A thiol group-containing hyperbranched organosilicon polymer of benzimidazole type, and a preparation method and application thereof

Abstract

The application discloses a kind of containing sulfydryl benzimidazole type hyperbranched organosilicon polymer and its preparation method and application, belong to antibacterial antifouling coating technical field.The application utilizes the controllable hydrolysis and condensation polymerization of sulfydryl benzimidazole group organosilicon monomer and the organosilicon monomer containing functional functional group under acidic environment, and sulfydryl benzimidazole type hyperbranched organosilicon polymer with high degree of branching structure is synthesized by two-step method, and the prepared benzimidazole group hyperbranched organosilicon polymer has antibacterial and structural double advantages: wherein sulfydryl benzimidazole group realizes high efficient broad-spectrum antibacterial to escherichia coli, staphylococcus aureus and aspergillus niger etc. by destroying microbial cell membrane and inhibiting proliferation;Hyperbranched topological structure realizes high crosslinking density while keeping low viscosity, and terminal siloxyl and active functional group can be crosslinked by itself or react with other polymer film forming material, and synergistically impart material with high hydrophobicity, excellent mechanical properties and temperature resistance, water resistance, anti-aging characteristics.

Description

Technical Field

[0001] This invention belongs to the field of antibacterial and antifouling coating technology, and more specifically, relates to a mercaptobenzimidazole-containing hyperbranched organosilicon polymer, its preparation method, and its application. Background Technology

[0002] With the development of new-generation aerospace equipment, marine equipment, large-scale buildings, industrial facilities, and transportation pipelines, the performance requirements for anti-corrosion and antifouling coatings are becoming increasingly stringent. In marine engineering, facilities such as cross-sea bridges, deep-sea oil and gas platforms, and ships require coatings with long-term corrosion resistance (corrosion resistance needs to be 3-6 times better than traditional coatings) and resistance to biofouling to reduce maintenance costs and extend service life. Aerospace equipment requires coatings to also be lightweight, high-temperature resistant, and fatigue-resistant. Industrial pipelines and building steel structures require coatings to remain stable under complex chemical corrosion, mechanical wear, and temperature and humidity changes, while meeting the environmental protection requirements of green construction and low VOC emissions.

[0003] Existing polymer-based antifungal and antifouling coatings generally suffer from significant defects: First, they lack durability, especially in dynamic erosion or high-stress environments, where they are prone to peeling or microcracks, leading to protective failure. Second, they have poor environmental adaptability, struggling to cope with complex scenarios such as temperature, salinity, and pH fluctuations. For example, traditional epoxy resin coatings are susceptible to pitting corrosion caused by chloride ion penetration in marine environments, and are prone to microcrack propagation under alternating stress. Polyurethane materials are prone to molecular chain breakage and mechanical property degradation under long-term aging in environments with ultraviolet radiation and high temperatures. Silicone coatings have high gas permeability and poor solvent resistance, and their adhesion and mechanical strength are insufficient to withstand the impact of high-speed airflow. Third, they lack environmental friendliness. While release-type antibacterial and antifungal agents, such as cuprous oxide, can inhibit microbial adhesion in the short term, the long-term release of copper ions can pollute water bodies, disrupt the marine ecological balance, and may accumulate through the food chain, threatening human health. In addition, some coatings rely on toxic solvents (such as carbon tetrachloride), exacerbating environmental pollution and operational risks.

[0004] Therefore, developing new high-performance anti-corrosion and anti-fouling coatings that combine efficient protection, environmental friendliness, and intelligent response has become the core direction for technological breakthroughs in this field.

[0005] Chinese invention patent CN105017830A discloses an antibacterial and antifouling agent and an antibacterial and antifouling coating. It uses a zinc oxide composite powder loaded with magnesium oxide and shell powder as a novel antibacterial and antifungal agent. However, it does not improve the anti-aging performance, temperature resistance and antifouling performance of polymer materials. In actual use, an antifouling coating still needs to be applied on the surface of the antifungal coating. The construction is not convenient and the durability is low and it is easy to be damaged.

[0006] Chinese patent CN107556856A discloses a nano-antibacterial and antifouling coating. It reduces the surface energy of an acrylic material system by introducing fluorinated silica filler and polydimethylsiloxane, thereby preventing microbial adhesion and achieving antifouling effects. However, it is ineffective against bacteria and mold, exhibiting poor antifungal and antibacterial properties. Furthermore, long-term use of polydimethylsiloxane and acrylic resin leads to phase separation, causing polydimethylsiloxane to migrate to the material surface, resulting in a gradual decline in the antifouling performance of the material system and poor overall stability.

[0007] Chinese patent CN118562339A discloses the preparation and application of an antibacterial and antifouling coating based on Cu2O blended PVDF. By employing specific solvents and reaction conditions, this coating system combines the excellent antibacterial properties of cuprous oxide with the low surface energy of polyvinylidene fluoride (PVDF). However, the cuprous oxide antibacterial and antifungal agent used suffers from copper ion leakage, and the large amount of organic solvents present during coating application further exacerbates environmental pollution, failing to meet green environmental protection requirements. Furthermore, the inherent problems of poor adhesion and abrasion resistance of PTFE materials limit its application in specialized fields such as aerospace and large ships.

[0008] Existing antibacterial and antifouling coating technologies (such as copper-based antibacterial agents polluting the environment, single-function coatings requiring multiple layers, poor aging resistance of substrate materials, and insufficient stability) struggle to achieve a balance between core performance characteristics such as high performance, efficient antibacterial and antifungal activity, long-lasting antifouling properties, environmental friendliness, durability, and cost control, thus limiting their application in high-end scenarios such as aerospace and shipbuilding. Therefore, developing novel, green, and environmentally friendly multifunctional antibacterial and antifouling coatings requires breakthroughs in synergistic antibacterial and antifouling mechanism design, optimization of substrate polymer material performance, and low-cost process innovation. This is of great significance for improving equipment reliability, reducing maintenance costs, and promoting sustainable development. Summary of the Invention

[0009] To address the aforementioned problems in existing technologies, the technical problem this invention aims to solve is to provide a method for preparing a mercaptobenzimidazole-containing hyperbranched organosilicon polymer. This method employs a one-pot synthesis, eliminating the need for heavy metal catalysts and highly toxic organic solvents, thus simplifying the preparation process. This invention also provides a mercaptobenzimidazole-containing hyperbranched organosilicon polymer prepared by the above method, which possesses environmentally friendly, highly effective antifungal properties, low surface energy, and expandable functionalization capabilities. Furthermore, this invention provides the application of the mercaptobenzimidazole-containing hyperbranched organosilicon polymer in antibacterial and antifouling coatings.

