A method for preparing a functional polymer-modified silica and a functional polymer-modified silica

Abstract

The application discloses a preparation method of functional polymer modified silicon dioxide and the functional polymer modified silicon dioxide and belongs to the technical field of inorganic surface modification. The preparation method of the functional polymer modified silicon dioxide comprises the following steps: (1) mixing a functional monomer shown in formula 1, an alkenyl modified silane coupling agent, an initiator and an organic solvent to obtain a system S1 through polymerization; and (2) mixing and reacting silicon dioxide and the system S1 to prepare the functional polymer modified silicon dioxide. The preparation method enables the functional polymer to be in-situ loaded on the surface of the silicon dioxide to prepare the modified silicon dioxide through a one-pot method, the preparation method is simple and efficient, and the loading amount of the functional polymer can be controlled. Formula 1.

Description

Technical Field

[0001] This invention relates to the technical field of inorganic surface modification, and more particularly to a method for preparing functional polymer-modified silica and functional polymer-modified silica. Background Technology

[0002] Modifying the physicochemical properties of inorganic surfaces using polymers has attracted widespread attention from both academia and industry. Through special design, inorganic surfaces can be modified with various functional groups, greatly expanding the applications of inorganic materials in various scenarios.

[0003] Currently, there are three methods for modifying inorganic surfaces with polymers: 1) anchoring polymers to inorganic surfaces through the reaction of specific functional groups; 2) performing surface-initiated polymerization on inorganic surfaces; and 3) polymerizing monomer-modified inorganic materials together.

[0004] In method 1), both the polymer and inorganic surfaces need to be modified with functional groups separately. The modified polymer is then reacted with the inorganic surface to obtain the final product. While this method allows for clear characterization of the polymer, the grafting efficiency is low due to the large steric hindrance of the polymer, and the total amount of surface-modified polymer is often low. In method 2), surface-initiated polymerization is a bottom-up grafting method. The inorganic surface is first modified with an initiator, and then the monomer undergoes a polymerization reaction on the inorganic surface. Because each reaction involves small molecules, the total amount of surface-grafted polymer is higher than in method 1). However, to characterize the polymer, the grafted polymer must be dissociated from the inorganic surface. In method 3), the inorganic surface is first modified with a monomer, which is then added to the monomer to undergo a polymerization reaction. This method has two problems: firstly, the monomer-modified inorganic material acts as a crosslinking point, making the reaction system prone to crosslinking; secondly, the polymer in solution cannot be completely grafted onto the inorganic surface. In summary, although the three methods can graft functional polymers onto inorganic surfaces, the steps are cumbersome and time-consuming.

[0005] Therefore, it is of great significance to study and develop a novel and efficient method for preparing silica-supported functional polymers. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a method for preparing functional polymer-modified silica and the functional polymer-modified silica. The preparation method achieves silica surface modification through a one-pot process, and has the advantages of simple operation and adjustable functional polymer loading.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] This invention provides a method for preparing functional polymer-modified silica, comprising the following steps:

[0009] (1) The functional monomer shown in Formula 1, the alkenyl-modified silane coupling agent, the initiator and the organic solvent are mixed and polymerized to obtain system S1;

[0010] (2) The functional polymer-modified silica is prepared by mixing and reacting silica with system S1;

[0011]

[0012] Formula 1;

[0013] Preferably, R1 is selected from H or C1-C6 straight-chain or branched alkyl groups;

[0014] Preferably, R2 is selected from -COOR3, -CONHR3, or C6-C. 14 aryl;

[0015] Preferably, R3 is selected from H, sulfonic acid group, and -(CH2). q R4, one or more of straight-chain or branched alkyl groups of C1-C6;

[0016] Preferably, q is selected from an integer between 0 and 5;

[0017] Preferably, R4 is selected from one or more of the following: C2-C6 straight-chain or branched alkenyl groups, C2-C6 straight-chain or branched alkynyl groups, C3-C6 heterocyclic alkyl groups, dimethylamino groups, azide groups, halogens, hydroxyl groups, and amino groups.

