Fluorine-containing compounds having a phenolic hydroxyl group, and a fluorine-containing polymer having a phenolic hydroxyl group prepared therefrom, and applications thereof

Abstract

The present application belongs to the field of fluorinated chemicals, and particularly relates to a fluorine-containing compound with phenolic hydroxyl structure, a fluorine-containing polymer with phenolic hydroxyl structure prepared by the fluorine-containing compound, and application, and the molecular formula is: wherein R1, R2, R3 and R4 are independently selected from F or fluorine-containing alkyl. The fluorine-containing compound with phenolic hydroxyl structure can be prepared by using gallic acid derivatives and fluorine-containing olefins as raw materials through a simple catalytic reaction, the fluorine-containing compound can be further reacted to synthesize fluorine-containing phenolic aldehyde resin, fluorine-containing epoxy resin, fluorine-containing polyurethane and fluorine-containing surfactant, and stably exists in the above material structure, so that the material has excellent water resistance and corrosion resistance, and the service life of the product is longer.

Description

Technical Field

[0001] This invention belongs to the field of fluorochemicals, specifically relating to a fluorinated compound with a phenolic hydroxyl structure, the fluorinated polymer with a phenolic hydroxyl structure prepared therefrom, and its applications. Background Technology

[0002] Fluoropolymers possess exceptional chemical resistance and thermodynamic stability, along with superior high-temperature resistance, mechanical properties, oil and water resistance, making them crucial in various industries. Fluoropolymers with phenolic hydroxyl groups can react with other reagents to introduce fluorinated hydrophobic and oleophobic groups, serving as intermediates in the preparation of resins and various fluorinated surfactants, thus demonstrating broad application prospects.

[0003] Patent CN119285857A discloses a fluoropolymer, its preparation method, and its applications, using vinylsulfonyl fluoride as a raw material for polymerization. This method has high production costs, a hazardous process, and uses expensive raw materials with high toxicity and hazard, making it unsuitable for scale-up experiments and large-scale industrial production. CN102597025B discloses a fluorinated compound, a fluorinated polymer, and a fluorinated copolymer. This patent provides a fluorinated compound and its polymer capable of producing highly durable water and oil repellent properties with low environmental impact. It achieves good performance through specific fluorinated monomer structural design. However, this technical solution does not involve fluorinated compounds containing phenolic hydroxyl structures, thus preventing further chemical modification or functionalization through phenolic hydroxyl groups, limiting its use in applications requiring the introduction of specific functional groups. Furthermore, this technical solution places high demands on monomer design, potentially increasing the complexity of the synthesis process and thus affecting industrial production efficiency. CN102596892B discloses a fluorinated compound and a fluorinated polymer, which can achieve high-durability water and oil repellency, and emphasizes its low environmental impact. Although this technical solution achieves good performance through specific phenylene linking units, its molecular structure lacks phenolic hydroxyl groups, thus preventing the introduction of other functional groups through reactions involving phenolic hydroxyl groups (such as esterification and etherification), limiting its potential for multifunctional modification. Furthermore, this technical solution requires strict control over the polymer's molecular structure, potentially leading to high processing difficulties and costs in large-scale production. Summary of the Invention

[0004] Therefore, the present invention provides a fluorinated compound with a phenolic hydroxyl structure, a fluorinated polymer with a phenolic hydroxyl structure prepared therefrom, and its applications, in order to solve the above-mentioned problems in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A fluorinated compound with a phenolic hydroxyl structure, having the molecular formula:

[0007]

[0008] R1, R2, R3, and R4 are independently selected from F or fluorinated alkyl groups.

[0009] The technical solution of this invention solves the following problems existing in the prior art: First, the prior art does not involve fluorinated compounds containing phenolic hydroxyl structures, thus making further chemical modification or functionalization through phenolic hydroxyl groups impossible. Second, the prior art has high requirements for monomer design, which may increase the complexity of the synthesis process and thus affect the efficiency of industrial production. Finally, the prior art has strict control over the molecular structure of polymers, which may lead to high process difficulty and cost in large-scale production.

[0010] Preferably, the method for preparing the fluorinated compound with the phenolic hydroxyl structure includes the following steps:

[0011] Gallic acid derivatives, catalysts, and acid-binding agents are mixed and stirred in a molar ratio of 1:0.1–0.6:1–8 under polar aprotic solvent or solvent-free conditions. Then, fluorinated olefins are added, and the reaction is carried out at -40–120°C for 2–18 h. After cooling, water is added, and the mixture is distilled and separated to obtain fluorinated compounds with phenolic hydroxyl structures. The molar ratio of fluorinated olefins to gallic acid derivatives participating in the reaction is 0.8–1.2:1.