[0010] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0011] A hyperbranched organosilicon polymer containing mercaptobenzimidazole has the following structural formula:

[0012]

[0013] Wherein, R is at least one of vinyl, acryloyloxy, alkyl, phenyl, urea, mercapto, thio, amino, trifluoropropyl, perfluorooctyl, chloromethyl, and epoxy.

[0014] A method for preparing the aforementioned mercaptobenzimidazole-containing hyperbranched organosilicon polymer involves, under inert gas protection, hydrolyzing a mercaptobenzimidazole-based organosilicon monomer, an organosilicon monomer containing functional groups, and water. After hydrolysis, an acidic catalyst and solvent are added for a heated reaction. The resulting product is obtained by rotary evaporation.

[0015] Preferably, the structural formula of the mercaptobenzimidazole-based organosilicon monomer is:

[0016]

[0017] R1 is at least one of methyl or ethyl.

[0018] Preferably, the organosilicon monomer containing the functional group is selected from one or more of γ-glycidoxypropyltrimethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, 3-ureapropyltrimethoxysilane, perfluorooctyltrimethoxysilane, trifluoropropyltrimethoxysilane, mercaptopropyltrimethoxysilane, chloromethyltrimethoxysilane, aminopropyltriethoxysilane, and phenyltriethoxysilane.

[0019] Preferably, the acidic catalyst is selected from one or more of formic acid, acetic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, trifluoroacetic acid, and oxalic acid.

[0020] Preferably, the solvent is selected from one or more of methanol, ethanol, toluene, xylene, ethyl acetate, methyl acetate, tetrahydrofuran, dioxane, dichloromethane, chloroform, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, acetone, and butanone.

[0021] Preferably, the hydrolysis reaction process is natural hydrolysis for 1 hour.

[0022] Preferably, the heating reaction process involves gradually increasing the temperature to 70–90°C and reacting for 2–12 hours.

[0023] Preferably, the molar ratio of the mercaptobenzimidazole-based organosilicon monomer, the organosilicon monomer containing the functional group, and water is 0.1–0.9:0.9–0.1:0.5–2. More preferably, the molar ratio of the mercaptobenzimidazole-based organosilicon monomer, the organosilicon monomer containing the functional group, and water is 0.3:0.7:0.5–2.

[0024] Preferably, the amount of the acidic catalyst is 0.3% to 1% of the total mass of the reactants.

[0025] Preferably, the amount of solvent used is 150% to 300% of the total mass of the reactants.

[0026] Preferably, the preparation process of the mercaptobenzimidazole-based organosilicon monomer is as follows: under nitrogen protection, mercaptobenzimidazole and a silane coupling agent containing glycidyl ether groups are mixed in a molar ratio of 1:3 to 2:1 to obtain a mixed silane coupling agent; the obtained mixed silane coupling agent, solvent and alkaline catalyst are reacted, and after cooling and rotary evaporation, mercaptobenzimidazole-based organosilicon monomer is obtained.

[0027] Preferably, the reaction temperature is 50–200°C and the reaction time is 0.1–24 h.

[0028] Preferably, the silane coupling agent containing glycidyl ether groups is one or more of γ-glycidyl etheroxypropyltrimethoxysilane and γ-glycidyl etheroxypropyltriethoxysilane.

[0029] The structural formula of the silane coupling agent containing glycidyl ether groups is:

[0030]

[0031] R1 is at least one of methyl or ethyl.

[0032] Preferably, the alkaline catalyst is selected from one or more tertiary amine catalysts such as triethylamine, N,N-diisopropylethylamine, 1,4-diazabicyclo, 4-dimethylaminopyridine, quinine ring, 1,8-diazabicycloundec-7-ene, and 1,5-diazabicyclo[4.3.0]non-5-ene.

[0033] Preferably, the amount of alkaline catalyst used is 0.01 to 10% of the total mass of the reactants.

[0034] The method for preparing the thiol-containing benzimidazole-type hyperbranched organosilicon polymer yields the thiol-containing benzimidazole-type hyperbranched organosilicon polymer.

[0035] The application of the aforementioned mercaptobenzimidazole-containing hyperbranched organosilicon polymer in antibacterial and antifouling coatings.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] (1) This invention utilizes hyperbranched molecular structure to enhance stability and synergistic effect. By introducing the three-dimensional cross-linked network of hyperbranched organosilicon (Si-O-Si skeleton), the high temperature resistance and UV aging resistance of the material system are significantly enhanced, avoiding failure caused by the decomposition of traditional antifungal agents. At the same time, the presence of abundant active functional groups and mercaptobenzimidazole groups in the molecular structure endows the mercaptobenzimidazole-containing hyperbranched organosilicon polymer with high compatibility and high reactivity, greatly improving the stability and durability of the coating.

[0038] (2) The special hyperbranched molecular structure of the present invention enables the coating surface to form dense antibacterial active sites composed of mercaptobenzimidazole groups, which can avoid metal pollution of water bodies by traditional heavy metal ion release coatings by destroying the microbial membrane structure and inhibiting DND / RNA transcription.

[0039] (3) The present invention adopts a one-pot synthesis method, which eliminates heavy metal catalysts and highly toxic organic solvents, simplifies the preparation process, and makes the mercaptobenzimidazole type hyperbranched organosilicon polymer more environmentally friendly in actual production, reducing pollution to the environment.

