to the amount of fluorine-containing monomer. When the content of trifluorooctyl acrylate in the block polymer is less than 5, the property of reducing surface tension is not obvious ; And when its content is greater than 30, the resulting fluorine-containing block polymer is insoluble in common solvents. The polymer of the present invention has good solubility in fluorine-free solvents (such as isopropanol, toluene, dioxane and dimethylformamide), high surface activity, few synthesis steps, low toxicity and easy degradation in the environment , has a good application prospect.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

The amphiphilic fluorine-containing block polymer of the present invention and its preparation method are specifically described below.

The present invention proposes an amphiphilic fluorine-containing block polymer, the structure of which is shown in general formula (I):

R ₁ is the leaving group of the RAFT reagent, Z is the stabilizing group of the RAFT reagent, R ₂ is -(CF ₂ ) ₅ CF ₃ , wherein m is an integer between 5 and 30, and n is between 5 and 30 an integer between .

RAFT reagents are a class of compounds with reversible addition-fragmentation chain transfer properties, and their molecular structures should have chemical bonds that are prone to addition reactions and fragmentation reactions. RAFT reagents have the function of controlling the molecular weight of polymers.

A preferred RAFT agent is 2-(dodecyltrithiocarbonate)-2-methylpropanoic acid (DDMAT, CAS: 461642-78-4). The R1 is -C(CH3)2-COOH, and Z is CH3(CH2)11-S-(C=S)-S-.

Ordinary trithioesters and dithioesters are common RAFT reagents. For their structural formulas and uses, please refer to: Macromolecules 2012, 45, 13, 5321–5342; compared with other RAFT reagents, DDMAT is easy to synthesize and has good regulation performance. The narrow molecular weight distribution of the polymer is therefore the best choice for the controlled preparation of this block polymer.

Furthermore, in the amphiphilic fluorine-containing polymer, m is an integer between 10 and 25, and n is an integer between 10 and 20, and the fluorine-containing block polymerization within this range It has better solubility and surface activity than substances outside the range.

In this polymer, the subscript m internal group is a 1:1 alternating copolymer chain formed by styrene and maleic anhydride, and its length affects the surface activity of the final polymer, with the transfer of polystyrene maleic anhydride macromolecules As the chain length of the agent increases, the activity of the obtained fluorosurfactant gradually decreases, and the properties of the amphiphilic fluorosurfactant are like a transition from a gemini-type fluorosurfactant to a polymer-type fluorosurfactant. At the same time, the length of the macromolecular chain transfer agent has a significant impact on the solvability of the amphiphilic fluorine-containing block polymer. When the number of monomer units in the molecule is less than 5, the solubility in common solvents is significantly reduced. The surface activity of the amphiphilic fluorine-containing block polymer in the present invention is also related to the amount of fluorine-containing monomer, when the content of trifluorooctyl acrylate (subscript n indicated group) is less in the block polymer When the content is greater than 5, the property of reducing surface tension is not obvious; and when the content is greater than 30, the resulting fluorine-containing block polymer is insoluble in common solvents.

The present invention also provides a preparation method for this type of amphiphilic fluorine-containing block polymer, comprising the following steps: A: firstly, at a temperature of -20 to 25°C, such as in an ice-water bath, under the condition of adding RAFT reagent and a free radical initiator Next, polymerize styrene and maleic anhydride at a molar ratio of 1 to 1.2:1, and the molar ratio of maleic anhydride, RAFT reagent and initiator is 5 to 30:1:0.01 to 0.2, vacuum and nitrogen, and then Raise the temperature to 50-90°C, react for 8-24 hours, add acetone, methyl ethyl ketone, methyl isobutyl ketone or propylene glycol methyl ether acetate to dissolve, then precipitate in methanol or other alcohol solvents, filter the precipitate and dry it to obtain The solid is a macromolecular chain transfer agent. Free radical initiators can be azo-based, such as azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanonitrile, azobisisobutyrate dimethyl ester, etc.; it can also be a peroxide , such as dibenzoyl peroxide, di-tert-butyl peroxide, tert-butyl peroxide benzoate, dicumyl peroxide, dilauroyl peroxide, etc. The preferred RAFT agent is DDMAT ((2-dodecyltrithiocarbonate)-2-methylpropionic acid), which is easy to synthesize and has good regulation performance on the system. The preferred initiator is azobisisobutyronitrile (AIBN), and the molar ratio of styrene and maleic anhydride is 1:1, because maleic anhydride and styrene are easy to form electron-complexing copolymers, and maleic anhydride is not easy to homogeneously Polymerization, when it is excessive, only oligomers can be obtained; although styrene can be homopolymerized, its polymerization rate is very slow, so the molar ratio of styrene and maleic anhydride is selected as 1:1 to synthesize macromolecular chain transfer agent.