[0012] The main reaction formula is:

[0013]

[0014] in, It is a gallic acid derivative;

[0015] It is a fluorinated olefin, and R1, R2, R3, and R4 are independently selected from F or fluorinated alkane.

[0016] The first step of the reaction involves mixing the gallic acid derivative, catalyst, and acid-binding agent in a specific ratio. This mixing process should be carried out under polar aprotic solvent or solvent-free conditions. The preferred polar aprotic solvent is one or a combination of acetonitrile, dimethylformamide, dimethyl sulfoxide, sulfolane, N,N-dimethylformamide, diethylene glycol monomethyl ether, or hexamethylphosphoric triamine. These solvents possess good solubility and thermal stability, effectively promoting the reaction. Under solvent-free conditions, the mixture must be thoroughly stirred to ensure uniform dispersion of the components. Subsequently, a fluorinated olefin is added to the mixture at a molar ratio of 0.8 to 1.2:1 to the gallic acid derivative. After adding the fluorinated olefin, the reaction temperature should be controlled within the range of -40 to 120°C, preferably -10 to 120°C, and the reaction time should be set to 2 to 18 hours. Under these conditions, the reaction rate is moderate, ensuring high selectivity and high yield of the target product. After the reaction is complete, the mixture is cooled to room temperature and diluted with an appropriate amount of water. The target product is then separated by distillation and liquid-liquid extraction. During the separation process, temperature and pressure must be carefully controlled to avoid decomposition or loss of the target product. After the above reaction is completed, the obtained fluorinated compound can be further chemically modified to prepare fluorinated polymers or fluorinated surfactants.

[0017] Preferably, the gallic acid derivative is selected from any compound of 3a-3r:

[0018]

[0019] These compounds provide sufficient active sites in the reaction to ensure the efficient introduction of fluorine-containing groups.

[0020] Preferably, the fluorinated olefin is any compound of hexafluoropropylene or hexafluoropropylene oligomer.

[0021] These compounds exhibit high reactivity and stability, and can effectively form chemical bonds with gallic acid derivatives.

[0022] Preferably, the acid-binding agent is at least one selected from triethylamine, sodium carbonate, potassium carbonate, sodium bicarbonate, and sodium tert-butoxide.

[0023] These compounds can effectively neutralize the acid byproducts generated during the reaction, thereby maintaining the stability of the reaction system.

[0024] Preferably, the reaction temperature is -10 to 120°C and the reaction time is 2 to 18 hours.

[0025] Preferably, under polar aprotic solvent conditions, the molar ratio of gallic acid analog to polar aprotic solvent is 1:2 to 10.

[0026] Preferably, the polar aprotic solvent is at least one of acetonitrile, dimethylformamide, dimethyl sulfoxide, sulfolane, N,N-dimethylformamide, diethylene glycol monomethyl ether, and hexamethylphosphoric triamine.

[0027] A fluorinated compound with a phenolic hydroxyl structure as described above is used in the preparation of fluorinated polymers or fluorinated surfactants.

[0028] Fluoropolymers containing phenolic hydroxyl structures prepared from fluorinated compounds with phenolic hydroxyl structures as described above include fluorinated phenolic resins, fluorinated epoxy resins, or fluorinated polyurethanes.

[0029] Fluorinated phenolic resins are obtained by reacting fluorinated compounds with phenolic hydroxyl structures with formaldehyde or paraformaldehyde.

[0030] Fluorinated epoxy resins are obtained by reacting fluorinated compounds with phenolic hydroxyl structures with epichlorohydrin or epichlorohydrin under alkaline conditions.

[0031] Fluorinated polyurethanes are obtained by reacting fluorinated compounds with phenolic hydroxyl structures with one or more of the following: toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), isoflurane diisocyanate (IPDI), hexamethylene diisocyanate (HDI), isoflurane diisocyanate (IPDI), phenylmethylene diisocyanate (XDI), tetramethyl isophenylmethylene diisocyanate (TMXDI), and dicyclohexylmethane-4,4'-diisocyanate (HMDI).

