A flexible grafted modified polysilazane-based coating material, its preparation method and use

Abstract

The application belongs to the technical field of protective coating, and particularly relates to a flexible chain graft modified polysilazane-based coating as well as a preparation method and application thereof. The flexible chain graft modified polysilazane-based coating comprises the following components in parts by weight: modified polysilazane 5-20 parts, active filler 5-15 parts, dispersion medium 60-80 parts, and auxiliary agent 0.1-0.5 parts; the modified polysilazane is prepared by grafting reaction of polysilazane and flexible high molecular compound. In the application, the flexible high molecular compound is grafted on the polysilazane, the modified flexible long chain can rotate freely, the coating is endowed with super-lubricating property, the brittleness of the coating is reduced, and the friction coefficient of the coating is reduced. The polysilazane takes Si-NH-Si bond as a repeating unit, can be easily combined with the -OH on the surface of a base material, and can form a covalent structure with metal atoms, so that the combination strength is high, the density after solidification is good, the hardness is high, and the wear resistance and corrosion resistance are strong.

Description

Technical Field

[0001] This invention belongs to the field of protective coating technology, specifically relating to a flexible linker-modified polysiloxane alkyl coating, its preparation method, and its application. Background Technology

[0002] In recent years, surface coating technology has become one of the effective methods to protect the surface of seabed equipment from biological pollution and corrosion and reduce navigation resistance. The coating method is simple, feasible, low-cost, and has strong protective capabilities, and has good application prospects.

[0003] Polysilazane coatings, as a type of low surface energy coating, contain abundant Si-N-Si bonds, which readily combine with -OH groups on the substrate surface, resulting in excellent adhesion to the substrate. Furthermore, polysilazane coatings exhibit high hardness and good wear resistance after curing. However, single polysilazane coatings suffer from high brittleness and a tendency to crack after curing. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a flexible linker-modified polysiloxane alkyl coating, its preparation method, and its application. The coating prepared using the flexible linker-modified polysiloxane alkyl coating of this invention exhibits good flexibility and excellent lubrication, wear resistance, and corrosion resistance.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a flexible, linked-branch modified polysilazane alkyl coating, comprising the following components in parts by weight:

[0007] The mixture contains 5-20 parts of modified polysilazane, 5-15 parts of active filler, 60-80 parts of dispersion medium, and 0.1-0.5 parts of additives.

[0008] The modified polysilazane is a flexible graft-modified polysilazane, which is prepared by grafting polysilazane and flexible polymer compound through a grafting reaction. The number average molecular weight of the flexible polymer compound is 1000 to 10000.

[0009] The flexible polymer compound includes one or more of monohydroxy compounds, dihydroxy compounds, and polyhydroxy compounds;

[0010] The monohydroxy compound includes one or more of perfluoropolyether alcohol, dimethyl hydroxy silicone oil, hydroxypropyl silicone oil, and perfluoropolyether siloxane;

[0011] The dihydroxy compound includes dihydroxy-terminated compounds or other dihydroxy compounds; the dihydroxy-terminated compounds include one or more of polyethylene glycol, polypropylene glycol, dihydroxy-terminated silicone oil, dihydroxypropyl silicone oil, dihydroxy-terminated perfluoropolyether, dihydroxy-terminated polybutadiene, dihydroxy-terminated polyphenylene ether, and dihydroxy-terminated long-chain alkyl silicone oil; the other dihydroxy compounds include perfluoropolyether diols and / or fluorinated polyether diols;

[0012] The polyhydroxy compound includes one or more of diglycerol, polyvinyl alcohol, linear polyhydroxy polyester, polyhydroxy polysulfide ester, and polyhydroxy polybutadiene.

[0013] Preferably, the polysilazane includes one or more of polymethylhydrosilazane, polyboronsilazane, propargyl polysilazane, polysiloxane, N-methylpolysilazane, hyperbranched allyl polysilazane, vinyl polysilazane, methyl polysilazane, fluorinated polysilazane, polyurea polysilazane, and perhydropolysilazane.

[0014] Preferably, the active filler comprises one or more of two-dimensional materials, modified two-dimensional materials, and other fillers; the two-dimensional materials comprise one or more of two-dimensional borides MBene, MXene, BN, VS2, MoS2, graphene, and WSe2; the modified two-dimensional materials comprise MXene@MoS2 and / or BN@GO; and the other fillers comprise one or more of metal oxides, fluorides, and borides.

[0015] Preferably, the components include the following parts by weight:

[0016] 2.6 parts modified polysilazane, 2.2 parts active filler, 15 parts dispersion medium and 0.06 parts additives.

