Multi-scale cross-linked fluorosilicone-based ceramic repair agent and preparation method therefor

Abstract

A multi-scale cross-linked fluorosilicone-based ceramic repair agent and a preparation method therefor. The ceramic repair agent is formed by mixing a component A and a component B, wherein the component A is an organosilicon polymer with a low polymerization degree that provides a small-scale cross-linked network, a fluorinated-modified polydimethylsiloxane that provides a medium-scale structural cross-linking, and a poly(arylene ether) cage silsesquioxane that provides a large-scale cross-linking system; and the component B is a cross-linking agent and a micro-nano additive. During a curing process, a silicon-oxygen main chain forms a large number of silicon-oxygen and silicon-hydrogen active bonds, which may react with hydroxyl and carboxyl groups of a 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.

Description

A multi-scale cross-linked fluorosilicon-based ceramic repair agent and a preparation method thereof TECHNICAL FIELD

[0001] 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. BACKGROUND

[0002] In today's industrial field, ceramic repair agents, as a kind of key technology, are widely used in various industries such as nuclear power, aerospace, shipbuilding, etc. Ceramic repair agent is a kind of high-performance, high-temperature-resistant and corrosion-resistant material, which is often used for repairing and protecting parts in high-temperature, acid-base and corrosive environments, and can effectively resist the erosion of corrosive media and prolong the service life of equipment. At present, most of the common repair agents are prepared by modifying epoxy resin, polyurethane and silicone rubber as the main resin matrix, and have basically reached the physical and chemical use limit of the matrix. For high-temperature (such as above 200 degrees Celsius), strong ultraviolet, acid-base and other harsh corrosive environments, and high-strength mechanical environments (such as seawater erosion), epoxy ceramic repair agents still have phenomena such as easy aging, cracking, mechanical property decline, adhesion reduction, etc. Especially, after partial shedding, foreign matter will be formed, which seriously threatens the safe operation of equipment. In addition, in high-end application scenarios, the ceramic repair agents commonly used in China are still mostly foreign products, such as related products of German Diamant and CP, British Belzona, American 3M, etc. There is also a risk of neck blockage due to technical blockade, etc.

[0003] Therefore, it is urgent to develop a new type of ceramic repair agent material which can maintain its structural strength and performance stability at 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, and has a self-cleaning function on the surface, and has good bonding performance with metal materials such as carbon steel and stainless steel.

[0004] SUMMARY

[0005] The purpose of the present application is to provide a multi-scale cross-linked fluorosilicon-based ceramic repair agent and a preparation method thereof. The material forms a multi-scale cross-linking system during the curing process of the fluorosilicon matrix, forms a ceramic-like inorganic-organic hybrid polymer network on the surface of the object to be repaired, and is anchored to the surface of the object in the form of chemical bonds to greatly improve the bonding strength. With the cross-linking characteristics of the fluorosilicon matrix, the repair agent has the characteristics of high temperature resistance, high wear resistance, self-lubricating and self-cleaning, oil resistance, resistance to daily ultraviolet radiation, and good corrosion resistance, etc. It can be used for repairing and protecting various industrial equipment and parts.

[0006] The technical scheme of the present application is as follows: a multi-scale cross-linked fluorosilicon-based ceramic repair agent is formed by mixing A component and B component, wherein the A component is a low degree of polymerization of silicone 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 the B component is a cross-linking agent and a micro-nano additive.

[0007] The weight ratio of the A component to the B component is 1:0.2 to 1:2.

[0008] The low degree of polymerization of silicone polymer in the A component providing a small scale cross-linking network is one or more of polysilane, polysiloxane, polysilazane, and polysilacarbon, the degree of polymerization is 10 to 500, and the end-capping group is one or more of silicon hydrogen, silicon hydroxyl, silicon carboxyl, and silicon amino.

[0009] The RF in the A component 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 degree of polymerization of X is 5 to 20, the degree of polymerization of Y is 3 to 15, the degree of polymerization of n is 3 to 20, and the end-capping group is one or more of imino, amino, carboxyl, hydroxyl, and ureido.

[0010] The silicon-based cross-linking 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.

[0011] 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 nanometers to 5000 nanometers.

[0012] The mass ratio of the low degree of polymerization of silicone polymer, the fluorinated modified polydimethylsiloxane, and the polyarylene cage siloxane in the A component is 1:1:1 to 4:2:1.

[0013] The mass ratio of the cross-linking agent to the micro-nano additive in the B component is 1:1 to 10:1.

