Preparation method and application of polysiloxane wrinkled particles
By introducing the hydrolysis products of MTS and MTES as surfactants and combining them with the soft template method, polysiloxane wrinkled particles were prepared, which solved the problem that it is difficult to prepare polysiloxane wrinkled particles by traditional methods and achieved a coating effect with high hydrophobicity and low thermal conductivity.
Patent Information
- Application Number
- CN202511082534.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-04
- Publication Date
- 2025-11-18
AI Technical Summary
Existing technologies make it difficult to prepare wrinkled particles using polysiloxane as the material. Traditional methods are not suitable, and the preparation process requires the addition of surfactants.
By introducing MTS and MTES during the reaction process and using their hydrolysis products as surfactants, combined with the soft template method, the shell hardness is reduced, avoiding the need for additional surfactants, and polysiloxane wrinkled particles are prepared.
The preparation process is simple, the particle morphology is adjustable, and its application in water-based coatings significantly improves the hydrophobicity and thermal insulation properties of the coating. The contact angle is higher than 92° and the thermal conductivity is lower than 0.164 W*m-1K-1.
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Figure CN120966009A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of high polymer materials, nanoparticles and coatings, and particularly relates to a preparation method of poly-siloxane wrinkle particles and application thereof. BACKGROUND
[0002] Due to the existence of surface tension, the colloidal particles prepared by common methods are spherical, and therefore the design and preparation of non-spherical particles are very important in both basic research and practical application. Among various non-spherical particles, particles with concave surfaces (including dimple-shaped particles, button-shaped particles, wrinkle-shaped particles, bowl-shaped particles, red blood cell-shaped particles, etc.) have attracted great research interest. As a kind of concave particles, wrinkle-shaped particles have many special properties, such as increasing the surface energy of a substance and improving the roughness of a substrate surface. At present, the wrinkle-shaped particles most studied are prepared from organic polymers. However, compared with the wrinkle-shaped particles prepared from known organic polymer materials, the wrinkle-shaped particles prepared from poly-siloxane have many advantages. For example, the poly-siloxane wrinkle-shaped particles can endow organic coatings with super-hydrophobicity, biocompatibility, modifiability, and improved thermal stability and chemical stability of the organic coatings. Since the hardness of poly-siloxane material is relatively high, the traditional method for preparing wrinkle-shaped particles is not suitable for preparing poly-siloxane wrinkle-shaped particles. Therefore, it is necessary and urgent to find a method for reducing the hardness of poly-siloxane particles so as to prepare wrinkle-shaped poly-siloxane particles. SUMMARY
[0003] Based on the above problems, the present application provides a preparation method of poly-siloxane wrinkle-shaped particles. The method generates a surfactant in the reaction process to stabilize the system, avoiding the additional addition of a surfactant in the preparation process of the particles. By introducing MTS, the hardness of the shell layer is reduced, and the shell layer is easily collapsed after removing the template, so that wrinkle-shaped poly-siloxane nanoparticles are obtained. The particles are applied to water-based coatings, which can significantly improve the hydrophobicity and thermal insulation of the coating.
[0004] In order to achieve the above purpose, the first technical solution of the present application discloses a preparation method of poly-siloxane wrinkle-shaped particles, comprising the following steps:
[0005] S1. uniformly mixing siloxane monomers and a soft template, and then adding them into distilled water to obtain a mixture solution;
[0006] S2. adjusting the pH of the mixture solution to be acidic and performing a reaction;
[0007] S3. adjusting the pH to be alkaline after the reaction of S2 ends and continuing the reaction;
[0008] S4. centrifuging the mixture solution after the reaction of S3 to obtain the polysiloxane wrinkle particles;
[0009] Preferably, the mass ratio of the METS, MTS and the soft template is 1:(5-10):(3-22).
[0010] Preferably, the soft template is any one or any combination of n-hexane, cyclohexane, toluene, xylene and styrene.