[0017] This invention also provides a method for preparing the flexible linking branch modified polysilazane alkyl coating described above, comprising the following steps:

[0018] Modified polysilazane is obtained by grafting a mixture of polysilazane, flexible polymer compound, catalyst and organic solvent.

[0019] Modified polysilazane, active filler, dispersion medium and additives are mixed to obtain a flexible linking branch modified polysilazane coating.

[0020] Preferably, the mass ratio of the polysilazane to the flexible polymer compound is (5-15):(1-5).

[0021] Preferably, the catalyst comprises dibutyltin dilaurate and / or N,N-dimethylethanolamine; the mass ratio of the polysilazane to the catalyst is (5-15):(0.01-0.1).

[0022] Preferably, the grafting reaction is carried out at a temperature of 30–60°C for 4–10 hours.

[0023] The present invention also provides the application of the flexible linking branch modified polysiloxane coating described in the above technical solution or the flexible linking branch modified polysiloxane coating prepared by the above preparation method in protective coatings.

[0024] The present invention also provides a flexible linking branch modified polysiloxane coating, which is obtained by spraying the flexible linking branch modified polysiloxane coating described in the above technical solution or the flexible linking branch modified polysiloxane coating prepared by the above preparation method onto the surface of a metal substrate, wherein the thickness of the flexible linking branch modified polysiloxane coating is 5 to 50 μm.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention provides a flexible, linked-branch modified polysilazane coating, comprising the following components in parts by weight: 5-20 parts modified polysilazane, 5-15 parts active filler, 60-80 parts dispersion medium, and 0.1-0.5 parts additives; wherein the modified polysilazane is a flexible, linked-branch modified polysilazane, obtained by grafting polysilazane and a flexible polymer compound, and the number-average molecular weight of the flexible polymer compound is 1000-10000.

[0027] This invention grafts a flexible polymer compound onto polysilazane. This flexible polymer compound possesses excellent lubricating properties and can modify polysilazane. The modified flexible long chains can rotate freely, endowing the coating surface with super-lubricating properties similar to a liquid. Almost all polar and non-polar liquids do not easily adhere to this liquid-like surface, allowing it to slide without residue, thus improving surface smoothness. Furthermore, the introduction of flexible chains significantly reduces the brittleness of the polysilazane coating, solving the problem of easy cracking and improving its flexibility. Additionally, the introduction of the long-chain flexible polymer compound with excellent lubricating properties also reduces the coefficient of friction of the coating. This invention uses liquid lubricant molecules with lubricating functions to toughen the coating while simultaneously providing lubrication. The polysilazane uses Si-NH-Si bonds as repeating units, readily combining with -OH groups on the substrate surface and forming Si-O-Cr and Si-O-Fe covalent structures with metal atoms such as Cr and Fe, resulting in strong bonding strength with the metal substrate. After curing, it transforms into a dense and high-hardness SiO₂. x The coating imparts excellent wear resistance and corrosion resistance.

[0028] The present invention also provides a flexible linker-modified polysiloxane alkyl lubricating, anti-corrosion and wear-resistant coating. When used as a lubricating coating for high-end equipment under extremely harsh working conditions (such as strong corrosion, high pressure seawater, microorganisms, high load, high speed, etc.), it not only has a low coefficient of friction and wear rate, but also has advantages such as excellent anti-corrosion performance and good adhesion to the substrate. Detailed Implementation

[0029] This invention provides a flexible, linked-branch modified polysilazane alkyl coating, comprising the following components in parts by weight:

[0030] The mixture contains 5-20 parts of modified polysilazane, 5-15 parts of active filler, 60-80 parts of dispersion medium, and 0.1-0.5 parts of additives.

[0031] The modified polysilazane is a flexible graft-modified polysilazane, which is prepared by grafting polysilazane and flexible polymer compound through a grafting reaction. The number average molecular weight of the flexible polymer compound is 1000 to 10000.

[0032] The flexible polymer compound includes one or more of monohydroxy compounds, dihydroxy compounds, and polyhydroxy compounds;

[0033] The monohydroxy compound includes one or more of perfluoropolyether alcohol, dimethyl hydroxy silicone oil, hydroxypropyl silicone oil, and perfluoropolyether siloxane;

[0034] The dihydroxy compound includes dihydroxy-terminated compounds or other dihydroxy compounds; the dihydroxy-terminated compounds include one or more of polyethylene glycol, polypropylene glycol, dihydroxy-terminated silicone oil, dihydroxypropyl silicone oil, dihydroxy-terminated perfluoropolyether, dihydroxy-terminated polybutadiene, dihydroxy-terminated polyphenylene ether, and dihydroxy-terminated long-chain alkyl silicone oil; the other dihydroxy compounds include perfluoropolyether diols and / or fluorinated polyether diols;

[0035] The polyhydroxy compound includes one or more of diglycerol, polyvinyl alcohol, linear polyhydroxy polyester, polyhydroxy polysulfide ester, and polyhydroxy polybutadiene.