B: the macromolecular chain transfer agent, initiator and trifluorooctyl acrylate gained in step A are joined in the fluorine-free solvent, and the mol ratio of tridefluorooctyl acrylate, macromolecular chain transfer agent and initiator is 5～30:1:0.1～0.5, react at 60～100°C for 8～24h, and obtain a transparent polymer solution. Trifluorooctyl acrylate monomer is soluble in common solvents, such as acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, etc., but its polymer is insoluble in common solvents, and usually requires special Solvents, such as fluorine-containing solvents, etc. Therefore, the present invention improves its solubility by first introducing SMA copolymer (styrene maleic anhydride), which is easily soluble in common solvents, and at the same time introduces hydrophilic groups, while controlling polyacrylic acid thirteen by active controllable polymerization. The chain length of octylfluorooctyl, found in the present invention, when the repeating unit of octyl trifluorooctyl acrylate is controlled below 30, the polymer is dissolved in common solvents, and when it is higher than 30, there will be precipitation .

When preparing SMA (styrene-maleic anhydride) macromolecular chain transfer agent, common solvents, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol methyl ether acetate, or other solvents that can dissolve SMA polymers Any solvent can be used as a polymerization solvent. When preparing the copolymer of trifluorooctyl acrylate, it is necessary to add a lipid solvent to improve its solubility, and butyl acetate is a good choice.

The mol ratio of styrene and maleic anhydride and RAFT reagent has determined the molecular weight of macromolecular chain transfer agent, in order to keep gained fluorine-containing block polymer to have good solubility and the performance that reduces surface tension, in step A, select The molar ratio of styrene and maleic anhydride is 1:1, and the molar ratio of maleic anhydride and RAFT agent is 10˜25:1, so that m=10˜25. In step B, the molar ratio of trifluorooctyl acrylate to the macromolecular chain transfer agent is 10-20:1, so that n=10-20. The molecular weight of the macromolecular chain transfer agent increases, which can improve its solubility, but the final performance of reducing surface tension will decrease.

The characteristics and performance of the present invention will be described in further detail below in conjunction with the examples.

Example 1

This example provides a method for preparing an amphiphilic fluorine-containing block polymer, which includes the following steps A and B to prepare an amphiphilic fluorine-containing block polymer:

A: Under ice-water bath conditions, add butanone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 5.58g (0.0153mol), azobisisobutyronitrile 0.251 in a 100ml single-necked flask g (0.00153mol), vacuumize and circulate nitrogen for 3 times, then adjust the temperature to 70°C, and react for 12h. Add butanone to dissolve, then precipitate in methanol to obtain a macromolecular chain transfer agent, filter to obtain the precipitate and carry out vacuum drying at 100 ° C to obtain 35.6 g of solids, with a yield of 97.6%, the macromolecular chain transfer agent (that is, the precipitate) The chemical composition is DDMAT-(maleic anhydride-styrene macromolecular chain) _m . GPC (gel permeation chromatography) test the molecular weight of the macromolecular chain transfer agent, Mn=2400, _MP =2590, PDI=1.08. Wherein, Mn is the number average molecular weight of the macromolecular chain transfer agent. _MP is the highest molecular weight of the macromolecular chain transfer agent. PDI is the dispersion coefficient of the macromolecular chain transfer agent, the closer the PDI is to 1, the more uniform the molecular weight of the macromolecular chain transfer agent. Wherein, the molecular weight Mr1 of maleic anhydride is 98, the molecular weight Mr2 of styrene is 104, and the molecular weight Mr3 of DDMAT is 365. According to the structural formula (I), it can be seen that m=(Mn-Mr3)÷(Mr1+Mr2)=(2400-365)÷(98+104)=10.1.