[0011] Preferably, the pH in S2 is 3-5, and the reaction time is 1-2h; wherein the pH is adjusted by an acid regulator, including any one or any combination of hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid.
[0012] Preferably, the pH in S3 is 10-12, and the reaction time is 2-3h; wherein the pH is adjusted by an alkaline regulator, including any one or any combination of sodium hydroxide, potassium hydroxide, calcium hydroxide and ammonium hydroxide.
[0013] Preferably, the stirring condition of the reaction in S2 and S3 is 250rmp, and the reaction temperature is 25-35℃.
[0014] Preferably, the stirring condition of the reaction in S2 and S3 is 250rmp, and the reaction temperature is 25-35℃.
[0015] Preferably, the stirring condition of the reaction in S2 and S3 is 250rmp, and the reaction temperature is 25-35℃.
[0016] The second technical solution of the present application discloses the application of the above polysiloxane wrinkle particles in water-based paint, wherein the water-based paint is polyurethane.
[0017] Further, the application specifically refers to adding the polysiloxane wrinkle particles into the polyurethane solution, mixing and coating to form a film, and drying to obtain the same, wherein the drying equipment is a vacuum oven, and the temperature is 60℃.
[0018] Preferably, the mass of the polysiloxane wrinkle particles added is 5%-10% of the mass of the polyurethane.
[0019] Beneficial effects: the present application proposes a preparation method of polysiloxane wrinkle particles, using MTS and MTES as raw materials, and through acid and alkali hydrolysis reaction, the hydrolysis products of MTS and MTES form a surfactant, which plays a stabilizing role on the emulsion formed by the whole system. The introduction of long alkyl chain siloxane monomer makes the hardness of the formed polysiloxane shell layer relatively small, so that the polysiloxane wrinkle particles are directly formed after removing the soft template; compared with the prior art, the beneficial effects of the present application are:
[0020] 1. The preparation method of the present application is a soft template method, which does not need to add additional surfactants to stabilize the emulsion, but uses the hydrolysis product of the reactants to act as a surfactant to stabilize the emulsion. Compared with the traditional method for preparing wrinkled particles, the advantage of the present application is that no surfactant needs to be added during the entire preparation process, and the preparation method is simple.
[0021] 2. The morphology of the polysiloxane wrinkled particles prepared by the present application can be controlled by changing the relative ratio between the reactants and the solvent. Mixing the prepared wrinkled particles of different morphologies with waterborne polyurethane coatings can significantly improve the hydrophobicity and thermal insulation of the polyurethane coating.
[0022] 3. In the design of the shell structure, the element composition of the shell layer can be changed by changing the relative amount of different monomers added, which also changes the hardness of the shell layer and the morphology of the particles.
[0023] 4. The contact angle of the coating obtained by mixing the polysiloxane wrinkled particles prepared by the present application with waterborne polyurethane is higher than 92°, and the thermal conductivity is lower than 0.164 W*m -1 K -1 . BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 It is a scanning electron micrograph of the polysiloxane wrinkled particles of Example 1.
[0025] Figure 2 It is a transmission electron micrograph of the polysiloxane wrinkled particles of Example 1.
[0026] Figure 3 It is an infrared spectrum of the polysiloxane wrinkled particles of Example 1.
[0027] Figure 4 It is a particle size distribution graph of the polysiloxane wrinkled particles of Example 1. DETAILED DESCRIPTION
[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0029] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all reasonable modifications and equivalents are intended to be included within the scope of the application. The application can also be used in connection with other related methods and apparatuses not specifically described above. Numerous other examples will be apparent to those skilled in the art. Therefore, the specific embodiments discussed above are not intended as limitation on the scope of the application, which is to be measured only in terms of the following claims.
[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. If there is a conflict between the definitions of terms in this specification and the patent statutes, the definitions in this specification are intended to prevail.
