A multi-scale cross-linked fluorosilicon-based ceramic repair and a method of making the same

Abstract

The present application belongs to the technical field of new materials resistant to seawater corrosion, and particularly relates to a multi-scale cross-linked fluorosilicon-based ceramic repair agent and a preparation method thereof. The agent is formed by mixing component A and component B, wherein component A is an oligomerization degree organic silicon polymer providing a small-scale cross-linking network, a fluorinated modified polydimethylsiloxane providing a medium structure scale cross-linking, and a polyarylene cage siloxane providing a large-scale cross-linking system; and component B is a cross-linking agent and a micro-nano additive. The present application has the beneficial effect that a large amount of siloxane is formed in the curing process by using a siloxane main chain, and a silicon-hydrogen active bond can react with a base hydroxyl group and a carboxyl group to be anchored on the base in the form of a covalent bond, thereby greatly improving the adhesion strength of the repair agent and the base material and the adhesion durability under mechanical and temperature fields.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology for seawater corrosion resistance, specifically relating to a multi-scale cross-linked fluorosilicone-based ceramic repair agent and its preparation method. Background Technology

[0002] In today's industrial sector, ceramic repair agents are widely used as a key technology across various industries, including nuclear power, aerospace, and shipbuilding. Ceramic repair agents are high-performance, high-temperature resistant, and corrosion-resistant materials, commonly used for the repair and protection of components in high-temperature, acid-alkali, and corrosive environments. They effectively resist the erosion of corrosive media and extend the service life of equipment. Currently, most common repair agents are modified from epoxy resin, polyurethane, and silicone rubber as the main resin base material, and have largely reached the physical and chemical limits of their base materials. However, for high-temperature environments (such as above 200 degrees Celsius), harsh corrosive environments such as strong ultraviolet radiation and acids and alkalis, and high-intensity mechanical environments (such as seawater erosion), epoxy-based ceramic repair agents still exhibit problems such as easy aging, cracking, decreased mechanical properties, and reduced adhesion. In particular, localized detachment can form foreign matter, seriously threatening the safe operation of equipment.

[0003] Therefore, there is an urgent need to develop a new type of ceramic repair agent material that can maintain its structural strength and performance stability under temperature conditions from room temperature to 250 degrees Celsius, has a surface hardness of more than 6H, can effectively resist seawater erosion and salt spray corrosion for a long time, has a self-cleaning function, and has good bonding performance with metal materials such as carbon steel and stainless steel. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-scale cross-linked fluorosilicone-based ceramic repair agent and its preparation method. This material forms a multi-scale cross-linked system on a fluorosilicone substrate during the curing process, creating a ceramic-like inorganic-organic hybrid polymer network on the surface of the object to be repaired. This network is anchored to the surface via chemical bonds, significantly improving adhesion strength. Utilizing the cross-linking properties of the fluorosilicone substrate, this repair agent exhibits high temperature resistance, high wear resistance, self-lubricating and self-cleaning properties, oil resistance, resistance to daily ultraviolet radiation, and good corrosion resistance, making it suitable for the repair and protection of various industrial equipment and components.

[0005] The technical solution of the present invention is as follows: a multi-scale cross-linked fluorosilicone-based ceramic repair agent, which is composed of a mixture of component A and component B, wherein component A is a low-polymerization degree organosilicon polymer that provides a small-scale cross-linking network, a fluorinated modified polydimethylsiloxane that provides a medium-scale cross-linking, and a polyarylene cage-type siloxane that provides a large-scale cross-linking system, and component B is a cross-linking agent and micro / nano additives.

[0006] The weight ratio of component A to component B is 1:0.2 to 1:2.

[0007] The low-polymerization-degree organosilicon polymer in component A that provides a small-scale crosslinking network is one or more of polysilane, polysiloxane, polysilazane, and polysiloxane, with a polymerization degree of 10 to 500, and the end-capping groups are one or more of silanehydrogen, silanol, silanol, and silanoamine.

[0008] In component A, RF is a fluorinated side chain, which is one or more of perfluorobutylethylene, perfluorohexylethylene, perfluoropropyl vinyl ether, perfluorobutyl vinyl ether, perfluorohexyl vinyl ether, perfluorobutyl ketone, perfluoropropyl ketone, and perfluorohexyl ketone. X has a degree of polymerization of 5 to 20, Y has a degree of polymerization of 3 to 15, n has a degree of polymerization of 3 to 20, and the end-capping group is one or more of imino, amino, carboxyl, hydroxyl, and urea groups.

