Perfluoropolyether modified silicon dioxide material and preparation method thereof

Abstract

The invention provides a perfluoropolyether modified silicon dioxide material and a preparation method thereof. The preparation method comprises the following steps: adding a functionalized fluorine-containing polymer into a first solvent, and adding a silane coupling agent and a catalyst for reaction to obtain functionalized fluorine-containing polymer modified siloxane; adding silicon dioxide into a second solvent and water, and then adding the functionalized fluorine-containing polymer modified siloxane, the main catalyst and the cocatalyst for reaction to obtain a crude product of functionalized fluorine-containing polymer modified silicon dioxide; and removing the solvent from the crude product, and drying to obtain the perfluoropolyether modified silicon dioxide material. According to the technical scheme, the problems that traditional silicon dioxide is large in surface hydroxyl number, prone to agglomeration in the material, uneven in dispersion, poor in compatibility with a base material and the like are solved, the compatibility of the silicon dioxide material and the base material is improved, dispersion is promoted, meanwhile, reactive groups on the surface of the silicon dioxide can react with the base material, and the service life of the silicon dioxide is prolonged. In-situ chemical crosslinking or in-situ synthesis with other materials can be realized, and the application range is wider.

Description

Technical Field

[0001] The invention relates to a perfluoropolyether modified silicon dioxide material and a preparation method thereof, belonging to the technical field of silicon dioxide material modification. Background Art

[0002] Silicon dioxide (SiO 2 ) is an inorganic compound with irregular Si-O crystals inside. It has the advantages of being non-toxic and tasteless, small particle size, large specific surface area, good insulation, and high temperature resistance. It is widely used in rubber and plastic materials, dyes and coatings, papermaking, and fine chemicals. However, due to the SiO 2 The surface contains a large number of silanol groups (Si-OH), which give the surface a large surface energy, making it easy for hydrogen bonds to form between particles, resulting in SiO 2 Agglomeration occurs to form agglomerates, and these hydroxyl groups have strong hydrophilicity, resulting in poor compatibility with polymer materials and uneven dispersion, making it difficult to meet higher and more complex application requirements.

[0003] At present, in order to consume the hydroxyl groups on the surface of silica, improve its dispersibility, and enhance its compatibility with the polymer material matrix, the most commonly used surface chemical modification method is silane coupling agent modification, such as CN104445218A. Siloxane coupling agents have two groups with different chemical properties, one end of which is polar and can combine with inorganic small molecules, and the other end is non-polar and can combine with organic macromolecules, making it a link between organic matter and small molecule particles. However, organic silicon materials have poor media resistance and are lipophilic in nature, and are easy to absorb oily dirt, thereby affecting the cleanliness of the material surface.

[0004] Perfluoropolyether (PFPE) is a perfluoropolymer composed of CF bonds, CO bonds and CC bonds. It has remarkable properties such as low friction coefficient, wide temperature range (-100℃ to +300℃), high thermal stability, low surface energy (as low as 10-14mN / m) and excellent chemical inertness. It is widely used in aerospace, oil and gas exploration and production, petrochemical and other fields, especially under extreme working conditions. It is a reliable wear-reducing and lubricating material. However, PFPE is incompatible with non-fluorine materials, which limits its application in many fields. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a modified silicon dioxide material and a preparation method thereof, which realizes SiO 2 The surface grafting of reactive perfluoropolyether-based polymers not only consumes SiO 2 The surface hydroxyl groups also improve its dispersibility in polymer materials.

[0006] To achieve the above object, the present invention provides a method for preparing a perfluoropolyether modified silica material, which comprises the following steps:

[0007] (a), adding a functionalized fluorine-containing polymer to a first solvent, and then adding a silane coupling agent and a catalyst to react to obtain a functionalized fluorine-containing polymer-modified siloxane, wherein the molar ratio of the functionalized fluorine-containing polymer to the silane coupling agent is 1:1-6;

[0008] (b), adding silica to a second solvent and water, and then adding the functionalized fluorinated polymer-modified siloxane, a main catalyst and a co-catalyst to react to obtain a crude product of the functionalized fluorinated polymer-modified silica, wherein the mass ratio of the silica to the functionalized fluorinated polymer-modified siloxane is 1-50:1;

[0009] (c) removing the solvent from the crude product and drying it to obtain a perfluoropolyether modified silica material.