[0040] (4) The high adhesion antibacterial and antifouling integrated coating of the present invention simplifies the construction steps. Thanks to the presence of a large number of silaneoxy active sites in the hyperbranched organosilicon polymer, it can form chemical bonds with the substrate surface, thus providing the coating with high adhesion. The Si-O-Si crosslinking network formed by the condensation between silicon-oxygen bonds further reduces the surface energy of the coating and enhances its antifouling performance. In addition, based on the high designability of the structure of the hyperbranched organosilicon polymer, the introduction of mercaptobenzimidazole groups as antibacterial active sites further endows the material with excellent antibacterial and antifungal properties. The combination of primer and topcoat functions can be achieved by a single spraying, which greatly reduces the number of coatings and shortens the construction time, thereby greatly reducing the construction steps.

[0041] (5) The thiol-benzimidazole-containing hyperbranched organosilicon polymer prepared by this invention has a unique molecular structure design, combining the chemical multifunctionality of hyperbranched structure, the flexibility and hydrophobicity of organosilicon material, and the antibacterial activity of thiol-benzimidazole unit, showing broad application prospects in the field of polymer functional coatings. Through intramolecular synergistic effect, this material can form a dense defensive barrier on the coating surface, which not only has long-term antibacterial adhesion and killing function, but also inhibits the attachment of marine fouling organisms, while endowing the substrate with self-cleaning, corrosion resistance and other properties, making it of great application potential in medical devices, aerospace, marine engineering equipment and environmentally friendly building coatings. Its environmentally friendly, highly effective anti-mildew and low surface energy and functional expansion characteristics provide innovative ideas for the development of a new generation of high-performance antibacterial and antifouling materials. Attached Figure Description

[0042] Figure 1 The synthetic route for preparing the hyperbranched organosilicon polymer containing mercaptobenzimidazole is shown in the diagram.

[0043] Figure 2 Figures show physical images of mercaptobenzimidazole and mercaptobenzimidazole-containing hyperbranched organosilicon polymers; Figure a shows a physical image of mercaptobenzimidazole, and Figure b shows a physical image of the mercaptobenzimidazole-containing hyperbranched organosilicon polymer prepared in Example 1.

[0044] Figure 3 The nuclear magnetic resonance spectrum of the hyperbranched organosilicon polymer containing mercaptobenzimidazole prepared in Example 1;

[0045] Figure 4 The infrared spectrum of the hyperbranched organosilicon polymer containing mercaptobenzimidazole prepared in Example 1;

[0046] Figure 5 This is a photograph of the cured mercaptobenzimidazole-containing hyperbranched organosilicon polymer obtained in Example 2.

[0047] Figure 6 The graph shows the thermal stability test results of the mercaptobenzimidazole-containing hyperbranched organosilicon polymer prepared in Example 2.

[0048] Figure 7 Figure A shows the wear resistance test results of the cured mercaptobenzimidazole-containing hyperbranched organosilicon polymer obtained in Example 5; Figure B shows the surface morphology of the coating material after testing and the surface roughness test results of the coating material after testing.

[0049] Figure 8 Figure 6 shows the contact angle test results of the cured mercaptobenzimidazole-containing hyperbranched organosilicon polymer obtained in Example 6; wherein, Figure A is the water contact angle diagram of the coating, and Figure B is the diiodomethane contact angle diagram of the coating.

[0050] Figure 9 The image shows the anti-graffiti performance test results of the mercaptobenzimidazole-containing hyperbranched organosilicon polymer cured product obtained in Example 6.

[0051] Figure 10 This is a graph showing the antibacterial properties of the cured product obtained in Example 8.

[0052] Figure 11 This is a test diagram of the antifouling performance of the cured product obtained in Example 8;

[0053] Figure 12 This is a test diagram of the anti-corrosion performance of the cured product obtained in Example 8;

[0054] Figure 13The image shows the thermal stability test results of the cured product obtained in Comparative Example 1.

[0055] Figure 14 The image shows the abrasion resistance test results of the cured product obtained in Comparative Example 2.

[0056] Figure 15 These are test graphs showing the antifouling performance of the cured products obtained in Example 7 and Comparative Example 3.

[0057] Figure 16 The graphs show the antibacterial properties of the cured products obtained in Example 7 and Comparative Example 3. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is further described below with reference to specific embodiments. Unless otherwise specified, the technical means used in the following embodiments are all conventional means well known to those skilled in the art. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0059] The mercaptobenzimidazole used in the following examples was purchased from Guangzhou Weber Technology Co., Ltd.; the coupling agent monomers were all purchased from Nanjing Nengde New Material Technology Co., Ltd.; and the solvents and catalysts used were all purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0060] The performance testing methods used in the following embodiments are as follows:

[0061] 1. Thermal stability test: Accurately weigh 5-10 mg of polymer sample and place it in an alumina crucible. Ensure the sample is evenly spread to avoid agglomeration affecting the test results. Use a thermogravimetric analyzer (TA Instruments Q500) under a nitrogen atmosphere, with a gas flow rate set to 50 mL / min and a heating rate set to 10 °C / min, starting from room temperature and increasing to 1000 °C, and record the thermal decomposition process of the polymer.

[0062] 2. Wear Resistance Testing: The wear resistance of the coating is typically tested using a friction and wear testing machine. First, prepare a sample with the coating, accurately measure and record its initial mass and dimensions, and securely mount the sample on the testing machine. Set the parameters according to the coating characteristics and expected operating conditions. During the test, the sample and the friction pair are moved relative to each other according to the set parameters to simulate actual wear conditions. After the test, measure the sample mass and dimensions again. By analyzing the changes in mass and dimensions before and after the test, combined with microscopic observation of the wear marks, the wear resistance of the coating is evaluated.

[0063] 3. Contact Angle Test: The coating was uniformly applied to the glass substrate and dried at room temperature for 24 hours. The contact angle was recorded using a Krüss DSA25 contact angle meter equipped with a high-speed camera system (500fps) in a constant temperature environment of 25℃, relative humidity of 50% ± 5%, droplet volume of 2μL ultrapure water / diiodomethane, and droplet release height of 2mm. Five different locations were measured for each sample, and the average value and standard deviation were calculated.

