Preparation method of macromolecular organosilicon monomer of silicone hydrogel contact lens

Abstract

The invention provides a preparation method of a macromolecular organosilicon monomer of a silicone hydrogel contact lens. The preparation method comprises the following steps: preparing a fluorine-containing hydrophilic alkynyl intermediate; the preparation method comprises the following steps: preparing an alkynyl-containing siloxane prepolymer, carrying out ring-opening polymerization on a cyclosiloxane monomer in the presence of a supported titanate catalyst, and carrying out molecular distillation purification; and performing catalytic reaction on the two in supercritical fluid through a palladium-ruthenium bimetallic catalyst to obtain a target monomer. The hydrophilicity is improved through branched polyglycerol, the oxygen permeability and stability are optimized through perfluoroalkyl ether, and a green process is realized by combining a supported catalyst and a supercritical technology. The product is good in hydrophilicity, high in oxygen permeability, excellent in pollution resistance, low in catalyst and solvent residue and suitable for large-scale production, and a high-quality monomer is provided for high-performance silicon hydrogel contact lenses.

Description

Technical Field

[0001] This invention relates to the field of contact lens technology, and more particularly to a method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses. Background Technology

[0002] Silicone hydrogels, as contact lens materials, have become a mainstream development direction due to their combination of the high oxygen permeability of polysiloxanes and the hydrophilicity of hydrogels. However, existing silicone hydrogel materials still have three major problems: First, the hydrophobicity of the polysiloxane backbone makes it easy for lipids and proteins from the eye to be adsorbed on the material surface, causing dryness and blurred vision when wearing them; second, traditional hydrophilic modification mostly relies on polyethylene glycol segments, which have insufficient long-term stability and are prone to losing hydrophilicity due to hydrolysis or oxidation; third, strong acid catalysts or toxic organic solvents are often used in the preparation process, which not only increases the difficulty of post-processing but also poses environmental and biosafety risks.

[0003] To address these issues, existing technologies often improve oxygen permeability by introducing fluorine-containing groups or enhance wettability by adding hydrophilic segments. However, these methods have the following limitations: fluorine-containing monomers often use acyl chloride raw materials, which easily generate corrosive byproducts during the reaction, and the fluorine distribution is uneven; the hydrophilic segments are mostly linear polyether structures, limiting the range of hydrophilicity adjustment; and the catalysts are mostly homogeneous systems, making them difficult to recover and their residues can affect the biocompatibility of the material. Furthermore, traditional synthesis processes rely on organic solvent purification, which can easily cause residual solvents to irritate the eyes.

[0004] Therefore, developing a novel macromolecular organosilicon monomer that combines high hydrophilicity, excellent anti-pollution properties, and a green and environmentally friendly preparation process is of great significance for upgrading the performance of silicone hydrogel contact lenses. Summary of the Invention

[0005] This invention provides a method for preparing macromolecular organosilicon monomers for silicone hydrogel contact lenses, thereby overcoming the deficiencies in the prior art.

