CN113480740A

CN113480740A - Preparation method of adjustable amphiphobic filler for silicone rubber and preparation of silicone rubber membrane

Info

Publication number: CN113480740A
Application number: CN202110806026.5A
Authority: CN
Inventors: 姜彦�; 张晓梅; 张洪文
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2021-10-08
Anticipated expiration: 2041-07-16
Also published as: CN113480740B

Abstract

The invention belongs to the field of hydrophobic and oleophobic materials, and particularly relates to a preparation method of an adjustable amphiphobic filler for silicon rubber and a preparation method of a silicon rubber membrane, wherein the preparation method comprises the following steps: firstly, preparing rodlike silicon dioxide with different length-diameter ratios by taking polyvinylpyrrolidone as a template agent and TEOS as a silicon source, and modifying the rodlike silicon dioxide with KH-570 respectively; then crosslinking vinyl-terminated polydimethylsiloxane (VS500) and hydrogen-containing silicone oil XL-1341 to prepare silicone rubber microspheres; then, carrying out hydrosilylation compounding on the two microspheres to obtain a composite microsphere with a special appearance; finally adding the mixture into the prepared silicon rubber membrane. According to the invention, the composite microspheres with special shapes, which are prepared by compounding the rod-shaped silicon dioxide and the silicone rubber microspheres, are added into the silicone rubber membrane, and the amphiphobicity of the silicone rubber membrane can be adjusted by controlling the addition amount.

Description

Preparation method of adjustable amphiphobic filler for silicone rubber and preparation of silicone rubber membrane

Technical Field

The invention belongs to the field of functional materials, and particularly relates to a preparation method of an adjustable amphiphobic filler for silicone rubber and a preparation method of a silicone rubber membrane.

Background

The composite microsphere is a particle formed by compounding two or more components or particles or surface coating, has a composite synergistic multifunctional effect, and can solve the problem of single nanoparticle agglomeration. The silicon dioxide is often used as an object of the composite microsphere, the shape and the size of the silicon dioxide can be controlled by changing reaction conditions, and the surface of the silicon dioxide has silicon hydroxyl groups which can provide reaction sites and have strong designability.

The rod-shaped silicon dioxide can be prepared by a template method, and the rod-shaped material has wide application prospect in the fields of catalysis, chemical engineering, energy sources and the like. The appearance of the rod-shaped silicon nano material with the controllable length-diameter ratio not only enhances the plasticity of the material, but also expands the application range of the rod-shaped silicon nano material. The properties of particles with different structures are remarkably different, and the nanoparticles with good morphology can be applied to many fields, which is the basis of researching advanced functional materials. Meanwhile, rod-shaped silica exhibits unique properties by introducing other elements, such as metals, nanomaterials, polymers, and the like.

The silicon rubber has good heat resistance, chemical stability, corrosion resistance and the like due to the particularity of the molecular structure, has a certain application prospect, and can be further expanded by doping functional filler into the silicon rubber. In most of the current researches, in order to improve the heat resistance, hydrophobicity, oleophobicity and other performances of the silicone rubber membrane, a large amount of filler is often required to be added, which causes the light transmittance of the silicone rubber membrane to be reduced and the optical performance of the silicone rubber membrane to be reduced. The adjustable amphiphobic filler for the silicone rubber prepared by the invention can improve the amphiphobic property and the heat resistance of the filler under the condition of adding the smallest possible amount, does not influence the optical performance of the filler, and even can play a certain role in permeability improvement.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention discloses a preparation method of an adjustable amphiphobic filler for silicon rubber and a preparation method of a silicon rubber membrane, wherein C ═ C groups on KH-570 modified rodlike silicon dioxide and Si-H bonds on silicon rubber microspheres are subjected to hydrosilylation reaction to obtain composite microspheres with special shapes as fillers, the composite microspheres are added into silicon rubber to be blended to prepare a membrane, and the C ═ C bonds on the surfaces of the fillers can be subjected to hydrosilylation with redundant Si-H bonds in the silicon rubber membrane to play a role similar to crosslinking, so that the silicon rubber membrane has a certain anti-reflection effect while the thermal stability is greatly improved, and the hydrophobic and oleophobic properties of the silicon rubber membrane can be controlled by changing the adding amount, so that the silicon rubber membrane is more widely applied.