[0036] Unless otherwise specified, all materials and equipment used in this invention are commercially available products in the field.

[0037] In this invention, the modified polysilazane is preferably 5 to 18 parts by weight, more preferably 6 to 15 parts, and even more preferably 8 to 12 parts by weight.

[0038] In this invention, the general structural formula of the polysilazane is shown in Formula 1:

[0039]

[0040] In this invention, the polysilazane preferably includes one or more of polymethylhydrosilazane, polyborosilazane, propargyl polysilazane, polysiloxane, N-methylpolysilazane, hyperbranched allyl polysilazane, vinyl polysilazane, methyl polysilazane, fluorinated polysilazane, polyurea polysilazane, and perhydropolysilazane. The polysilazane can react at the molecular level with organic compounds having active functional groups (-OH) to develop into a multifunctional coating that combines friction reduction, wear resistance, and corrosion protection.

[0041] In this invention, the flexible polymer compound is a single- and / or multi-hydroxyl long-chain flexible polymer compound with excellent lubrication properties. The flexible polymer compound has an active functional group -OH, which can undergo a grafting reaction with Si-H in polysilazane at the molecular level to form Si-O bonds, improving the toughness of the polysilazane. The flexible polymer compound has liquid-like properties, which can improve surface slippage, reduce the coefficient of friction of the coating, and improve lubrication performance. The flexible chains endow the coating surface with super-lubricating properties, making it difficult for almost all polar and non-polar liquids to adhere to the coating surface, allowing them to slide off without residue.

[0042] The monohydroxy compound is preferably a perfluoropolyether alcohol or a perfluoropolyether siloxane; the number average molecular weight of the monohydroxy compound is preferably 2000-3000.

[0043] The dual-hydroxyl-terminated compound is preferably polyethylene glycol or dual-hydroxyl-terminated silicone oil; the other dual-hydroxyl-terminated compounds are preferably perfluoropolyether diols or fluorinated polyether diols; the number-average molecular weight of the dual-hydroxyl-terminated compounds is preferably 2000-3500.

[0044] The polyhydroxy compound is preferably polyhydroxy polybutadiene; the number-average molecular weight of the polyhydroxy compound is preferably 2000-3000.

[0045] In this invention, the grafting rate of the flexible chain in the modified polysilazane is preferably 50-98%.

[0046] The active filler is preferably 7 to 13 parts by weight, more preferably 9 to 11 parts by weight, based on the modified polysilazane.

[0047] In this invention, the active filler preferably comprises one or more of two-dimensional materials, modified two-dimensional materials, and other fillers; the two-dimensional material preferably comprises one or more of two-dimensional borides MBene, MXene, BN, VS2, MoS2, graphene, and WSe2; the modified two-dimensional material preferably comprises MXene@MoS2 and / or BN@GO, and the modified two-dimensional material is preferably synthesized by a one-step hydrothermal method; the other fillers preferably comprise one or more of metal oxides, fluorides, and borides, and the fluorides preferably comprise PTFE. More preferably, the active filler is a 1:1 mass ratio of MXene@MoS2 and boron trioxide, a 1:1 mass ratio of BN@GO and PTFE, a 1:1 mass ratio of MXene@MoS2 and zirconium boride, a 1:1 mass ratio of MXene@MoS2 and BN@GO, or a 1:1 mass ratio of MXene@MoS2 and calcium fluoride. The active filler described in this invention can significantly improve the wear resistance of the coating and also impart anti-corrosion function to the coating; the two-dimensional material surface is oriented and can reduce the coefficient of friction and reduce wear when it slides with its counterpart.

[0048] The dispersion medium is preferably 65-75 parts by weight, more preferably 68-72 parts by weight, based on the weight of the modified polysilazane.

[0049] In this invention, the dispersion medium preferably includes one or more of the following: n-butyl ether, xylene, 1,1,2-trichlorotrifluoroethane, perfluorohexane, perfluorocyclohexane, perfluorotoluene, perfluoroheptane, and perfluorotrialkylamine. When the dispersion medium is preferably two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0050] The additive is preferably 0.2 to 0.4 parts by weight, more preferably 0.25 to 0.35 parts by weight, based on the weight of the modified polysilazane.