[0064] 4. Anti-graffiti performance test: Write on the surface of the coated sample using oil-based and water-based markers, then wipe it with a damp paper towel. The anti-graffiti performance of the material is judged by observing the degree of writing residue.

[0065] 5. Antifouling Performance Test: First, the operation was conducted in a glass tank. 3000g of artificial seawater, 3g of diatomaceous earth, and 10-15 drops of diatom culture medium were mixed together and thoroughly stirred. Then, the tank was placed under sunlight at room temperature for 7 days, until diatoms grew over a certain area in the glass tank. Next, a glass slide coated with the sample to be tested was immersed in this tank and cultured for a period of time under the same conditions. After the sample was immersed in the aforementioned artificial seawater, it was removed from the tank, and the sample surface and the back of the glass slide were washed with artificial seawater. Finally, an optical microscope was used to observe the algae coverage on the sample surface.

[0066] 6. Antibacterial Performance Test: The antibacterial performance of the sample coating against *Escherichia coli* and *Staphylococcus aureus* was tested using the LB plate count method and microscopic observation. The specific steps are as follows: 1) First, prepare 20 mL of a 10% concentration... 8 1) A CFU / mL colony suspension was prepared by placing 18mm × 18mm glass slides coated with the sample coating into the suspension and incubating at 37°C with constant temperature shaking for 24 hours. 2) After 24 hours of incubation, the glass slides coated with the sample coating were removed, and the uncoated side of the glass slides was cleaned with sterile PBS buffer. The cleaned glass slides were then placed in 20mL of sterile PBS buffer and sonicated for 15 minutes to allow the E. coli and Staphylococcus aureus attached to the coating to fall off. 3) The sonicated solution was then diluted 1000 times, and 20μL of the diluted solution was inoculated onto the surface of LB medium and incubated at 37°C for 24 hours. 4) The number of colonies growing on the surface of the LB medium was counted using the LB plate count method.

[0067] 7. Coating corrosion resistance test: Immerse coated and uncoated steel plates in natural seawater for more than 7 days, then remove them and observe the degree of rust on the surface with the naked eye to judge the corrosion resistance of the coating material.

[0068] The synthetic route diagram of the mercaptobenzimidazole-containing hyperbranched organosilicon polymer provided in this application is as follows: Figure 1 As shown.

[0069] This application achieves a breakthrough in anti-mildew and anti-fouling performance through molecular-level innovation, based on the highly branched structure design of hyperbranched organosilicon polymers and the synergistic effect of mercaptobenzimidazole functional groups. The principle is as follows: the abundant alkoxy groups and active functional groups in the hyperbranched framework form strong chemical bonds with the substrate, enhancing coating adhesion and environmental resistance; the dense silica network generated by self-crosslinking significantly enhances water resistance and hydrophobicity, reducing surface energy to physically block pollutant adhesion; simultaneously, the introduced mercaptobenzimidazole groups achieve excellent broad-spectrum antibacterial and anti-mildew properties through a dual mechanism of disrupting microbial cell membrane integrity and interfering with DNA / RNA replication, even without the addition of heavy metal ions. This structure integrates the triple advantages of chemical anchoring, physical antifouling, and bioinhibition, giving it high durability, environmental friendliness, and long-lasting antifouling capabilities in practical applications, making it suitable for extremely complex environments such as aerospace, marine equipment, and industrial facilities.

[0070] Example 1

[0071] A method for preparing a mercaptobenzimidazole-containing hyperbranched organosilicon polymer includes the following steps:

[0072] 1) Under nitrogen protection, 1 mol of mercaptobenzimidazole and 1 mol of γ-glycidyl etheroxypropyltrimethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent.

[0073] 2) Mix 1 mol of the mixed silane coupling agent obtained in step 1) with 3 mol of methanol in a three-necked flask, add 2 wt% triethylamine catalyst, and gradually raise the temperature from room temperature to 50°C at a rate of 20°C / min. React for 1 h, and after the reaction is complete, allow it to cool naturally to room temperature. Use a rotary evaporator at 50°C to remove the solvent and catalyst to obtain a mercaptobenzimidazole organosilicon monomer, which is a pale yellow transparent liquid.

[0074] 3) Add 0.9 mol of the mercaptobenzimidazole organosilicon monomer obtained in step 2), 0.1 mol of phenyltrimethoxysilane monomer and 1.3 mol of deionized water to a three-necked flask equipped with a condenser and a mechanical stirrer and hydrolyze naturally at room temperature for 1 h to obtain a mixture;

[0075] 4) Mix 1 mol of the mixture obtained in step 3) with 2 mol of ethanol, add 0.5 wt% hydrochloric acid catalyst, and gradually raise the temperature to 70℃ and react for 6 h at a rate of 20℃ / min. After the reaction is completed, allow the mixture to cool naturally and remove the solvent, catalyst and reaction byproducts at 60℃ using a rotary evaporator to obtain a mercaptobenzimidazole-containing hyperbranched organosilicon polymer, which is a pale yellow transparent liquid with low viscosity and high fluidity.

[0076] Depend on Figure 2 It can be seen that the obtained mercaptobenzimidazole-containing hyperbranched organosilicon polymer exhibits the characteristics of a low-viscosity liquid state, and its room temperature viscosity is only 207 mPa·s.

[0077] Depend on Figure 3 It can be seen that the calculated degree of branching of the hyperbranched organosilicon polymer exceeds 0.8, which conforms to the general rule that the degree of branching of hyperbranched organosilicon polymers is greater than 0.5, proving the successful synthesis of the hyperbranched organosilicon polymer.

[0078] Depend on Figure 4 The change in the infrared characteristic peak at 1100°C proves the formation of Si-O-Si bonds, which further proves the synthesis of hyperbranched organosilicon polymers.

[0079] Example 2

[0080] A method for preparing a mercaptobenzimidazole-containing hyperbranched organosilicon polymer includes the following steps:

[0081] 1) Under nitrogen protection, 2 mol of mercaptobenzimidazole and 1 mol of γ-glycidyl etheroxypropyltriethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent.