In order to realize the purpose of the invention, the adopted technical scheme is as follows:

a preparation method of an adjustable amphiphobic filler for silicone rubber comprises the following steps

(1) Preparation of modified rod-like silica: adding KH-570 into deionized water, adjusting the pH value, pre-hydrolyzing for a period of time (preferably, adjusting the pH value by using 0.12g/mL hydrochloric acid solution) to obtain pre-hydrolyzed KH-570, adding a rod-shaped silicon dioxide, ethanol and water mixed solution which is subjected to magnetic stirring into the pre-hydrolyzed KH-570, fully mixing (preferably, the solid-to-liquid ratio of the rod-shaped silicon dioxide to the KH-570 is 0.05-0.1 g/mL), and reacting for 2-5 hours in an oil bath at 70-80 ℃. And (3) centrifugally separating the reacted mixed solution, taking a white precipitate, repeatedly carrying out ultrasonic cleaning and centrifugal separation on the white precipitate by using ethanol (preferably, repeating the ultrasonic cleaning and the centrifugal separation for 3 times), putting the white precipitate into an oven to dry the white precipitate overnight (preferably, the drying temperature is 65-80 ℃), and grinding the white precipitate to obtain the modified rod-like silicon dioxide.

In the present step (1), the rod-like silica preferably has an aspect ratio of 4.14 to 19.86.

In the step (1), preferably, the volume ratio of water to ethanol in the mixture of rod-shaped silica, ethanol and water is 1: 6; the adding amount of the rod-shaped silicon dioxide in the ethanol-water mixed solution is 0.01-0.03 g/mL;

wherein the volume ratio of the KH-570 to the deionized water is 1: 2-4.

Preferably, in step (1), the preparation of the rod-shaped silica: weighing 100-150mg/L polyvinylpyrrolidone n-amyl alcohol solution, then sequentially adding absolute ethyl alcohol, water, prepared 0.18-0.20M sodium citrate solution and ammonia water, adding tetraethyl orthosilicate after uniformly stirring, and standing for 16-24 h. Centrifuging the reaction solution for 5-10min at the rotating speed of 2500-.

(2) Preparation of the silicone rubber microspheres: uniformly mixing vinyl-terminated polydimethylsiloxane I, a hydrogen-containing silicone oil cross-linking agent I and n-hexane I, and adding a Pt catalyst to obtain a mixed solution; and adding the mixed solution into a deionized water solution of a surfactant while stirring, and stirring for reaction at room temperature (preferably, the reaction is carried out for 1-3 h at room temperature, then the temperature is raised to 50-60 ℃ for reaction for 36-48 h; preferably, the mixing method comprises the steps of firstly regulating the rotation speed to 1000-1100 r/min for a period of time and then regulating the rotation speed to 300-400 r/min). After centrifugal separation, taking the upper layer, repeatedly carrying out ultrasonic cleaning and centrifugal separation (preferably 3-4 times), and drying to obtain the silicone rubber microspheres; compared with the polydimethylsiloxane singly using the vinyl-terminated end, the crosslinking density of the polydimethylsiloxane using the two vinyl-terminated ends in the step can be changed, the vinyl contents and the molecular weights of the two vinyl-terminated ends are different, but the type of the polydimethylsiloxane using the vinyl-terminated end does not need to be particularly limited, and the reaction can be carried out under the action of a catalyst as long as the mole number of the vinyl and the mole number of the silicon-hydrogen bond in the hydrogen-containing silicone oil are calculated to be equal.

In the step (2), the reaction system is preferably kept for 3-5min at the rotating speed of 1000-1100 r/min. The mass ratio of the Pt catalyst to the vinyl-terminated polydimethylsiloxane I is 0.02-0.04: 10.

In the step (2), the concentration of the deionized water solution of the surfactant is 12-18 g/L, and the surfactant is composed of Tween 20 and span 80 in a mass ratio of 7: 1.

