A hydrophilic lubricating coating based on two-step orthogonal initiated polymerization reaction and its preparation method and application

Abstract

The present invention relates to the technical field of material surface modification, and discloses a hydrophilic lubricating coating based on a two-step orthogonal initiated polymerization reaction, and a preparation method and application thereof, wherein the hydrophilic lubricating coating comprises a copolymer of component A and component B; component A comprises an initiating monomer, which comprises one or more initiating groups; component B comprises a lubricating monomer, which comprises one or more double bonds B, and one or more hydrophilic groups; the copolymer is formed by polymerization of double bonds B in component B initiated by free radicals generated by the initiating groups in component A; and the hydrophilic lubricating coating is covalently connected to the surface of a substrate. The present invention constructs a hydrophilic lubricating coating through a two-step orthogonal initiated polymerization reaction, which significantly improves the grafting rate of the coating surface, thereby improving the lubrication performance. In addition, the hydrophilic lubricating coating is bonded to the surface of the substrate through a covalent bond, can withstand long-term immersion and flushing of liquids, and is compatible with a variety of sterilization methods such as epoxy sterilization, moist heat sterilization, and irradiation sterilization.

Description

Technical Field

[0001] The invention relates to the technical field of material surface modification, in particular to a hydrophilic lubricating coating based on a two-step orthogonal initiated polymerization reaction and a preparation method and application thereof. Background Art

[0002] In modern industry and medical fields, lubricating coating technology plays a vital role in reducing friction, reducing wear and extending equipment life. Especially in high-precision and high-demand application environments, traditional lubricating coating technology has been unable to meet the growing demand. Hydrophilic lubricating coatings are increasingly widely used in biomedical devices and other high-precision equipment due to their superior friction performance and biocompatibility. Existing hydrophilic lubricating coatings are mostly prepared by single-step polymerization reactions. Although they can achieve the expected effect to a certain extent, they often have problems such as poor coating stability, insufficient adhesion and poor lubrication effect. In order to improve the lubrication performance, the methods of patent publication numbers CN104936626A and CN115970070A introduce reactive groups into hydrophilic polymers and introduce these polymers into the coatings through free radical polymerization, thereby increasing the number of lubricating groups in the coatings that can form a water-slip layer. However, the preparation process of reactive hydrophilic polymers is relatively complicated, involving multi-step reactions and precise control, and its scope of application is relatively limited. In addition, the hydrophilic polymer chains prepared by this method are often tightly adsorbed on the surface of the substrate, limiting the extension of the chain segments and the formation of the water-slip layer, thereby weakening the lubrication effect to a certain extent. Summary of the invention

[0003] Technical Problems Solved by the Invention

[0004] The purpose of the present invention is to provide a hydrophilic lubricating coating based on a two-step orthogonal initiated polymerization reaction, a preparation method and application thereof, the coating is attached to the surface of a substrate by covalent bonding, and the amount of lubricating groups introduced into the coating is significantly increased. The hydrophilic lubricating coating provided by the present invention solves the problems of poor stability, insufficient adhesion and poor lubrication effect of lubricating coatings in the prior art.

[0005] Technical solution adopted by the present invention

[0006] A hydrophilic lubricating coating based on a two-step orthogonal initiated polymerization reaction, comprising a copolymer of component A and component B;

[0007] Component A includes an initiating monomer including one or more initiating groups;

[0008] Component B includes a lubricating monomer including one or more double bonds B and one or more hydrophilic groups;

[0009] The copolymer is formed by polymerization of double bonds B in component B initiated by free radicals generated by the initiating groups in component A;

[0010] as well as

[0011] The hydrophilic lubricating coating is covalently attached to the surface of the substrate.

[0012] In the present invention, the concentration of the initiating monomer solution is 1-30wt%, the concentration of the lubricating monomer solution is 5-100wt%; the ratio of the initiating group to the lubricating group in the coating is 1:10-1:500.