[0014] A preparation method of a multi-scale cross-linked fluorosilicon-based ceramic repair agent, comprising the following steps:

[0015] A component: the silicone polymer, fluorinated modified polydimethylsiloxane, polyarylene cage siloxane are dissolved in propylene glycol methyl ether acetate according to the above ratio, the solid content is 30%-70%, under the nitrogen environment at 30 DEG C, the mechanical stirring is adopted for 1-3 hours;

[0016] B component: the micro-nano additive is added into the silicon-based crosslinking agent at a uniform speed of 15-20 grams per hour, the mechanical stirring is adopted, the stirring speed is 1500-2000 revolutions per minute, and the temperature is 35-40 DEG C.

[0017] The application has the advantages that: the common repair agent at present is mostly carbon-based resin base material, such as epoxy resin, which is used as the main material for filling and repairing the damage of industrial equipment surface metal, ceramic and plastic base material or protecting the surface thereof. However, such material still has some disadvantages, such as weak adhesion with the base, easy cracking and falling under the coupling of mechanical-temperature field in long-term service; the repair agent has high hardness but high brittleness, leading to easy wear under high strength, and low coatable thickness, so that it is difficult to achieve the coating layer with centimeter thickness; the surface layer of the repair agent has poor self-cleaning performance, and is easy to stick oil stains, leading to difficult cleaning of the repaired surface. The application adopts fluorosilicon flexible ceramic preparation technology, uses organic-inorganic phase hybrid synthesis method, customizes the design of silicon-based main chain and fluorinated side chain, so that the ceramic repair agent has the following advantages.

[0018] 1. The silicon-oxygen main chain forms a large number of silicon-oxygen in the curing process, and the silicon-hydrogen active bond can react with the hydroxyl and carboxyl groups of the base to be anchored on the base in the form of covalent bond, thereby greatly improving the adhesion strength of the repair agent and the base material and the adhesion durability under mechanical and temperature field.

[0019] 2. By embedding some flexible chain segments into the silicon-based main chain, the flexibility of the repair agent is improved, which enhances the overall wear resistance of the coating and improves the applicability of the construction, and the thickness can be coated to several centimeters thick.

[0020] 3. The perfluoro side group will float on the outer surface of the coating during the curing process due to the polarity effect, so that the surface energy of the outer surface of the repair agent coating is very low, the water-oil contact angle is large, and the self-cleaning effect of oil stains is achieved.

[0021] 4. By designing a multi-scale crosslinking system, the oligomeric silicone polymer, fluorinated modified polydimethylsiloxane and polyarylene cage siloxane form crosslinking networks at the nanometer, hundred nanometer and micrometer scales respectively, and are intertwined with each other, so as to build a high-density bulk environment, thereby improving the mechanical properties, heat expansion resistance, mechanical strength, corrosion resistance, acid and alkali resistance and ultraviolet resistance of the repair agent.

[0022] 5. The resin base material is a silicon-based main chain, and a plurality of nano-scale ceramic powders are compounded to partially ceramize into a more solid repair material at a certain temperature, so that the surface hardness breaks through 8H, and the temperature limit can reach more than 200 degrees Celsius, which can be used in more harsh environments.

[0023] 6. The ceramic repair agent can be cured in 1 to 3 hours, which is convenient for on-site operation. In addition, since water vapor can help silicon-oxygen hydrolysis and silicon-hydrogen crosslinking, the repair agent can be applied in a humid environment, even in the rain, which expands the construction conditions and reduces the difficulty. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic diagram of fluorinated modified polydimethylsiloxane;

[0025] Figure 2 is a structural schematic diagram of polyarylene cage siloxane;

[0026] Figure 3 is a kind of arylene group R group in polyarylene cage siloxane. DETAILED DESCRIPTION

[0027] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0028] A multi-scale cross-linked fluorosilicon-based ceramic repair agent is formed by mixing A component and B component, wherein the A component is a low degree of polymerization organosilicon 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 the B component is a cross-linking agent and a micro-nano additive.

[0029] The weight ratio of the A component to the B component is 1:0.2 to 1:2.

[0030] The low degree of polymerization organosilicon polymer in the A component providing a small-scale cross-linking network is one or more of polysilane, polysiloxane, polysilazane, and polysilacarbane, the degree of polymerization is 10 to 500, and the end-capping group is one or more of silicon-hydrogen, silicon-hydroxyl, silicon-carboxyl, and silicon-amino.

[0031] The fluorinated polydimethylsiloxane in the A component providing a medium structure scale cross-linking has a structure as shown in Figure 1, 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 degree of polymerization of X is 5 to 20, the degree of polymerization of Y is 3 to 15, the degree of polymerization of n is 3 to 20, and the end-capping group is one or more of imino, amino, carboxyl, hydroxyl, and ureido.