[0006] This invention provides a method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses, comprising the following steps: (1) Terminal alkyne polyglycerol and perfluoroalkyl ethyl iodide were reacted with an alkaline acid-binding agent at -5-2℃ for 2-4 h, and then the temperature was raised to 35-40℃ for 5-8 h. The fluorinated hydrophilic alkyne intermediate was obtained by supercritical CO2 extraction and purification. The molecular weight of the terminal alkyne polyglycerol was 1000-1500, the degree of polymerization of the glycerol unit was 15-25, the degree of substitution of the terminal alkyne group was ≥95%, and the number of hydroxyl groups was 15-25. The molar ratio of terminal alkyne polyglycerol to perfluoroalkyl ethyl iodide and alkaline acid-binding agent was 1:1.5-2.5:1.5-2.5. The reaction site was the nucleophilic substitution reaction between the iodine atom in the perfluoroalkyl ethyl iodide and the hydroxyl group of the terminal alkyne polyglycerol. (2) Dodecylcyclohexasiloxane, octamethylcyclotetrasiloxane, and γ-azidopropyltriisopropoxysilane are mixed in a molar ratio of 1:0.8-2.0:0.5-1.2. A supported titanate catalyst of 4%-8% of the total mass of the reactants is added, and 2,2,6,6-tetramethylpiperidine nitroxide radical of 0.05%-0.12% of the total mass of the reactants is added as a polymerization inhibitor. The ring-opening copolymerization reaction is carried out in a gradient pressure mode: the reaction is first carried out at 0.1 MPa for 6-8 h, and then the pressure is increased to 0.3 MPa for 8-16 h. The reaction temperature is 50-90℃. After centrifugation to remove the catalyst, the azidosiloxane prepolymer is obtained by molecular distillation. The azidosiloxane prepolymer has a single azidofunctionality and contains a siloxane backbone in its molecular structure. The number of repeating units satisfies: a is 150-400 and b is 12-35. (3) The fluorinated hydrophilic alkynyl intermediate obtained in step (1) and the azido-containing siloxane prepolymer obtained in step (2) are mixed at a mass ratio of 1:15-40, a supercritical fluid solvent is added, and a palladium-based composite catalyst with a concentration of 50-200 ppm is added under nitrogen protection. The reaction proceeds at 60-100℃ and 5-8 MPa. The reaction progress is monitored by in-situ infrared spectroscopy. The reaction is terminated when the alkynyl characteristic peak disappears by more than 90%. The target monomer is obtained by depressurization precipitation and vacuum drying. The click chemical reaction is a cycloaddition reaction between the alkynyl group of the fluorinated hydrophilic alkynyl intermediate and the azido group of the azido-containing siloxane prepolymer to generate a 1,2,3-triazole ring. The target monomer is a bifunctional macromonomer. The molecular structure contains polyglycerol segments, perfluoroalkyl segments and siloxane backbone. The number of repeating units satisfies: a is 150-400, b is 12-35 and c is 8-20.

[0007] According to the present invention, a method for preparing a macromolecular organosilicon monomer for a silicone hydrogel contact lens is provided, wherein the alkaline acid-binding agent in step (1) is a mixture of tetramethylguanidine and 1,8-diazabicycloundec-7-ene in a volume ratio of 1:1 to 2:1, and the reaction solvent is 1,4-dioxane.

[0008] According to the present invention, a method for preparing a macromolecular organosilicon monomer for a silicone hydrogel contact lens is provided, wherein the supported titanate catalyst in step (2) is mesoporous TiO2 supported tetrabutyl titanate with a loading of 15%-25%; and the purity of γ-azidopropyltriisopropoxysilane is ≥99%.

[0009] According to the present invention, a method for preparing a macromolecular organosilicon monomer for a silicone hydrogel contact lens is provided, wherein the supercritical fluid solvent in step (3) is a mixture of supercritical propane and supercritical ethanol, with a mass ratio of 3:1 to 5:1.

[0010] According to the present invention, a method for preparing a macromolecular organosilicon monomer for a silicone hydrogel contact lens is provided. In step (3), the palladium-based composite catalyst is a palladium-ruthenium bimetal supported on carbon nanotubes, wherein the mass ratio of palladium to ruthenium is 3:1-5:1, and the concentration of the catalyst in the reaction solution is 80-150 ppm.

[0011] According to the present invention, a method for preparing a macromolecular organosilicon monomer for a silicone hydrogel contact lens is provided, wherein in step (1), the perfluoroalkyl ethyl iodine is perfluorohexyl ethyl iodine.

[0012] According to the present invention, a method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses is provided. In step (3), the vacuum drying conditions are: temperature 40-50℃, vacuum degree ≤10Pa, and drying time 12-24h.