[0009] The silicon-based crosslinking agent in component B is one or more of γ-aminopropyltriethoxysilane, 3-(N-cyclohexylamino)propylmethyldimethoxysilane, 3-(N-cyclohexylamino)propyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, N,N-dimethyl-3-aminopropylmethyldimethoxysilane, and 3-isocyanate propyltriethoxysiloxane.

[0010] The micro-nano additives in component B are one or more of silicon dioxide, aluminum oxide, silicon nitride, silicon carbide, zirconium oxide, and yttrium oxide, with a particle size of 50 nanometers to 5000 nanometers.

[0011] The mass ratio of the low-polymerization-degree organosilicon polymer, fluorinated modified polydimethylsiloxane, and polyarylene cage-type siloxane in component A is from 1:1:1 to 4:2:1.

[0012] The mass ratio of crosslinking agent to micro / nano additive in component B is 1:1 to 10:1.

[0013] A method for preparing a multi-scale cross-linked fluorosilicone-based ceramic repair agent includes the following:

[0014] Component A: Dissolve the organosilicon polymer, fluorinated modified polydimethylsiloxane, and polyarylene cage-type siloxane in propylene glycol methyl ether acetate in the above proportions, with a solid content of 30% to 70%, and stir mechanically for 1 to 3 hours under nitrogen atmosphere at 30°C.

[0015] Component B: Micro-nano additives are added to the silicon-based crosslinking agent at a rate of 15-20 grams per hour, and mechanical stirring is used at a speed of 1500-2000 revolutions per minute and a temperature of 35-40℃.

[0016] The beneficial effects of this invention are as follows: Most common repair agents currently use carbon-based resin substrates, such as epoxy resin, as the main material to fill and repair damage to metal, ceramic, and plastic substrates on the surface of industrial equipment, or to protect their surfaces. However, such materials still have some drawbacks, such as weak adhesion to the substrate, making them prone to cracking and detachment under the coupling effect of mechanical and temperature fields during long-term service; although the repair agent has high hardness, it is also brittle, making it susceptible to wear under high-intensity conditions, and the coating thickness is relatively low, making it difficult to achieve a coating layer on the centimeter level; the repair agent has poor self-cleaning properties, easily attracting oil and dirt, making the repaired surface difficult to clean. This invention employs fluorosilicone flexible ceramic preparation technology, using an organic-inorganic phase hybrid synthesis method, and custom-designing the silicon-based main chain and fluorinated side chains, giving this ceramic repair agent the following advantages.

[0017] 1. During the curing process, the silicon-oxygen backbone forms a large number of silicon-oxygen and silicon-hydrogen active bonds, which can react with the hydroxyl and carboxyl groups of the substrate and anchor to the substrate in the form of covalent bonds, thereby greatly improving the adhesion strength between the repair agent and the substrate and the adhesion durability under mechanical and temperature fields.

[0018] 2. By embedding some flexible segments into the silicon-based main chain, the flexibility of the repair agent is improved to a certain extent. This enhances the overall wear resistance of the coating and improves the applicability of the application, allowing the coating thickness to reach several centimeters.

[0019] 3. During the curing process, the perfluorinated side groups float to the outer surface of the coating due to polarity, resulting in a very low surface energy and a large water-oil contact angle on the outer surface of the repair agent coating, thus playing a role in oil resistance and self-cleaning.

[0020] 4. Through the design of a multi-scale cross-linking system, low-polymerization-degree organosilicon polymers, fluorinated modified polydimethylsiloxanes, and polyarylene cage-type siloxanes form cross-linking networks at the nanoscale, hundred-nanometer scale, and micrometer scale, respectively, and entangle with each other to construct a high-density bulk environment, thereby improving the mechanical properties of the repair agent, including resistance to thermal expansion, mechanical strength, corrosion resistance, acid and alkali resistance, and UV resistance.