[0051] In this invention, the additives preferably include one or more of wetting and dispersing agents, defoamers, and leveling agents; the wetting and dispersing agents preferably include Tech-5061 and / or Tech-5063; the defoamers preferably include Tech-367N and / or Tech-341; and the leveling agents preferably include Tech-154N and / or Tech-2730. When the additives preferably include wetting and dispersing agents, defoamers, and leveling agents, the mass ratio of the wetting and dispersing agents, defoamers, and leveling agents is preferably (0.9–1.1):(1.0–1.2):(0.8–1.0), more preferably 1:1:1, 1:1.1:1, or 1.1:1.2:0.9. The additives of this invention can ensure that the modified polysilazane lubricating, anti-corrosion, and wear-resistant integrated coating does not easily settle, the active filler is uniformly dispersed in the system, and has good wetting and leveling properties on the substrate surface; the formed coating is dense and free of defects such as bubbles and nodules.

[0052] In this invention, the flexible linker-modified polysilazane alkyl coating preferably comprises the following components in parts by weight:

[0053] 2.6 parts modified polysilazane, 2.2 parts active filler, 15 parts dispersion medium and 0.06 parts additives.

[0054] The present invention also provides a method for preparing the flexible linking branch modified polysiloxane coating described above, comprising the following steps:

[0055] Modified polysilazane is obtained by grafting a mixture of polysilazane, flexible polymer compound, catalyst and organic solvent.

[0056] Modified polysilazane, active filler, dispersion medium and additives are mixed to obtain a flexible linking branch modified polysilazane coating.

[0057] This invention involves mixing polysilazane, a flexible polymer compound, a catalyst, and an organic solvent to carry out a grafting reaction, thereby obtaining modified polysilazane.

[0058] In this invention, the mass ratio of the polysilazane to the flexible polymer compound is preferably (5-15):(1-5), more preferably (6-12):(2-4), even more preferably (8-10):(2.5-3.5), and even more preferably 2:0.7.

[0059] In this invention, the organic solvent preferably includes one or more of tetrahydrofuran, xylene, N,N-dimethylformamide, and n-butyl ether. The mass of the organic solvent is preferably 50-150% of the mass of the polysilazane.

[0060] In this invention, the catalyst preferably comprises dibutyltin dilaurate (DBTL) and / or N,N-dimethylethanolamine (DMEA). The mass ratio of the polysilazane to the catalyst is preferably (5-15):(0.01-0.1), more preferably 2:0.003.

[0061] In this invention, the preferred method for mixing the polysilazane, flexible polymer compound, catalyst, and organic solvent is to first mix the polysilazane and organic solvent, and then add the flexible polymer compound and catalyst for a second mixing. Both the first and second mixing methods are preferably performed by stirring. This invention does not have specific requirements regarding the stirring speed; uniform mixing is sufficient.

[0062] In this invention, the grafting reaction is preferably carried out under a protective atmosphere, and the protective atmosphere gas preferably includes argon. The process before the grafting reaction preferably includes: first introducing argon gas into the reaction vessel to purge air and moisture from the reaction vessel. The temperature of the grafting reaction is preferably 30–60°C, more preferably 35–65°C, even more preferably 48–52°C, and even more preferably 50°C; the time is preferably 4–10 hours, more preferably 5–9 hours, and even more preferably 6–8 hours.

[0063] In this invention, the grafting reaction preferably includes solvent removal, and the solvent removal method is preferably rotary evaporation.

[0064] After obtaining the modified polysilazane, the present invention mixes the modified polysilazane, active filler, dispersion medium and additives to obtain a flexible linking branch modified polysilazane coating.

[0065] In this invention, the mixing of the modified polysilazane, active filler, dispersion medium and additives preferably includes: first mixing the active filler and a portion of the dispersion medium to obtain a mixed slurry; and second mixing the mixed slurry, modified polysilazane, active filler, remaining dispersion medium and additives to obtain a flexible linking branch modified polysilazane coating.

[0066] In this invention, the mass of the partially dispersed medium is preferably 60% of the mass of the dispersed medium. This invention does not impose special requirements on the methods of the first and second mixing, such as stirring.

[0067] The present invention also provides the application of the flexible linking branch modified polysiloxane coating described in the above technical solution or the flexible linking branch modified polysiloxane coating prepared by the preparation method described in the above technical solution in protective coatings.

[0068] The present invention also provides a flexible linking branch modified polysiloxane coating, which is obtained by spraying the flexible linking branch modified polysiloxane coating or the flexible linking branch modified polysiloxane coating prepared by the preparation method described in the above technical solution onto the surface of a metal substrate, wherein the thickness of the flexible linking branch modified polysiloxane coating is 5 to 50 μm.

[0069] In this invention, the process before spraying preferably includes: sandblasting the metal substrate; the surface roughness of the metal substrate after sandblasting is preferably 0.5–4.0 μm, more preferably 1.0–3.0 μm, and even more preferably 2.6 μm. This invention does not impose any special requirements on the sandblasting conditions; conditions well-known to those skilled in the art can be used. This invention does not impose any special limitations on the type of metal substrate; types well-known to those skilled in the art can be used.