[0013] This invention provides a method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses. It uses terminal alkyne polyglycerol as the hydrophilic segment raw material. Compared to traditional polyethylene glycol, its branched structure provides more hydroxyl sites, significantly improving hydrophilicity. Furthermore, polyglycerol exhibits better biocompatibility than polyether compounds, effectively reducing the risk of eye irritation. Simultaneously, the branched structure inhibits protein adsorption through steric hindrance, greatly improving the material's anti-fouling performance and extending lens wearing comfort. Perfluoroalkyl ethyl iodine is used instead of traditional acyl chloride-based fluorinated raw materials. Fluorinated segments are introduced through a nucleophilic substitution reaction between the hydroxyl groups of terminal alkyne polyglycerol and iodine atoms. The reaction process generates no corrosive byproducts, making it more gentle and environmentally friendly. The fluorinated segments are connected to the polyglycerol segments by stable carbon-oxygen covalent bonds, avoiding the hydrolysis defects of traditional fluorinated monomers. Moreover, the fluorine element is uniformly distributed in the side chains, synergistically acting with the breathable channels formed by the polysiloxane backbone, significantly improving the material's oxygen permeability compared to existing products. A ring-opening copolymerization of γ-azidopropyltriisopropoxysilane and dodecylcyclohexasiloxane precisely introduces monoazide functionality, ensuring the uniformity of the prepolymer structure. The use of a supported titanate catalyst not only achieves high catalytic efficiency but also a recovery rate exceeding 90%, completely resolving the corrosion and residue issues of traditional strong acid catalysts. The palladium-ruthenium bimetallic composite catalyst realizes the transformation from homogeneous to heterogeneous catalysis, significantly improving catalytic efficiency compared to single-metal catalysts, with residue levels below 1 ppm, meeting the stringent requirements for biomedical materials. Supercritical CO2 extraction technology is introduced to purify fluorinated hydrophilic intermediates, replacing traditional organic solvent washing and reducing solvent residue to below 0.01%. Supercritical fluid is used as the reaction solvent for the synthesis of the target monomer, offering adjustable solubility; after the reaction, direct separation can be achieved through depressurization, eliminating organic solvent contamination. Molecular distillation technology is used for the purification of siloxane prepolymers, further ensuring the high purity and biosafety of the material. By adjusting the degree of polymerization of polyglycerol, the number of repeating units in siloxane segments, and the length of perfluoroalkyl chains, the hydrophilicity, oxygen permeability, and anti-fouling properties of the material can be precisely controlled, meeting the differentiated performance requirements of the material in different scenarios such as daily wear and long-term wear, thus expanding its application range. Detailed Implementation

[0014] The embodiments described in this invention are only some, not all, of the embodiments of this invention. Generally, the components or methods described in the embodiments of this invention can be arranged and designed in various different configurations.

[0015] Therefore, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0016] This application provides a method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses, comprising the following steps: (1) Terminal alkyne polyglycerol and perfluoroalkyl ethyl iodide were reacted with an alkaline acid-binding agent at -5-2℃ for 2-4 h, and then the temperature was raised to 35-40℃ for 5-8 h. The fluorinated hydrophilic alkyne intermediate was obtained by supercritical CO2 extraction and purification. The molecular weight of the terminal alkyne polyglycerol was 1000-1500, the degree of polymerization of the glycerol unit was 15-25, the degree of substitution of the terminal alkyne group was ≥95%, and the number of hydroxyl groups was 15-25. The molar ratio of terminal alkyne polyglycerol to perfluoroalkyl ethyl iodide and alkaline acid-binding agent was 1:1.5-2.5:1.5-2.5. The reaction site was the nucleophilic substitution reaction between the iodine atom in the perfluoroalkyl ethyl iodide and the hydroxyl group of the terminal alkyne polyglycerol. (2) Dodecylcyclohexasiloxane, octamethylcyclotetrasiloxane, and γ-azidopropyltriisopropoxysilane are mixed in a molar ratio of 1:0.8-2.0:0.5-1.2. A supported titanate catalyst of 4%-8% of the total mass of the reactants is added, and 2,2,6,6-tetramethylpiperidine nitroxide radical of 0.05%-0.12% of the total mass of the reactants is added as a polymerization inhibitor. The ring-opening copolymerization reaction is carried out in a gradient pressure mode: the reaction is first carried out at 0.1 MPa for 6-8 h, and then the pressure is increased to 0.3 MPa for 8-16 h. The reaction temperature is 50-90℃. After centrifugation to remove the catalyst, the azidosiloxane prepolymer is obtained by molecular distillation. The azidosiloxane prepolymer has a single azidofunctionality and contains a siloxane backbone in its molecular structure. The number of repeating units satisfies: a is 150-400 and b is 12-35. (3) The fluorinated hydrophilic alkynyl intermediate obtained in step (1) and the azido-containing siloxane prepolymer obtained in step (2) are mixed at a mass ratio of 1:15-40, a supercritical fluid solvent is added, and a palladium-based composite catalyst with a concentration of 50-200 ppm is added under nitrogen protection. The reaction proceeds at 60-100℃ and 5-8 MPa. The reaction progress is monitored by in-situ infrared spectroscopy. The reaction is terminated when the alkynyl characteristic peak disappears by more than 90%. The target monomer is obtained by depressurization precipitation and vacuum drying. The click chemical reaction is a cycloaddition reaction between the alkynyl group of the fluorinated hydrophilic alkynyl intermediate and the azido group of the azido-containing siloxane prepolymer to generate a 1,2,3-triazole ring. The target monomer is a bifunctional macromonomer. The molecular structure contains polyglycerol segments, perfluoroalkyl segments and siloxane backbone. The number of repeating units satisfies: a is 150-400, b is 12-35 and c is 8-20.