B: Add 8g (0.0033mol) of the macromolecular chain transfer agent prepared in step A to a 100ml one-mouth bottle, dissolve it with 20g butanone, then add 14g (0.0335mol) of trifluorooctyl acrylate, 20g of butyl acetate, azo 1.082 g (0.00066 mol) of diisobutyronitrile was reacted at 80° C. for 12 hours to obtain a light yellow transparent solution, and the amphiphilic fluorine-containing block polymer obtained by polymerization was dissolved in the solution. The conversion rate of tridecfluorooctyl acrylate was tested to be 95.2%, and the polymer molecular weight was measured by GPC, Mn=6440, _MP =7400, PDI=1.15. Wherein, Mn is the number average molecular weight of the polymer. _MP is the highest molecular weight of the polymer. PDI is the dispersion coefficient of the polymer, and the closer the PDI is to 1, the more uniform the molecular weight of the polymer. The molecular weight Mr4 of trifluorooctyl acrylate is 418. According to the structural formula (I), it can be seen that n=(6440-2400)÷Mr4=4040÷418=9.7.

Example 2

This example provides a method for preparing an amphiphilic fluorine-containing block polymer, which includes the following steps A and B to prepare an amphiphilic fluorine-containing block polymer:

A: Under ice-water bath condition, add methyl isobutyl ketone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 5.58g (0.0153mol), azobis 0.251 g (0.00153 mol) of isobutyronitrile, evacuated and circulated with nitrogen for 3 times, then adjusted the temperature to 75°C, and reacted for 16 hours. Add methyl isobutyl ketone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100 ° C to obtain 35.1 g of solid (macromolecular chain transfer agent), yield 96.2%, GPC test molecular weight, Mn=2300, _MP = 2490, PDI = 1.08. m=(Mn-Mr3)÷(Mr1+Mr2)=(2300-365)÷(98+104)=9.6.

B: Add 8g (0.0035mol) of macromolecular chain transfer agent prepared in step A in a 100ml one-port bottle, dissolve with 20g butanone, then add 14.84g (0.0355mol) of trifluorooctyl acrylate, 20g of butyl acetate, even 1.082 g (0.00066 mol) of nitrogen bisisobutyronitrile was reacted at 85° C. for 16 hours to obtain a light yellow transparent solution, and the amphiphilic fluorine-containing block polymer obtained by polymerization was dissolved in the solution. The conversion rate of tridecafluorooctyl acrylate was tested to be 95.6%, and the molecular weight of the polymer was tested by GPC, Mn=6350, _MP =7240, PDI=1.14. n=(6350-2300)÷418=9.7.

Example 3

This example provides a method for preparing an amphiphilic fluorine-containing block polymer, which includes the following steps A and B to prepare an amphiphilic fluorine-containing block polymer:

A: Under the condition of ice-water bath, add 30g of methyl isobutyl ketone, 15g (0.153mol) of maleic anhydride, 15.9g (0.153mol) of styrene, 2.79g (0.0077mol) of DDMAT, azobis 0.126 g (0.00077 mol) of isobutyronitrile, vacuumed and circulated with nitrogen for 3 times, then adjusted the temperature to 90°C, and reacted for 8 hours. Add methyl isobutyl ketone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100 ° C to obtain 32.1 g of solid (macromolecular chain transfer agent), yield 95.3%, GPC test molecular weight, Mn=4280, _MP = 4540, PDI = 1.06. m=(4280-365)÷(98+104)=19.4.

B: Add 8g (0.0018mol) of the macromolecular chain transfer agent prepared in part A in a 100ml single-mouth bottle, dissolve it with 20g butanone, then add 14.38g (0.0188mol) of trifluorooctyl acrylate, 20g of butyl acetate, and 1.082 g (0.00066 mol) of nitrogen diisobutyronitrile was reacted at 100° C. for 24 hours to obtain a light yellow transparent solution, and the amphiphilic fluorine-containing block polymer obtained by polymerization was dissolved in the solution. The conversion rate of tridecafluorooctyl acrylate was tested to be 95.9%, and the polymer molecular weight was measured by GPC, Mn=8450, _MP =9550, PDI=1.13. n=(8450-4280)÷418=10.0.

