Hydrophilic modification method for cushion silicone rubber surface

Abstract

The invention provides a cushion silicon rubber surface hydrophilic modification method, which comprises the following steps: carrying out hydroxylation reaction on silicon rubber subjected to ethanol and ultrapure water ultrasonic washing and drying to hydroxylate the surface of the silicon rubber; immersing the hydroxylated silicone rubber in an acidic aqueous solution containing a silane coupling agent, so that the hydroxylated silicone rubber is grafted with the silane coupling agent; immersing the silicone rubber grafted with the silane coupling agent in an alkaline solution containing a photoinitiator, so that the silicone rubber is grafted with the photoinitiator; the silicone rubber grafted with the photoinitiator is immersed in an aqueous solution of a monomer containing double bonds, and surface hydrophilic modified silicone rubber is obtained through an ultraviolet cross-linking reaction; the static water contact angle of the silicone rubber subjected to surface hydrophilic modification is less than or equal to 50 degrees. On the premise that the excellent performance of the silicon rubber is reserved, the hydrophilicity of the surface of the silicon rubber is remarkably improved, and the modified silicon rubber has excellent hydrophilic lubricating performance at the same time.

Description

[Technical field]

[0001] The invention relates to the technical field of hydrophilic modification of silicone rubber, and in particular to a method for hydrophilic modification of the surface of silicone rubber of a buffer pad. [Background technology]

[0002] A cushion is a device used to reduce impact, vibration or noise, usually made of elastic material. Silicone rubber is a common material for cushions because of its good elasticity, high temperature resistance and chemical stability. The non-polar silicon oxygen chain and special self-helical molecular structure of silicone rubber material give it an extremely low surface energy, thus showing strong hydrophobicity. Hydrophobic silicone rubber shows poor friction reduction effect during its application, and has no wetting effect on water and most coatings, resulting in poor stability of functional materials attached to silicone rubber, greatly reducing its practical application value.

[0003] At present, the modification methods reported at home and abroad can improve the hydrophilicity of silicone rubber to varying degrees, but bulk modification will destroy the structure of silicone rubber itself and affect its excellent performance; plasma, ultraviolet ozone, and physical adsorption modification can make the silicone rubber surface temporarily hydrophilic, but the modified silicone rubber is not resistant to wear and immersion; chemical grafting can make hydrophilic substances firmly grafted to the silicone rubber surface in the form of covalent bonds, but most of the current chemical grafting is to first graft silane coupling agents on the silicone rubber surface, and then use the chemical groups at the other end of the silane coupling agent to directly graft hydrophilic substances through chemical reactions. Due to the limited end group types of silane coupling agents, the types of hydrophilic substances that can be used for grafting are also limited. Therefore, it is urgent to design a new method for hydrophilic modification of silicone rubber surface.

[0004] The presence of "organic" groups on the "inorganic" skeleton gives polysiloxane many unique properties, such as the physiological inertness, weather resistance, and oxidation resistance of inorganic substances and the thermoplasticity and easy processing of organic substances, making it possible to be used in many different forms such as liquids, emulsions, compounds, resins, and rubbers in the sealing rings and insulating sleeves of potentiometers, seals and shockproof parts for automobiles and ships, sealing rings for fuel, lubricating oil, and hydraulic oil systems, and bushings, cushions, and protective covers of engines and transmissions. [Summary of the invention]

[0005] The technical problem to be solved by the present invention is to provide a method for hydrophilic modification of the surface of silicone rubber of a buffer pad, which method significantly improves the hydrophilicity of the silicone rubber surface while retaining the excellent performance of the silicone rubber itself, so that the modified silicone rubber also has excellent hydrophilic lubrication properties.