[0013] In the present invention, component A includes one or more double bonds A; the hydrophilic lubricating coating is covalently attached to the surface of the substrate via route one or route two:

[0014] Route 1: The initiator is fixed on the surface of the substrate or below by chemical means or physical adsorption; the initiator generates free radicals to initiate the polymerization of double bonds A; for example, by immersing the substrate in a solution containing the initiator.

[0015] The second approach is to break the chemical bonds on the surface of the substrate through irradiation, and the generated free radicals initiate the polymerization of double bonds A.

[0016] In the present invention, the double bond A in component A originates from the carbon-carbon double bond in the structure of the initiating group itself, or the double bond A in component A originates from the carbon-carbon double bond introduced by the initiating group through chemical modification.

[0017] Here, the carbon-carbon double bond introduced by chemical modification is used for illustration. Specifically, the preparation method of the initiator containing a carbon-carbon double bond (component A) is as follows: raw material I and raw material II undergo a chemical reaction to obtain an initiator containing a carbon-carbon double bond; the molar ratio of raw material I to raw material II is 0.2~5:1; raw material I is a compound containing both a carbon-carbon double bond and a reactive group A; raw material II is a compound containing both an initiating group and a reactive group B; the reactive group A in raw material I can undergo a chemical reaction with the reactive group B in raw material II.

[0018] In the above, the acrylamide initiator is specifically used as an example to explain:

[0019] Scenario 1:

[0020] The raw material I and the raw material II undergo an acylation reaction to obtain an acrylation initiator;

[0021] The molar ratio of raw material I to raw material II is 1-5:1;

[0022] Raw material I is a compound containing both a carbon-carbon double bond and an acylation group; preferably, raw material I is CH2=CHCO-R, CH2=C(CH3)CO-R, CH2=CHCOO-R-CO-R', CH2=C(CH3)COO-R-CO-R', CH2=CHCONH2-R-CO-R', CH2=C(CH3)CONH2-R-CO-R', R represents any group or polymer molecular chain, and R' represents a group that is easy to leave when an acylation reaction occurs.

[0023] Specifically, the raw material I can be acrylic anhydride, methacrylic anhydride, acryloyl chloride, methacryloyl chloride, methacryloyl bromide, acryloyl bromide, acrylic acid, methacrylic acid, acrylic acid-N-succinimide ester, methacrylic acid-N-succinimide ester, acrylate-polyethylene glycol-active ester, methacrylate-polyethylene glycol-active ester. Raw material II is a compound containing both an initiating group and active hydrogen, preferably, an initiator with an amino group, a hydroxyl group, or a thiol group.

[0024] Scenario 2:

[0025] The raw material I and the raw material II undergo an acylation reaction to obtain an acrylation initiator;

[0026] The molar ratio of raw material I to raw material II is 0.2-5:1;

[0027] Raw material I is a compound containing both a carbon-carbon double bond and active hydrogen. Specifically, raw material I can be CH2=CHCOO-R-OH, CH2=C(CH3)COO-R-OH, CH2=CHCONH-R-OH, CH2=C(CH3)CONH-R-OH, CH2=CHCOO-R-NH2•HCl, CH2=C(CH3)COO-R-NH2•HCl, CH2=CHCONH-R-NH2•HCl, CH2=C(CH3)CONH-R-NH2•HCl, CH2=C(CH3)COO-R-NH2, CH2=C(CH3)CONH-R-NH2, where R represents any group or polymer molecular chain.

[0028] The starting material II is a compound containing both an initiating group and an acylating group.

[0029] Based on the above, we know that for component A, those skilled in the art can select an initiator with C=C in its structure according to actual needs, or introduce C=C by conventional chemical modification of the initiator. For the latter, the applicant has made the above feasible modification method.

[0030] In the present invention, the initiator includes one or more groups that can generate free radicals and then initiate polymerization of monomers under one or more stimulations of light, heat, electricity, magnetic field, ultrasound, and chemistry.