[0017] To further optimize the above technical solution, the alkaline acid-binding agent in step (1) is a mixture of tetramethylguanidine and 1,8-diazabicycloundec-7-ene, with a volume ratio of 1:1 to 2:1, and the reaction solvent is 1,4-dioxane.

[0018] To further optimize the above technical solution, the supported titanate catalyst in step (2) is mesoporous TiO2 supported tetrabutyl titanate with a loading of 15%-25%; the purity of γ-azidopropyltriisopropoxysilane is ≥99%.

[0019] To further optimize the above technical solution, the supercritical fluid solvent in step (3) is a mixture of supercritical propane and supercritical ethanol, with a mass ratio of 3:1 to 5:1.

[0020] To further optimize the above technical solution, the palladium-based composite catalyst in step (3) is a palladium-ruthenium bimetal supported on carbon nanotubes, wherein the mass ratio of palladium to ruthenium is 3:1-5:1, and the concentration of the catalyst in the reaction solution is 80-150 ppm.

[0021] To further optimize the above technical solution, the perfluoroalkyl ethyl iodine in step (1) is perfluorohexyl ethyl iodine.

[0022] To further optimize the above technical solution, the vacuum drying conditions in step (3) are: temperature 40-50℃, vacuum degree ≤10Pa, and drying time 12-24h.

[0023] To provide a clearer and more detailed description of the preparation method of a macromolecular organosilicon monomer for silicone hydrogel contact lenses provided in this invention, specific embodiments will be described below.

[0024] Example 1:

[0025] This embodiment aims to prepare a high-performance macromolecular organosilicon monomer for silicone hydrogel contact lenses. The specific operation is as follows: First, a fluorinated hydrophilic alkyne intermediate was prepared. 120 g of terminal alkyne polyglycerol was weighed and slowly added to a three-necked flask containing 500 mL of 1,4-dioxane. After complete dissolution, a basic acid-binding agent (85 g) was added, consisting of a mixture of tetramethylguanidine and 1,8-diazabicycloundec-7-ene at a volume ratio of 1.5:1. The mixture was stirred for 10 minutes to ensure homogeneity. The reaction apparatus was then placed in a low-temperature bath and cooled to -3°C. 150 g of perfluorohexylethyl iodide was slowly added dropwise through a constant-pressure dropping funnel, with the reaction temperature strictly controlled to not exceed 2°C. The addition was completed over approximately 1.5 hours. After the addition was complete, the mixture was kept at a low temperature and stirred for another 2.5 hours (this process involves a nucleophilic substitution reaction between the hydroxyl groups of the terminal alkyne polyglycerol and the iodine atom of the perfluorohexylethyl iodide). The low-temperature bath was then removed, and the reaction system was heated to 38°C and held at this temperature for 6 hours. The reaction progress was monitored by thin-layer chromatography until the starting material spot disappeared. After the reaction was completed, the reaction solution was transferred to a supercritical extraction vessel and purified using supercritical CO2: the extraction temperature was set at 40℃, the pressure at 15MPa, the CO2 flow rate at 20g / h, and the extraction time at 3 hours. Finally, 185g of pale yellow viscous liquid was obtained, which is the fluorinated hydrophilic alkyne intermediate (monoyne functionality). The calculated yield was 88%.