[0070] The present invention does not impose any special limitations on the spraying process; any process known to those skilled in the art can be used.

[0071] In this invention, the coating process preferably includes a curing treatment, which preferably includes heat curing or ultraviolet curing. The heat curing temperature is preferably 60-180°C, more preferably 80-160°C, even more preferably 100-140°C, and even more preferably 120°C. The curing time is preferably 1-6 hours, more preferably 2-4 hours.

[0072] In this invention, the UV curing time is preferably 1 to 6 hours, more preferably 2 to 4 hours; the wavelength of the UV light is preferably 365 nm or 172 nm; after UV curing, it is preferable to further cure the coating completely in a high humidity and heat environment. The high humidity and heat environment mentioned in this invention does not have any special requirements, and conditions commonly used by those skilled in the art can be used.

[0073] In this invention, the thickness of the flexible linker-modified polysilazane alkyl coating is preferably 15–40 μm.

[0074] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, of the flexible linking branch modified polysiloxane coating, its preparation method, and its application, is provided but should not be construed as limiting the scope of protection of the present invention.

[0075] Example 1

[0076] Ar gas was introduced into a dry single-necked flask to remove air and moisture. 4.0 g of perhydropolysilazane and 6.0 g of anhydrous tetrahydrofuran were added to the flask and stirred thoroughly. Then, 1.4 g of hydroxyl-terminated silicone oil with a molecular weight of 2000–3500 and 0.006 g of catalyst DBTL were added. The system temperature was raised to 50 °C, and the reaction was carried out under Ar protection for 6 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified perhydropolysilazane.

[0077] 1.4 g of MXene was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of ammonium tetrathiomolybdate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler MXene@MoS2.

[0078] Weigh 2.2g of active filler MXene@MoS2 and boron trioxide (mass ratio 1:1) and mix with 2.6g of modified perhydropolysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061 (wetting and dispersing agent), 0.02g of Tech-367N (defoamer), and 0.02g of Tech-2730 (leveling agent) and continue stirring for 10min to obtain a flexible linking branch modified polysilazane lubricating, anti-corrosion, and wear-resistant coating.

[0079] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0080] After the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating is uniformly sprayed onto the surface of the metal substrate, it is surface dried at room temperature and then cured at 120℃ for 2 hours to obtain the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating.

[0081] Example 2

[0082] Ar gas was introduced into a dry single-necked flask to remove air and moisture. 2.0 g of vinyl polysilazane and 3.0 g of anhydrous tetrahydrofuran were added to the flask and stirred thoroughly. Then, 0.7 g of perfluoropolyether alcohol with a molecular weight of 2000–3000 and 0.003 g of catalyst DBTL were added. The system temperature was raised to 50 °C, and the reaction was carried out for 6 hours under Ar protection. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified vinyl polysilazane.

[0083] 1.4 g of GO was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of BN was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler BN@GO.

[0084] Weigh 2.2g of active filler BN@GO and PTFE (mass ratio 1:1) and mix with 2.6g of modified vinyl polysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061, 0.02g of Tech-367N and 0.02g of Tech-2730 and continue stirring for 10 minutes to obtain a flexible linker-modified polysilazane lubricating, anti-corrosion and wear-resistant coating.

[0085] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0086] After the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating is uniformly sprayed onto the surface of the metal substrate, it is surface dried at room temperature and then cured at 120℃ for 2 hours to obtain the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating.

[0087] Example 3

[0088] Ar gas was introduced into a dry single-necked flask to remove air and moisture. 2.0 g of methylpolysilazane and 3.0 g of anhydrous tetrahydrofuran were added to the flask and stirred thoroughly. Then, 0.7 g of polyhydroxy polybutadiene with a molecular weight of 2000–3000 and 0.003 g of catalyst DBTL were added. The system temperature was raised to 50 °C, and the reaction was carried out under Ar protection for 6 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain modified methylpolysilazane.

[0089] 1.4 g of MXene was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of ammonium tetrathiomolybdate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler MXene@MoS2.

[0090] Weigh 2.2g of active filler MXene@MoS2 and zirconium boride (mass ratio 1:1) and mix with 2.6g of modified methyl polysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061, 0.02g of Tech-367N and 0.02g of Tech-2730 and stir continuously for 10min to obtain a flexible linking branch modified polysilazane lubricating, anti-corrosion and wear-resistant coating.

[0091] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0092] After the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating is uniformly sprayed onto the surface of the metal substrate, it is surface dried at room temperature and then cured at 120℃ for 2 hours to obtain the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating.