[0032] The structure of the cage siloxane in the A component providing a large-scale crosslinking system is shown in Figure 2, and the preparation process is as follows: the aromatic hydrocarbon (and fast hydrocarbon) with bromine at both ends is converted into a metal organic compound by a Grignard reaction or an organic lithium reaction, the metal organic compound is reacted with ClSi(OEt) 3 to obtain an arylene disilane, and then the disilane is hydrolyzed and polycondensed in THF or EtOH under acid or base catalysis to obtain a polyarylene cage siloxane. In the formula, R is one or more of the compounds shown in Figure 3, and R' is a capping agent, which is one or more of an imino group, a carboxyl group, a hydroxyl group, and a urea group.

[0033] The silicon-based crosslinking agent in the B component is one or more of γ-aminopropyl triethoxysilane, 3-(N-cyclohexylamino)propyl methyldimethoxysilane, 3-(N-cyclohexylamino)propyl trimethoxysilane, 3-aminopropyl methyldiethoxysilane, 3-aminopropyl methyldimethoxysilane, N,N-dimethyl 3-aminopropyl methyldimethoxysilane, and 3-isocyanate propyl triethoxysiloxane.

[0034] 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 nm to 5000 nm.

[0035] The mass ratio of the oligomerized organic silicone polymer, the fluorinated modified polydimethylsiloxane, and the polyarylene cage siloxane in the A component is 1:1:1 to 4:2:1.

[0036] The mass ratio of the crosslinking agent and the micro-nano additive in the B component is 1:1 to 10:1.

[0037] The multi-scale crosslinked fluorosilicon-based ceramic repair agent provided by the application has the following characteristics:

[0038] The repair agent prepared by the application uses a silicon atom as a base material to construct a main chain structure, so that an inorganic-organic hybrid effect is generated on the molecular chain, and the material has stronger hardness, wear resistance, and mechanical strength.

[0039] A multi-level crosslinking network is adopted, an organic silicone polymer is used as a small-scale dense crosslinking network to construct a dense crystal nucleus structure, a fluorinated polydimethylsiloxane system is used as a medium-scale crosslinking network, and finally a cage-shaped polysiloxane system is used as a large-scale crosslinking network, so that a multi-dimensional body macromolecular crosslinking system is constructed by interpenetrating the multi-scale crosslinking networks, and the compactness and mechanical properties of the material are greatly improved.

[0040] The fluorinated molecules are introduced in the form of branched side chains, and float on the outer surface of the coating layer during the curing process due to the polarity effect, so that the coating layer has many advantages of fluororesin, such as self-cleaning property, ultraviolet resistance, and anti-static property, while having a low fluorine content.

[0041] The present application will be further described with reference to Examples 1-5, but the present application is not limited to these examples.

[0042] Example 1: The A component is 80 g of polysiloxane having a degree of polymerization of 60, 50 g of perfluorobutylvinyl modified polydimethylsiloxane having a degree of polymerization of 10, and end groups of amino, 50 g of polyarylsiloxane cage having R groups of benzene rings, and end groups of hydroxyl. The B component is 30 g of 3-aminopropylmethyldiethoxysilane, 10 g of silicon nitride having a particle size of 100 nm, and 5 g of aluminum oxide having a particle size of 50 nm.

[0043] Example 2: The A component is 70 g of polysilazane having a degree of polymerization of 50, 60 g of perfluorobutylvinyl ether modified polydimethylsiloxane having a degree of polymerization of 12, and end groups of carboxyl, 50 g of polyarylsiloxane cage having R groups of benzene rings, and end groups of amino. The B component is 35 g of 3-isocyanatepropyltriethoxysilane, 10 g of silicon carbide having a particle size of 100 nm, and 5 g of aluminum oxide having a particle size of 100 nm.

[0044] Example 3: The A component is 100 g of polysilazane having a degree of polymerization of 30, 50 g of perfluorobutylvinyl ether modified polydimethylsiloxane having a degree of polymerization of 12, and end groups of silicon hydride, 50 g of polyarylsiloxane cage having R groups of biphenyl, and end groups of amino. The B component is 42 g of N,N-dimethyl 3-aminopropylmethyldimethoxysilane, 8 g of silicon carbide having a particle size of 100 nm, and 5 g of aluminum oxide having a particle size of 100 nm.