[0032] The aforementioned fluoropolymers exhibit excellent water and corrosion resistance and remain stable within the material structure, thus significantly extending the product's service life. Furthermore, due to the introduction of phenolic hydroxyl groups into the molecular structure, these polymers can be further chemically modified to incorporate other functional groups, thereby expanding their application range.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] This invention provides a fluorinated compound with a phenolic hydroxyl structure that can be prepared from gallic acid derivatives and fluorinated olefins through a simple catalytic reaction. The prepared fluorinated compound can be further reacted to synthesize fluorinated phenolic resins, fluorinated epoxy resins, fluorinated polyurethanes, and fluorinated surfactants, and is stably present in the structure of the above materials, thereby giving the materials excellent waterproof and corrosion-resistant properties, thus extending the service life of the products. Detailed Implementation

[0035] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] Gallic acid derivatives with R being a 3a chain, triethylamine, and NaF were placed in a reaction vessel at a molar ratio of 1:3:0.4. Hexafluoropropylene gas was slowly introduced while stirring, and the reaction vessel temperature was controlled at -30℃ for 8 hours. After the reaction was completed and the vessel returned to room temperature, a small amount of water was added, and the mixture was transferred to a separatory funnel. The lower liquid was then distilled at 160℃ and 0.01 MPa to obtain a fluorinated compound with a phenolic hydroxyl structure.

[0038] The chemical reaction formula is as follows:

[0039] ;

[0040] The molar ratio of hexafluoropropylene gas participating in the reaction to the gallic acid derivative with R being a 3a chain is 1:1.

[0041] Application Example 1

[0042] The fluorinated compound with a phenolic hydroxyl structure obtained in Example 1 was added to a reactor along with formaldehyde (prepared as a 37% aqueous solution) at a molar ratio of 1:2.2. 0.5% by weight of oxalic acid catalyst and an appropriate amount of ethanol were added to aid dissolution. The mixture was refluxed at 80°C for 2 hours to complete hydroxymethylation. The temperature was then raised to 100-110°C for dehydration and polycondensation under reduced pressure for 1.5 hours until the resin viscosity increased significantly. After cooling, the resin was pulverized, washed with water to remove residues, and vacuum dried at 60°C to obtain a fluorinated phenolic resin.

[0043] The performance obtained from the test:

[0044] Thermal stability (TGA): Initial decomposition temperature (T5%) > 350℃, while the highest temperature of traditional phenolic resin is about 300℃. This is because fluorine atoms improve the heat resistance.

[0045] Hydrophobicity: Water contact angle > 90°, while traditional phenolic resins have an angle of approximately 80°. This is due to the fluorine groups reducing surface energy.

[0046] Solvent resistance (24h immersion in acetone): mass loss rate <3%, while traditional phenolic resin data shows mass loss >8%, thanks to the fluorine groups resisting solvent erosion.

[0047] In Application Example 1, using the fluorinated phenolic hydroxyl compound prepared in Example 1 as the key monomer, a fluorinated phenolic resin was successfully synthesized through hydroxymethylation and dehydration polycondensation with formaldehyde under oxalic acid catalysis. The outstanding performance of this resin stems from the fluoroalkyl / fluoroolefin groups introduced into the monomer. These fluorinated groups, together with the phenolic ring, construct a rigid framework, and the strong CF bonds significantly enhance the material's thermal stability, resulting in an initial decomposition temperature (T5%) higher than 350°C, far exceeding the approximately 300°C of traditional phenolic resins. Simultaneously, the inherently extremely low surface energy of the fluorinated groups causes the polymer surface to tend to accumulate fluorine, forming a highly hydrophobic interface with a water contact angle greater than 90° (compared to approximately 80° for traditional resins). Furthermore, these fluorinated groups form a dense chemically inert barrier within the material, effectively resisting the penetration and erosion of polar solvents such as acetone, resulting in a mass loss rate of less than 3% after 24 hours of immersion, significantly lower than the more than 8% of traditional resins.

[0048] Example 2

[0049] Gallic acid derivatives with R being a 3a chain, sodium tert-butoxide, and NaF were placed in a reaction vessel at a molar ratio of 1:3:0.4. Hexafluoropropylene dimer was slowly added dropwise while stirring. The reaction vessel temperature was maintained at 10°C for 10 hours. After the reaction was complete and the contents returned to room temperature, a small amount of water was added. The mixture was then transferred to a separatory funnel, and the lower liquid was distilled at 160°C and 0.01 MPa to obtain a fluorinated compound with a phenolic hydroxyl structure. The chemical reaction formula is as follows:

[0050] ;

[0051] The ratio of the total molar amount of hexafluoropropylene dimer to the molar amount of gallic acid derivative with R being a 3a chain is 1:1.