In the step (2), the preferable selection is that in the step (2), the mass ratio of the vinyl-terminated polydimethylsiloxane I, the hydrogen-containing silicone oil cross-linking agent I and the n-hexane I is 9-10: 0.6-0.8: 11 to 13.

In the step (2), the mass ratio of the mixed solution to the surfactant is preferably 10: 1.5-2.0.

The preferable scheme in the step (2): reacting for 1-3 h at room temperature, then heating to 50-60 ℃ and reacting for 36-48 h, wherein the silicone rubber microspheres can be prepared within the mentioned time and temperature range, and the growth of the silicone rubber microspheres is not facilitated due to too short time or too high temperature.

(3) Preparing the composite microspheres: weighing the silicone rubber microspheres prepared in the step (2) and a certain amount of the modified rod-shaped silicon dioxide prepared in the step (1), mixing, adding a dispersing agent (preferably n-hexane or cyclohexane or alkane with similar properties), and mechanically stirring and dispersing at room temperature for 30-45 min to obtain a dispersion liquid; then, a catalyst is added (preferably, the catalyst is added by diluting the catalyst by dropping n-hexane, and then dropping a dispersion, preferably, a Pt catalyst), and after the temperature rise reaction (preferably, the temperature rise reaction is a reaction at 30 to 35 ℃ for 30 to 45min, and then the temperature rise reaction is carried out at 50 ℃ for 20 to 30 hours (more preferably, 1 d)). And (3) carrying out centrifugal separation to obtain a lower-layer precipitate, repeatedly carrying out centrifugal cleaning on the precipitate (preferably, carrying out centrifugal cleaning for 3-4 times by using normal hexane), and then putting the precipitate into an oven for drying (preferably, the drying temperature is 65-80 ℃) to obtain the silicon dioxide/silicone rubber composite microsphere, namely the adjustable amphiphobic filler for the silicone rubber. In the step (3), the mass of the modified rod-like silicon dioxide is 10-50% of that of the silicon rubber microspheres.

In the step (3), preferably, the mass of the modified silicon dioxide is 20-30% of that of the silicon rubber microspheres; the grain diameter of the silicon rubber microsphere is 40-60 mu m.

In the step (3), it is further preferable that the mass fraction of the Pt catalyst diluent is 0.6 to 1 wt%, and the volume ratio of the Pt catalyst diluent to n-hexane in the dispersion is 1:9 to 10.

The preparation method of the silicone rubber membrane comprises the following steps:

weighing vinyl-terminated polydimethylsiloxane II, vinyl-terminated polydimethylsiloxane III, hydrogen-containing silicone oil cross-linking agent II and n-hexane II, ultrasonically dissolving the materials to be complete, pouring the solution into a three-neck flask, uniformly stirring, adding the adjustable amphiphobic filler for the silicone rubber, uniformly stirring, heating to volatilize the solvent, cooling to room temperature, adding an inhibitor (the inhibitor is used for a platinum catalyst in an experiment, such as alkenyl siloxane of tetramethyl tetravinylcyclotetrasiloxane, and can also be used for pyridine, an organic phosphine compound, an unsaturated amino compound and the like), then uniformly stirring, adding the catalyst, uniformly stirring, pouring into a mold, vacuumizing, defoaming, preserving heat and curing to obtain the silicone rubber film.

Preferably, the mass ratio of the vinyl-terminated polydimethylsiloxane II to the vinyl-terminated polydimethylsiloxane III to the hydrogen-containing silicone oil cross-linking agent II to the n-hexane II is 2-4: 1-3: 0.6-1.2: 3.

Furthermore, the mass ratio of the adjustable amphiphobic filler, the inhibitor and the catalyst for the silicone rubber is 1-4: 10-20: 6-12.

Furthermore, the content of the adjustable dual-property filler for the silicon rubber in the silicon rubber film is 0.04-0.2%.

Preferably, the heat preservation curing is carried out for 24-48 h at the temperature of 80-100 ℃.