[0010] According to a specific embodiment of the present invention, preferably, the structure of the functionalized fluorine-containing polymer is R f -bR; where R f It is perfluoropolyether and its derivatives, and R is polysiloxane.

[0011] According to a specific embodiment of the present invention, preferably, the perfluoropolyether includes but is not limited to one or a combination of two or more of K-type perfluoropolyether, D-type perfluoropolyether, Y-type perfluoropolyether and Z-type perfluoropolyether.

[0012] According to a specific embodiment of the present invention, preferably, the perfluoropolyether derivative includes but is not limited to one or a combination of two or more of perfluoropolyether vinyl ether, perfluoropolyether carboxylic acid, perfluoropolyether methyl ester, etc.

[0013] In the above preparation method, preferably, the polysiloxane comprises one or a combination of two or more of hydrogen-containing silicone oil, mercapto-containing silicone oil, and amino-containing silicone oil;

[0014] The hydrogen-containing silicone oil includes one or a combination of two or more of single-ended silicon hydrogen silicone oil, double-ended silicon hydrogen silicone oil, and side silicon hydrogen silicone oil;

[0015] The mercapto-containing silicone oil includes one or a combination of terminal mercapto silicone oil and pendant mercapto silicone oil;

[0016] The amino-containing silicone oil includes one or a combination of terminal amino silicone oil and pendant amino silicone oil.

[0017] According to a specific embodiment of the present invention, preferably, the first solvent is a fluorocarbon solvent. More preferably, the fluorocarbon solvent includes but is not limited to one or a combination of two or more of perfluorocyclic ether, hydrofluoroether, 1,3-di(trifluoromethyl)benzene, etc.

[0018] According to a specific embodiment of the present invention, preferably, in step (a), the catalyst includes but is not limited to one or a combination of two or more of Custer catalyst, benzoyl peroxide, di-tert-butyl peroxide, Pt / C, etc.

[0019] According to a specific embodiment of the present invention, preferably, in step (a), the amount of the catalyst used is 0.01%-10% of the total mass of the reaction materials, more preferably 0.05%-3.5%.

[0020] According to a specific embodiment of the present invention, preferably, in step (a), the silane coupling agent includes but is not limited to vinyltrimethoxysilane, vinyltriethoxysilane, acryltrimethoxysilane, acryltriethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, methylacryldimethoxysilane, methylacryldiethoxysilane, aminopropylvinyldimethoxysilane, aminopropylvinyldiethoxysilane, vinyldimethylchlorosilane, etc., or a combination of two or more thereof.

[0021] According to a specific embodiment of the present invention, preferably, in step (b), the main catalyst includes but is not limited to one or a combination of two or more of hydrochloric acid, sulfuric acid, phosphoric acid, oxalic acid, formic acid, citric acid, acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, etc.

[0022] According to a specific embodiment of the present invention, preferably, the co-catalyst includes but is not limited to one or a combination of two or more of dibutyltin dilaurate, ethylenediaminetetraacetic acid, zinc gluconate, magnesium stearate, potassium phthalamide, etc.

[0023] According to a specific embodiment of the present invention, preferably, in step (b), the amount of the main catalyst is 0.01%-5% (more preferably 0.05%-2.5%) of the total mass of the reaction materials, and the amount of the co-catalyst is 0.01%-5% (more preferably 0.01%-2.0%) of the total mass of the reaction materials.

[0024] According to a specific embodiment of the present invention, preferably, in step (a) and step (b), the reaction temperature is 25-300°C, and the reaction time is 1-72h, more preferably, the reaction temperature is 25-200°C, and the reaction time is 1-36h.