[0093] Example 4

[0094] Ar gas was introduced into a dry single-necked flask to remove air and moisture. 2.0 g of N-methylpolysilazane and 3.0 g of anhydrous tetrahydrofuran were added to the flask and stirred thoroughly. Then, 0.7 g of polyethylene glycol with a molecular weight of 2000–3000 and 0.003 g of catalyst DBTL were added. The system temperature was raised to 50 °C, and the reaction was carried out under Ar protection for 6 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain modified N-methylpolysilazane.

[0095] 1.4 g of MXene was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of ammonium tetrathiomolybdate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler MXene@MoS2.

[0096] 1.4 g of GO was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of BN was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler BN@GO.

[0097] Weigh 2.2g of active fillers MXene@MoS2 and BN@GO (mass ratio 1:1) and mix with 2.6g of modified N-methylpolysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061, 0.02g of Tech-367N and 0.02g of Tech-2730 and continue stirring for 10min to obtain a flexible linking branch modified polysilazane lubricating, anti-corrosion and wear-resistant coating.

[0098] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0099] After the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating is uniformly sprayed onto the surface of the metal substrate, it is surface dried at room temperature and then cured at 120℃ for 2 hours to obtain the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating.

[0100] Example 5

[0101] Ar gas was introduced into a dry single-necked flask to remove air and moisture. 2.0 g of vinyl polysilazane and 3.0 g of anhydrous tetrahydrofuran were added to the flask and stirred thoroughly. Then, 0.7 g of perfluoropolyether siloxane with a molecular weight of 2000–3000 and 0.003 g of catalyst DBTL were added. The system temperature was raised to 50 °C, and the reaction was carried out under Ar protection for 6 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified vinyl polysilazane.

[0102] 1.4 g of MXene was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of ammonium tetrathiomolybdate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler MXene@MoS2.

[0103] Weigh 2.2g of active filler MXene@MoS2 and calcium fluoride (mass ratio 1:1) and mix with 2.6g of modified vinyl polysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061, 0.02g of Tech-367N and 0.02g of Tech-2730 and continue stirring for 10min to obtain a flexible linker-modified polysilazane lubricating, anti-corrosion and wear-resistant coating.

[0104] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0105] After the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating is uniformly sprayed onto the surface of the metal substrate, it is surface dried at room temperature and then cured at 120℃ for 2 hours to obtain the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating.

[0106] Example 6

[0107] Ar gas was introduced into a dry single-necked flask to remove air and moisture. 4.0 g of perhydropolysilazane and 6.0 g of anhydrous tetrahydrofuran were added to the flask and stirred thoroughly. Then, 0.8 g of hydroxyl-terminated silicone oil with a molecular weight of 2000–3500 and 0.004 g of catalyst DBTL were added. The system temperature was raised to 50 °C, and the reaction was carried out under Ar protection for 6 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified perhydropolysilazane.

[0108] 1.4 g of MXene was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of ammonium tetrathiomolybdate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler MXene@MoS2.

[0109] Weigh 2.2g of active filler MXene@MoS2 and boron trioxide (mass ratio 1:1) and mix with 2.6g of modified perhydropolysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061 (wetting and dispersing agent), 0.02g of Tech-367N (defoamer), and 0.02g of Tech-2730 (leveling agent) and continue stirring for 10min to obtain a flexible linking branch modified polysilazane lubricating, anti-corrosion, and wear-resistant coating.

[0110] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0111] After the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating is uniformly sprayed onto the surface of the metal substrate, it is surface dried at room temperature and then cured at 120℃ for 2 hours to obtain the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating.

[0112] Example 7

[0113] Ar gas was introduced into a dry single-necked flask to remove air and moisture. 4.0 g of perhydropolysilazane and 6.0 g of anhydrous tetrahydrofuran were added to the flask and stirred thoroughly. Then, 2.0 g of hydroxyl-terminated silicone oil with a molecular weight of 2000–3500 and 0.008 g of catalyst DBTL were added. The system temperature was raised to 50 °C, and the reaction was carried out under Ar protection for 6 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified perhydropolysilazane.

[0114] 1.4 g of MXene was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of ammonium tetrathiomolybdate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler MXene@MoS2.

[0115] Weigh 2.2g of active filler MXene@MoS2 and boron trioxide (mass ratio 1:1) and mix with 2.6g of modified perhydropolysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061 (wetting and dispersing agent), 0.02g of Tech-367N (defoamer), and 0.02g of Tech-2730 (leveling agent) and continue stirring for 10min to obtain a flexible linking branch modified polysilazane lubricating, anti-corrosion, and wear-resistant coating.

[0116] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0117] After the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating is uniformly sprayed onto the surface of the metal substrate, it is surface dried at room temperature and then cured at 120℃ for 2 hours to obtain the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating.