[0021] 5. Using a silicon-based main chain as the resin substrate and compounding various nano-level ceramic powders, it can be partially ceramicized at a certain temperature to become a more robust repair agent material, thereby enabling the surface hardness to exceed 8H and the temperature resistance limit to reach over 200 degrees Celsius, allowing it to be used in more demanding environments.

[0022] 6. This ceramic repair agent can cure within 1 to 3 hours, making it easy to apply on-site. In addition, since moisture can help with the hydrolysis of silicon and oxygen and the cross-linking of silicon and hydrogen, this repair agent can be applied in humid or even rainy environments, expanding the application conditions and reducing the difficulty. Attached Figure Description

[0023] Figure 1 A schematic diagram of the structure of fluorinated modified polydimethylsiloxane;

[0024] Figure 2 A schematic diagram of the structure of polyarylene cage-type siloxanes;

[0025] Figure 3 This refers to the types of aryl R groups in polyaryl cage-type siloxanes. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] A multi-scale crosslinked fluorosilicone-based ceramic repair agent is composed of a mixture of component A and component B. Component A consists of a low-polymerization degree organosilicon polymer that provides a small-scale crosslinking network, a fluorinated modified polydimethylsiloxane that provides a medium-scale crosslinking network, and a polyarylene cage-type siloxane that provides a large-scale crosslinking system. Component B consists of a crosslinking agent and micro / nano additives.

[0028] The weight ratio of component A to component B is 1:0.2 to 1:2.

[0029] The low-polymerization-degree organosilicon polymer in component A that provides a small-scale crosslinking network is one or more of polysilane, polysiloxane, polysilazane, and polysiloxane, with a degree of polymerization of 10 to 500, and end-capping groups of one or more of silanehydrogen, silanol, silanic acid, and silanamino.

[0030] The structure of the fluorinated polydimethylsiloxane in component A, which provides intermediate-scale crosslinking, is as follows: Figure 1 As shown, RF is a fluorinated side chain, which is one or more of perfluorobutylethylene, perfluorohexylethylene, perfluoropropyl vinyl ether, perfluorobutyl vinyl ether, perfluorohexyl vinyl ether, perfluorobutyl ketone, perfluoropropyl ketone, and perfluorohexyl ketone; X has a degree of polymerization of 5 to 20; Y has a degree of polymerization of 3 to 15; n has a degree of polymerization of 3 to 20; and the end-capping group is one or more of imino, amino, carboxyl, hydroxyl, and urea groups.

[0031] The cage-like siloxane in component A provides a large-scale cross-linking system with the following structure: Figure 2 As shown, the preparation process is as follows: aromatic hydrocarbons (and fast hydrocarbons) with bromine at both ends are converted into organometallic compounds through Grignard reactions or organolithium reactions. These compounds then react with ClSi(OEt)3 to obtain aryldisilanes. Subsequently, the disilanes are subjected to acid or base catalysis, hydrolysis, and condensation in THF or EtOH to obtain polyaryl cage-type siloxanes. Where R is... Figure 3 One or more of the compounds shown, where R' is a capping agent and is one or more of imino, carboxyl, hydroxyl, and urea groups.

[0032] The silicon-based crosslinking agent in component B is one or more of γ-aminopropyltriethoxysilane, 3-(N-cyclohexylamino)propylmethyldimethoxysilane, 3-(N-cyclohexylamino)propyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, N,N-dimethyl-3-aminopropylmethyldimethoxysilane, and 3-isocyanate propyltriethoxysiloxane.

[0033] The micro-nano additives in component B are one or more of silicon dioxide, aluminum oxide, silicon nitride, silicon carbide, zirconium oxide, and yttrium oxide, with a particle size of 50 nanometers to 5000 nanometers.

[0034] In component A, the mass ratio of low-polymerization-degree organosilicon polymer, fluorinated modified polydimethylsiloxane, and polyarylene cage-type siloxane is 1:1:1 to 4:2:1.

[0035] In component B, the mass ratio of crosslinking agent to micro / nano additives is 1:1 to 10:1.

[0036] The multi-scale cross-linked fluorosilicone-based ceramic repair agent provided by this invention has the following characteristics:

[0037] The repair agent prepared by this invention uses silicon atoms as the substrate to construct the main chain structure, which causes the molecular chain to produce an inorganic-organic hybrid effect, thereby giving the material stronger hardness, wear resistance and mechanical strength.