[0052] Application Example 2

[0053] The fluorinated compound with a phenolic hydroxyl structure obtained in Example 2, epichlorohydrin, and NaOH (added as a 10 wt% NaOH solution) were added to a reaction vessel in a molar ratio of 1:4:1.2. The reaction was carried out at a constant temperature of 60°C for 3 hours to generate a fluorochlorohydrin intermediate. Subsequently, the temperature was raised to 80°C, and twice the molar amount of the fluorinated compound with a phenolic hydroxyl structure obtained in Example 2 (added as a 10 wt% NaOH solution) was added dropwise. The reaction was carried out for 2 hours, and the NaCl precipitate was filtered off. The organic phase was washed with deionized water until neutral. The mixture was then distilled at 120°C and -0.1 MPa under reduced pressure to remove excess epichlorohydrin, yielding a fluorinated epoxy resin.

[0054] Performance testing:

[0055] Thermal decomposition temperature (TGA): The initial decomposition temperature (T5%) is 380–400℃, while that of conventional epoxy resin is 320–330℃;

[0056] Hydrophobicity: Water contact angle >105°, while traditional epoxy resin data is about 80°. This is because the fluorine groups reduce the surface energy.

[0057] Solvent resistance (24h immersion in acetone): mass loss rate <1.5%, while traditional epoxy resin data shows mass loss >5%, thanks to the fluorine groups resisting solvent erosion.

[0058] Application Example 2 first reacts with epichlorohydrin to form a fluorochlorohydrin intermediate, followed by a ring-closing reaction to form an epoxy resin. The introduced fluoroalkyl / fluoroolefinic structure plays a decisive role in the performance of this resin. Its high-bond-energy CF bond effectively enhances the stability of the polymer backbone and may strengthen intermolecular forces, giving the material excellent heat resistance, with an initial decomposition temperature (T5%) reaching 380-400℃, significantly exceeding the 320-330℃ of traditional epoxy resins. The strong ability of the fluorine group to reduce the surface energy of the material endows this resin with excellent hydrophobicity, with a water contact angle greater than 105°, far superior to the approximately 80° of traditional epoxy resins. More importantly, the formed fluorinated "protective layer" exhibits extremely strong resistance to organic solvents, especially acetone, resulting in a mass loss rate of less than 1.5% after 24 hours of acetone immersion, while the loss of traditional resins is greater than 5%.

[0059] Example 3

[0060] Gallic acid derivatives with R being a 3a chain, sodium tert-butoxide, and NaF were placed in a reaction vessel at a molar ratio of 1:3:0.4. Hexafluoropropylene trimer was slowly added dropwise while stirring. The reaction vessel temperature was maintained at 10°C for 12 hours. After the reaction was complete and the vessel returned to room temperature, a small amount of water was added. The mixture was then transferred to a separatory funnel, and the lower liquid was distilled at 160°C and 0.01 MPa to obtain a fluorinated compound with a phenolic hydroxyl structure. The chemical reaction formula is as follows:

[0061] ;

[0062] The molar ratio of hexafluoropropylene trimer to gallic acid derivative with R being a 3a chain is 1:1.

[0063] Application Example 3

[0064] 1 mol of the fluorinated compound with a phenolic hydroxyl structure prepared in Example 3 and 30 ml of anhydrous DMF solvent were added to a drying reactor. The mixture was heated to 60 °C under nitrogen protection to dissolve the compound. 2.0 mol of toluene diisocyanate (TDI-80, containing 80% 2,4-isomer) was added dropwise. The temperature was controlled at 70 ± 2 °C. After reacting for 2 hours, 0.2 mol of chain extender (1,4-butanediol) was added, and the reaction was continued for 1 hour (-NCO group conversion rate > 98%). After the viscosity of the system increased significantly, the mixture was discharged and vacuum dried at 80 °C for 24 hours to obtain fluorinated polyurethane.

[0065] Performance testing:

[0066] Thermal decomposition temperature (TGA): The initial decomposition temperature (T5%) is 350–360℃, while that of conventional polyurethane is 270–280℃;

[0067] Hydrophobicity: Water contact angle >115°, while traditional polyurethane data is about 80°. This is due to the fluorine groups reducing surface energy.

[0068] Solvent resistance (24h immersion in acetone): mass loss rate <2%, while traditional polyurethane data shows mass loss >20%, thanks to the fluorine groups resisting solvent erosion.