[0082] 2) Mix 1 mol of the mixed silane coupling agent obtained in step 1) with 1 mol of ethyl acetate in a three-necked flask, add 10 wt% N,N-diisopropylethylamine catalyst, and gradually raise the temperature from room temperature to 200 °C at a rate of 20 °C / min for 0.1 h. After the reaction is complete, allow it to cool naturally to room temperature, and remove the solvent and catalyst using a rotary evaporator at 55 °C to obtain a mercaptobenzimidazole organosilicon monomer, which is a pale yellow transparent liquid.

[0083] 3) Add 0.3 mol of the mercaptobenzimidazole organosilicon monomer obtained in step 2), 0.7 mol of methyltrimethoxysilane and 1.5 mol of deionized water to a three-necked flask equipped with a condenser and a mechanical stirrer and hydrolyze naturally at room temperature for 1 h to obtain a mixture;

[0084] 4) Mix 1 mol of the mixture obtained in step 3) with 3 mol of ethyl acetate, add 0.01 wt% sulfuric acid catalyst, and gradually raise the temperature to 90℃ and react for 12 h at a rate of 20℃ / min. After the reaction is completed, allow it to cool naturally to room temperature. Use a rotary evaporator at 60℃ to remove the solvent, catalyst and reaction byproducts to obtain a mercaptobenzimidazole-containing hyperbranched organosilicon polymer, which is a pale yellow transparent liquid with low viscosity and high fluidity.

[0085] Depend on Figure 5 It can be seen that after curing the above-prepared mercaptobenzimidazole-containing hyperbranched organosilicon polymer at 100°C for 24 hours, the resulting film material is light yellow and transparent, with strong density and good film-forming properties.

[0086] Depend on Figure 6 It can be seen that, in the context of Figure 5 When the cured films containing mercaptobenzimidazole hyperbranched organosilicon polymers were subjected to thermal stability tests, the product prepared in Example 2 had a thermal decomposition temperature exceeding 350°C for 95% of the time, and a char residue rate exceeding 41% at 1000°C, demonstrating excellent heat resistance.

[0087] Example 3

[0088] A method for preparing a mercaptobenzimidazole-containing hyperbranched organosilicon polymer includes the following steps:

[0089] 1) Under nitrogen protection, 1 mol of mercaptobenzimidazole and 3 mol of γ-glycidyl etheroxypropyltrimethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent.

[0090] 2) After mixing 1 mol of the mixed silane coupling agent obtained in step 1) with 1.5 mol of acetone in a three-necked flask, 0.1 wt% of 1,4-diazabicyclic catalyst was added and the temperature was gradually increased from room temperature to 100 °C at a rate of 20 °C / min. The reaction was carried out for 24 h. After the reaction was completed, the mixture was naturally cooled to room temperature. The solvent and catalyst were removed by rotary evaporator at 50 °C to obtain mercaptobenzimidazole organosilicon monomer, which was a pale yellow transparent liquid.

[0091] 3) Add 0.5 mol of the mercaptobenzimidazole organosilicon monomer obtained in step 2), 0.5 mol of phenyltrimethoxysilane and 0.5 mol of deionized water to a three-necked flask equipped with a condenser and a mechanical stirrer, and allow it to hydrolyze naturally at room temperature for 1 h to obtain a mixture;

[0092] 4) Mix 1 mol of the mixture obtained in step 3) with 2 mol of ethyl acetate, add 10 wt% oxalic acid catalyst, and gradually heat to 70 °C for 4 h at a heating rate of 20 °C / min. After the reaction is complete, allow the mixture to cool naturally and remove the solvent, catalyst and reaction byproducts at 60 °C using a rotary evaporator to obtain a mercaptobenzimidazole-containing hyperbranched organosilicon polymer, which is a pale yellow transparent liquid with low viscosity and high fluidity.

[0093] Example 4

[0094] A method for preparing a mercaptobenzimidazole-containing hyperbranched organosilicon polymer includes the following steps:

[0095] 1) Under nitrogen protection, 1 mol of mercaptobenzimidazole and 1.5 mol of γ-glycidyl etheroxypropyltrimethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent.

[0096] 2) After mixing 1 mol of the mixed silane coupling agent obtained in step 1) with 3 mol of dichloromethane in a three-necked flask, 3 wt% of 4-dimethylaminopyridine catalyst was added and the temperature was gradually increased from room temperature to 150°C at a rate of 20°C / min for 0.5 h. After the reaction was completed, the mixture was naturally cooled to room temperature and the solvent and catalyst were removed at 60°C using a rotary evaporator to obtain a mercaptobenzimidazole organosilicon monomer, which is a pale yellow transparent liquid.

[0097] 3) Add 0.3 mol of the mercaptobenzimidazole organosilicon monomer obtained in step 2), 0.5 mol of γ-glycidyl etheroxypropyltrimethoxysilane, 0.2 mol of methacryloyloxypropyltrimethoxysilane and 2 mol of deionized water to a three-necked flask equipped with a condenser and a mechanical stirrer, and allow it to hydrolyze naturally at room temperature for 1 h to obtain a mixture.

[0098] 4) Mix 1 mol of the mixture obtained in step 3) with 2 mol of chloroform, add 2 wt% trifluoroacetic acid catalyst, and gradually heat to 90℃ for 2 h at a heating rate of 20℃ / min. After the reaction is completed, allow it to cool naturally, and remove the solvent, catalyst and reaction byproducts at 55℃ using a rotary evaporator to obtain a mercaptobenzimidazole-containing hyperbranched organosilicon polymer, which is a pale yellow transparent liquid with low viscosity and high fluidity.

[0099] Example 5

[0100] A method for preparing a mercaptobenzimidazole-containing hyperbranched organosilicon polymer includes the following steps:

[0101] 1) Under nitrogen protection, 1.5 mol of mercaptobenzimidazole and 1 mol of γ-glycidyl etheroxypropyltriethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent.