[0031] In the present invention, the initiator includes a group that can generate free radicals and then initiate polymerization of monomers under one or more stimulations of light, heat, electricity, magnetic field, ultrasound, and chemical reaction. Specifically, the aforementioned initiator includes at least one of an azo initiator, an organic peroxide, an alkyl halide, an alkoxyamine, a thioester, a type I (cleavage type) free radical photoinitiator, and a type II (hydrogen transfer type or charge transfer type) free radical photoinitiator.

[0032] Specifically, the azo initiator molecule contains at least one nitrogen-nitrogen double bond, preferably, at least one of azonitrile, azoamide, azoamidine, and azoimidazoline; the organic peroxide includes at least one of a hydroperoxide, a dialkyl peroxide, a diacyl peroxide, a peroxyester, and a peroxydicarbonate;

[0033] The alkyl halide as an initiator refers to a compound containing a halogen atom, which is used as an initiator for free radical polymerization; specifically, the polymerization reaction can be initiated by generating free radicals through light irradiation, thermal decomposition, or metal catalysis. Preferably, the compound contains C-Cl, C-Br, or CI; more preferably, the compound contains C-Br.

[0034] Alkoxyamines contain a nitroxide free radical part and a cleavable carbon-nitrogen bond. When they are heated to a certain temperature or in the presence of a reducing agent, they will break and produce two free radicals, one of which will participate in the polymerization reaction. The stimulus conditions here can be light or heat stimulation. Common alkoxyamine initiators have a structure similar to RCON-R', where R and R' can be alkyl, aryl or other organic groups; specifically, they include compounds formed by at least one nitroxide free radical and carbon free radical in 2,2,6,6-tetramethylpiperidin-1-oxyl free radical (TEMPO), TEMPO-methacrylate, 4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl free radical (OXO-TEMPO), 2,2,6,6-tetramethyl-1-piperidinyloxy-4-amino (AMINO-TEMPO), N-alkoxy-2,2,6,6-tetramethylpiperidin-4-ol ester, and N-alkoxy-2,2,6,6-tetramethylpiperidinone.

[0035] The thioester includes at least one of dithioester, trithiocarbonate, and dithiocarbamate.

[0036] Type I (cleavage-type) free radical photoinitiators include benzoin and its derivatives (such as benzoin, benzoin dimethyl ether, benzoin ethyl ether, benzoin isopropyl ether), α-hydroxyalkyl phenones (such as 2-hydroxy-2-methyl-1-phenylpropane-1-one [Darocur 1173]), α-aminoalkyl phenones (such as 2-methyl-4'-(N,N-dimethylamino)-2-morpholinyl-1-(3-trifluoromethylphenyl)butan-1-one [Irgacure 184]), acylphosphine oxides (such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide [Lucirin TPO], 2,4,6-trimethylbenzoyl-1-[4-(2-morpholinyl)phenyl]-2-morpholinyl-1- ... At least one of: a dialkylthiophenone (e.g., α-dialkylthiophenone derivatives), a halogenated methyl aromatic ketone (e.g., 2,2-dimethoxy-2-phenylacetophenone [DMPA]), an organic sulfur-containing compound (e.g., 2-mercapto-2-morpholinyl-1-(4-methylthiophenyl)butan-1-one [Irgacure 907]), and a benzoyl formate (e.g., 2-benzoyl-2-(O-ethyl)-1,3-dioxolane-4-one [DETX]).