[0031] Example 1 Preparation of polysiloxane wrinkle particles
[0032] S1. Put 0.8g MTES (methyl triethoxysilane), 0.2g MTS (mercaptopropyl trimethoxysilane) and 1.0g dimethylbenzene into a centrifuge tube, mix well; then add the mixture into 50g distilled water, start stirring;
[0033] S2. Add 37% mass fraction of concentrated hydrochloric acid into the above system, adjust the pH value of the system to 4, and react for 1h under acid condition;
[0034] S3. Add concentrated ammonia into the system after the reaction in S2 is completed, adjust the pH value of the system to 11, and continue to react for 2h under alkaline condition;
[0035] S4. Centrifugal separate the polysiloxane wrinkle particles after the reaction in S3 is completed, and clean twice with a mixture of ethanol and water to obtain clean polysiloxane wrinkle particles;
[0036] The reactions in S2 and S3 above are both carried out under stirring condition, the stirring rate is 250rmp, and the reaction temperature is 25°C.
[0037] Example 2 Preparation of polysiloxane wrinkle particles
[0038] The preparation method is the same as that in Example 1, except that 1.0g dimethylbenzene is replaced by 1.0g styrene.
[0039] Test Example 1
[0040] The polyorganosiloxane folded particles obtained in Example 1 were washed and dried, and then observed under a scanning electron microscope and a transmission electron microscope. The scanning electron microscope and transmission electron microscope images are shown in Figs. 1 and 2, respectively. As can be seen from the figures, the particles prepared have a clear folded structure. Figure 1 、 Figure 2
[0041] Figure 3 The infrared spectrum of the polyorganosiloxane folded particles is shown in Fig. 3. As can be seen from the figure, the absorption band at 3465 cm -1 is attributed to the stretching vibration of (Si-O)-H. A very strong absorption band appears at 1271 cm -1 , and a clear peak appears at 783 cm -1 , which is attributed to the bending and stretching vibration of (Si-O-) Si-CH3 group. The absorption bands at 1135, 1033 and 438 cm -1 are caused by the stretching and bending vibration of Si-O-Si (Si-OH). The absorption band at 2979 cm -1 is the stretching vibration of C-H (CH2). The above analysis shows that the condensation reaction of MTES has occurred. In addition, the absorption band at 2545 cm -1 is attributed to the stretching vibration of C-S, indicating that MTS also participates in the reaction. Figure 4 The particle size distribution of the polyorganosiloxane folded particles is shown in Fig. 4. As can be seen from the figure, the average particle size of the particles is 745.8 nm.
[0042] Application of polyorganosiloxane folded particles
[0043] The polyorganosiloxane folded particles prepared in Example 1 were applied to water-based paint for preparing a paint film. The water-based paint was polyurethane, and the preparation method was as follows: the polyorganosiloxane folded particles were uniformly dispersed in water, then the dispersion was added to the water-based polyurethane and mixed uniformly, and finally the mixture was coated onto a film-forming paper and dried in an oven at 60°C to form a film.
[0044] Experimental group 1
[0045] S1. Preparation of polyurethane emulsion
[0046] Into a three-necked flask equipped with a nitrogen inlet, 5.20 g of polytetramethylene ether glycol and 3.42 g of isophorone diisocyanate were injected. Subsequently, 0.794 g of dimethylol propionic acid and 3 g of N,N-dimethylformamide were added to the above mixture, and reacted for 1.5 h, then 0.24 g of 1,4-butanediol and an appropriate amount of catalyst (dibutyltin dilaurate, stannous octoate) were added, and heated to 85°C, and the reaction was continued for 5 h. After the reaction temperature was reduced to 35°C, 0.60 g of triethylamine was added to neutralize the mixture for 1 h. Finally, the obtained prepolymer was emulsified with deionized water under high-speed shearing at 1500 rpm for 1.5 h to obtain a stable and uniform aqueous polyurethane emulsion.
[0047] S2. Preparation of polyurethane film
[0048] The polyurethane solution prepared in Example 1 was mixed with the polydimethylsiloxane pleated particles, and then directly dropped onto a film forming paper, and placed in a vacuum oven at 60°C for drying. The mass of the polydimethylsiloxane pleated particles was 5% of the mass of the polyurethane.