[0102] 2) Mix 1 mol of the mixed silane coupling agent obtained in step 1) with 1 mol of N-methylpyrrolidone in a three-necked flask, add 1 wt% quinine ring catalyst, and gradually raise the temperature from room temperature to 90°C at a rate of 20°C / min. React for 12 h. After the reaction is complete, cool naturally to room temperature and remove the solvent and catalyst at 60°C using a rotary evaporator to obtain a mercaptobenzimidazole organosilicon monomer, which is a pale yellow transparent liquid.

[0103] 3) Add 0.2 mol of the mercaptobenzimidazole organosilicon monomer obtained in step 2), 0.8 mol of 3-ureapropyltrimethoxysilane and 0.5 mol of deionized water to a three-necked flask equipped with a condenser and a mechanical stirrer, and allow it to hydrolyze naturally at room temperature for 1 h to obtain a mixture.

[0104] 4) Mix 1 mol of the mixture obtained in step 3) with 3 mol of dimethyl sulfoxide, add 0.5 wt% phosphoric acid catalyst, and gradually raise the temperature from room temperature to 70 °C for 6 h at a rate of 20 °C / min. After the reaction is complete, allow it to cool naturally to room temperature. Use a rotary evaporator at 70 °C to remove the solvent, catalyst and reaction byproducts to obtain a mercaptobenzimidazole-containing hyperbranched organosilicon polymer, which is a pale yellow transparent liquid with low viscosity and high fluidity.

[0105] The above-prepared mercaptobenzimidazole-containing hyperbranched organosilicon polymer was cured at 100°C for 24 hours to form a film, and its abrasion resistance was tested. The results are as follows: Figure 7 As shown.

[0106] Depend on Figure 7 It can be seen that the introduction of urea groups enhances the intermolecular forces between materials, resulting in only shallow scratches on the coating surface after 3000 cycles of wire brushing. The deepest scratch is less than 1.5 micrometers, and the scratch range is small, demonstrating excellent wear resistance.

[0107] Example 6

[0108] A method for preparing a mercaptobenzimidazole-containing hyperbranched organosilicon polymer includes the following steps:

[0109] 1) Under nitrogen protection, 1 mol of mercaptobenzimidazole and 1 mol of γ-glycidyl etheroxypropyltrimethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent.

[0110] 2) Mix 1 mol of the mixed silane coupling agent obtained in step 1) with 2 mol of toluene in a three-necked flask, add 0.5 wt% of 1,8-diazabicycloundec-7-ene catalyst, and gradually raise the temperature from room temperature to 120 °C at a rate of 20 °C / min. React for 1 h, and after the reaction is complete, allow it to cool naturally to room temperature. Remove the solvent and catalyst using a rotary evaporator at 70 °C to obtain a mercaptobenzimidazole organosilicon monomer, which is a pale yellow transparent liquid.

[0111] 3) Add 0.3 mol of the mercaptobenzimidazole organosilicon monomer obtained in step 2), 0.4 mol of perfluorooctyltrimethoxysilane, 0.3 mol of trifluoropropyltrimethoxysilane and 1.1 mol of deionized water to a three-necked flask equipped with a condenser and a mechanical stirrer, and allow it to hydrolyze naturally at room temperature for 1 h to obtain a mixture.

[0112] 4) Mix 1 mol of the mixture obtained in step 3) with 3 mol of xylene, add 0.5 wt% acetic acid catalyst, and gradually raise the temperature to 70℃ and react for 6 h at a rate of 20℃ / min. After the reaction is completed, allow it to cool naturally to room temperature. Use a rotary evaporator at 60℃ to remove the solvent, catalyst and reaction byproducts to obtain a mercaptobenzimidazole-containing hyperbranched organosilicon polymer, which is a pale yellow transparent liquid with low viscosity and high fluidity.

[0113] The above-prepared mercaptobenzimidazole-containing hyperbranched organosilicon polymer was cured at 100°C for 24 hours to form a film, and its performance was tested. The results are as follows: Figure 8 and Figure 9 As shown.

[0114] Depend on Figure 8 It can be seen that, thanks to the introduction of Si-O-Si bonds, the material exhibits excellent resistance to both oil and water. The coating has a contact angle of 107° for oily liquids and 108° for aqueous liquids. Its surface energy is only 10.88 according to the Owens method, which shows good hydrophobic and oleophobic properties.

[0115] Depend on Figure 9 It can be seen that the material exhibits excellent resistance to graffiti. Graffiti was applied to the coating surface using both water-based and oil-based pens. After 10, 20, and 30 minutes, the surface was wiped with a damp paper towel. It was observed that no oil-based or water-based pen residue remained on the coating surface after wiping at different time intervals, demonstrating the material's excellent resistance to graffiti from both oil-based and water-based contaminants.

[0116] Example 7

[0117] A method for preparing a mercaptobenzimidazole-containing hyperbranched organosilicon polymer includes the following steps:

[0118] 1) Under nitrogen protection, 1 mol of mercaptobenzimidazole and 1 mol of γ-glycidyl etheroxypropyltrimethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent.

[0119] 2) Mix 1 mol of the mixed silane coupling agent obtained in step 1) with 3 mol of N,N-dimethylacetamide in a three-necked flask, add 1 wt% of 1,5-diazabicyclo[4.3.0]non-5-ene catalyst, and gradually raise the temperature from room temperature to 120°C at a rate of 20°C / min. React for 0.5 h. After the reaction is completed, allow it to cool naturally to room temperature. Remove the solvent and catalyst using a rotary evaporator at 80°C to obtain a mercaptobenzimidazole organosilicon monomer, which is a pale yellow transparent liquid.

[0120] 3) Add 0.3 mol of the mercaptobenzimidazole organosilicon monomer obtained in step 2), 0.4 mol of mercaptopropyltrimethoxysilane, 0.3 mol of chloromethyltrimethoxysilane and 0.8 mol of deionized water to a three-necked flask equipped with a condenser and a mechanical stirrer, and hydrolyze naturally at room temperature for 1 h to obtain a mixture;

[0121] 4) Mix 1 mol of the mixture obtained in step 3) with 2 mol of N,N-dimethylformamide, add 1 wt% nitric acid catalyst, and gradually raise the temperature to 70℃ for 6 h at a rate of 20℃ / min. After the reaction is complete, allow it to cool naturally to room temperature. Use a rotary evaporator at 80℃ to remove the solvent, catalyst and reaction byproducts to obtain a mercaptobenzimidazole-containing hyperbranched organosilicon polymer, which is a pale yellow transparent liquid with low viscosity and high fluidity.