Example 4

This example provides a method for preparing an amphiphilic fluorine-containing block polymer, which includes the following steps A and B to prepare an amphiphilic fluorine-containing block polymer:

A: Under ice-water bath conditions, add butanone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 3.71g (0.0102mol), azobisisobutyronitrile 0.167 in a 100ml single-necked flask g (0.00102mol), evacuate and circulate nitrogen for 3 times, then adjust the temperature to 60°C, and react for 24h. Add butanone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100°C to obtain 32.5 g of solid (macromolecular chain transfer agent), yield 93.9%, GPC molecular weight, Mn=3380, _MP =3620 , PDI = 1.07. m=(3380-365)÷(98+104)=14.9.

B: Add 8g (0.0024mol) of the macromolecular chain transfer agent prepared in part A in a 100ml single-mouth bottle, dissolve it with 20g butanone, then add 15.1g (0.037mol) of trifluorooctyl acrylate, 20g of butyl acetate, and 0.0787 g (0.00048 mol) of nitrogen bisisobutyronitrile was reacted at 60°C for 8 hours to obtain a light yellow transparent solution, and the amphiphilic fluorine-containing block polymer obtained by polymerization was dissolved in the solution. The conversion rate of tridecafluorooctyl acrylate was tested to be 97.6%, and the polymer molecular weight was measured by GPC, Mn=9660, _MP =11850, PDI=1.23. n=(9660-3380)÷418=15.0.

Example 5

This example provides a method for preparing an amphiphilic fluorine-containing block polymer, which includes the following steps A and B to prepare an amphiphilic fluorine-containing block polymer:

A: Under ice-water bath conditions, add propylene glycol methyl ether acetate 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 2.23g (0.0061mol), azobisiso 0.167 g (0.00102 mol) of butyronitrile, vacuumed and circulated with nitrogen for 3 times, then adjusted the temperature to 80°C, and reacted for 24 hours. Add propylene glycol methyl ether acetate to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100 ° C to obtain 31.4 g of solid (macromolecular chain transfer agent), yield 94.8%, GPC test molecular weight, Mn=5350, M _P =5830, PDI=1.09. m=(5350-365)÷(98+104)=24.7.

B: Add 8g (0.0015mol) of the macromolecular chain transfer agent prepared in part A in a 100ml single-mouth bottle, dissolve it with 20g butanone, then add 12.65g (0.0303mol) of trifluorooctyl acrylate, 20g of butyl acetate, and 0.0787 g (0.00048 mol) of nitrogen bisisobutyronitrile was reacted at 70° C. for 16 hours to obtain a light yellow transparent solution, and the amphiphilic fluorine-containing block polymer obtained by polymerization was dissolved in the solution. The conversion rate of tridecafluorooctyl acrylate was tested to be 98.3%, and the polymer molecular weight was measured by GPC, Mn=13660, _MP =16800, and PDI=1.23. n=(13660-5350)÷418=19.9.

Example 6

This example provides a method for preparing an amphiphilic fluorine-containing block polymer, which includes the following steps A and B to prepare an amphiphilic fluorine-containing block polymer:

A: Under ice-water bath conditions, add butanone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 11.3g (0.031mol), azobisisobutyronitrile 0.167 in a 100ml single-necked flask g (0.00102mol), evacuate and circulate nitrogen for 3 times, then adjust the temperature to 60°C, and react for 24h. Add butanone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100°C to obtain 39.83 g of solid (macromolecular chain transfer agent), with a yield of 94.4%, and the molecular weight measured by GPC, Mn=1350, _MP =1480 , PDI=1.1. m=(1350-365)÷(98+104)=4.9.

B: Add 8g (0.0059mol) of the macromolecular chain transfer agent prepared in part A in a 100ml one-mouth bottle, dissolve it with 20g butanone, then add 12.89g (0.0308mol) of trifluorooctyl acrylate, 20g of butyl acetate, and 0.0969 g (0.00059 mol) of nitrogen bisisobutyronitrile was reacted at 80° C. for 16 hours to obtain a light yellow transparent solution, and the amphiphilic fluorine-containing block polymer obtained by polymerization was dissolved in the solution. The conversion rate of tridecfluorooctyl acrylate was tested to be 96.6%, and the polymer molecular weight was measured by GPC, Mn=3460, _MP =4150, PDI=1.20. n=(3460-1350)÷418=5.0.