[0006] The present invention is achieved in that:

[0007] A method for hydrophilic modification of the surface of a buffer pad silicone rubber comprises the following steps:

[0008] Step 1: Prepare piranha solution, place the silicone rubber that has been washed with ethanol and ultrapure water for several times and dried in the above solution, take it out and dry it at 35-40°C for 25-30 minutes to obtain silicone rubber with surface hydroxylation;

[0009] Step 2: prepare an acidic solution of a silane coupling agent, place the silicone rubber with surface hydroxylation in the solution, take it out and dry it after 0.5-3 hours, and obtain the silicone rubber grafted with the silane coupling agent;

[0010] Step 3: Dissolve UV 2959 photoinitiator in a solvent to prepare an alkaline solution, store it away from light and set aside for use; place the silicone rubber grafted with siloxane coupling agent in the above solution for ring-opening reaction, react at 60-80° C. for 2-3 hours, then take it out and dry it to obtain silicone rubber with surface grafted photoinitiator;

[0011] Step 4: Prepare a monomer aqueous solution containing double bonds, immerse the silicone rubber with the surface grafted photoinitiator in the monomer aqueous solution, perform ultraviolet light crosslinking reaction, take out and dry after UV 254-295nm, 4-18h, to obtain a silicone rubber with hydrophilic surface modification;

[0012] The static water contact angle of the silicone rubber after the surface hydrophilic modification is less than or equal to 50°

[0013] Furthermore, in step 1, the size of the silicone rubber is 1x1.5 cm, the drying temperature is room temperature, the ratio of the piranha solution is H2SO4 (98%) / H2O2 (30%) (V:V=3:1), and the amount used is 12-24 mL.

[0014] Furthermore, the silane coupling agent in step 2 is selected from one or more of γ-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, γ-glycidyloxytrimethylsilane, 2-(3,4-epoxycycloethyl)ethyltrimethoxysilane, 3-glycidylpropyl(dimethoxy)methylsilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0015] Furthermore, in step 2, the mixed solution of 0.4-1 wt. % silane coupling agent aqueous solution and 0.4-1 wt. % acetic acid aqueous solution is dried at room temperature.

[0016] Furthermore, the solvent in step 3 is ethanol, methanol or water.

[0017] Furthermore, in step 3, the mass concentration of UV 2959 photoinitiator is 5-10wt.%, the pH of the alkaline solution is 12-14, and the drying temperature is room temperature.

[0018] Further, the double bond-containing monomer in step 4 is selected from one or more of diacetone acrylamide, N-(hydroxymethyl)acrylamide, N,N'-methylenebisacrylamide, 1,6-hexanediol dimethacrylate, dimethacrylate glycerol, N-(2-hydroxypropyl)methacrylamide, N-(2-amino-2-oxoethyl)acrylamide, 1,3-bis(allyloxy)propan-2-ol, N-[tris(hydroxymethyl)methyl]acrylamide, 3-(3-methacrylamidopropyl)dimethylamino)propane-1-sulfonate, mono-2-(methacryloyloxy)ethyl maleate, pyromellitic anhydride dimethacrylate glycerol, choline sulfate, choline phosphorylation, and choline carboxylate.

[0019] Furthermore, the concentration of the aqueous solution of the monomer containing double bonds is 0.04-0.12 g / mL, and the drying temperature is room temperature.

[0020] The present invention has the following advantages:

[0021] The present invention, without changing the silicone rubber body, first grafts a silane coupling agent on the silicone rubber surface through hydroxylation; utilizes a silane coupling agent having at least one terminal alkoxy group at one end of the molecular chain and a terminal epoxy group at the other end, and makes the terminal epoxy group react with the photoinitiator UV 2959 to undergo a ring-opening reaction, thereby obtaining silicone rubber grafted with the photoinitiator through chemical bonding;

[0022] UV 2959 photoinitiator is a highly efficient non-yellowing ultraviolet photoinitiator, suitable for the photoinitiated polymerization of most water-based acrylates and unsaturated polyester resins and other hydrophilic substances. Therefore, the surface of silicone rubber grafted with photoinitiator can be grafted with a variety of different hydrophilic substances by ultraviolet light, thereby achieving the purpose of hydrophilic modification of the silicone rubber surface.

[0023] The present invention can significantly improve the hydrophilicity of the silicone rubber surface, change the static contact angle of the silicone rubber surface from >120° to <50°, effectively solve the hydrophobicity problem of the silicone rubber surface, make it wettable to water and most coatings, and can attach most functional materials to the silicone rubber, thus significantly improving the practical application value of the silicone rubber.

Brief Description of the Drawings

[0024] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0025] Figure 1 The schematic diagram is a principle diagram of a method for hydrophilic modification of the surface of silicone rubber of a buffer pad according to the present invention.