[0122] Example 8

[0123] A method for preparing a mercaptobenzimidazole-containing hyperbranched organosilicon polymer includes the following steps:

[0124] 1) Under nitrogen protection, 1 mol of mercaptobenzimidazole and 1 mol of γ-glycidyl etheroxypropyltrimethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent.

[0125] 2) Mix 1 mol of the mixed silane coupling agent obtained in step 1) with 3 mol of tetrahydrofuran in a three-necked flask, add 1 wt% of 1,5-diazabicyclo[4.3.0]non-5-ene catalyst, and gradually raise the temperature from room temperature to 120°C at a rate of 20°C / min. React for 0.5 h. After the reaction is completed, allow it to cool naturally to room temperature. Remove the solvent and catalyst using a rotary evaporator at 60°C to obtain a mercaptobenzimidazole organosilicon monomer, which is a pale yellow transparent liquid.

[0126] 3) Add 0.3 mol of the mercaptobenzimidazole organosilicon monomer obtained in step 2), 0.3 mol of aminopropyltriethoxysilane, 0.4 mol of phenyltriethoxysilane and 1.3 mol of deionized water to a three-necked flask equipped with a condenser and a mechanical stirrer, and allow it to hydrolyze naturally at room temperature for 1 h to obtain a mixture;

[0127] 4) Mix 1 mol of the mixture obtained in step 3) with 2 mol of dioxane, add 0.3 wt% formic acid catalyst, and gradually raise the temperature to 70°C and react for 4 h at a rate of 20°C / min. After the reaction is complete, allow it to cool naturally to room temperature. Use a rotary evaporator at 50°C to remove the solvent, catalyst and reaction byproducts to obtain a mercaptobenzimidazole-containing hyperbranched organosilicon polymer, which is a pale yellow transparent liquid with low viscosity and high fluidity.

[0128] The polymer coating obtained by curing the above-prepared mercaptobenzimidazole-containing hyperbranched organosilicon polymer at 100°C for 24 hours was subjected to antibacterial, antifouling, and anticorrosive performance tests. The results are as follows: Figures 10-12 As shown.

[0129] Depend on Figure 10 It can be seen that when antibacterial experiments were conducted on petri dishes coated with hyperbranched organosilicon polymer and uncoated petri dishes, the coated petri dishes showed fewer colonies.

[0130] Depend on Figure 11 It can be seen that when antimicrobial adsorption tests were conducted on steel sheets coated with hyperbranched organosilicon polymer coatings and uncoated steel sheets, the results showed that there were almost no microorganisms attached to the surface of the coated steel sheets, while a large number of microorganisms appeared on the surface of the uncoated steel sheets.

[0131] Depend on Figure 12 It can be seen that when seawater corrosion tests were conducted on steel sheets coated with hyperbranched organosilicon polymer coating and uncoated steel sheets respectively, the coated steel sheets showed only slight corrosion at the scratches after being immersed in seawater, while no obvious corrosion was observed in other areas. In contrast, the uncoated steel sheets showed extensive corrosion.

[0132] In summary, it can be seen that the thiol-containing benzimidazole-type hyperbranched organosilicon polymer prepared by the above method has both long-lasting antibacterial properties and surface anti-fouling and anti-corrosion properties.

[0133] Comparative Example 1

[0134] Under nitrogen protection, 2 mol of mercaptobenzimidazole and 1 mol of γ-glycidyl etheroxypropyltriethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent. The obtained mixed silane coupling agent was then mixed with ethyl acetate in a three-necked flask, and 10 wt% N,N-diisopropylethylamine catalyst was added. The temperature was gradually increased to 200 °C at a rate of 20 °C / min, and the reaction was carried out for 0.1 h. After the reaction was completed, the mixture was allowed to cool naturally, and the solvent and catalyst were removed using a rotary evaporator to obtain a mercaptobenzimidazole-based organosilicon monomer, which was a pale yellow transparent liquid.

[0135] The obtained mercaptobenzimidazole organosilicon monomer was cured at 100°C for 24 hours and then subjected to thermal stability testing. The results are as follows: Figure 13 As shown.

[0136] Depend on Figure 13 It is known that mercaptobenzimidazole silane coupling agents have poor heat resistance, with a 95% thermal decomposition temperature of 330℃ and a char residue rate of only 2% at 1000℃.

[0137] Comparative Example 2

[0138] Under nitrogen protection, 1.5 mol of mercaptobenzimidazole and 1 mol of γ-glycidyl etheroxypropyltriethoxysilane were added to a three-necked flask equipped with a condenser and a mechanical stirrer and stirred until homogeneous to obtain a mixed silane coupling agent. The obtained mixed silane coupling agent was then mixed with N-methylpyrrolidone in a three-necked flask, and 1 wt% quinine ring catalyst was added. The temperature was gradually increased to 90 °C at a rate of 20 °C / min and the reaction was carried out for 12 h. After the reaction was completed, the mixture was allowed to cool naturally, and the solvent and catalyst were removed using a rotary evaporator to obtain a mercaptobenzimidazole-based organosilicon monomer, which was a pale yellow transparent liquid.

[0139] The mercaptobenzimidazole-based organosilicon monomer prepared above was cured at 100°C for 24 hours, and then its wear resistance was tested. The results are as follows: Figure 14 As shown.

[0140] Depend on Figure 14 As can be seen from A, due to the lack of high crosslinking density resulting from the absence of a hyperbranched structure, the coating exhibits extremely poor wear resistance. After 3000 tests, large and obvious scratch areas appeared on the coating surface. Figure 14 As shown in B, the deepest scratch exceeds 4 micrometers. Compared with the hyperbranched silicone polymer coating in Example 5, both the scratch area and scratch depth are significantly increased, resulting in poor wear resistance.