Example 7

This example provides a method for preparing an amphiphilic fluorine-containing block polymer, which includes the following steps A and B to prepare an amphiphilic fluorine-containing block polymer:

A: Under ice-water bath conditions, add 30g of acetone, 15g (0.153mol) of maleic anhydride, 15.9g (0.153mol) of styrene, 1.86g (0.0051mol) of DDMAT, and 0.167g of azobisisobutyronitrile into a 100ml single-necked flask (0.00102mol), vacuumize and circulate nitrogen for 3 times, then adjust the temperature to 50°C, and react for 24h. Add acetone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100 ° C to obtain 30.89 g of solid (macromolecular chain transfer agent), yield 94.3%, GPC test molecular weight, Mn=6360, _MP =6870, PDI = 1.08. m=(6360-365)÷(98+104)=29.7.

B: Add 8g (0.0013mol) of the macromolecular chain transfer agent prepared in part A in a 100ml single-mouth bottle, dissolve it with 20g butanone, then add 15.1g (0.037mol) of trifluorooctyl acrylate, 20g of butyl acetate, and 0.0787 g (0.00048 mol) of nitrogen bisisobutyronitrile was reacted at 80° C. for 16 hours to obtain a light yellow transparent solution, and the amphiphilic fluorine-containing block polymer obtained by polymerization was dissolved in the solution. The conversion rate of tridefluorooctyl acrylate was tested to be 96.2%, and the polymer molecular weight was measured by GPC, Mn=18690, _MP =22050, and PDI=1.18. n=(18690-6360)÷418=29.5.

Example 8

This example provides a method for preparing an amphiphilic fluorine-containing block polymer, which includes the following steps A and B to prepare an amphiphilic fluorine-containing block polymer:

A: Under ice-water bath conditions, add butanone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 1.90g (0.0052mol), azobisisobutyronitrile 0.167 in a 100ml single-necked flask g (0.00102mol), evacuate and circulate nitrogen for 3 times, then adjust the temperature to 60°C, and react for 24h. Add butanone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100°C to obtain 31.2 g of solid (macromolecular chain transfer agent), yield 95.0%, GPC molecular weight, Mn=6080, _MP =6750 , PDI=1.11. m=(6080-365)÷(98+104)=28.3.

B: Add 8g (0.0013mol) of the macromolecular chain transfer agent prepared in part A in a 100ml single-mouth bottle, dissolve it with 20g butanone, then add 3.0g (0.0072mol) of trifluorooctyl acrylate, 10g of butyl acetate, and 0.0213 g (0.00013 mol) of nitrogen bisisobutyronitrile was reacted at 80° C. for 16 hours to obtain a light yellow transparent solution, and the amphiphilic fluorine-containing block polymer obtained by polymerization was dissolved in the solution. The conversion rate of tridecfluorooctyl acrylate was tested to be 93.9%, and the polymer molecular weight was measured by GPC, Mn=8250, _MP =9900, PDI=1.20. n=(8250-6080)÷418=5.2.

Example 9

This example provides a method for preparing an amphiphilic fluorine-containing block polymer, which includes the following steps A and B to prepare an amphiphilic fluorine-containing block polymer:

A: Under the condition of ice-water bath, add butanone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 10.22g (0.028mol), azobisisobutyronitrile 0.046 in a 100ml single-necked flask g (0.00028mol), evacuate and circulate nitrogen for 3 times, then adjust the temperature to 60°C, and react for 24h. Add butanone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100 ° C to obtain 39.1 g of solid (macromolecular chain transfer agent), with a yield of 95.1%, and the molecular weight measured by GPC, Mn = 1480, M _P = 1610 , PDI = 1.09. m=(1480-365)÷(98+104)=5.5.

B: Add 8g (0.0054mol) of the macromolecular chain transfer agent prepared in part A in a 100ml one-mouth bottle, dissolve it with 20g butanone, then add 67.8g (0.162mol) of trifluorooctyl acrylate, 40g of butyl acetate, and 0.4433 g (0.0027 mol) of nitrogen bisisobutyronitrile was reacted at 80° C. for 16 hours to obtain a light yellow transparent solution, and the amphiphilic fluorine-containing block polymer obtained by polymerization was dissolved in the solution. The conversion rate of trifluorooctyl acrylate was tested to be 97.3%, and the polymer molecular weight was measured by GPC, Mn=13680, _MP =16560, PDI=1.21. n=(13680-1480)÷418=29.2.