[0026] Figure 2 The static water contact angle test diagram of the material surface of Comparative Example 1 and Examples 1-6.

[0027] Figure 3 This is the infrared spectrum of the silicone rubber of Comparative Example 1.

[0028] Figure 4 This is the infrared spectrum of the silicone rubber of Example 5.

[0029] Figure 5 This is the infrared spectrum of the silicone rubber of Example 6. [Specific implementation method]

[0030] The following will be combined with the embodiments of the present invention and the attached Figure 1-5 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. Unless otherwise specified, the numerical values ​​set forth in these embodiments do not limit the scope of the present invention. The techniques and methods known to ordinary technicians in the relevant fields may not be discussed in detail, but in appropriate cases, the techniques and methods should be regarded as part of the specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0031] The experimental methods in the following examples without specifying specific conditions are usually measured in accordance with national standards; if there are no corresponding national standards, they are carried out in accordance with the general international standards or the standard requirements proposed by relevant enterprises.

[0032] The coating components of the organic silica gel in each embodiment are shown in Table 1 below:

[0033] Table 1 Coating components of organic silica gel in various examples

[0034] Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 KH560 / √ √ √ √ √ √ UV2959 / √ √ √ √ √ √ MBA / / √ / √ / √ monomer / DAAM DAAM NMAM NMAM DA+NM DA+NM

[0035] Among them, KH560 is γ-glycidyloxypropyltrimethoxysilane; UV 2959 is 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone; MBA is N,N'-methylenebisacrylamide; DAAM is diacetone acrylamide; NMAM is N-(hydroxymethyl)acrylamide; DA+NM is a mixed solution of diacetone acrylamide and N-(hydroxymethyl)acrylamide. The principle of the modification method of the present invention is as follows Figure 1 shown.

[0036] The organic silica gel used below is vulcanized methyl vinyl silicone rubber with a size of 1.5 cm×1 cm×0.2 cm.

[0037] Comparative Example 1

[0038] The processing steps of the original organic silica gel are as follows: the organic silica gel is ultrasonically washed several times with a 75% ethanol aqueous solution and ultrapure water, and then dried at room temperature.

[0039] Example 1

[0040] A method for hydrophilic modification of the surface of silicone rubber of a buffer pad, comprising the following steps:

[0041] Step 1: The organic silica gel is ultrasonically washed several times with 75% ethanol aqueous solution and ultrapure water, and dried at room temperature; a piranha solution of H2SO4 (98%):H2O2 (30%) (V:V=9mL:3mL) is prepared, and the washed and dried silicone rubber is placed in the piranha solution, heated in a 35°C water bath for 30 minutes, taken out, and dried at room temperature to obtain a silicone rubber with surface hydroxylation;

[0042] Step 2: 0.4wt.% KH560 aqueous solution and 0.4wt.% acetic acid aqueous solution are mixed to prepare an acidic silane coupling agent solution; the surface hydroxylated silicone rubber is placed in the above solution and soaked for 3 hours, then taken out and dried at room temperature to obtain silicone rubber grafted with silane coupling agent;

[0043] Step 3: prepare an ethanol solution of pH=12 and 5wt.% UV2959, and place the silicone rubber grafted with the siloxane coupling agent in the above solution for ring-opening reaction under light-proof conditions, react at 80°C for 2h, and then dry at room temperature to obtain silicone rubber with a surface grafted with a photoinitiator;

[0044] Step 4: Prepare 2 mL of 0.04 g / mL DAAM aqueous solution, immerse the silicone rubber with surface grafted photoinitiator in the above monomer aqueous solution, carry out UV crosslinking reaction, after UV 254 nm, 6 hours, dry at room temperature to obtain silicone rubber with surface hydrophilic modification.