[0045] Example 4: The A component is 100 g of polysilazane having a degree of polymerization of 50, 60 g of perfluorohexylvinyl modified polydimethylsiloxane having a degree of polymerization of 8, and end groups of hydroxyl, 50 g of polyarylsiloxane cage having R groups of benzene rings, and end groups of amino. The B component is 35 g of 3-isocyanatepropyltriethoxysilane, 10 g of silicon carbide having a particle size of 100 nm, and 5 g of aluminum oxide having a particle size of 100 nm.

[0046] Example 5: The A component is 90 g of polysiloxane having a degree of polymerization of 80, 50 g of perfluorohexylvinyl modified polydimethylsiloxane having a degree of polymerization of 15, and end groups of amino, 30 g of polyarylsiloxane cage having R groups of biphenyl, and end groups of hydroxyl. The B component is 20 g of γ-aminopropyltriethoxysilane, 10 g of silicon nitride having a particle size of 100 nm, and 5 g of zirconium oxide having a particle size of 500 nm.

[0047] A method for preparing a multi-scale cross-linked fluorosilicon-based ceramic repair agent, comprising the following:

[0048] A component, the silicone polymer, fluorinated modified polydimethylsiloxane, polyarylene cage siloxane is dissolved in propylene glycol methyl ether acetate according to the above-mentioned proportion, the solid content is 30%~70%, under the nitrogen environment at 30 DEG C, the mechanical stirring is adopted for 1~3 hours.

[0049] B component: the micro-nano additive is added into the silicon-based crosslinking agent at the uniform speed of 15~20 grams per hour, the mechanical stirring is adopted, the stirring speed is 1500~2000 revolutions per minute, and the temperature is 35~40 DEG C.

[0050] The prepared A component and B component are mixed.

[0051] The main index parameters are shown in Table 1

[0052] Table 1 main index parameters of the physical properties of fluorosilicon-based ceramic repair material

Claims

1. A multi-scale crosslinked fluorosilicon-based ceramic restorative, characterized in that: A component and B component are mixed, wherein the A component is low degree of polymerization 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 crosslinking agent and micro-nano additive.

2. A multi-scale crosslinked fluorosilicon-based ceramic repair according to claim 1, wherein: The weight ratio of the A component and the B component is 1:0.2 to 1:

2.

3. A multi-scale crosslinked fluorosilicon-based ceramic repair according to claim 1, wherein: The low degree of polymerization of silicone polymer in the A component providing small scale crosslinking network is one or more of polysilane, polysiloxane, polysilazane and polysilacarbon, the degree of polymerization is 10 to 500, and the end capping group is one or more of silicon hydrogen, silicon hydroxyl and silicon carboxyl.

4. A multi-scale crosslinked fluorosilicon-based ceramic repair according to claim 3, wherein: The RF in the A component 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 degree of polymerization of X is 5 to 20, the degree of polymerization of Y is 3 to 15, the degree of polymerization of n is 3 to 20, and the end capping group is one or more of imino, amino, carboxyl, hydroxyl and ureido.

5. The multi-scale cross-linked fluorosilicone-based ceramic repairing agent according to claim 1, characterized in that: The silicon-based crosslinking agent in the B component is one or more of γ-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.

6. A multiscale crosslinked fluorosilicon-based ceramic repair according to claim 5, wherein: The micro-nano additive in the B component is one or more of silicon dioxide, aluminum trioxide, silicon nitride, silicon carbide, zirconium oxide and yttrium oxide, and the particle size is 50 nanometers to 5000 nanometers.

7. A multiscale crosslinked fluorosilicon-based ceramic repair according to claim 3, wherein: The mass ratio of the low degree of polymerization of silicone polymer, the fluorinated modified polydimethylsiloxane and the polyarylene cage siloxane in the A component is 1:1:1 to 4:2:

1.

8. A multiscale crosslinked fluorosilicon-based ceramic repair according to claim 5, wherein: The mass ratio of the crosslinking agent and the micro-nano additive in the B component is 1:1 to 10:

1.

9. A preparation method of a multi-scale crosslinked fluorosilicon-based ceramic repair agent, characterized in that: The A component: the organic silicone polymer, the fluorinated modified polydimethylsiloxane and the polyarylene cage siloxane are dissolved in propylene glycol methyl ether acetate according to the above-mentioned ratio, the solid content is 30% to 70%, and the stirring is carried out at 30 DEG C in a nitrogen environment by using a mechanical method for 1 to 3 hours; The B component: the micro-nano additive is added into the silicon-based crosslinking agent at a uniform speed of 15 to 20 grams per hour, the stirring is carried out by using a mechanical method, the stirring speed is 1500 to 2000 revolutions per minute, and the temperature is 35 to 40 DEG C.

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