[0026] Next, the prepolymer containing azide-based siloxanes was prepared. 200g of dodecylcyclohexasiloxane, 95g of octamethylcyclotetrasiloxane, and 52g of γ-azidopropyltriisopropoxysilane (purity ≥99%) were weighed out according to a molar ratio of dodecylcyclohexasiloxane: octamethylcyclotetrasiloxane: γ-azidopropyltriisopropoxysilane = 1:1.5:0.8. These three components were added to a 1000mL three-necked flask, followed by the addition of 0.36g of 2,2,6,6-tetramethylpiperidine nitroxide radical (0.08% of the total mass of the reactants) as a polymerization inhibitor. The mixture was magnetically stirred for 30 minutes to ensure homogeneity. Next, a supported titanate catalyst (mesoporous TiO2 supported tetrabutyl titanate, 20% loading, 21.4 g) was added at 6% of the total mass of the reactants. After installing the reflux condenser, the ring-opening copolymerization reaction was carried out using a gradient pressure boosting mode: first, the reaction was carried out at 0.1 MPa pressure and 60°C for 7 hours, then the pressure was increased to 0.3 MPa and the temperature to 80°C, and the reaction was continued for 12 hours. After the reaction was completed, the reaction solution was transferred to a centrifuge tube and centrifuged at 8000 r / min for 15 minutes. The supernatant was filtered under reduced pressure to remove residual catalyst, and then further purified by molecular distillation (distillation temperature set at 180°C and vacuum degree at 5 Pa). Finally, 310 g of colorless, transparent, viscous liquid was obtained, which is the azido-containing siloxane prepolymer (single azido functionality), with a yield of 92%.

[0027] Finally, the target monomer was prepared. 80g of the fluorinated hydrophilic alkynyl intermediate obtained in step 1 (containing mono-alkynyl groups) and 320g of the azido-containing siloxane prepolymer obtained in step 2 (containing mono-azido groups) were weighed and added to a 500mL high-pressure reactor at a mass ratio of 1:4. Then, 600g of supercritical fluid solvent (made by mixing supercritical propane and supercritical ethanol at a mass ratio of 4:1) was added. After stirring was turned on to completely dissolve the solid, the stirring was turned off, and nitrogen gas was introduced to replace the air in the reactor 3 times (each replacement was maintained at a nitrogen pressure of 0.2MPa for 5 minutes). Then, a palladium-ruthenium bimetallic supported carbon nanotube catalyst (with a palladium to ruthenium mass ratio of 4:1, a catalyst concentration of 100 ppm in the reaction solution, and an actual added mass of 0.4 g) was added. The reactor was sealed, stirring was started, and the temperature was raised to 80°C. Simultaneously, the pressure inside the reactor was increased to 6 MPa using a pressure pump. The reaction was carried out under these conditions for 5 hours (this process involves a click cycloaddition reaction between the alkynyl and azide groups, generating a 1,2,3-triazole saturated heterocycle). The reaction was monitored in real time using in-situ infrared spectroscopy. When the wavelength reached 2100 cm⁻¹... -1 When more than 95% of the characteristic absorption peak of the alkynyl group disappeared, the reaction was stopped. After the reaction was completed, the pressure in the reactor was slowly released to atmospheric pressure, and a white solid precipitated in the reactor. This solid was transferred to a vacuum drying oven and dried at 45°C and a vacuum of 5 Pa for 18 hours, finally yielding 365g of white elastic solid, which is the target monomer (bifunctional), with a yield of 86%.

[0028] To the target unit 1 ¹H-NMR analysis showed that the number of repeating units in its molecular structure was: a=220 (siloxane segment 1), b=20 (siloxane segment 2), and c=12 (polyglycerol segment). Performance tests showed that the water contact angle of its cured film was 35°, the oxygen permeability coefficient (Dk value) was 145 barrers, and the adsorption capacity for lysozyme was 8 μg / cm³. 2 The residual amounts of palladium and ruthenium were both below 0.5 ppm, and the total residual amount of organic solvents was 0.008%.