[0069] In Application Example 3, the compound containing a specific phenolic hydroxyl structure prepared in Example 3 was used as the core fluorinated monomer. This monomer contains long-chain fluoroalkyl groups introduced by the hexafluoropropylene trimer. Under anhydrous DMF solvent and nitrogen protection, 1 mole of this fluorinated monomer was first reacted with 2.0 moles of toluene diisocyanate (TDI-80) at approximately 70°C for 2 hours to form a prepolymer. Subsequently, 0.2 moles of 1,4-butanediol were added for chain extension, and the reaction continued until the -NCO conversion exceeded 98%. After a significant increase in system viscosity, post-treatment yielded a fluorinated polyurethane. The superior performance of this polymer is directly attributed to the high content of fluoroalkyl structures introduced into the monomer. These fluoroalkyl groups not only enhance the rigidity of the molecular chain, but their extremely high CF bond energy significantly improves the thermal stability of the material, resulting in an initial decomposition temperature (T5%) of 350–360°C, far superior to the 270–280°C of traditional polyurethanes. Particularly noteworthy is the strong surface energy reduction property of the fluoroalkyl groups, which allows them to effectively accumulate on the surface of polyurethane materials, forming a highly hydrophobic interface with a water contact angle greater than 115°, far exceeding the approximately 80° of traditional polyurethane. Simultaneously, these long-chain fluoroalkyl groups construct a dense, chemically inert physical barrier within the material, significantly hindering the penetration, swelling, and degradation by solvents such as acetone. This results in exceptionally excellent solvent resistance; the mass loss rate after 24-hour acetone immersion is less than 2%, compared to a typical loss of over 20% for traditional polyurethane.

[0070] The above content is only a preferred embodiment and application example of the present invention. Those skilled in the art should understand that the present application is not limited to the above embodiments. Based on the concept of the present invention, the present application may have various changes and improvements. The scope of protection of the present application is defined by the appended claims, the description and their equivalents.

Claims

1. A method for preparing a fluorinated compound with a phenolic hydroxyl structure, characterized in that, The molecular formula of the fluorinated compound with the phenolic hydroxyl structure is: R1, R2, R3, and R4 are independently selected from F or fluorinated alkyl groups; The preparation method of the fluorinated compound with the phenolic hydroxyl structure includes the following steps: Gallic acid derivatives, NaF, and an acid-binding agent were mixed and stirred in a molar ratio of 1:0.1–0.6:1–8 under polar aprotic solvent or solvent-free conditions. Then, a fluorinated olefin was added, and the mixture was reacted at -40–120°C for 2–18 h. After cooling, water was added, and the mixture was distilled and separated to obtain a fluorinated compound with a phenolic hydroxyl structure. The molar ratio of the fluorinated olefin to the gallic acid derivative in the reaction was 0.8–1.2:

1. The main reaction formula is: in, It is a gallic acid derivative; It is a fluorinated olefin, and R1, R2, R3, and R4 are independently selected from F or fluorinated alkyl groups; The gallic acid derivative is selected from any compound in 3a-3g: 。 2. The method for preparing the fluorinated compound with a phenolic hydroxyl structure as described in claim 1, characterized in that, The fluorinated olefin is any compound of hexafluoropropylene or hexafluoropropylene oligomers.

3. The method for preparing the fluorinated compound with a phenolic hydroxyl structure as described in claim 1, characterized in that, The acid-binding agent is at least one of triethylamine, sodium carbonate, potassium carbonate, sodium bicarbonate, and sodium tert-butoxide.

4. The method for preparing the fluorinated compound with a phenolic hydroxyl structure as described in claim 1, characterized in that, The conditions for the distillation process are: 155–160℃, 0.0067–0.013 MPa.

5. The method for preparing the fluorinated compound with a phenolic hydroxyl structure as described in claim 1, characterized in that, Under polar aprotic solvent conditions, the molar ratio of gallic acid derivative to polar aprotic solvent is 1:2 to 10.

6. The method for preparing the fluorinated compound with a phenolic hydroxyl structure as described in claim 1, characterized in that, The polar aprotic solvent is at least one of acetonitrile, dimethylformamide, dimethyl sulfoxide, sulfolane, and hexamethylphosphoric triamine.

7. The application of a fluorinated compound with a phenolic hydroxyl structure prepared by any one of claims 1-6, characterized in that, It is used to prepare fluoropolymers, including fluorophenolic resins, fluoroepoxy resins, or fluoropolyurethanes.

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