[0118] Comparative Example 1

[0119] Ar gas was introduced into a dry single-necked flask to remove air and moisture. 4.0 g of perhydropolysilazane and 6.0 g of anhydrous tetrahydrofuran were added to the flask and stirred thoroughly. Then, 0.15 g of hydroxyl-terminated silicone oil with a molecular weight of 2000–3500 and 0.003 g of catalyst DBTL were added. The system temperature was raised to 50 °C, and the reaction was carried out under Ar protection for 6 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified perhydropolysilazane.

[0120] 1.4 g of MXene was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of ammonium tetrathiomolybdate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler MXene@MoS2.

[0121] Weigh 2.2g of active filler MXene@MoS2 and boron trioxide (mass ratio 1:1) and mix with 2.6g of modified perhydropolysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061 (wetting and dispersing agent), 0.02g of Tech-367N (defoamer), and 0.02g of Tech-2730 (leveling agent) and continue stirring for 10min to obtain a flexible linking branch modified polysilazane lubricating, anti-corrosion, and wear-resistant coating.

[0122] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0123] After the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating is uniformly sprayed onto the surface of the metal substrate, it is surface dried at room temperature and then cured at 120℃ for 2 hours to obtain the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating.

[0124] Comparative Example 2

[0125] Ar gas was introduced into a dry single-necked flask to remove air and moisture. 4.0 g of perhydropolysilazane and 6.0 g of anhydrous tetrahydrofuran were added to the flask and stirred thoroughly. Then, 5.0 g of hydroxyl-terminated silicone oil with a molecular weight of 2000–3500 and 0.004 g of catalyst DBTL were added. The system temperature was raised to 50 °C, and the reaction was carried out under Ar protection for 6 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified perhydropolysilazane.

[0126] 1.4 g of MXene was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of ammonium tetrathiomolybdate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler MXene@MoS2.

[0127] Weigh 2.2g of active filler MXene@MoS2 and boron trioxide (mass ratio 1:1) and mix with 2.6g of modified perhydropolysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061 (wetting and dispersing agent), 0.02g of Tech-367N (defoamer), and 0.02g of Tech-2730 (leveling agent) and continue stirring for 10min to obtain a flexible linking branch modified polysilazane lubricating, anti-corrosion, and wear-resistant coating.

[0128] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0129] After the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating is uniformly sprayed onto the surface of the metal substrate, it is surface dried at room temperature and then cured at 120℃ for 2 hours to obtain the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coating.

[0130] Comparative Example 3

[0131] 1.4 g of MXene was weighed and uniformly dispersed in 420 mL of N,N-dimethylformamide. The mixture was stirred magnetically for 30 min, then 2.1 g of ammonium tetrathiomolybdate was added, and the mixture was stirred for another 30 min. The mixture was then transferred to a reaction vessel and reacted at 200 °C for 6 h. After complete cooling, the mixture was centrifuged at 10,000 rpm for 5 min, and then washed three times with deionized water and ethanol / acetone (V / V = 1:1) to obtain the active filler MXene@MoS2.

[0132] Weigh 2.2g of active filler MXene@MoS2 and calcium fluoride (mass ratio 1:1) and mix with 2.6g of vinyl polysilazane. Then add 15.0g of 1,1,2-trichlorotrifluoroethane and stir thoroughly. After stirring, add 0.02g of Tech-5061, 0.02g of Tech-367N and 0.02g of Tech-2730 and stir continuously for 10min to obtain unmodified polysilazane coating.

[0133] The metal substrate was sandblasted to achieve a surface roughness of 2.6 μm.

[0134] Unmodified polysiloxane alkyl coating was uniformly sprayed onto the surface of a metal substrate, allowed to dry at room temperature, and then cured at 120°C for 2 hours to obtain an unmodified polysiloxane alkyl coating.

[0135] Test Example 1

[0136] The performance of the flexible linking branch modified polysiloxane lubricating, anti-corrosion and wear-resistant coatings obtained in Examples 1-7 and Comparative Examples 1-2, and the unmodified polysiloxane coating obtained in Comparative Example 3 were tested. The test results are shown in Table 1.

[0137] Thickness test: The coating thickness was tested using a thickness gauge in accordance with the method of GB 1764-79(89).

[0138] Adhesion performance test: Adhesion test is conducted according to the cross-cut test method of GB / T 9286-1998. Grade 0 has the strongest adhesion, and the higher the value, the weaker the adhesion.

[0139] Tribological performance testing was conducted under the following conditions: load of 1N, paired Si3N4 microspheres with Φ=6mm, reciprocating mode frequency of 1Hz, and test time of 30min.