Preferably, the catalyst is a Karstedt catalyst, a platinum-vinylalkoxysilane complex, a platinum-divinyldiphenyldisiloxane complex, a nitrogen-containing compound-modified platinum complex or a platinum-alkynol complex.

Compared with the prior art, the invention has the following beneficial effects: according to the invention, a silicon-hydrogen addition reaction is carried out on C ═ C groups on the rodlike silicon dioxide modified by the silane coupling agent and Si-H bonds on the silicon rubber microspheres to obtain the composite microspheres with special shapes, and the composite microspheres are doped into the silicon rubber membrane, so that the hydrophobic and oleophobic properties of the silicon rubber membrane can be controlled by controlling the addition amount, and a certain antireflection effect is achieved.

Drawings

FIG. 1 is a Fourier Infrared Spectroscopy (ATR/FTIR) chart of the rod-shaped silica (a) prepared in step (1) of comparative example 1 and KH-570 modified rod-shaped silica (b) prepared in step (2).

Fig. 2 is a graph of fourier infrared spectroscopy (ATR/FTIR) of the silicone rubber microspheres (a) prepared in step (3) of comparative example 1 and the composite microspheres prepared in step (4).

Fig. 3 is a Scanning Electron Microscope (SEM) image of the silicone rubber microspheres (a) prepared in step (3) and the composite microspheres (b) prepared in step (4) of comparative example 1.

Fig. 4 is a thermogravimetric analysis curve (TG) of the pure silicone rubber film (a) prepared in step (5) of comparative example 1 and the silicone rubber film (b) after filler incorporation prepared in step (5) of comparative example 2.

Detailed Description

The present invention is not limited to the following embodiments, and those skilled in the art can implement the present invention in other embodiments according to the disclosure of the present invention, or make simple changes or modifications on the design structure and idea of the present invention, and fall into the protection scope of the present invention. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is described in more detail below with reference to the following examples:

the vinyl terminated polydimethylsiloxanes in the following examples and comparative examples were obtained from Anbia Special Silicone (Nantong) Inc. the vinyl terminated polydimethylsiloxanes VS500 had a vinyl content of 0.15mmoles/g, a viscosity of 500cst, a refractive index of 1.405, the vinyl terminated polydimethylsiloxanes VS5000 had a vinyl content of 0.06mmoles/g, a viscosity of 5000cst, and a refractive index of 1.405.

Comparative example 1

(1) Preparation of rod-shaped silica

150mL of 100mg/L polyvinylpyrrolidone n-amyl alcohol solution is weighed, then 2.01mL of absolute ethyl alcohol, 4.02mL of water, 2.01mL of 0.18M sodium citrate solution and 2.01mL of ammonia water are added in sequence, 1.5mL of TEOS is added after uniform stirring, and the mixture is kept stand for 16h at 15 ℃. Centrifuging the reaction solution for 7min at the rotating speed of 5000r/min, respectively performing ultrasonic dispersion and centrifugal separation on the product by using water and absolute ethyl alcohol respectively, washing for 3 times, and drying the product in an oven at the temperature of 60 ℃ for 12 h.

(2) Preparation of modified rod-shaped silica

Weighing 0.1g of the rod-shaped silica prepared in the step (1), adding the rod-shaped silica into a mixed solution of 18mL of ethanol and 3mL of water, magnetically stirring for 0.5h to obtain a rod-shaped silica ethanol-water mixed solution, adding 10mL of KH-570 into 15mL of deionized water, adjusting the pH value to 5, and then performing prehydrolysis for 1h to obtain prehydrolyzed KH-570.