[0018] The C1-C6 straight-chain or branched alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, and isohexyl. In some specific embodiments of the present invention, methyl is preferred.

[0019] The C6-C 14 The aryl group includes, but is not limited to, phenyl, naphthyl, anthracene, phenanthryl, and biphenyl. In some specific embodiments of the present invention, phenyl is preferred.

[0020] The C2-C6 straight-chain or branched alkenyl groups include, but are not limited to, vinyl, propenyl, allyl, isopropenyl, butenyl, pentenyl, or hexenyl. In some specific embodiments of the present invention, vinyl is preferred.

[0021] The C2-C6 straight-chain or branched alkynyl groups include, but are not limited to, acetylenol, propynol, butynol, pentynol, or hexynol. In some specific embodiments of the present invention, acetylenol is preferred.

[0022] The heteroatom of the C3-C6 heterocyclic alkyl group is selected from one or more of oxygen, nitrogen, and sulfur atoms.

[0023] The number of heteroatoms is preferably 1 or 2.

[0024] The C3-C6 heterocyclic alkyl groups include, but are not limited to, epoxy ethyl, azacyclobutyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, tetrahydrofuranyl, tetrahydropyranyl, and thiomorpholinyl. In some specific embodiments of the present invention, epoxy ethyl is preferred.

[0025] Preferably, the structure of the alkenyl-modified silane coupling agent of the present invention is shown in Formula 2:

[0026]

[0027] Formula 2;

[0028] Preferably, R5 is selected from -R9CR 10 CH2;

[0029] Preferably, R9 is selected from -OCO, -NHCO, or C6-C. 14 aryl;

[0030] Preferred, R 10 Selected from H or C1-C4 straight-chain or branched alkyl groups;

[0031] Preferably, R6, R7, and R8 are independently selected from C1-C 10 Straight-chain or branched alkyl groups;

[0032] Preferably, e is selected from an integer between 3 and 8; more preferably, it is 3.

[0033] The C1-C4 straight-chain or branched alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc.

[0034] The C1-C 10 The straight-chain or branched alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, etc.

[0035] Preferably, the C6-C of the present invention 14 The aryl group is replaced by a substituent selected from C1-C1. 10 It consists of one or more of the following: straight-chain or branched alkyl groups, C1-C4 alkoxy groups, C3-C6 cycloalkyl groups, halogens, and amino groups.

[0036] More preferably, the number of substituents is 1, 2 or 3.

[0037] The C1-C4 alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, and butoxy groups.

[0038] The C3-C6 cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclohexyl, and cyclopentyl.

[0039] The halogen is fluorine, chlorine, bromine or iodine; more preferably chlorine.

[0040] The reaction equation for the preparation method described in this invention is as follows:

[0041]

[0042] Wherein, n and m are positive integers;

[0043] The silane coupling agent forms Si-O-Si bonds with the carrier silicon dioxide;

[0044] The R1-R 10 The range of 'e' is the same as above, and will not be repeated here;

[0045] The R 6 / 7 / 8 It is represented as R6, R7, or R8.

[0046] Preferably, the functional unit shown in Formula 1 of this invention is selected from any of the following structures:

[0047]

[0048] Preferably, the alkenyl-modified silane coupling agent shown in Formula 2 is selected from any of the following structures:

[0049]

[0050] Preferably, the silica is selected from one or more of nano silica, micro silica, mesoporous silica, diatomaceous earth, silica, montmorillonite, and silicon wafers.

[0051] The polymerization method described in this invention is preferably free radical polymerization, anionic polymerization, or hindered Lewis acid-base pair catalytic polymerization; more preferably, it is free radical polymerization.

[0052] Preferably, the polymerization temperature in step (1) of this invention is 60°C-110°C; more preferably, it is 65°C-75°C.

[0053] The polymerization time is preferably 12-60 h; more preferably 48 h.

[0054] Preferably, the reaction temperature in step (2) is 60°C-130°C; more preferably, it is 65°C-110°C.

[0055] The reaction time is preferably 6-48 h; more preferably 12 h.

[0056] Preferably, the initiator of the present invention is selected from azobisisobutyronitrile or benzoyl peroxide; more preferably, it is azobisisobutyronitrile.