[0037] Type II (hydrogen transfer or charge transfer) free radical photoinitiators refer to compounds that generate free radicals through hydrogen transfer or charge transfer mechanisms under light. This type of photoinitiator usually involves two components: one is a photosensitizer and the other is a hydrogen donor or electron donor. Under light, the photosensitizer absorbs energy and is excited to an excited state, and then generates free radicals through hydrogen transfer or charge transfer reactions. For the hydrogen transfer type, it includes ketone photoinitiators and amine compounds, acylphosphine oxides and amine compounds, halomethyl ketones and amine compounds, and benzothiazole derivatives and amine compounds. Among them, ketone photoinitiators and amine compounds: photoinitiators such as benzophenone (BPO), 2-hydroxy-2-methyl-1-phenylpropane-1-one (Darocur1173) or 2,2-dimethoxy-2-phenylacetophenone (DMPA), hydrogen donors such as diethylaniline (DEA) or diisopropylaniline (DIPA); acylphosphine oxides and amine compounds: Lucirin TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) or Lucirin TPO-L, hydrogen donors such as triethylamine (TEA) or tri-n-butylamine (TBA); halogenated methyl ketones and amine compounds: such as 2,2-dimethoxy-2-phenylacetophenone (DMPA) and N,N-dimethylaniline (DMBA); benzothiazole derivatives and amine compounds: such as 2-mercapto-2-morpholinyl-1-(4-methylthiophenyl)butan-1-one (Irgacure 907) and N,N-dimethylaniline (DMBA). For the charge transfer type, it includes cationic photoinitiators and electron donors, carbonyl compounds and amine compounds. Cationic photoinitiators and electron donors: cationic photoinitiators such as triarylsulfonium salts (such as ETAB, ESAC), electron donors such as triethylamine (TEA) or tri-n-butylamine (TBA); carbonyl compounds and amine compounds: such as 2,2,6,6-tetramethylpiperidin-1-oxyl free radical (TEMPO) and diethylaniline (DEA).

[0038] In the present invention, the initiating group includes a group that can generate free radicals and then initiate monomer polymerization under one or more stimulations of light, heat, electricity, magnetic field, ultrasound, and chemistry. The initiator containing the aforementioned initiating group includes at least one of an azo initiator, an organic peroxide, an alkyl halide, an alkoxyamine, a thioester, a type I (cleavage type) free radical photoinitiator, and a type II (hydrogen transfer type or charge transfer type) free radical photoinitiator.

[0039] In the present invention, the hydrophilic group includes at least one of hydroxyl, amino, amino hydrochloride, quaternary ammonium salt, sulfonic acid, sulfonate, carboxylic acid, carboxylate, amide, phosphorylcholine, sulfobetaine, carboxybetaine, pyrrolidone, and polyethylene glycol.

[0040] In the present invention, the stimulation method used to induce the initiator to generate free radicals is stimulation one, and the stimulation method used to induce the initiating group to generate free radicals is stimulation two, and stimulation one and stimulation two are orthogonal. In other words, the stimulation methods for initiating the polymerization reaction in two steps are orthogonal. That is, the first stimulation method used to initiate the polymerization of component A will not activate the initiating group in component A. If the first step is thermal initiation, then the initiating group in the second step is selected to be a group that is stable to heat but can initiate polymerization under other stimuli, such as a thermally stable photoinitiator.

[0041] The present invention provides a method for preparing a hydrophilic lubricating coating covalently connected to a substrate surface, comprising the following steps:

[0042] (1) The initiator is carried on the surface of the substrate or above the surface;

[0043] (2) contacting the substrate in (1) with component A, and the double bond A in component A initiates polymerization of the initiator to form a first coating;

[0044] (3) Component B is used to contact the substrate in (2), and the free radicals generated by the initiating groups in component A initiate the polymerization of the double bonds in component B to obtain a second coating.

[0045] In the present invention, the substrate includes at least one of a metal material, an inorganic non-metal material and a polymer material; in detail, the metal material includes stainless steel, iron and its alloys, magnesium and its alloys, titanium and its alloys, zinc and its alloys and cobalt-based alloys; the inorganic non-metal material includes titanium dioxide, titanium oxide, titanium nitride, ceramics, silicon, silicon dioxide, silicon carbide, calcium phosphate, silicon nitride, calcium phosphate, aluminosilicate, bioglass, hydroxyapatite, carbon material, diamond and diamond-like carbon; the polymer material includes polyester, polyethylene, polyvinyl chloride, polyvinyl alcohol, polypropylene, polycarbonate, polyglycolic acid, polymethyl methacrylate, polytetrafluoroethylene, polyoxymethylene, polystyrene, polyvinyl acetate, polylactic acid, polylactic acid-glycolic acid copolymer, polytrimethylene carbonate, polyhydroxyalkanoate, polybutylene succinate, polyamide, polydioxane, epoxy resin, silicone rubber, silicone gel, polyacrylic acid and its derivatives, polyethylene glycol and its derivatives, polyvinyl alcohol, polycaprolactone and polyurethane.