Further ultrasonically dispersing the rod-shaped silicon dioxide ethanol water mixed solution subjected to magnetic stirring for 15min, pouring the rod-shaped silicon dioxide ethanol water mixed solution and the pre-hydrolyzed KH-570 into a three-neck flask provided with a mechanical stirring and reflux condensing tube, and reacting for 2h under an oil bath at 70 ℃. Centrifuging the reacted mixed solution, taking white precipitate, ultrasonically cleaning with ethanol, centrifuging, repeating for 3 times, drying in a 65 ℃ oven overnight, and grinding to obtain modified rod-shaped silicon dioxide;

(3) preparation of silicone rubber microspheres

100g of deionized water was weighed, 1.4g of tween 20 and 0.2g of span 80 surfactant were added thereto, and the mixture was ultrasonically mixed and poured into a three-necked flask. Weighing 10g of vinyl-terminated polydimethylsiloxane (VS500), 0.72g of hydrogen-containing silicone oil XL-1341 and 12.5g of n-hexane, uniformly mixing, and adding 0.02g of Pt catalyst to obtain a mixed solution; weighing 10g of the mixed solution, adding the mixed solution into a surfactant solution while stirring, mixing, firstly adjusting the rotation speed to 1000r/min for a period of time, then adjusting the rotation speed to 350r/min, reacting at room temperature for 1h, and then heating to 50 ℃ for reaction for 48 h. After centrifugal separation, taking the upper layer, ultrasonically cleaning the upper layer by using ethanol, centrifugally separating the upper layer for 3 times, and then putting the upper layer into an oven for drying to obtain the silicone rubber microspheres;

(4) preparation of composite microspheres

Weighing the silicone rubber microspheres prepared in the step (3) and a certain amount of the modified rod-like silicon dioxide prepared in the step (2) into a three-neck flask, adding 45mL of n-hexane, and mechanically stirring and dispersing at room temperature for 40min to obtain a dispersion liquid; then 0.02g of Pt catalyst diluted with 5mL of n-hexane was added dropwise to the three-necked flask, and the temperature was raised to 30 ℃ to react for 30 min. Then the temperature is raised to 50 ℃ again for reaction for 1 d. Centrifuging to obtain lower layer precipitate, centrifuging with n-hexane for 4 times, and drying in 65 deg.C oven to obtain rod-like silicon dioxide/silicone rubber composite microsphere.

(5) Preparation of rod-shaped silicon dioxide/silicon rubber composite membrane

8g of VS5000, 4g of VS500, 0.64g of XL-1341 and 12g of n-hexane were weighed out and dissolved by ultrasound until completion. After the solution is transparent, the solution is poured into a three-neck flask and stirred for 15 min. Adding 0.005g of the composite microspheres prepared in the step (4), stirring for 10min, heating to 70-80 ℃, reacting at constant temperature until the solvent is volatilized, cooling to room temperature, adding 0.07g of tetramethyltetravinylcyclotetrasiloxane, and stirring for 30 min. 0.05g of Pt catalyst was added and stirred for 30 min. Pouring the liquid into a mould, putting the mould into an oven, vacuumizing and defoaming twice, and preserving heat and curing for 24 hours at 100 ℃.

Comparative example 2

Compared with the comparative example 1, the difference lies in that the amount of the added composite microspheres is different, specifically:

steps (1) to (4) were the same as in comparative example 1.

8g of VS5000, 4g of VS500, 0.64g of XL-1341 and 12g of n-hexane were weighed out and dissolved by ultrasound until completion. After the solution is transparent, the solution is poured into a three-neck flask and stirred for 15 min. Adding 0.01g of the composite microspheres prepared in the step (4), stirring for 10min, heating to 70-80 ℃, reacting at constant temperature until the solvent is volatilized, cooling to room temperature, adding 0.07g of tetramethyltetravinylcyclotetrasiloxane, and stirring for 30 min. 0.05g of Pt catalyst was added and stirred for 30 min. Pouring the liquid into a mould, putting the mould into an oven, vacuumizing and defoaming twice, and preserving heat and curing for 24 hours at 100 ℃.

Comparative example 3

steps (1) to (4) were the same as in comparative example 1.

8g of VS5000, 4g of VS500, 0.64g of XL-1341 and 12g of n-hexane were weighed out and dissolved by ultrasound until completion. After the solution is transparent, the solution is poured into a three-neck flask and stirred for 15 min. Adding 0.015g of the composite microspheres prepared in the step (4), stirring for 10min, heating to 70-80 ℃, reacting at constant temperature until the solvent is volatilized, cooling to room temperature, adding 0.07g of tetramethyltetravinylcyclotetrasiloxane, and stirring for 30 min. 0.05g of Pt catalyst was added and stirred for 30 min. Pouring the liquid into a mould, putting the mould into an oven, vacuumizing and defoaming twice, and preserving heat and curing for 24 hours at 100 ℃.