[0057] The organic solvents in step (1) include, but are not limited to, one or more of tetrahydrofuran, acetone, toluene, xylene, dimethyl sulfoxide, dimethylformamide, 1,4-dioxane, dichloromethane, chloroform, and 1,2-dichloroethane.

[0058] The present invention does not have any particular limitation on the order of adding the functional monomer, alkenyl-modified silane coupling agent and initiator in step (1). They can be added at the same time or in steps.

[0059] The present invention does not impose any particular limitation on the proportions of the functional monomer, the alkenyl-modified silane coupling agent, the initiator, and the silica, which can be adjusted according to actual needs to obtain the desired functional polymer-modified silica.

[0060] The present invention also provides a functional polymer-modified silica, which is prepared by the above-described preparation method;

[0061] Preferably, the polymer loading of the functional polymer-modified silica is 1wt%-40wt%.

[0062] This invention also provides the application of the above-mentioned functional polymer-modified silica in composite materials or supported catalysts.

[0063] Compared with the prior art, the method for preparing functional polymer-modified silica provided by the present invention includes the following steps: (1) mixing the functional monomer shown in Formula 1, the alkenyl-modified silane coupling agent, the initiator and the organic solvent, and polymerizing to obtain system S1; (2) mixing silica and system S1 to react and prepare the functional polymer-modified silica; wherein, R1 is selected from H or C1-C6 straight-chain or branched alkyl groups; R2 is selected from -COOR3, -CONHR3 or C6-C 14 The aryl group; R3 is selected from H, sulfonic acid group, -(CH2). qR4 is one or more of C1-C6 straight-chain or branched alkyl groups; q is selected from integers between 0 and 5; R4 is selected from one or more of C2-C6 straight-chain or branched alkenyl groups, C2-C6 straight-chain or branched alkynyl groups, C3-C6 heterocyclic alkyl groups, dimethylamino groups, azide groups, halogen groups, hydroxyl groups, and amino groups. The preparation method of this invention uses a one-pot method to in-situ load functional polymers onto the surface of silica to prepare modified silica. The preparation method is simple and efficient, and the loading amount of functional polymers can be controlled. Attached Figure Description

[0064] Figure 1 The graph shows the thermogravimetric analysis results of the final product obtained in Example 13;

[0065] Figure 2 The solid-state carbon NMR spectrum of the final product obtained in Example 13 and its assignment. Detailed Implementation

[0066] To further illustrate the present invention, the preparation method of functional polymer-modified silica and the functional polymer-modified silica provided by the present invention will be described in detail below with reference to embodiments.

[0067] Example 1

[0068] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 1 g of acrylic acid, and 4 mL of dimethyl sulfoxide were added. After reacting at 70°C for 24 hours, 1 g of nano-silica (15 nm) was added, and the reaction continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with dimethyl sulfoxide, and centrifuged three times. After drying, a sample of polyacrylic acid loaded on a silica surface was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 40%.

[0069] Example 2

[0070] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 1 g of methyl methacrylate (MDMA), and 4 mL of tetrahydrofuran were added. After reacting at 70°C for 24 hours, 1 g of nano-silica (15 nm) was added, and the reaction was continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with tetrahydrofuran, and centrifuged three times. After drying, a sample of polymethyl methacrylate (PMMA) loaded on a silica surface was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 35%.

[0071] Example 3

[0072] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 1 g of dimethylaminoethyl methacrylate (DMME), and 4 mL of tetrahydrofuran were added. After reacting at 70°C for 24 hours, 1 g of nano-silica (15 nm) was added, and the reaction was continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with tetrahydrofuran, and centrifuged three times. After drying, a sample of poly(dimethylaminoethyl methacrylate) loaded on a silica surface was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 36%.

[0073] Example 4

[0074] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 1 g of glycidyl methacrylate, and 4 mL of dimethyl sulfoxide were added. After reacting at 70°C for 24 hours, 1 g of diatomaceous earth was added, and the reaction was continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with dimethyl sulfoxide, and centrifuged three times. After drying, a sample of diatomaceous earth surface loaded with poly(glycidyl methacrylate) was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 20%.