[0038] By employing a multi-level cross-linking network, a dense crystal nucleus structure is constructed using organosilicon polymers as a small-scale dense cross-linking network, followed by a medium-scale cross-linking network using fluorinated polydimethylsiloxane system, and finally a cage-like polysiloxane system as a large-scale cross-linking network. The interpenetration of these multi-scale cross-linking networks constructs a multi-dimensional macromolecular cross-linking system, which greatly improves the density and mechanical properties of the material.

[0039] Fluorinated molecules are introduced in the form of branched side chains. During the curing process, they float on the outer surface of the coating due to polarity. This allows the coating to have many advantages of fluoropolymers with a low fluorine content, such as self-cleaning, UV resistance, and antistatic properties.

[0040] The present invention will be further described in detail below with reference to Examples 1-5, but the present invention is not limited to these examples.

[0041] Example 1: Component A consists of 80 grams of polysiloxane with a degree of polymerization of 60, 50 grams of polydimethylsiloxane modified with perfluorobutylethylene and a degree of polymerization of 10, with amino end-capping groups, and 50 grams of polyarylethene cage-type siloxane with a benzene ring R group and hydroxyl end-capping groups. Component B consists of 30 grams of 3-aminopropylmethyldiethoxysilane, 10 grams of silicon nitride with a particle size of 100 nanometers, and 5 grams of aluminum oxide with a particle size of 50 nanometers.

[0042] Example 2: Component A consists of 70 grams of polysilazane with a degree of polymerization of 50, 60 grams of polydimethylsiloxane modified with perfluorobutyl vinyl ether and a degree of polymerization of 12, with carboxyl end-capping groups, and 50 grams of polyarylene cage-type siloxane with a benzene ring R group and an amino end-capping group. Component B consists of 35 grams of 3-isocyanate propyltriethoxysiloxane, 10 grams of silicon carbide with a particle size of 100 nanometers, and 5 grams of aluminum oxide with a particle size of 100 nanometers.

[0043] Example 3: Component A consists of 100g of polysilazane with a degree of polymerization of 30, 50g of polydimethylsiloxane modified with perfluorobutyl vinyl ether and a degree of polymerization of 12, with silane-hydrogen end-capping groups, and 50g of polyarylene cage-type siloxane with biphenyl R group and amino end-capping groups. Component B consists of 42g of N,N-dimethyl-3-aminopropylmethyldimethoxysilane, 8g of silicon carbide with a particle size of 100 nm, and 5g of aluminum oxide with a particle size of 100 nm.

[0044] Example 4: Component A consists of 100g of polysilazane with a degree of polymerization of 50, 60g of polydimethylsiloxane modified with perfluorohexylethylene and a degree of polymerization of 8, with hydroxyl end-capping groups, and 50g of polyarylene cage-type siloxane with a benzene ring R group and amino end-capping groups. Component B consists of 35g of 3-isocyanate propyltriethoxysiloxane, 10g of silicon carbide with a particle size of 100 nm, and 5g of aluminum oxide with a particle size of 100 nm.

[0045] Example 5: Component A consists of 90 grams of polysiloxane with a degree of polymerization of 80, 50 grams of perfluorohexylethylene-modified polydimethylsiloxane with a degree of polymerization of 15 and amino-terminated groups, and 30 grams of polyarylene cage-type siloxane with biphenyl R group and hydroxyl-terminated groups. Component B consists of 20 grams of γ-aminopropyltriethoxysilane, 10 grams of silicon nitride with a particle size of 100 nm, and 5 grams of zirconium oxide with a particle size of 500 nm.

[0046] A method for preparing a multi-scale cross-linked fluorosilicone-based ceramic repair agent includes the following:

[0047] Component A consists of an organosilicon polymer, fluorinated modified polydimethylsiloxane, and polyarylene cage-type siloxane dissolved in propylene glycol methyl ether acetate in the above proportions, with a solid content of 30% to 70%, and mechanically stirred for 1 to 3 hours under nitrogen atmosphere at 30°C.

[0048] Component B: Micro-nano additives are added to the silicon-based crosslinking agent at a rate of 15-20 grams per hour, and mechanical stirring is used at a speed of 1500-2000 revolutions per minute and a temperature of 35-40℃.