Comparative example 1

This comparative example provides a method for preparing a fluorine-containing block polymer with an excessively long hydrophobic fluorine chain, comprising the following steps A and B to prepare a fluorine-containing block polymer:

A: Under the condition of ice-water bath, add butanone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 10.22g (0.028mol), azobisisobutyronitrile 0.046 in a 100ml single-necked flask g (0.00028mol), evacuate and circulate nitrogen for 3 times, then adjust the temperature to 60°C, and react for 24h. Add butanone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100 ° C to obtain 39.1 g of solid (macromolecular chain transfer agent), with a yield of 95.1%, and the molecular weight measured by GPC, Mn = 1480, M _P = 1610 , PDI = 1.09. m=(1480-365)÷(98+104)=5.5.

B: Add 8g (0.0054mol) of the macromolecular chain transfer agent prepared in part A in a 100ml one-mouth bottle, dissolve it with 20g butanone, then add 93.97g (0.2248mol) of trifluorooctyl acrylate, 40g of butyl acetate, and Azodiisobutyronitrile 0.4433g (0.0027mol) was reacted at 80°C for 16h to obtain a turbid yellow solution with gel precipitation on the wall of the bottle. The conversion rate of tridecafluorooctyl acrylate was tested to be 96.8%, and the polymer molecular weight was measured by GPC, Mn=18330, _MP =24400, PDI=1.33. n=(18330-1480)÷418=40.3.

Comparative example 2

This comparative example provides a method for preparing a fluorine-containing block polymer with an overlong hydrophilic macromolecular segment, comprising the following steps A and B to prepare a fluorine-containing block polymer:

A: Under the condition of ice-water bath, add butanone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 1.387g (0.0038mol), azobisisobutyronitrile 0.046 in a 100ml single-necked flask g (0.00028mol), evacuate and circulate nitrogen for 3 times, then adjust the temperature to 60°C, and react for 24h. Add butanone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100°C to obtain 30.6 g of solid (macromolecular chain transfer agent), yield 94.6%, GPC molecular weight, Mn = 8550, M _P = 10100 , PDI = 1.18. m=(8550-365)÷(98+104)=40.5.

B: Add 8g (0.0009mol) of the macromolecular chain transfer agent prepared in part A in a 100ml single-mouth bottle, dissolve it with 20g butanone, then add 4.055g (0.0097mol) of trifluorooctyl acrylate, 40g of butyl acetate, and Azodiisobutyronitrile 0.0657g (0.0004mol) was reacted at 80°C for 16h to obtain a light yellow transparent solution. The conversion rate of tridefluorooctyl acrylate was tested to be 95.1%, and the polymer molecular weight was measured by GPC, Mn=12850, _MP =16580, PDI=1.29. n=(12850-8550)÷418=10.3.

Comparative example 3

This comparative example provides a method for preparing a fluorine-containing block polymer in which both the hydrophilic macromolecular segment and the hydrophobic fluorine chain are too short, including the following steps A and B to prepare a fluorine-containing block polymer:

A: Under ice-water bath conditions, add butanone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 14.6g (0.040mol), azobisisobutyronitrile 1.3136 in a 100ml single-necked flask g (0.008mol), evacuate and circulate nitrogen for 3 times, then adjust the temperature to 60°C, and react for 24h. Add butanone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100°C to obtain 42.4 g of solid (macromolecular chain transfer agent), yield 93.2%, GPC molecular weight, Mn = 1070, M _P = 1240 , PDI = 1.16. m=(1070-365)÷(98+104)=3.5.

B: Add 8g (0.0075mol) of the macromolecular chain transfer agent prepared in part A in a 100ml one-mouth bottle, dissolve it with 20g butanone, then add 10.95g (0.0262mol) of trifluorooctyl acrylate, 40g of butyl acetate, and Azodiisobutyronitrile 0.4433g (0.0027mol) was reacted at 80°C for 16h to obtain a turbid yellow solution with gel precipitation on the wall of the bottle. The conversion rate of tridecfluorooctyl acrylate was tested to be 94.5%, and the polymer molecular weight was measured by GPC, Mn=2450, _MP =3280, PDI=1.34. n=(2450-1070)÷418=3.3.