[0075] Example 5

[0076] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 1 g of hydroxyethyl methacrylate, and 4 mL of dimethyl sulfoxide were added. After reacting at 70°C for 24 hours, 1 g of silica was added, and the reaction was continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with dimethyl sulfoxide, and centrifuged three times. After drying, a sample of silica surface loaded with polyhydroxyethyl methacrylate was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 25%.

[0077] Example 6

[0078] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 1 g of chloropropyl methacrylate, and 4 mL of tetrahydrofuran were added. After reacting at 70°C for 24 hours, 1 g of montmorillonite was added, and the reaction was continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with tetrahydrofuran, and centrifuged three times. After drying, a montmorillonite-supported polychloropropyl methacrylate sample was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 32%.

[0079] Example 7

[0080] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), and 4 mL of tetrahydrofuran were added and reacted at 70°C for 12 hours. Then, 1 g of methyl methacrylate was added, and the reaction was continued for another 12 hours. After the reaction was complete, the sample was centrifuged, ultrasonically washed with tetrahydrofuran, and centrifuged three times. After drying, a sample of polymethyl methacrylate loaded on a silica surface was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 29%.

[0081] Example 8

[0082] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 1 g of methyl methacrylate (MDMA), and 4 mL of tetrahydrofuran were added and reacted at 70°C for 12 hours. Then, 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570) was added and reacted for another 12 hours. Finally, 1 g of nano-silica (15 nm) was added, and the reaction continued for another 12 hours. After the reaction was complete, the sample was centrifuged, ultrasonically washed with tetrahydrofuran, and centrifuged three times. After drying, a sample of polymethyl methacrylate (PMMA) loaded on a silica surface was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 33%.

[0083] Example 9

[0084] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 1 g of p-vinylbenzenesulfonic acid, and 4 mL of dimethyl sulfoxide were added. After reacting at 70°C for 24 hours, 1 g of nano-silica (15 nm) was added, and the reaction was continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with tetrahydrofuran, and centrifuged three times. After drying, a sample of polymethyl methacrylate (PMMA) loaded on a silica surface was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 32%.

[0085] Example 10

[0086] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacrylamide)propyltrimethoxysilane, 1 g of methyl methacrylate (MDMA), and 4 mL of tetrahydrofuran were added. After reacting at 70°C for 24 hours, 1 g of nano-silica (15 nm) was added, and the reaction continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with tetrahydrofuran, and centrifuged three times. After drying, a sample of polymethyl methacrylate (PMMA) loaded on a silica surface was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 40%.

[0087] Example 11

[0088] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 1 g of methyl methacrylate (MDMA), and 4 mL of tetrahydrofuran were added. After reacting at 70°C for 24 hours, 1 g of silicon wafer was added, and the reaction continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with tetrahydrofuran, and centrifuged three times. After drying, a sample of polymethyl methacrylate (PMMA) loaded on a silica surface was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 1%.

[0089] Example 12

[0090] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 1 g of methyl methacrylate (MDMA), and 4 mL of tetrahydrofuran were added. After reacting at 70°C for 24 hours, 1 g of 0.5 μm silica was added, and the reaction was continued for another 12 hours. After the reaction was completed, the sample was centrifuged, ultrasonically washed with tetrahydrofuran, and centrifuged three times. After drying, a sample of polymethyl methacrylate (PMMA) loaded on a silica surface was obtained. Thermogravimetric analysis (TGA) showed that the polymer loading was 5%.

[0091] Example 13

[0092] In a reaction flask, 3 mg of azobisisobutyronitrile (AIBN), 60 mg of 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), 0.5 g of methyl methacrylate (MMA), 0.5 g of glycidyl methacrylate (GMA), and 4 mL of dimethyl sulfoxide (DMSO) were added. After reacting at 70°C for 24 hours, 1.5 g of nano-silica (15 nm) was added, and the reaction continued for another 12 hours. After the reaction was complete, the sample was centrifuged, ultrasonically washed with DMS, and centrifuged three times. After drying, samples of polymethyl methacrylate and glycidyl methacrylate loaded on a silica surface were obtained. These samples were analyzed by thermogravimetric analysis (TGA). Figure 1 As shown, the polymer loading was 21.8%.