[0046] The present invention provides an application of the aforementioned hydrophilic lubricating coating based on two-step orthogonal initiated polymerization as a hydrophilic lubricating coating for medical devices.

[0047] The beneficial effects achieved by the present invention are:

[0048] (1) The present invention combines the lubricating coating with the substrate through a two-step orthogonal polymerization reaction through covalent bonds, which can effectively improve the bonding strength between the coating and the substrate and give the coating good stability.

[0049] (2) The present invention initiates monomer polymerization through surface initiation, constructs a coating containing an initiator on the surface of the substrate, and then uses the initiator in the coating to initiate polymerization of hydrophilic lubricating monomers to form a hydrophilic lubricating coating. This method can greatly increase the amount of lubricating groups in the coating, thereby improving the lubrication performance of the coating.

[0050] (3) The present invention utilizes a cheap, clean and safe two-step orthogonal initiated polymerization technology to covalently bond a hydrophilic lubricating coating on the surface of a substrate; this method is technically safe, economical and suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 and Figure 2 This is the result of EDS analysis of the N element of the hydrophilic lubricating coating material PP-PMPC-1 obtained by one-step polymerization in Comparative Example 1 and the hydrophilic lubricating coating material PP-PMPC obtained in Example 1.

[0052] Figure 3 PP substrate, hydrophilic lubricating coating material PP-PMPC-1 of comparative example 1 initiating polymerization reaction in one step, hydrophilic lubricating coating material PP-PMPC obtained in example 1, PP-PMPC rinsed with deionized water for 30 days, PP-PMPC wet heat sterilized at 121°C for 30 min, and water contact angle of PP-PMPC after ethylene oxide sterilization.

[0053] Figure 4 The friction coefficient of PP substrate, the hydrophilic lubricating coating material PP-PMPC-1 obtained by one-step polymerization in Comparative Example 1, the hydrophilic lubricating coating material PP-PMPC obtained in Example 1, the PP-PMPC rinsed with deionized water for 30 days, the PP-PMPC sterilized with wet heat at 121°C for 30 min, and the PP-PMPC after ethylene oxide sterilization. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0055] Example 1

[0056] This embodiment provides a method for preparing a hydrophilic lubricating coating based on a two-step orthogonal initiated polymerization reaction, comprising:

[0057] (1) A 5 wt% benzophenone / ethanol solution was prepared and nitrogen was passed through for 30 min; a polypropylene (PP) substrate was placed in the benzophenone / ethanol solution and exposed to ultraviolet light for 30 min to obtain a polypropylene substrate containing a photoinitiator (PP-BP);

[0058] (2) preparing a 10 wt% 2-[(2-bromo-2-methylpropionyl)oxy]ethyl methacrylate (CAS: 213453-08-8) / ethanol initiator monomer solution, immersing the PP-BP obtained in step (1) in the initiator monomer solution, passing nitrogen for 30 min, and then irradiating with ultraviolet light for 30 min to obtain a substrate (PP-Br) having an initiator coating on the surface;

[0059] (3) Prepare a lubricating monomer solution containing 1 g of 2-methacryloyloxyethyl phosphorylcholine (MPC), 16 mg of copper bromide (CuBr), 20 μL of N,N,N,N,N-pentamethyldiethylenetriamine (PMEDTA) and 10 mL of ethanol, and pass nitrogen for 30 min. Immerse the PP-Br obtained in step (2) in the lubricating monomer solution and react under nitrogen protection for 6 h. Then take out the sample and wash it with deionized water to obtain a substrate containing a lubricating coating (PP-PMPC).