[0141] Comparative Example 3

[0142] 0.4 mol of mercaptopropyltrimethoxysilane, 0.3 mol of chloromethyltrimethoxysilane, and 0.8 mol of deionized water were added to a three-necked flask equipped with a condenser and a mechanical stirrer. The mixture was allowed to hydrolyze naturally at room temperature for 1 h to obtain a mixture. 1 mol of the prepared mixture was mixed with 2 mol of N,N-dimethylformamide, and 1 wt% nitric acid catalyst was added. The mixture was gradually heated to 70 °C and reacted for 6 h at a heating rate of 20 °C / min. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The solvent, catalyst, and reaction byproducts were removed using a rotary evaporator at 80 °C to obtain a hyperbranched organosilicon polymer, which is a colorless and transparent liquid with low viscosity and high fluidity.

[0143] The products obtained in Example 7 and Comparative Example 3 were cured at 100°C for 24 hours to form films, and their performance was tested. The results are as follows: Figure 15 and Figure 16 As shown.

[0144] Depend on Figure 15 It can be seen that the coating prepared in Example 7 exhibits excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, while the coating prepared in Comparative Example 3, which lacks a mercaptobenzimidazole group, has poor inhibitory effect on the proliferation of Staphylococcus aureus and Escherichia coli, and the material's antibacterial and antifouling properties are insufficient.

[0145] Depend on Figure 16 It can be seen that the coating prepared in Example 7 showed no obvious algae adhesion on the surface after being soaked in Chaetoceros muelleri and Rhomboidia crescentis, demonstrating highly efficient anti-fouling performance. In contrast, the coating prepared in Comparative Example 3 showed a large number of algal microorganisms multiplying on the surface after being soaked in Chaetoceros muelleri and Rhomboidia crescentis for one week.

[0146] Example 9

[0147] The products obtained in Examples 1-8 and Comparative Examples 1-3 were subjected to performance tests, and the results are shown in Table 1.

[0148] Table 1. Performance test results of the products obtained in Examples 1-8 and Comparative Examples 1-3

[0149]

[0150]

[0151] As shown in Table 1, the introduction of the thiol-benzimidazole group, which possesses excellent antibacterial and anti-aging properties, endows the hyperbranched organosilicon polymer with superior antibacterial properties. In the antibacterial test, the number of residual colonies on the coating surface was significantly suppressed. The introduction of the hyperbranched structure gives the coating superior wear resistance. Compared with the coating without the hyperbranched structure, the damaged area and maximum damage depth are significantly reduced after the wear resistance test. The introduction of siloxane segments and the high crosslinking density endow the coating material with low surface energy. In the mold adsorption test, no obvious mold adhesion was observed on the coating surface. These characteristics enable the prepared thiol-benzimidazole-based hyperbranched organosilicon polymer to exhibit excellent antibacterial, antifungal, and stain-resistant properties.

[0152] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A thiol group-containing hyperbranched organosilicon polymer of the benzimidazole type, characterized in that, The structural formula is: ， R is at least one of vinyl, acryloxy, alkyl, phenyl, urea, mercapto, amino, trifluoro propyl, perfluoro octyl, chloromethyl, epoxy.

2. A method for preparing the thiol group-containing hyperbranched organosilicon polymer of claim 1, characterized by, Under the protection of inert gas, the mercapto benzimidazole organic silicon monomer, the organic silicon monomer containing functional functional groups and water are subjected to hydrolysis reaction, after the hydrolysis is completed, an acidic catalyst and a solvent are added to carry out temperature rising reaction, after rotary evaporation, the mercapto benzimidazole type hyperbranched organic silicon polymer is prepared. The structural formula of the mercapto benzimidazole organic silicon monomer is: ， R1 is at least one of methyl and ethyl; The organic silicon monomer containing functional functional groups is selected from one or more of gamma-glycidyl ether propyl trimethoxysilane, methyl trimethoxysilane, phenyl trimethoxysilane, methyl methacryloxy propyl trimethoxysilane, 3-urea propyl trimethoxysilane, perfluoro octyl trimethoxysilane, trifluoro propyl trimethoxysilane, mercapto propyl trimethoxysilane, chloromethyl trimethoxysilane, amino propyl triethoxysilane and phenyl triethoxysilane.

3. The method for preparing a thiol group-containing hyperbranched organosilicon polymer of the benzimidazole type according to claim 2, characterized by, The acidic catalyst is selected from one or more of formic acid, acetic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, trifluoroacetic acid and oxalic acid.

4. The method for preparing a thiol group-containing hyperbranched organosilicon polymer of claim 2, characterized by, The solvent is selected from one or more of methanol, ethanol, toluene, xylene, ethyl acetate, methyl acetate, tetrahydrofuran, dioxane, dichloromethane, chloroform, N, N-dimethyl formamide, N, N-dimethyl acetamide, N-methyl pyrrolidone, dimethyl sulfoxide, acetone and butanone.

5. The method for preparing a thiol group-containing hyperbranched organosilicon polymer of claim 3, characterized by, The preparation process of the mercapto benzimidazole organic silicon monomer is that under the protection of nitrogen, mercapto benzimidazole and silane coupling agent containing glycidyl ether group are mixed in a molar ratio of 1:3-2:1 to obtain mixed silane coupling agent; the obtained mixed silane coupling agent, solvent and alkaline catalyst are reacted, and after cooling and rotary evaporation, the mercapto benzimidazole organic silicon monomer is prepared.

6. The method for preparing a thiol group-containing hyperbranched organosilicon polymer of the benzimidazole type according to claim 2, characterized by, The molar ratio of the mercapto benzimidazole organic silicon monomer, the organic silicon monomer containing functional functional groups and water is 0.1-0.9:0.9-0.1:0.5-2.

7. The mercapto benzimidazole type hyperbranched organic silicon polymer prepared by the preparation method of the mercapto benzimidazole type hyperbranched organic silicon polymer in any one of claims 2-6.

8. The application of the mercapto benzimidazole type hyperbranched organic silicon polymer in claim 7 in antibacterial and antifouling coatings.

Images