[0029] Example 2:

[0030] This embodiment describes the preparation process after adjusting the raw material ratio and reaction conditions, as follows: In the preparation of the fluorinated hydrophilic alkyne intermediate, 100g of terminal alkyne polyglycerol (molecular weight 1000, degree of polymerization of glycerol unit 15, degree of substitution of terminal alkyne 95%) was weighed and dissolved in 400mL of 1,4-dioxane. An alkaline acid-binding agent (total mass 68g) was added, which was a mixture of tetramethylguanidine and 1,8-diazabicycloundec-7-ene in a volume ratio of 1:1. After cooling to -5℃, 120g of perfluorohexylethyl iodine was added dropwise, with the temperature controlled not to exceed 0℃ during the dropwise addition. After the dropwise addition was completed, the reaction was carried out at low temperature for 2 hours (nucleophilic substitution of hydroxyl groups with iodine). Then the temperature was raised to 35℃ and the reaction was carried out for 5 hours. After supercritical CO2 extraction (under the same conditions as in Example 1), 152g of intermediate (monoyne) was obtained, with a yield of 85%.

[0031] In the preparation of the azidosiloxane prepolymer, 180g of dodecylcyclohexasiloxane, 50g of octamethylcyclotetrasiloxane, and 30g of γ-azidopropyltriisopropoxysilane were weighed according to the molar ratio of dodecylcyclohexasiloxane: octamethylcyclotetrasiloxane: γ-azidopropyltriisopropoxysilane = 1:0.8:0.5. A polymerization inhibitor accounting for 0.05% of the total mass of the reactants was added, and a supported titanate catalyst with a loading of 15% (accounting for 6% of the total mass) was used. The reaction was first carried out at 0.1MPa and 50℃ for 6 hours, and then at 0.3MPa and 75℃ for 8 hours. After molecular distillation, 230g of prepolymer (monazido) was obtained, with a yield of 90%.

[0032] In the preparation of the target monomer, 60g of intermediate (alkynyl) and 240g of prepolymer (azido) were mixed at a mass ratio of 1:4, and a supercritical solvent (propane-ethanol mass ratio 3:1) was added. A palladium-ruthenium catalyst with a concentration of 80ppm was added, and the reaction was carried out at 70℃ and 5MPa for 4 hours (alkynyl-azido click reaction). After vacuum drying, 260g of the target monomer (bifunctional) was obtained, with a yield of 87%. Performance tests showed that its repeating unit number was a=150 (siloxane segment 1), b=12 (siloxane segment 2), and c=8 (polyglycerol segment); the water contact angle was 38°, the Dk value was 130 barrers, and the protein adsorption capacity was 10μg / cm³. 2 Catalyst residue ≤0.8ppm, solvent residue 0.01%.

[0033] Example 3:

[0034] This embodiment further optimizes the product performance by adjusting parameters, and the specific process is as follows: In the preparation of the fluorinated hydrophilic alkyne intermediate, terminal alkyne polyglycerol with a molecular weight of 1500 was selected, the reaction temperature was controlled at 2℃, the molar ratio of terminal alkyne polyglycerol to perfluorohexyl ethyl iodide was 1:2.5, the supercritical CO2 extraction time was extended to 4 hours, and the yield of the final intermediate (monoyne) was 86%.

[0035] In the preparation of the azidosiloxane prepolymer, the molar ratio of raw materials was adjusted to dodecylcyclohexasiloxane: octamethylcyclotetrasiloxane: γ-azidopropyltriisopropoxysilane = 1:2.0:1.2, the catalyst loading was increased to 25%, the final temperature of ring-opening polymerization was increased to 90℃, the total reaction time was extended to 24 hours, and the yield of the prepolymer (monazido) after purification was 89%.

[0036] In the preparation of the target monomer, the mass ratio of intermediate to prepolymer was 1:40, the mass ratio of propane to ethanol in the supercritical solvent was 5:1, the catalyst concentration was 150 ppm, the reaction temperature was 100℃, the pressure was 8 MPa, and the reaction time was 7 hours (alkynyl-azido-click reaction). The final target monomer had repeating units of a=400 (siloxane segment 1), b=35 (siloxane segment 2), and c=20 (polyglycerol segment). Performance tests showed that it had a water contact angle of 32°, a Dk value of 160 barrers, and a protein adsorption capacity of 6 μg / cm³. 2 It has superior overall performance.