[0049] Experimental group 2
[0050] The same as Experimental group 1, except that 5.20 g of polytetramethylene ether glycol was replaced by poly 5.20 g of polypropylene glycol ether.
[0051] Experimental group 3
[0052] The same as Experimental group 1, except that 3.42 g of isophorone diisocyanate was replaced by 2.68 g of toluene diisocyanate.
[0053] Experimental group 4
[0054] The same as Experimental group 1, except that 0.24 g of 1,4-butanediol was replaced by 1.65 g of ethylene glycol.
[0055] Performance test of polyurethane film
[0056] Test results: According to the contact angle test, the water contact angles of the four kinds of polyurethane films prepared by this method were 101.5°, 100.8°, 101.3° and 99.7°, respectively. In addition, through the thermal conductivity test of the prepared polyurethane, the thermal conductivities of the four kinds of polyurethane films were 0.136 W*m -1 K -1 , 0.138 W*m -1 K -1 , 0.135 W*m -1 K -1 and 0.132 W*m -1 K -1 , respectively.
[0057] Comparative experiment
[0058] In Example 1, 0.8g MTES and 0.2g MTS were replaced by 1.0g MTES, and other steps were the same as Example 1. Then the prepared polysiloxane particles were applied to the polyurethane film, and the application method was the same as S2. Then the prepared polyurethane film was tested for performance.
[0059] Test results: According to the contact angle test, the water contact angle of the four kinds of polyurethane films prepared by this method was 87.6°, 86.8°, 88.3° and 88.7° respectively. In addition, through the test of the thermal conductivity of the prepared polyurethane, the thermal conductivity of the four kinds of polyurethane films was 0.158W*m -1 K -1 , 0.161W*m -1 K -1 , 0.156W*m -1 K -1 and 0.153W*m - 1 K -1 .
[0060] It can be seen that the polysiloxane wrinkle particles prepared by the application are mixed with water-based polyurethane, and the coating obtained has a higher contact angle (higher than 92°) and a lower thermal conductivity.
[0061] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.
[0062] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any change or replacement easily thought of by those skilled in the art within the technical range disclosed by the present application shall be included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A method for preparing polysiloxane wrinkled particles, characterized in that, Includes the following steps: S1. Mix the siloxane monomer and the soft template evenly, then add it to distilled water to obtain a mixture solution; S2. Adjust the pH of the mixture solution to acidic conditions and proceed with the reaction; S3. After the S2 reaction is completed, adjust the pH to alkaline and continue the reaction; S4. After the reaction in S3 is completed, the mixture solution is centrifuged to obtain polysiloxane wrinkled particles; The siloxane monomers are METS and MTS; the reactions in S2 and S3 are carried out under stirring conditions.
2. The preparation method according to claim 1, characterized in that, The mass ratio of METS, MTS to soft template is 1:(5-10):(3-22).
3. The preparation method according to claim 1, characterized in that, The soft template is any one or any combination of n-hexane, cyclohexane, toluene, xylene, and styrene.
4. The preparation method according to claim 1, characterized in that, The pH of S2 is 3-5, and the reaction time is 1-2 hours.
5. The preparation method according to claim 1, characterized in that, The pH of S3 is 10-12, and the reaction time is 2-3 hours.
6. The preparation method according to claim 1, characterized in that, The stirring conditions for the reactions described in S2 and S3 are 250 rpm and the reaction temperature is 25-35℃.
7. Polysiloxane wrinkled particles obtained by any of the preparation methods described in claims 1-6.
8. The application of the polysiloxane wrinkled particles according to claim 7 in water-based coatings, characterized in that, The water-based coating is polyurethane.
9. The application according to claim 8, characterized in that, The specific application involves adding polysiloxane wrinkled particles to a polyurethane solution, mixing, coating into a film, and drying.
10. The application according to claim 9, characterized in that, The polysiloxane wrinkled particles are added at a mass of 5%-10% of the polyurethane mass.