[0025] According to a specific embodiment of the present invention, preferably, in step (a), the molecular weight of the functionalized fluorine-containing polymer is 1000-80000 g / mol, more preferably 1000-8000 g / mol.

[0026] According to a specific embodiment of the present invention, preferably, in step (b), the particle size of the silicon dioxide is 0.005-5000 μm, more preferably 0.01-50 μm.

[0027] According to a specific embodiment of the present invention, preferably, in step (b), the second solvent includes but is not limited to one or a combination of two or more of ethanol, isopropanol, propylene glycol, ethylene glycol, acetone, acetonitrile, tetrahydrofuran, diethylene glycol dimethyl ether, diethyl ether, tert-butyl ether, etc.

[0028] The present invention also provides a perfluoropolyether modified silica material, which is prepared by the above method.

[0029] The preparation method of the perfluoropolyether modified silicon dioxide material provided by the present invention realizes SiO 2 The surface grafting of reactive perfluoropolyether-based polymers (functionalized fluorinated polymer-modified siloxanes) not only consumes SiO 2 The surface hydroxyl groups improve its dispersibility in polymer materials and solve the problem that PFPE has poor compatibility with other materials and easy migration due to its unique fluorine atom-wrapped molecular chain. 2 The reactive groups on the surface enable in-situ synthesis or in-situ cross-linking with materials containing active groups, further broadening the scope of SiO 2 It has immeasurable economic value in high-tech fields.

[0030] The technical solution of the present invention solves the problems of large number of hydroxyl groups on the surface of traditional silica, easy agglomeration in the material, uneven dispersion, poor compatibility with the substrate, etc., improves the compatibility of the silica material with the substrate and promotes dispersion. At the same time, the reactive groups on its surface can achieve in-situ chemical crosslinking or in-situ synthesis with other materials, and has a wider range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the infrared spectrum of double-terminal hydrogen-containing perfluoropolyether-b-polysiloxane.

[0032] Figure 2 This is the infrared spectrum of vinyltrimethoxysilane.

[0033] Figure 3 This is the infrared spectrum of the crude product (α-silyl hydrogen, ω-trimethoxysilane perfluoropolyether).

[0034] Figure 4 This is the infrared spectrum of silicon dioxide.

[0035] Figure 5 This is the infrared spectrum of the crude product (α-silyl hydrogen, ω-trimethoxysilane perfluoropolyether) modified silica.

[0036] Figure 6 This is the H-NMR spectrum of the crude product (α-silyl hydrogen, ω-trimethoxysilane perfluoropolyether) after modification of silica.

[0037] Figure 7 The water contact angle test results of the silica-coated glass surface after modification in Example 1.

[0038] Figure 8 The water contact angle test results of the silica-coated glass surface after modification in Example 2.

[0039] Fig. 9 The water contact angle test results of the silica-coated glass surface after modification in Example 3.

[0040] Fig.10 The water contact angle test results of the silica-coated glass surface after modification in Example 4 are shown.

[0041] Fig.11 This is the water contact angle test result of the silica-coated glass surface after modification in Example 5.

[0042] Fig.12 The water contact angle test results of the silica-coated glass surface after modification in Example 6 are shown.

[0043] Fig.13 The water contact angle test results of the unmodified silica-coated glass surface are shown in Table 1. DETAILED DESCRIPTION

[0044] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0045] In the specification and claims, "including" and "comprising" should be understood as meaning "including, but not limited to", and the specific details disclosed are intended to make the present invention easier to understand. The technical solution of the present invention is also that adopted by technicians in the relevant field to implement the present solution using one or more technical details.

[0046] Analysis and evaluation method: The perfluoropolyether modified silica film was prepared on the transparent glass surface by the Czochralski method, and the contact angles of water and n-hexadecane were tested according to the international test standard GB / T 24368-2009.

[0047] Particle size test: Malvern Zetasizer Nano ZS90 was used to test the particle size of silica before and after modification, referring to the national standard GB / T 15445.2-2006.