[0060] Example 2

[0061] This embodiment provides a method for preparing a hydrophilic lubricating coating based on a two-step orthogonal initiated polymerization reaction, comprising:

[0062] (1) The stainless steel substrate (SS) was immersed in a 3M NaOH aqueous solution for 3 hours, and then rinsed with deionized water and ethanol to obtain a hydroxylated stainless steel substrate SS-OH;

[0063] (2) preparing a solution containing 5wt% 3-(trimethoxysilyl)propyl-2-bromo-2-methylpropionate (CAS: 314021-97-1), 5wt% H2O, and 90wt% ethanol, and mixing them evenly. The SS-OH obtained in step (1) is immersed in the solution, reacted at room temperature for 1 hour, then washed with ethanol, and then cured at about 80°C for 1 hour to obtain a substrate SS-Br containing a surface initiator;

[0064] (3) Prepare 10 mL of 50 wt% acrylic anhydride / anhydrous tetrahydrofuran solution (solution 1) and 50 mL of anhydrous tetrahydrofuran solution containing 10 wt% photoinitiator 2959 (2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, CAS: 106797-53-9) and 10 wt% triethylamine (solution 2), slowly drop solution 1 into solution 2, and stir at room temperature for 24 hours, then separate and purify with a silica gel column to obtain acryloyl 2959 (MA-I2959);

[0065] (4) Prepare an initiator monomer solution containing 1 g MA-I2959, 16 mg copper bromide (CuBr), 20 μL N,N,N,N,N-pentamethyldiethylenetriamine (PMEDTA) and 10 mL ethanol, and pass nitrogen for 30 min. Soak the SS-Br obtained in step (2) in the lubricating monomer solution and react under nitrogen protection for 6 h. Then take out the sample and wash it with deionized water to obtain a coating substrate containing photoinitiator (SS-I2959);

[0066] (5) A 20 wt% vinyl pyrrolidone (NVP) / ethanol lubricating monomer solution was prepared, and the SS-I2959 obtained in step (4) was immersed in the lubricating monomer solution, nitrogen was passed for 30 min, and then ultraviolet light was irradiated for 30 min to obtain a substrate with a surface lubricating coating (SS-PVP).

[0067] Example 3

[0068] This embodiment provides a method for preparing a hydrophilic lubricating coating based on a two-step orthogonal initiated polymerization reaction, comprising:

[0069] (1) The polyurethane substrate (PU) was immersed in an isopropanol solution containing 1 wt% tert-butyl peroxycarbonate-2-ethylhexyl ester (TBEC, CAS: 34443-12-4) at room temperature for 3 hours to obtain a substrate PU-TBEC containing an initiator on the surface;

[0070] (2) preparing an initiator monomer ethanol solution containing 10 wt% of acryloyl 2959 (MA-I2959) and 0.5 wt% of ferrous gluconate, immersing the PU-TBEC obtained in step (1) in the initiator monomer solution, reacting at room temperature for 12 hours, and obtaining a coating substrate containing photoinitiator (PU-I2959) through redox initiation polymerization;

[0071] (3) A 15 wt% [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propyl)ammonium hydroxide (SBMA) / water lubricating monomer solution was prepared, and the PU-I2959 obtained in step (2) was immersed in the lubricating monomer solution, nitrogen was passed for 30 min, and then ultraviolet light was irradiated for 30 min to obtain a substrate with a surface lubricating coating (PU-PSBMA).