[0140] Wear rate test: The wear amount is measured using a surface profilometer, and then the wear rate is calculated using the wear rate calculation formula.

[0141]

[0142] In the formula, ΔV represents the wear volume change, in mm. 3 S represents stroke, in meters (m); P represents load size, in nitrogen (N).

[0143] Table 1 Performance parameters of the coatings in Examples 1-7 and Comparative Examples 1-3

[0144]

[0145] As shown in Table 1, this invention modifies different polysilazanes using different flexible polymer compounds, and then combines them with active fillers to obtain a high-performance lubricating, wear-resistant, and anti-corrosion coating. The examples and comparative data show that when the content of the flexible polymer compound is too low, the coating cannot provide excellent lubrication performance; the coating is brittle, defective, has poor anti-corrosion performance, and a high wear rate. Conversely, when the content of the flexible polymer compound is too high, the lubricating phase is sufficient, the surface is smooth without obvious defects, and the lubrication and anti-corrosion performance are excellent, but the coating adhesion weakens, the hardness decreases, and the wear resistance deteriorates. When the mass ratio of polysilazane to flexible polymer compound is (5-15):(1-5), the coating exhibits excellent lubrication, wear resistance, and anti-corrosion performance.

[0146] The flexible linker-modified polysiloxane alkyl coating provided by this invention not only has excellent lubrication and wear resistance, but also excellent corrosion resistance.

[0147] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on the present invention without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A flexible, grafted modified polysilazane-based coating, characterized in that, Components comprising the following weight parts: Modified polysilazane 5-20 parts, active filler 5-15 parts, dispersion medium 60-80 parts and auxiliary agent 0.1-0.5 parts; The modified polysilazane is a flexible link graft modified polysilazane, which is prepared by graft reaction of polysilazane and flexible high molecular compound, the number average molecular weight of the flexible high molecular compound is 1000-10000; the flexible high molecular compound is double-end hydroxyl silicone oil or perfluoropolyether siloxane; The active filler is MXene@MoS2 and di boron trioxide with a mass ratio of 1:1, MXene@MoS2 and zirconium boride with a mass ratio of 1:1, MXene@MoS2 and BN@GO with a mass ratio of 1:1, or MXene@MoS2 and calcium fluoride with a mass ratio of 1:1; The preparation method of the flexible link graft modified polysilazane-based coating comprises the following steps: Mix polysilazane, flexible high molecular compound, catalyst and organic solvent to carry out graft reaction to obtain modified polysilazane; Mix modified polysilazane, active filler, dispersion medium and auxiliary agent to obtain flexible link graft modified polysilazane-based coating. The mass ratio of the polysilazane and flexible high molecular compound is 2:0.

7.

2. The flexible, grafted modified polysilazane-based coating of claim 1, wherein, The polysilazane includes one or more of polymethylhydrogen silazane, polyborosilazane, propargyl polysilazane, polysiloxysilazane, N-methyl polysilazane, hyperbranched allyl polysilazane, vinyl polysilazane, methyl polysilazane, fluorine-containing polysilazane, polyurea silazane and perhydrogen polysilazane.

3. The flexible, grafted modified polysilazane-based coating of claim 1, wherein, Components comprising the following weight parts: Modified polysilazane 2.6 parts, active filler 2.2 parts, dispersion medium 15 parts and auxiliary agent 0.06 parts.

4. Process for the preparation of the flexible grafted modified polysilazane based coating according to any one of claims 1 to 3, characterized in that, The preparation method comprises the following steps: Mix polysilazane, flexible high molecular compound, catalyst and organic solvent to carry out graft reaction to obtain modified polysilazane; the mass ratio of the polysilazane and flexible high molecular compound is 2:0.7; Mix modified polysilazane, active filler, dispersion medium and auxiliary agent to obtain flexible link graft modified polysilazane-based coating.

5. The preparation method according to claim 4, characterized in that, The catalyst includes dibutyltin dilaurate and / or N,N-dimethylethanolamine; the mass ratio of the polysilazane and catalyst is (5-15):(0.01-0.1).

6. The preparation method according to claim 4, characterized in that, The temperature of the graft reaction is 30-60°C, and the time is 4-10h.

7. Application of the flexible link graft modified polysilazane-based coating of any one of claims 1-3 or the flexible link graft modified polysilazane-based coating prepared by the preparation method of any one of claims 4-6 in protective coating.

8. A flexible link graft modified polysilazane-based coating, which is obtained by spraying the flexible link graft modified polysilazane-based coating of any one of claims 1-3 or the flexible link graft modified polysilazane-based coating prepared by the preparation method of any one of claims 4-6 on the surface of a metal substrate, and the thickness of the flexible link graft modified polysilazane-based coating is 5-50μm.

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