[0048] The structure of bi-terminal silyl perfluoropolyether-b-polysiloxane is shown below:

[0049]

[0050] Example 1

[0051] This embodiment provides a perfluoropolyether modified silica material, and the preparation method thereof includes:

[0052] 20g of bifunctional silane-hydrogen perfluoropolyether-b-polysiloxane, 10mL of 1,3-di(trifluoromethyl)benzene and 20μL of Custer catalyst were added to a three-necked flask and stirred for 30min, then 3.7g of vinyltrimethoxysilane was added, the temperature was raised to 70℃ and the reaction was carried out for 12h to obtain a crude product. The infrared spectrum is shown in FIG. Figure 1 , Figure 2 , Figure 3 As shown, the structural formula of the crude product (α-silicon hydrogen, ω-trimethoxysilane perfluoropolyether) is as follows:

[0053]

[0054] 50g of silica, 3g of deionized water, 100g of ethanol, 0.5g of trifluoromethanesulfonic acid and 0.1g of dibutyltin dilaurate were added to a three-necked flask, stirred at room temperature for 10min, then the crude product obtained in the previous step was added, and the temperature was raised to 60°C for reaction for 8h. After the reaction was completed, the solvent was filtered out, and the filter cake was dried at 100°C to obtain the target product. The infrared spectrum is shown in FIG. Figure 4-Figure 5 As shown, the product 1 HNMR spectrum Figure 6 shown.

[0055] from Figure 4 , Figure 5 It can be seen from the infrared spectrum that after the fluorine-containing polymer is grafted onto the surface of silica by chemical means, the hydroxyl groups on the surface of silica are significantly reduced, and the infrared characteristic peak of Si-H appears. Figure 6 shown 1 The H NMR spectrum further confirmed the successful preparation of the modified material. Figure 7 The water contact angle test results after coating the glass surface with the modified material.

[0056] The structural formula of the target product is shown below:

[0057]

[0058] Example 2

[0059] This embodiment provides a perfluoropolyether modified silica material, and the preparation method thereof includes:

[0060] 10 g of side-group hydrogen-containing perfluoropolyether-b-polysiloxane, 8 mL of perfluorocyclic ether and 0.5 g of benzoyl peroxide were added to a reaction kettle and stirred for 10 min. Then 8.9 g of methylacryldiethoxysilane was added, the temperature was raised to 150° C. and the reaction was performed for 5 h to obtain a crude product.

[0061] 40g of silicon dioxide, 3g of deionized water, 120g of isopropanol, 1.0g of trifluoroacetic acid and 0.2g of magnesium stearate were added to the reaction kettle, stirred at room temperature for 6min, and then the crude product obtained in the previous step was added, and the temperature was raised to 260°C for reaction for 24h. After the reaction was completed, the solvent was filtered out, and the filter cake was dried at 110°C to obtain the target product. Figure 8 The water contact angle test results after coating the glass surface with the modified material.

[0062] Example 3

[0063] This embodiment provides a perfluoropolyether modified silica material, and the preparation method thereof includes:

[0064] 16 g of bifunctional silicon hydrogen perfluoropolyether-b-polysiloxane and 15 mL of hydrofluoroether were added to a reaction kettle and stirred for 5 min. Then 3.3 g of vinyldimethylsilyl chloride was added and the temperature was raised to 200° C. and reacted for 6 h to obtain a crude product.

[0065] 80g of silicon dioxide, 5g of deionized water, 250g of acetone, 0.2g of phosphoric acid and 0.1g of potassium phthalamide were added to the reactor, stirred at room temperature for 5min, and then the crude product obtained in the previous step was added, and the temperature was raised to 240°C for reaction for 48h. After the reaction was completed, the solvent was filtered out, and the filter cake was dried at 150°C to obtain the target product. Fig. 9 The water contact angle test results after coating the glass surface with the modified material.

[0066] Example 4

[0067] This embodiment provides a perfluoropolyether modified silica material, and the preparation method thereof includes:

[0068] 25 g of double bond-containing perfluoropolyether-b-polysiloxane and 35 mL of 1,3-di(trifluoromethyl)benzene were added to a reaction kettle and stirred for 25 min. Then 5.7 g of aminopropyltriethoxysilane was added, and the temperature was raised to 170° C. and reacted for 20 h to obtain a crude product.