Comparative example 4

steps (1) to (4) were the same as in comparative example 1.

8g of VS5000, 4g of VS500, 0.64g of XL-1341 and 12g of n-hexane were weighed out and dissolved by ultrasound until completion. After the solution is transparent, the solution is poured into a three-neck flask and stirred for 15 min. Adding 0.02g of the composite microspheres prepared in the step (4), stirring for 10min, heating to 70-80 ℃, reacting at constant temperature until the solvent is volatilized, cooling to room temperature, adding 0.07g of tetramethyltetravinylcyclotetrasiloxane, and stirring for 30 min. 0.05g of Pt catalyst was added and stirred for 30 min. Pouring the liquid into a mould, putting the mould into an oven, vacuumizing and defoaming twice, and preserving heat and curing for 24 hours at 100 ℃.

Example 1

Compared with the comparative example 1, the difference is that the prepared rod-shaped silica has different length-diameter ratios, specifically:

150mL of 100mg/L polyvinylpyrrolidone n-pentanol solution is weighed, then 2.01mL of absolute ethyl alcohol, 2.01mL of water, 2.01mL of 0.18M sodium citrate solution and 2.01mL of ammonia water are added in sequence, 1.5mL of TEOS is added after uniform stirring, and the mixture is kept stand for 16h at 15 ℃. Centrifuging the reaction solution for 7min at the rotating speed of 5000r/min, respectively performing ultrasonic dispersion and centrifugal separation on the product by using water and absolute ethyl alcohol respectively, washing for 3 times, and drying the product in an oven at the temperature of 60 ℃ for 12 h.

Steps (2) to (4) were the same as in comparative example 2.

Step (5) is omitted.

Example 2

150mL of 100mg/L polyvinylpyrrolidone n-amyl alcohol solution is weighed, then 1.5mL of absolute ethyl alcohol, 4.5mL of water, 2.01mL of 0.18M sodium citrate solution and 2.01mL of ammonia water are added in sequence, 1.5mL of TEOS is added after uniform stirring, and the mixture is kept stand for 16h at 15 ℃. Centrifuging the reaction solution for 7min at the rotating speed of 5000r/min, respectively performing ultrasonic dispersion and centrifugal separation on the product by using water and absolute ethyl alcohol respectively, washing for 3 times, and drying the product in an oven at the temperature of 60 ℃ for 12 h.

Steps (2) to (4) were the same as in comparative example 2.

Step (5) is omitted.

Example 3

150mL of 100mg/L polyvinylpyrrolidone n-amyl alcohol solution is weighed, then 1.5mL of absolute ethyl alcohol, 4.5mL of water, 2.01mL of 0.18M sodium citrate solution and 2.01mL of ammonia water are added in sequence, 1.5mL of TEOS is added after uniform stirring, and the mixture is kept stand for 16h at 35 ℃. Centrifuging the reaction solution for 7min at the rotating speed of 5000r/min, respectively performing ultrasonic dispersion and centrifugal separation on the product by using water and absolute ethyl alcohol respectively, washing for 3 times, and drying the product in an oven at the temperature of 60 ℃ for 12 h.

Steps (2) to (4) were the same as in comparative example 2.

Step (5) is omitted.

Tests prove that compared with the method of directly adding the pure modified silicon dioxide, the method of adding the silicon rubber in the form of the microspheres needs less parts. In this application, the effect of the amount of the composite microspheres on the amphiphobic property of the silicone rubber membrane in the embodiment of thermal stability of the silicone rubber can be improved only by adding 0.16g of microspheres in 100g of silicone rubber in a microsphere manner is shown in table 1:

TABLE 1

Tests prove that the rodlike silicon dioxide and the spherical silicon dioxide are respectively compounded with the silicone rubber microspheres, and compared with the spherical silicon dioxide/silicone rubber composite microspheres, the rodlike silicon dioxide/silicone rubber composite microspheres are more favorable for forming double-high-hydrophobicity performance in terms of the morphological structure (under the same operation steps, only the shapes of the silicon dioxide are different, and the lipophobicity of the spherical silicon dioxide/silicone rubber composite microspheres is slightly inferior because the rodlike structure on the surfaces of the microspheres is more favorable for liquid to be in a Cassie state). The length-diameter ratio of the rod-shaped silicon dioxide is required to a certain degree, the length-diameter ratio of the rod-shaped silicon dioxide compounded on the surface of the silicone rubber microsphere has amphiphobicity within the range of 4-16, and in the embodiment, the influence of the length-diameter ratio of the rod-shaped silicon dioxide on the amphiphobicity of the silicone rubber membrane is shown in table 2 (the water phase is deionized water, the oil phase is formamide, and the water drop size is 4-5 mu L):

TABLE 2

In the aspect of use, after the filler prepared in the application is added into silicon rubber, the light transmission effect of the filler is not influenced, the anti-reflection effect is achieved to a certain degree, the haze increasing degree is small along with the increase of the filler in a certain range, the filler can be used in the field of amphiphobic materials and the field of optics, and the specific detection performance is shown in table 3.

TABLE 3

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and their concepts should be equivalent or changed within the technical scope of the present invention.

Claims

1. A preparation method of an adjustable amphiphobic filler for silicone rubber is characterized by comprising the following steps:

(1) preparation of modified rod-like silica: adding a silane coupling agent KH-570 or vinyl trimethoxy silane (A-171) into deionized water, adjusting the pH value, carrying out prehydrolysis for 1-2 h, adding a rod-shaped silicon dioxide, ethanol and water mixed solution which is stirred and mixed by magnetic force, fully mixing, and reacting for 2-5 h in an oil bath at 70-80 ℃; centrifugally separating the reacted mixed solution, taking white precipitate, repeatedly carrying out ultrasonic cleaning and centrifugal separation by using ethanol, then putting the white precipitate into a drying oven for drying, and grinding to obtain the modified rod-shaped silicon dioxide;

(2) preparation of the silicone rubber microspheres: uniformly mixing vinyl-terminated polydimethylsiloxane I, a hydrogen-containing silicone oil cross-linking agent I and n-hexane I, adding a Pt catalyst to obtain a mixed solution, adding the mixed solution into a deionized water solution of a surfactant while stirring, carrying out stirring reaction, carrying out centrifugal separation, taking an upper layer, repeatedly carrying out ultrasonic cleaning and centrifugal separation, and drying to obtain silicone rubber microspheres;

(3) preparing the adjustable amphiphobic filler for the silicone rubber: weighing the silicone rubber microspheres prepared in the step (2) and the modified rod-like silicon dioxide prepared in the step (1), mixing, adding the mixture into a dispersing agent, stirring and mixing, adding a catalyst, heating for reaction, performing centrifugal separation to obtain a lower-layer precipitate, repeatedly centrifugally cleaning the precipitate, and drying in an oven to obtain the adjustable amphiphobic filler for the silicone rubber; the mass of the modified rod-shaped silicon dioxide is 10-50% of that of the silicon rubber microspheres.

2. The method for preparing an adjustable amphiphobic filler for silicone rubber according to claim 1, wherein the rod-like silica described in the step (1) has an aspect ratio of 4.14 to 19.86.

3. The method for preparing the adjustable amphiphobic filler for the silicone rubber according to claim 1, wherein the solid-to-liquid ratio of the rod-shaped silica to the KH-570 in the step (1) is 0.05 to 0.1 g/mL; the volume ratio of KH-570 to deionized water is 1: 2-4, and the pH value is adjusted to 4-5;

and/or the volume ratio of water to ethanol in the rod-shaped silicon dioxide, ethanol and water mixed solution is 1: 6, the adding amount of the rod-shaped silicon dioxide in the ethanol-water mixed solution is 0.01-0.03 g/mL.