[0045] Example 2

[0046] A method for hydrophilic modification of the surface of silicone rubber of a buffer pad, comprising the following steps:

[0047] Step 1: The organic silica gel is ultrasonically washed several times with 75% ethanol aqueous solution and ultrapure water, and dried at room temperature; a piranha solution of H2SO4 (98%):H2O2 (30%) (V:V=12mL:4mL) is prepared, and the washed and dried silicone rubber is placed in the piranha solution, heated in a 37°C water bath for 28 minutes, taken out, and dried at room temperature to obtain a silicone rubber with surface hydroxylation;

[0048] Step 2: 0.6wt.% KH560 aqueous solution and 0.6wt.% acetic acid aqueous solution are mixed to prepare an acidic silane coupling agent solution; the surface hydroxylated silicone rubber is placed in the above solution and soaked for 2.5 hours, then taken out and dried at room temperature to obtain silicone rubber grafted with silane coupling agent;

[0049] Step 3: prepare an ethanol solution of pH=12 and 6wt.% UV2959, and place the silicone rubber grafted with the siloxane coupling agent in the above solution for ring-opening reaction under light-proof conditions, react at 75°C for 2.5h, and then dry at room temperature to obtain silicone rubber with a surface grafted with a photoinitiator;

[0050] Step 4: Dissolve 200 mg of MBA in 4 mL of ethanol and 2 mL of deionized water.

[0051] Take 1 mL of the above-mentioned MBA solution and 2 mL of 0.05 g / mL DAAM aqueous solution to prepare a monomer aqueous solution, immerse the silicone rubber with the surface grafted photoinitiator in the above-mentioned monomer aqueous solution, and carry out ultraviolet light cross-linking reaction. After UV 254 nm and 8 hours, dry at room temperature to obtain a silicone rubber with surface hydrophilic modification.

[0052] Example 3

[0053] A method for hydrophilic modification of the surface of silicone rubber of a buffer pad, comprising the following steps:

[0054] Step 1: The organic silica gel is ultrasonically washed several times with a 75% ethanol aqueous solution and ultrapure water, and dried at room temperature; the washed and dried silicone rubber is treated with UVO for 20 minutes to obtain a surface hydroxylated silicone rubber;

[0055] Step 2: 0.8wt.% KH560 aqueous solution and 0.8wt.% acetic acid aqueous solution are mixed to prepare an acidic silane coupling agent solution; the surface hydroxylated silicone rubber is placed in the above solution and soaked for 2.5 hours, then taken out and dried at room temperature to obtain silicone rubber grafted with silane coupling agent;

[0056] Step 3: prepare an ethanol solution of pH=13 and 7wt.% UV2959, and place the silicone rubber grafted with the siloxane coupling agent in the above solution for ring-opening reaction under light-proof conditions, react at 70°C for 2h, and then dry at room temperature to obtain silicone rubber with a surface grafted with a photoinitiator;

[0057] Step 4: Prepare 2 mL of 0.07 g / mL NMAM aqueous solution, immerse the silicone rubber with surface grafted photoinitiator in the above monomer aqueous solution, carry out UV crosslinking reaction, after UV 254 nm, 10 hours, dry at room temperature to obtain silicone rubber with surface hydrophilic modification.

[0058] Example 4

[0059] A method for hydrophilic modification of the surface of silicone rubber of a buffer pad, comprising the following steps:

[0060] Step 1: The organic silica gel is ultrasonically washed several times with a 75% ethanol aqueous solution and ultrapure water, and dried at room temperature; the washed and dried silicone rubber is treated with UVO for 25 minutes to obtain a surface hydroxylated silicone rubber;

[0061] Step 2: 0.8wt.% KH560 aqueous solution and 0.8wt.% acetic acid aqueous solution are mixed to prepare an acidic silane coupling agent solution; the surface hydroxylated silicone rubber is placed in the above solution and soaked for 2 hours, then taken out and dried at room temperature to obtain silicone rubber grafted with silane coupling agent;

[0062] Step 3: prepare an ethanol solution of pH=13 and 7wt.% UV2959, and place the silicone rubber grafted with the siloxane coupling agent in the above solution for ring-opening reaction under light-proof conditions, react at 65°C for 2.5h, and then dry at room temperature to obtain silicone rubber with a surface grafted with a photoinitiator;

[0063] Step 4: Dissolve 300 mg of MBA in 6 mL of ethanol and 3 mL of deionized water.

[0064] Take 1 mL of the above-mentioned MBA solution and 2 mL of 0.09 g / mL NMAM aqueous solution to prepare a monomer aqueous solution, immerse the silicone rubber with the surface grafted photoinitiator in the above-mentioned monomer aqueous solution, and carry out ultraviolet light cross-linking reaction. After UV 254 nm and 12 hours, dry at room temperature to obtain a silicone rubber with surface hydrophilic modification.