[0069] 45g of silica, 8g of deionized water, 150g of ethylene glycol, 0.5g of citric acid and 0.2g of ethylenediaminetetraacetic acid were added to the reaction kettle, stirred at room temperature for 5min, and then the crude product obtained in the previous step was added, and the temperature was raised to 100°C for reaction for 72h. After the reaction was completed, the solvent was filtered out, and the filter cake was dried at 200°C to obtain the target product. Fig.10 The water contact angle test results after coating the glass surface with the modified material.

[0070] Example 5

[0071] This embodiment provides a perfluoropolyether modified silica material, and the preparation method thereof includes:

[0072] 11 g of terminal acryloxy perfluoropolyether-b-polysiloxane and 60 mL of 1,3-di(trifluoromethyl)benzene were added to a three-necked flask and stirred for 25 min. Then 11.3 g of aminopropyltrimethoxysilane was added and the temperature was raised to 50° C. to react for 72 h to obtain a crude product.

[0073] 70g of silicon dioxide, 15g of deionized water, 110g of diethylene glycol dimethyl ether, 2.0g of oxalic acid and 2.0g of zinc gluconate were added to the reaction kettle, stirred at room temperature for 20min, and then the crude product obtained in the previous step was added, and the temperature was raised to 260°C for reaction for 36h. After the reaction was completed, the solvent was filtered out, and the filter cake was dried at 200°C to obtain the target product. Fig.11 The water contact angle test results after coating the glass surface with the modified material.

[0074] Example 6

[0075] This embodiment provides a perfluoropolyether modified silica material, and the preparation method thereof includes:

[0076] 37 g of hydrogen-containing perfluoropolyether-b-polysiloxane, 20 mL of 1,3-di(trifluoromethyl)benzene and 2.0 g of di-tert-butyl peroxide were added to a reaction kettle and stirred for 30 min. Then 10.6 g of aminopropylvinyldiethoxysilane was added, the temperature was raised to 160° C. and the reaction was carried out for 36 h to obtain a crude product.

[0077] 65 g of silica, 22 g of deionized water, 100 g of tert-butyl ether, 5.0 g of formic acid and 0.2 g of dibutyltin dilaurate were added to a reaction kettle, stirred at room temperature for 5 min, and then the crude product obtained in the previous step was added, and the temperature was raised to 200° C. to react for 10 h. After the reaction was completed, the solvent was filtered out, and the filter cake was dried at 100° C. to obtain the target product. Fig.12 The water contact angle test results after coating the glass surface with the modified material.

[0078] Comparative Example

[0079] This comparative example is unmodified silica. Fig.13The water contact angle test results after coating the glass surface with unmodified silica.

[0080] Table 1 shows the water and n-hexadecane contact angles and particle size test results of the perfluoropolyether-modified silica prepared in Examples 1-6.

[0081] Table 1 shows the water and n-hexadecane contact angles and particle size of perfluoropolyether modified silica

[0082] sample Water contact angle (°) n-Hexadecane contact angle (°) Particle size (nm) Example 1 146 132 352 Example 2 138 121 546 Example 3 141 123 431 Example 4 143 126 403 Example 5 149 135 311 Example 6 142 123 374 Comparative Example 110 46 1512

[0083] Table 1 above and Figure 7-Figure 13 The test results shown show that: f After the silica was modified with -bR, the water contact angle of the modified silica increased from 110° to 138-149°. f -bR has excellent low surface energy.

Claims

1. A method for preparing a perfluoropolyether modified silica material, The following steps are involved: (a), adding a functionalized fluorine-containing polymer to a first solvent, and then adding a silane coupling agent and a catalyst to react to obtain a functionalized fluorine-containing polymer-modified siloxane, wherein the molar ratio of the functionalized fluorine-containing polymer to the silane coupling agent is 1:1-6; (b), adding silica to a second solvent and water, and then adding the functionalized fluorinated polymer-modified siloxane, a main catalyst and a co-catalyst to react to obtain a crude product of the functionalized fluorinated polymer-modified silica, wherein the mass ratio of the silica to the functionalized fluorinated polymer-modified siloxane is 1-50:1; (c) removing the solvent from the crude product and drying it to obtain a perfluoropolyether modified silica material.