[0049] Mix the prepared components A and B.

[0050] The main indicators and parameters are shown in Table 1.

[0051] Table 1. Main Physical Properties of Fluorosilicone-Based Ceramic Repair Agents

[0052]

[0053]

Claims

1. A multi-scale crosslinked fluorosilicon-based ceramic restorative, characterized in that: A component and B component, wherein the A component is an oligomerization degree of silicone polymer providing small-scale crosslinking network, fluorinated modified polydimethylsiloxane providing medium structure scale crosslinking and polyarylene cage siloxane providing large-scale crosslinking system, the B component is a silicon-based crosslinking agent and a micro-nano additive; the oligomerization degree of silicone polymer providing small-scale crosslinking network in the A component is one or more of polysilane, polysiloxane, polysilazane and polysilacarbon, the polymerization degree is 10-500, and the end-capping group is one or more of silicon hydrogen, silicon hydroxyl and silicon carboxyl; the fluorinated modified polydimethylsiloxane providing medium structure scale crosslinking has the structural formula ， wherein RF is a fluorinated side chain, which is one or more of perfluorobutyl ethylene, perfluorohexyl ethylene, perfluoropropyl vinyl ether, perfluorobutyl vinyl ether, perfluorohexyl vinyl ether, perfluorobutyl ketone, perfluoropropyl ketone and perfluorohexyl ketone, the polymerization degree of X is 5-20, the polymerization degree of Y is 3-15, the polymerization degree of n is 3-20, and the end-capping group is one or more of imino, amino, carboxyl, hydroxyl and urea; the polyarylene cage siloxane providing large-scale crosslinking system in the A component is ， wherein R' is an end-capping agent, which is one or more of imino, carboxyl, hydroxyl and urea, and R is one or more of the following compounds, 。 2. A multiscale crosslinked fluorosilicon-based ceramic repair according to claim 1, wherein: The weight ratio of the A component to the B component is 1:0.2-1:

2.

3. A multi-scale crosslinked fluorosilicon-based ceramic repair according to claim 1, wherein: The silicon-based crosslinking agent in the B component is one or more of gamma-aminopropyl triethoxysilane, 3-(N-cyclohexylamino) propyl methyl dimethoxysilane, 3-(N-cyclohexylamino) propyl trimethoxysilane, 3-aminopropyl methyl diethoxysilane, 3-aminopropyl methyl dimethoxysilane, N,N-dimethyl 3-aminopropyl methyl dimethoxysilane and 3-isocyanate propyl triethoxysiloxane.

4. A multi-scale crosslinked fluorosilicon-based ceramic repair according to claim 1, wherein: The micro-nano additive in the B component is one or more of silicon dioxide, aluminum oxide, silicon nitride, silicon carbide, zirconium oxide and yttrium oxide, and the particle size is 50-5000 nanometers.

5. A multiscale crosslinked fluorosilicon-based ceramic repair according to claim 1, wherein: The mass ratio of the oligomerization degree of silicone polymer providing small-scale crosslinking network, the fluorinated modified polydimethylsiloxane providing medium structure scale crosslinking and the polyarylene cage siloxane providing large-scale crosslinking system in the A component is 1:1:1-4:2:

1.

6. A multiscale crosslinked fluorosilicon-based ceramic repair according to claim 3, wherein: The mass ratio of the silicon-based crosslinking agent to the micro-nano additive in the B component is 1:1-10:

1.

7. A preparation method of the multi-scale crosslinking fluorosilicon-based ceramic repair agent according to any one of claims 1-6, characterized in that: The A component: the oligomerization degree of silicone polymer providing small-scale crosslinking network, the fluorinated modified polydimethylsiloxane providing medium structure scale crosslinking and the polyarylene cage siloxane providing large-scale crosslinking system are dissolved in propylene glycol methyl ether acetate in a certain proportion, the solid content is 30%-70%, and the mixture is stirred in a nitrogen environment at 30 DEG C by a mechanical method for 1-3 hours. Group B component: the micro-nano additive is added into the silicon-based crosslinking agent at a speed of 15-20 grams per hour, and is stirred by a mechanical method at a speed of 1500-2000 revolutions per minute and a temperature of 35-40℃.

Images