[0065] Example 5

[0066] A method for hydrophilic modification of the surface of silicone rubber of a buffer pad, comprising the following steps:

[0067] Step 1: The organic silica gel is ultrasonically washed several times with 75% ethanol aqueous solution and ultrapure water, and dried at room temperature; a piranha solution of H2SO4 (98%):H2O2 (30%) (V:V=15mL:5mL) is prepared, and the washed and dried silicone rubber is placed in the piranha solution, heated in a 40°C water bath for 30 minutes, taken out, and dried at room temperature to obtain a silicone rubber with surface hydroxylation;

[0068] Step 2: 0.7wt.% KH560 aqueous solution and 0.7wt.% acetic acid aqueous solution are mixed to prepare an acidic silane coupling agent solution; the surface hydroxylated silicone rubber is placed in the above solution and soaked for 2 hours, then taken out and dried at room temperature to obtain silicone rubber grafted with silane coupling agent;

[0069] Step 3: prepare an ethanol solution of pH=14 and 8wt.% UV2959, and place the silicone rubber grafted with the siloxane coupling agent in the above solution for ring-opening reaction under light-proof conditions, react at 60°C for 2h, and then dry at room temperature to obtain silicone rubber with a surface grafted with a photoinitiator;

[0070] Step 4: Mix 2 mL of 0.10 g / mL DAAM aqueous solution and 2 mL of 0.10 g / mL NMAM aqueous solution to prepare a monomer solution, immerse the silicone rubber with surface grafted photoinitiator in the above monomer aqueous solution, and perform ultraviolet light cross-linking reaction. After UV 254 nm and 14 hours, dry at room temperature to obtain silicone rubber with surface hydrophilic modification.

[0071] Example 6

[0072] A method for hydrophilic modification of the surface of silicone rubber of a buffer pad, comprising the following steps:

[0073] Step 1: The organic silica gel is ultrasonically washed several times with a 75% ethanol aqueous solution and ultrapure water, and dried at room temperature; the washed and dried silicone rubber is treated with UVO for 30 minutes to obtain a surface hydroxylated silicone rubber;

[0074] Step 2: 1.0wt.% KH560 aqueous solution and 1.0wt.% acetic acid aqueous solution are mixed to prepare an acidic silane coupling agent solution; the surface hydroxylated silicone rubber is placed in the above solution and soaked for 3 hours, then taken out and dried at room temperature to obtain silicone rubber grafted with silane coupling agent;

[0075] Step 3: prepare an ethanol solution of pH=14 and 10wt.% UV2959, and place the silicone rubber grafted with the siloxane coupling agent in the above solution for ring-opening reaction under light-proof conditions, react at 65°C for 3h, and then dry at room temperature to obtain silicone rubber with a surface grafted with a photoinitiator;

[0076] Step 4: Dissolve 600 mg of MBA in 12 mL of ethanol and 6 mL of deionized water.

[0077] Take 1 mL of the above-mentioned MBA solution, 2 mL of 0.12 g / mL DAAM aqueous solution and 2 mL of 0.12 g / mL NMAM aqueous solution, mix the three solutions to prepare a monomer solution, immerse the silicone rubber with surface grafted photoinitiator in the above-mentioned monomer aqueous solution, carry out ultraviolet light cross-linking reaction, after UV 254 nm, 18 hours, and dry at room temperature to obtain the silicone rubber with surface hydrophilic modification.

[0078] The static water contact angle test graph of the silicone rubber surface prepared in the above embodiments is as follows: Figure 2 As shown, Figure 2 A is comparative example 1, B is example 1, C is example 2, D is example 3, E is example 4, F is example 5, and G is example 6; the contact angles are shown in Table 2 below:

[0079] Table 2 Static water contact angle test of silicone rubber surface in each case

[0080] Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Contact angle (°) 125 26 24 49 10 45 0

[0081] The experimental data in Table 2 prove that, compared with the organic silicone rubber that has not been hydrophilically modified, the hydrophilic modified silicone rubber prepared by the method of the present invention can significantly improve the hydrophilicity of the silicone rubber surface under the use of most hydrophilic monomers; this shows that the method of the present invention has a wider application and better improvement on the hydrophilicity of silicone rubber.