Comparative example 4

This comparative example provides a method for preparing a fluorine-containing block polymer in which both the hydrophilic macromolecular segment and the hydrophobic fluorine chain are too long, including the following steps A and B to prepare a fluorine-containing block polymer:

A: Under the condition of ice-water bath, add butanone 30g, maleic anhydride 15g (0.153mol), styrene 15.9g (0.153mol), DDMAT 1.387g (0.0038mol), azobisisobutyronitrile 0.046 in a 100ml single-necked flask g (0.00028mol), evacuate and circulate nitrogen for 3 times, then adjust the temperature to 60°C, and react for 24h. Add butanone to dissolve, then precipitate in methanol, filter the precipitate and carry out vacuum drying at 100°C to obtain 30.14 g of solid (macromolecular chain transfer agent), yield 93.3%, GPC molecular weight, Mn=8750, _MP =10850 , PDI = 1.24. m=(8750-365)÷(98+104)=41.5.

B: Add 8g (0.0009mol) of the macromolecular chain transfer agent prepared in part A in a 100ml single-mouth bottle, dissolve it with 20g butanone, then add 16.72g (0.040mol) of trifluorooctyl acrylate, 40g of butyl acetate, and Azodiisobutyronitrile 0.0657g (0.0004mol) was reacted at 80°C for 16h to obtain a turbid yellow solution with gel precipitation on the bottle wall. The conversion rate of tridecafluorooctyl acrylate was tested to be 96.3%, and the polymer molecular weight was measured by GPC, Mn=26650, _MP =37580, PDI=1.41. n=(26650-8750)÷418=42.8.

Comparative example 5

In this comparative example, a macromolecular chain transfer agent of trifluorooctyl acrylate was first synthesized.

A: Add 15g methyl ethyl ketone, DDMAT 1.31g (0.00036mol) in 100ml one-port bottle, then add trifluorooctyl acrylate 15.1g (0.036mol), butyl acetate 15g, azobisisobutyronitrile 0.0787g (0.00048 mol), react at 80°C for 16h to obtain a light yellow turbid solution, separate layers after standing still, filter to obtain a precipitate, dry the precipitate, and use acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, methyl isobutyl ketone Common solvents such as propylene glycol methyl ether acetate, butanone and butyl acetate mixed solvents with a mass ratio of 1:0.5~2 cannot be dissolved.

Test example 1

Use surface tensiometer (Wuhan Huatian electric power, model HTYZL-H), reference standard GB11985-1989, each polymer product of above-mentioned embodiment 1～9 and comparative example 1～5 is organic phase, pure water is injected into organic phase by capillary. In the phase, the volume of the water droplet formed at the end of the vertical capillary is measured when it comes into contact with the organic phase and falls off the tube section. The two liquid phases can be obtained by balancing the weight of the droplet with the force of the interfacial tension supporting it, and adding a correction factor. interfacial tension. The interfacial tension was calculated from the volume of the droplet, the radius of the capillary, the density difference between the two liquid phases, and the acceleration of gravity. The measured surface tension is shown in Table 1 below.

Each embodiment of table 1 and comparative example test the section tension result table of polymkeric substance and water

Interfacial tension mN/m Example 1 18.5 Example 2 18.2 Example 3 12.6 Example 4 8.8 Example 5 20.7 Example 6 28.1 Example 7 21.4 Example 8 30.3 Example 9 23.5 Comparative example 1 37.4 Comparative example 2 44.2 Comparative example 3 50.9 Comparative example 4 34.8 Comparative example 5 ——

It can be seen from the above Table 1 that the effect of reducing surface tension of the polymers of Examples 1-9 is obviously better than that of Comparative Examples 1-4. Wherein, embodiment 4 has obtained the best effect of reducing surface tension.

It can be seen that the length of the macromolecular chain transfer agent has a significant impact on the solventability of the amphiphilic fluorine-containing block polymer. When the number of styrene-maleic anhydride macromolecular chain units in the molecule is significantly less than 5, the The solubility in ordinary solvents is significantly reduced, as in Comparative Example 3, turbidity occurs. When the number of styrene-maleic anhydride macromolecular chain units in the molecule is obviously greater than 30, the performance of reducing surface tension decreases, such as Comparative Example 2 and Comparative Example 4.