[0072] Example 4

[0073] This embodiment provides a method for preparing a hydrophilic lubricating coating based on a two-step orthogonal initiated polymerization reaction, comprising:

[0074] (1) preparing a dimethyl sulfoxide solution containing 10 wt% hydroxyethyl methacrylate (HEMA), 10 wt% acrylic acid (AA), 0.2 wt‰ copper bromide (CuBr2), 0.2 wt‰ tris(2-pyridylmethyl)amine (TPMA), and 5 wt% barium titanate nanoparticles (BaTiO3);

[0075] (2) The substrate (PP-Br) having an initiator coating on its surface obtained in Example 1 was immersed in the dimethyl sulfoxide solution in step (1), and degassed by freeze-thaw for three times. Then, the substrate was placed in an ultrasonic bath at 40 kHz and 70 W, and the polymerization reaction was initiated by ultrasound for 6 hours to obtain a substrate (PP-PHEMA / AA) having a lubricating coating on its surface.

[0076] Comparative Example 1

[0077] This comparative example provides a method for preparing a hydrophilic lubricating coating based on a one-step initiated polymerization reaction, comprising:

[0078] (1) A 5 wt% benzophenone / ethanol solution was prepared and nitrogen was passed through for 30 min; a polypropylene (PP) substrate was placed in the benzophenone / ethanol solution and exposed to ultraviolet light for 30 min to obtain a polypropylene substrate (PP-BP) containing a photoinitiator on the surface;

[0079] (2) A 10 wt% 2-methacryloyloxyethyl phosphorylcholine (MPC) / ethanol lubricating monomer solution was prepared, and the PP-BP obtained in step (1) was immersed in the lubricating monomer solution, nitrogen was passed for 30 min, and then ultraviolet light was irradiated for 30 min to obtain a hydrophilic lubricating coating substrate (PP-PMPC-1) with a one-step initiated polymerization reaction.

[0080] Test example

[0081] 1. Surface element analysis

[0082] The hydrophilic lubricating coating material PP-PMPC prepared by two-step orthogonal polymerization in Example 1 and the hydrophilic lubricating coating material PP-PMPC-1 prepared by one-step polymerization in Comparative Example 1 were subjected to EDS material surface element analysis (see Figure 1 and Figure 2 ).

[0083] The N element is a characteristic mark of the PMPC lubricating group, and its content directly reflects the content of the lubricating group in the coating. Figure 1 and Figure 2 It can be seen that the two-step orthogonal polymerization method of the present invention significantly increases the amount of lubricating groups introduced into the coating compared to the one-step polymerization method.

[0084] 2. Water contact angle

[0085] The hydrophilic lubricating coating material PP-PMPC prepared in Example 1 was used as a sample for the experiment. The obtained material was rinsed with deionized water for 30 days and sterilized with wet heat at 121°C for 30 min, and then the water contact angle test was performed. The hydrophilic lubricating coating material PP-PMPC-1 prepared in Example 1 by one-step polymerization was tested for water contact angle (see Figure 3 ).

[0086] 3. Friction coefficient

[0087] The hydrophilic lubricating coating material PP-PMPC prepared in Example 1 was used as a sample for the experiment. The obtained material was rinsed with deionized water for 30 days and sterilized with wet heat at 121°C for 30 min, and then the friction coefficient was tested. The friction coefficient of the hydrophilic lubricating coating material PP-PMPC-1 prepared in Example 1 by one-step polymerization was tested (see Figure 4 ).

[0088] Friction coefficient test method: Use MCR302 rheometer to measure the friction coefficient of the material. Fix the sample in the liquid tank of the rotational rheometer, add deionized water, and apply a positive pressure load of 1N on the sample surface. The rotor rotates unidirectionally at a speed of 1mm / s, measure the friction force and calculate the friction coefficient.

[0089] pass Figure 3 and Figure 4 It can be seen that the lubricating coating material prepared by the two-step orthogonal polymerization method of the present invention exhibits better hydrophilicity and lubricity than the coating prepared by the one-step polymerization method, and the coating has good stability.