2. The method according to claim 1, in, The functionalized fluorinated polymer has a structure of R f -bR; Among them, R f It is perfluoropolyether and its derivatives, and R is polysiloxane.

3. The method according to claim 2, in, The perfluoropolyether includes one or a combination of two or more of K-type perfluoropolyether, D-type perfluoropolyether, Y-type perfluoropolyether and Z-type perfluoropolyether.

4. The method according to claim 3, in, The perfluoropolyether derivative includes one or a combination of two or more of perfluoropolyether vinyl ether, perfluoropolyether carboxylic acid and perfluoropolyether methyl ester.

5. The method according to claim 2, in, The polysiloxane includes one or a combination of two or more of hydrogen-containing silicone oil, mercapto-containing silicone oil, and amino-containing silicone oil; The hydrogen-containing silicone oil includes one or a combination of two or more of single-ended silicon hydrogen silicone oil, double-ended silicon hydrogen silicone oil, and side silicon hydrogen silicone oil; The mercapto-containing silicone oil includes one or a combination of terminal mercapto silicone oil and pendant mercapto silicone oil; The amino-containing silicone oil includes one or a combination of terminal amino silicone oil and pendant amino silicone oil.

6. The method according to claim 1, in, The first solvent is a fluorocarbon solvent.

7. The method according to claim 6, in, The fluorocarbon solvent includes one or a combination of two or more of perfluorocyclic ether, hydrofluoroether and 1,3-di(trifluoromethyl)benzene.

8. The method according to claim 1, in, In step (a), the catalyst comprises one or a combination of two or more of Custer catalyst, benzoyl peroxide, di-tert-butyl peroxide, and Pt / C.

9. The method according to claim 1 or 8, in, In step (a), the amount of the catalyst used is 0.01%-10% of the total mass of the reaction materials.

10. The method according to claim 1, in, In step (a), the silane coupling agent includes one or a combination of two or more of vinyltrimethoxysilane, vinyltriethoxysilane, acryltrimethoxysilane, acryltriethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, methylacryldimethoxysilane, methylacryldiethoxysilane, aminopropylvinyldimethoxysilane, aminopropylvinyldiethoxysilane and vinyldimethylchlorosilane.

11. The method according to claim 1, in, In step (b), the main catalyst comprises one or a combination of two or more of hydrochloric acid, sulfuric acid, phosphoric acid, oxalic acid, formic acid, citric acid, acetic acid, trifluoroacetic acid, and trifluoromethanesulfonic acid; The co-catalyst includes one or a combination of two or more of dibutyltin dilaurate, ethylenediaminetetraacetic acid, zinc gluconate, magnesium stearate, and potassium phthalamide.

12. The method according to claim 1 or 11, in, In step (b), the amount of the main catalyst is 0.01%-5% of the total mass of the reaction materials, and the amount of the co-catalyst is 0.01%-5% of the total mass of the reaction materials.

13. The method according to claim 1, in, In step (a) and step (b), the reaction temperature is 25-300° C., and the reaction time is 1-72 h.

14. The method according to claim 1, in, In step (a), the molecular weight of the functionalized fluorine-containing polymer is 1000-80000 g / mol.

15. The method according to claim 1, in, In step (b), the particle size of the silicon dioxide is 0.005-5000 μm.

16. The method according to claim 1, in, In step (b), the second solvent includes one or a combination of two or more of ethanol, isopropanol, propylene glycol, ethylene glycol, acetone, acetonitrile, tetrahydrofuran, diethylene glycol dimethyl ether, diethyl ether, and tert-butyl ether.

17. A perfluoropolyether modified silica material prepared by the method according to any one of claims 1 to 16.

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