[0037] Based on the preparation process and performance test results of Examples 1-3, it can be seen that the preparation method provided by this invention successfully prepares high-performance macromolecular organosilicon monomers by selecting terminal alkyne polyglycerol as the hydrophilic segment, perfluoroalkyl ethyl iodine as the fluorinated raw material, combining a supported titanate catalyst and a palladium-ruthenium bimetallic catalyst, and supercritical fluid purification and reaction technology. By adjusting the raw material ratio, reaction conditions, and catalyst parameters, the number of repeating units in the product structure can be precisely controlled, thereby specifically adjusting the hydrophilicity, oxygen permeability, and antifouling properties of the material. Simultaneously, the entire preparation process uses a green and environmentally friendly catalyst and solvent system, with catalyst residue below 1 ppm and solvent residue below 0.01%, fully meeting the safety requirements of biomedical materials. The above results fully verify the feasibility and innovation of the method of this invention. The prepared monomer is superior to existing technologies in terms of hydrophilicity, oxygen permeability, antifouling properties, and biosafety. Furthermore, the process is stable and controllable, suitable for large-scale industrial production, providing reliable technical support for the development of high-performance silicone hydrogel contact lens materials.

[0038] This invention provides a method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses. It uses terminal alkyne polyglycerol as the hydrophilic segment raw material. Compared to traditional polyethylene glycol, its branched structure provides more hydroxyl sites, significantly improving hydrophilicity. Furthermore, polyglycerol exhibits better biocompatibility than polyether compounds, effectively reducing the risk of eye irritation. Simultaneously, the branched structure inhibits protein adsorption through steric hindrance, greatly improving the material's anti-fouling performance and extending lens wearing comfort. Perfluoroalkyl ethyl iodine is used instead of traditional acyl chloride-based fluorinated raw materials. Fluorinated segments are introduced through a nucleophilic substitution reaction between the hydroxyl groups of terminal alkyne polyglycerol and iodine atoms. The reaction process generates no corrosive byproducts, making it more gentle and environmentally friendly. The fluorinated segments are connected to the polyglycerol segments by stable carbon-oxygen covalent bonds, avoiding the hydrolysis defects of traditional fluorinated monomers. Moreover, the fluorine element is uniformly distributed in the side chains, synergistically acting with the breathable channels formed by the polysiloxane backbone, significantly improving the material's oxygen permeability compared to existing products. By combining γ-azidopropyltriisopropoxysilane with dodecylcyclohexasiloxane for ring-opening copolymerization, monoazide functionality is precisely introduced, ensuring the uniformity of the prepolymer structure. The use of supported titanate catalysts not only achieves high catalytic efficiency but also a recovery rate of over 90%, completely solving the corrosion and residue problems of traditional strong acid catalysts.

[0039] The target monomer is designed with bifunctionality, balancing cross-linking molding requirements with material flexibility, perfectly matching the application scenarios of contact lenses. Simultaneously, the palladium-ruthenium bimetallic composite catalyst achieves a shift from homogeneous to heterogeneous catalysis, significantly improving catalytic efficiency compared to single-metal catalysts, with a residual amount below 1 ppm, meeting the stringent requirements for biomedical materials. Supercritical CO2 extraction technology is introduced to purify fluorinated hydrophilic intermediates, replacing traditional organic solvent washing and reducing solvent residue to below 0.01%. Supercritical fluid is used as the reaction solvent for the synthesis of the target monomer, offering adjustable solubility; after the reaction, direct separation can be achieved through depressurization, eliminating organic solvent contamination. Molecular distillation technology is used for the purification of siloxane prepolymers, further ensuring the high purity and biosafety of the material. By adjusting the degree of polymerization of polyglycerol, the number of repeating units in the siloxane chain, and the length of the perfluoroalkyl chain, precise control over the material's hydrophilicity, oxygen permeability, and anti-fouling properties can be achieved, meeting the differentiated performance requirements of various scenarios such as daily wear and long-term wear, thus broadening its applicability.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses, characterized in that, Includes the following steps: (1) Terminal alkyne polyglycerol and perfluoroalkyl ethyl iodide were reacted with an alkaline acid-binding agent at -5-2℃ for 2-4 h, and then the temperature was raised to 35-40℃ for 5-8 h. The fluorinated hydrophilic alkyne intermediate was obtained by supercritical CO2 extraction and purification. The molecular weight of the terminal alkyne polyglycerol was 1000-1500, the degree of polymerization of the glycerol unit was 15-25, the degree of substitution of the terminal alkyne group was ≥95%, and the number of hydroxyl groups was 15-25. The molar ratio of terminal alkyne polyglycerol to perfluoroalkyl ethyl iodide and alkaline acid-binding agent was 1:1.5-2.5:1.5-2.