The surface activity of this amphiphilic fluorine-containing block polymer is also related to the amount of fluorine-containing monomer (tridecafluorooctyl acrylate polymer chain). When the content of indicator group) is significantly less than 5, the property of reducing surface tension is not obvious, as in Comparative Example 3. However, when the content of trifluorooctyl acrylate is greater than 30, the obtained fluorine-containing block polymer is insoluble in common solvents, such as Comparative Example 1 and Comparative Example 4.

For the amphiphilic fluoropolymer, m is an integer between 10 and 25, and n is an integer between 10 and 20. Compared with the fluorine-containing block polymer within this range, It has better solubility and surface activity, such as Examples 1-5, which are better than Examples 7-9.

The polymer of the invention has good solubility in fluorine-free solvents, high surface activity, few synthesis steps, low toxicity in the environment and easy degradation, and has good application prospects.

The embodiments described above are some, not all, embodiments of the present invention. The detailed description of the embodiments of the invention is not intended to limit the scope of the claimed invention but to represent only selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Claims (9)

1. An amphiphilic fluorine-containing block polymer, characterized in that the structure of the polymer is shown in general formula (I):

(I) In general formula (I), R ₁ is the leaving group of RAFT reagent, Z is the stabilizing group of RAFT reagent, R ₂ is -(CF ₂ ) ₅ CF ₃ , wherein m is an integer between 5 and 30 , n is an integer between 5 and 30; wherein, the R ₁ is -C(CH ₃ ) ₂ -COOH, and Z is CH ₃ (CH ₂ ) ₁₁ -S-(C=S)-S-. 2. The amphiphilic fluorine-containing block polymer according to claim 1, characterized in that, said m is an integer between 10 and 25, and n is an integer between 10 and 20. 3. a preparation method of the amphiphilic fluorine-containing block polymer as described in any one of claims 1 to 2, is characterized in that, comprises the following steps: A: Under the condition of adding the first fluorine-free solvent, RAFT reagent and the first initiator at the temperature of -20°C~25°C, mix styrene and maleic anhydride in a molar ratio of 1~1.2:1, and the obtained The molar ratio of the maleic anhydride, the RAFT reagent and the first initiator is 5~30:1:0.01~0.2, the reaction environment is set to an oxygen-free environment, and then the temperature is raised to 50-90°C to carry out the polymerization reaction 8-24 h, add a solvent after the reaction to dissolve the reaction product, then add another solvent to precipitate the precipitate, filter the precipitate and dry it to obtain a solid that is a macromolecular chain transfer agent; B: the macromolecular chain transfer agent obtained in step A, the second initiator and trifluorooctyl acrylate are added in the second fluorine-free solvent, and the tridefluorooctyl acrylate, macromolecular chain transfer agent and The molar ratio of the second initiator is 5-30:1:0.1-0.5, the reaction is carried out at 60-100° C. for 8-24 h, and a transparent solution containing the polymer is obtained through the reaction. 4. the preparation method of amphiphilic fluorine-containing block polymer according to claim 3 is characterized in that, described RAFT reagent is 2-(dodecyl trithiocarbonate group)-2-formazan Propionic acid; the first initiator and the second initiator are azobisisobutyronitrile. 5. the preparation method of amphiphilic fluorine-containing block polymer according to claim 3 is characterized in that, in step A, the first fluorine-free solvent is butanone, acetone, methyl isobutyl One of ketone and propylene glycol methyl ether acetate. 6. the preparation method of amphiphilic fluorine-containing block polymer according to claim 3 is characterized in that, in step B, described second fluorine-free solvent is butanone and butyl acetate according to mass ratio 1 : 0.5~2 mixed solvent. 7. The preparation method of amphiphilic fluorine-containing block polymer according to claim 3, characterized in that: in step A, styrene and maleic anhydride are mixed at a molar ratio of 1:1. 8. according to the preparation method of the described amphiphilic fluorine-containing block polymer of claim 3 or 7, it is characterized in that: in step A, the mol ratio of maleic anhydride and RAFT reagent is 10～25:1; In step B, the molar ratio of trifluorooctyl acrylate to the macromolecular chain transfer agent is 10-20:1. 9. The application of the amphiphilic fluorine-containing block polymer according to any one of claims 1 to 2, wherein the polymer is used as a surfactant in cleaning agents and cosmetics.