[0093] Figure 2 The solid-state carbon NMR spectrum and signal assignment of the final product obtained in Example 13 show that polymethyl methacrylate and glycidyl methacrylate were successfully loaded onto the silica surface. This indicates that the surface functional polymers in the functionally modified silica prepared by the method described in this invention are characterizable.

[0094] Example 14

[0095] 0.1g of the functional polymer-modified silica obtained in Example 5 was added to the raw material (50g) for synthesizing polyurethane. The polyurethane was prepared from polybutylene adipate (2000 g / mol), 1,4-butanediol, and diphenylmethane diisocyanate. The resulting composite polyurethane material had 30% higher wear resistance than the polyurethane material without silica.

[0096] Example 15

[0097] 1g of the functional polymer-modified silica obtained in Example 6 was reacted with 0.2g of triethylamine in 15mL of acetone at 80°C for 6 hours. The mixture was filtered, centrifuged, washed three times with acetone, and dried to obtain quaternary ammonium salt-modified silica, which can be used as a catalyst for the cycloaddition reaction of propylene oxide and carbon dioxide.

[0098] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing functional polymer-modified silica, characterized in that, Includes the following steps: (1) The functional monomer shown in Formula 1, the alkenyl-modified silane coupling agent, the initiator and the organic solvent are mixed and polymerized to obtain system S1; (2) The functional polymer-modified silica is prepared by mixing and reacting silica with system S1; Formula 1; Wherein, R1 is selected from H or C1-C6 straight-chain or branched alkyl groups; R2 is selected from -COOR3, -CONHR3, or C6-C. 14 aryl; R3 is selected from H, sulfonic acid group, and -(CH2). q R4, one or more of straight-chain or branched alkyl groups of C1-C6; q is an integer between 0 and 5; R4 is selected from one or more of the following: C2-C6 straight-chain or branched alkenyl groups, C2-C6 straight-chain or branched alkynyl groups, C3-C6 heterocyclic alkyl groups, dimethylamino groups, azide groups, halogen groups, hydroxyl groups, and amino groups.

2. The preparation method according to claim 1, characterized in that, The structure of the alkenyl-modified silane coupling agent is shown in Formula 2: Formula 2; R5 is selected from -R9CR 10 CH2; R9 is selected from -OCO, -NHCO, or C6-C. 14 aryl; R 10 Selected from H or C1-C4 straight-chain or branched alkyl groups; R6, R7, and R8 are independently selected from C1-C 10 Straight-chain or branched alkyl groups; e is an integer between 3 and 8.

3. The preparation method according to claim 2, characterized in that, The C6-C 14 The aryl group is replaced by a substituent selected from C1-C1. 10 It consists of one or more of the following: straight-chain or branched alkyl groups, C1-C4 alkoxy groups, C3-C6 cycloalkyl groups, halogens, and amino groups.

4. The preparation method according to any one of claims 1-3, characterized in that, The functional unit shown in Formula 1 is selected from any of the following structures:

5. The preparation method according to claim 4, characterized in that, The alkenyl-modified silane coupling agent shown in Formula 2 is selected from any of the following structures:

6. The preparation method according to claim 2, characterized in that, The silica is selected from one or more of the following: nano silica, micro silica, mesoporous silica, diatomaceous earth, silica, montmorillonite, and silicon wafers.

7. The preparation method according to claim 2, characterized in that, The polymerization temperature in step (1) is 60°C-110°C; The reaction temperature in step (2) is 60°C-130°C.

8. The preparation method according to claim 2, characterized in that, The initiator is selected from azobisisobutyronitrile or benzoyl peroxide.

9. A functional polymer-modified silica, characterized in that, Prepared by the preparation method according to any one of claims 1-8; The polymer loading of the functional polymer-modified silica is 1wt%-40wt%.

10. The application of the functional polymer-modified silica according to claim 9 in composite materials or supported catalysts.

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