5. The reaction site was the nucleophilic substitution reaction between the iodine atom in the perfluoroalkyl ethyl iodide and the hydroxyl group of the terminal alkyne polyglycerol. (2) Dodecylcyclohexasiloxane, octamethylcyclotetrasiloxane, and γ-azidopropyltriisopropoxysilane are mixed in a molar ratio of 1:0.8-2.0:0.5-1.

2. A supported titanate catalyst of 4%-8% of the total mass of the reactants is added, and 2,2,6,6-tetramethylpiperidine nitroxide radical of 0.05%-0.12% of the total mass of the reactants is added as a polymerization inhibitor. The ring-opening copolymerization reaction is carried out in a gradient pressure mode: the reaction is first carried out at 0.1 MPa for 6-8 h, and then the pressure is increased to 0.3 MPa for 8-16 h. The reaction temperature is 50-90℃. After centrifugation to remove the catalyst, the azidosiloxane prepolymer is obtained by molecular distillation. The azidosiloxane prepolymer has a single azidofunctionality and contains a siloxane backbone in its molecular structure. The number of repeating units satisfies: a is 150-400 and b is 12-35. (3) The fluorinated hydrophilic alkynyl intermediate obtained in step (1) and the azido-containing siloxane prepolymer obtained in step (2) are mixed at a mass ratio of 1:15-40, a supercritical fluid solvent is added, and a palladium-based composite catalyst with a concentration of 50-200 ppm is added under nitrogen protection. The reaction proceeds at 60-100℃ and 5-8 MPa. The reaction progress is monitored by in-situ infrared spectroscopy. The reaction is terminated when the alkynyl characteristic peak disappears by more than 90%. The target monomer is obtained by depressurization precipitation and vacuum drying. The click chemical reaction is a cycloaddition reaction between the alkynyl group of the fluorinated hydrophilic alkynyl intermediate and the azido group of the azido-containing siloxane prepolymer to generate a 1,2,3-triazole ring. The target monomer is a bifunctional macromonomer. The molecular structure contains polyglycerol segments, perfluoroalkyl segments and siloxane backbone. The number of repeating units satisfies: a is 150-400, b is 12-35 and c is 8-20.

2. The method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses according to claim 1, characterized in that, The alkaline acid-binding agent mentioned in step (1) is a mixture of tetramethylguanidine and 1,8-diazabicycloundec-7-ene in a volume ratio of 1:1 to 2:1, and the reaction solvent is 1,4-dioxane.

3. The method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses according to claim 1, characterized in that, The supported titanate catalyst in step (2) is mesoporous TiO2 supported tetrabutyl titanate with a loading of 15%-25%; the purity of γ-azidopropyltriisopropoxysilane is ≥99%.

4. The method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses according to claim 1, characterized in that, The supercritical fluid solvent mentioned in step (3) is a mixture of supercritical propane and supercritical ethanol, with a mass ratio of 3:1 to 5:

1.

5. The method for preparing a macromolecular organosilicon monomer for silicone hydrogel contact lenses according to claim 1, characterized in that, The palladium-based composite catalyst mentioned in step (3) is a palladium-ruthenium bimetal supported on carbon nanotubes, wherein the mass ratio of palladium to ruthenium is 3:1-5:1, and the concentration of the catalyst in the reaction solution is 80-150 ppm.

6. The method for preparing a macromolecular organosilicon monomer for a silicone hydrogel contact lens according to claim 1, characterized in that, In step (1), the perfluoroalkyl ethyl iodine is perfluorohexyl ethyl iodine.

7. The method for preparing a macromolecular organosilicon monomer for a silicone hydrogel contact lens according to claim 1, characterized in that, The conditions for vacuum drying in step (3) are: temperature 40-50℃, vacuum degree ≤10Pa, and drying time 12-24h.