4. The method for preparing the adjustable amphiphobic filler for the silicone rubber according to claim 1, wherein the concentration of the deionized water solution of the surfactant in the step (2) is 12-18 g/L, and the surfactant consists of Tween 20 and span 80 in a mass ratio of 7: 1;

and/or in the step (2), the mass ratio of the vinyl-terminated polydimethylsiloxane I, the hydrogen-containing silicone oil cross-linking agent I and the n-hexane I is 9-10: 0.6-0.8: 11-13;

and/or the mass ratio of the mixed solution to the pure surfactant in the step (2) is 10: 1.5-2.0;

and/or, the reaction in the step (2) is carried out for 1-3 h at room temperature, and then the temperature is raised to 50-60 ℃ for reaction for 36-48 h

And/or the mass ratio of the Pt catalyst to the vinyl-terminated polydimethylsiloxane I in the step (2) is 0.02-0.04: 10;

and/or, the mass of the modified silicon dioxide in the step (3) is 20-30% of that of the silicon rubber microspheres, and the particle size of the silicon rubber microspheres is 40-60 μm.

5. The method for preparing the adjustable amphiphobic filler for the silicone rubber according to claim 1, wherein the temperature rise reaction in the step (3) is a reaction at 30-35 ℃ for 30-45 min, and then a reaction at 50 ℃ for 20-30 h.

6. The method for preparing the adjustable amphiphobic filler for silicone rubber according to claim 1, wherein the method for preparing the rod-like silica according to step (1) comprises the steps of: weighing 150mg/L of 100-plus-one polyvinylpyrrolidone n-amyl alcohol solution, then sequentially adding anhydrous ethanol, water, prepared 0.18-0.20M sodium citrate solution and ammonia water with the mass concentration of 20-25%, stirring uniformly, adding tetraethyl orthosilicate, standing for 16-24h, centrifuging for 5-10min at the rotation speed of 5000r/min for 2500-plus-one, separating out precipitates, respectively performing ultrasonic dispersion and centrifugal separation on the precipitates by using the water and the anhydrous ethanol, washing for 2-5 times, and then drying the product in an oven at the temperature of 60-80 ℃ for 12-24 h.

7. The preparation of the silicone rubber membrane is characterized in that: the method comprises the following steps: weighing vinyl-terminated polydimethylsiloxane II, vinyl-terminated polydimethylsiloxane III, hydrogen-containing silicone oil cross-linking agent II and n-hexane II, ultrasonically dissolving the materials to be complete, pouring the solution into a three-neck flask, uniformly stirring, adding the adjustable amphiphobic filler for the silicone rubber prepared according to any one of claims 1 to 6, uniformly stirring, heating to volatilize the solvent, cooling to room temperature, adding an inhibitor, uniformly stirring, adding a catalyst, uniformly stirring, pouring into a mold, vacuumizing, defoaming, preserving heat and curing to obtain the silicone rubber film.

8. The method for preparing the adjustable amphiphobic filler for the silicone rubber according to claim 7, wherein the mass ratio of the vinyl-terminated polydimethylsiloxane II, the vinyl-terminated polydimethylsiloxane III, the hydrogen-containing silicone oil cross-linking agent II and the n-hexane II is 2-4: 1-3: 0.6-1.2: 3;

the mass ratio of the adjustable amphiphobic filler, the inhibitor and the catalyst for the silicone rubber is 1-4: 10-20: 6-12;

the content of the adjustable dual-property filler for the silicon rubber in the silicon rubber film is 0.04-0.2%;

the heat preservation and solidification refers to heat preservation and solidification for 24-48 hours at the temperature of 80-100 ℃.

9. The method for preparing the tunable amphiphobic filler for silicone rubber according to claim 8, wherein the catalyst is Karstedt's catalyst, a platinum-vinylalkoxysilane complex, a platinum-divinyldiphenyldisiloxane complex, a nitrogen-containing compound-modified platinum complex, or a platinum-alkynol complex.

10. The method for producing an adjustable amphiphobic filler for silicone rubber according to claim 7, wherein said inhibitor is an alkenyl siloxane, pyridine, organophosphine compound or unsaturated amino compound.