Claims

1. A hydrophilic lubricating coating based on a two-step orthogonal initiated polymerization reaction, characterized in that: A copolymer comprising component A and component B; Component A includes an initiating monomer including one or more double bonds A, and one or more initiating groups; Component B includes a lubricating monomer including one or more double bonds B and one or more hydrophilic groups; The copolymer is formed by polymerization of double bonds B in component B initiated by free radicals generated by the initiating groups in component A; as well as The hydrophilic lubricating coating is covalently attached to the surface of the substrate; A method for preparing a hydrophilic lubricating coating covalently attached to a substrate surface comprises the following steps: (1) The substrate has an initiator on or above the surface, or the substrate can directly generate free radicals under irradiation; (2) contacting the substrate in (1) with component A to initiate polymerization of double bonds A in component A to form a first coating; (3) Component B is used to contact the substrate in (2), and the free radicals generated by the initiating groups in component A initiate the polymerization of the double bonds in component B to obtain a second coating.

2. The hydrophilic lubricating coating based on two-step orthogonal initiated polymerization according to claim 1, characterized in that: The initiating groups include groups that generate free radicals under one or more stimulations of light, heat, electricity, magnetic field, ultrasound, and chemical reaction to initiate polymerization of monomers.

3. The hydrophilic lubricating coating based on two-step orthogonal initiated polymerization according to claim 1, characterized in that: The hydrophilic group includes at least one of hydroxyl, amino, amino hydrochloride, quaternary ammonium salt, sulfonic acid, sulfonate, carboxylic acid, carboxylate, amide, phosphorylcholine, sulfobetaine, carboxybetaine, pyrrolidone, and polyethylene glycol.

4. The hydrophilic lubricating coating based on two-step orthogonal initiated polymerization according to any one of claims 1 to 3, characterized in that: The hydrophilic lubricating coating is covalently attached to the substrate surface via either route 1 or route 2: Path 1: The initiator is fixed on the surface of the substrate or below by chemical means or physical adsorption; the initiator generates free radicals to initiate the polymerization of double bond A; The second approach is to break the chemical bonds on the surface of the substrate through irradiation, and the generated free radicals initiate the polymerization of double bonds A.

5. The hydrophilic lubricating coating based on two-step orthogonal initiated polymerization according to claim 4, characterized in that: The double bond A in component A originates from the carbon-carbon double bond in the structure of the initiating group itself, or the double bond A in component A originates from the carbon-carbon double bond introduced by the initiating group through chemical modification.

6. The hydrophilic lubricating coating based on two-step orthogonal initiated polymerization according to claim 4, characterized in that: The initiator includes a group that generates free radicals under stimulation conditions to initiate monomer polymerization, and the stimulation conditions include at least one of light, heat, electricity, magnetic field, ultrasound, and chemical reaction; the initiator includes at least one of an azo initiator, an organic peroxide, a halide, an alkoxyamine, a thioester, a type I free radical photoinitiator, and a type II free radical photoinitiator.

7. The hydrophilic lubricating coating based on two-step orthogonal initiated polymerization according to claim 6, characterized in that: The initiator comprises at least one of features (A) to (G): (A) The azo initiator molecule contains at least one nitrogen-nitrogen double bond; (B) organic peroxides include at least one of hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, and peroxydicarbonates; (C) the alkyl halide includes at least one of an alkyl chloride, an alkyl bromide, and an alkyl iodide; (D) Alkoxyamines are a class of compounds containing CON groups in their molecules. Under light or heat stimulation, their CO bonds can undergo homolytic cleavage reactions to generate free radicals. (E) the thioester includes at least one of dithioester, trithiocarbonate, and dithiocarbamate; (F) Type I free radical photoinitiator includes at least one of benzil, α-hydroxy ketone, α-amino ketone, acylphosphine oxide, dialkoxyacetophenone, halogenated methyl aromatic ketone, organic sulfur-containing compound, and benzoyl formate; (G) Type II free radical photoinitiators include at least one of benzophenones, thioxanthones, anthraquinones, acylphosphine oxides, and amine co-initiators.

8. A use of the coating according to any one of claims 1 to 7 as a surface engineering, characterized in that: Surface engineering includes aerospace, automotive industry, manufacturing, electronics industry, construction industry, and medical devices.

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