[0082] The infrared spectra of the comparative example 1 without hydrophilic modification and the examples 5 and 6 after hydrophilic modification were tested. The infrared spectra were as follows: Figure 3 , 4 , 5, where the abscissa Wavenumber represents the wave number, and the ordinate Transmittance represents the transmittance. It can be seen from the figure that the absorption wave number is 1657cm -1 Up to 1380cm -1 There are many forms of carbonyl absorption vibration; in particular, in contrast Figure 4 and Figure 5 , we can find that 1621cm -1 The vibration absorption at can be attributed to the carbonyl absorption vibration of the secondary amide in MBA. It can be seen that a new bond is formed through the reaction of the present invention, indicating that the reaction of the present invention can be carried out, and the surface of the hydrophilically modified silicone rubber has good hydrophilicity.

[0083] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for hydrophilic modification of the surface of a buffer pad silicone rubber, characterized in that: The steps include: The silicone rubber which has been ultrasonically washed with ethanol and ultrapure water and dried is subjected to a hydroxylation reaction to hydroxylate the surface of the silicone rubber; the hydroxylated silicone rubber is immersed in an acidic aqueous solution containing a silane coupling agent to graft the silane coupling agent; The silicone rubber grafted with a silane coupling agent is immersed in an alkaline solution containing a photoinitiator to graft the photoinitiator; the silicone rubber grafted with the photoinitiator is immersed in an aqueous solution containing a double bond monomer, and undergoes an ultraviolet light cross-linking reaction to obtain a silicone rubber with a hydrophilic surface modification; The static water contact angle of the silicone rubber after the surface hydrophilic modification is less than or equal to 50°.

2. The method for hydrophilic modification of the surface of a buffer pad silicone rubber according to claim 1, characterized in that: The silicone rubber surface hydroxylation reaction may be carried out by any one of plasma treatment, UVO treatment and piranha solution treatment.

3. The method for hydrophilic modification of the surface of a buffer pad silicone rubber according to claim 1, characterized in that: The silane coupling agent is selected from one or more of γ-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, γ-glycidyloxytrimethylsilane, 2-(3,4-epoxycycloethyl)ethyltrimethoxysilane, 3-glycidylpropyl(dimethoxy)methylsilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

4. The method for hydrophilic modification of the surface of a buffer pad silicone rubber according to claim 1, characterized in that: The double bond-containing monomer is selected from one or more of diacetone acrylamide, N-(hydroxymethyl) acrylamide, N,N'-methylenebisacrylamide, 1,6-hexanediol dimethacrylate, glycerol dimethacrylate, N-(2-hydroxypropyl) methacrylamide, N-(2-amino-2-oxoethyl) acrylamide, 1,3-bis(allyloxy)propan-2-ol, N-[tris(hydroxymethyl)methyl]acrylamide, 3-(3-methacrylamidopropyl)dimethylamino)propane-1-sulfonate, mono-2-(methacryloyloxy)ethyl maleate, pyromellitic anhydride glycerol dimethacrylate, choline sulfate, choline phosphorylation, and choline carboxylate.

5. The method for hydrophilic modification of the surface of a buffer pad silicone rubber according to claim 2, characterized in that: The piranha solution has a ratio of 98% H2SO4:30% H2O2=3:1, calculated in terms of V:V, a temperature of 35-40°C, and a processing time of 25-30 minutes.

6. The method for hydrophilic modification of the surface of a buffer pad silicone rubber according to claim 1, characterized in that: The acidic silane coupling agent solution is a mixture of 0.4-1wt.% silane coupling agent aqueous solution and 0.4-1wt.% acetic acid aqueous solution; the alkaline photoinitiator solution is 5-10wt.% UV2959 ethanol solution, pH=12-14; the concentration of the double bond-containing monomer aqueous solution is 0.04-0.12g / mL.

7. The method for hydrophilic modification of the surface of a buffer pad silicone rubber according to claim 1, characterized in that: The ultraviolet light cross-linking reaction is UV 254-295nm, and the reaction time is 4-18h.

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