Bio-based super-hydrophobic ultraviolet curing coating as well as preparation method and application thereof

Abstract

The invention discloses a bio-based super-hydrophobic ultraviolet curing coating which is prepared from the following raw materials in parts by weight: 33-66 parts of plant oil-based active monomers, 20-45 parts of polythiol, 1-40 parts of modified cellulose, 15-150 parts of an organic solvent and 1-5 parts of a photoinitiator, wherein the plant oil-based active monomer is prepared from epoxidized plant oil, unsaturated organic matters and a Lewis acid catalyst, and the unsaturated organic matters contain hydroxyl and carbon-carbon double bonds located at the tail end of a molecular chain. According to the bio-based super-hydrophobic ultraviolet curing coating disclosed by the invention, a three-dimensional interpenetrating network structure is obtained by cross-linking the plant oil-based active monomer, the polythiol and the cellulose in an ultraviolet curing process, a chemical bonding type surface microstructure super-hydrophobic material with excellent wear resistance is constructed, and the preparation method is simple. The invention further discloses application of the bio-based super-hydrophobic ultraviolet curing coating in surface treatment of a base material.

Description

Technical Field

[0001] The present invention belongs to the technical field of photocurable coatings, and particularly relates to a bio-based superhydrophobic ultraviolet (UV) curable coating, its preparation method and application. Background Art

[0002] As a green and environmentally friendly process, the UV curing technology has been developed since the 1960s and is widely used in the coating field due to its characteristics of rapid polymerization, high energy efficiency. This technology generates active free radicals by irradiating a photoinitiator with UV light, triggering a chain polymerization reaction of double bonds in the resin, and completing cross-linking and curing to form a film within seconds. Its curing process includes three stages: photoinitiation, chain growth, and chain termination. Existing UV curing systems rely on petroleum-based acrylate resins that are not environmentally friendly. Coatings made from a single bio-based material cannot achieve superhydrophobic function and require low surface energy micro-nano particles to increase their roughness. Cellulose is a renewable biomass polysaccharide that is widely distributed and abundant in nature. As a natural polymer material with good biocompatibility and renewability, it is an ideal filler for superhydrophobic coatings. However, cellulose has strong polarity, which leads to easy agglomeration in the matrix resin, thus affecting the superhydrophobic performance of the coating.

[0003] Traditional superhydrophobic coatings mostly rely on physical adsorption methods to construct micro-nano structures, such as using silica, carbon nanotubes or metal oxide nanoparticles combined with silicone resins / fluorocarbons. The initial contact angle of such coatings can reach more than 150°. However, the surface micro-structures are combined by van der Waals forces or hydrogen bonds and are prone to structural collapse under working conditions such as mechanical friction, raindrop impact or UV aging. Existing improvement schemes such as chemical vapor deposition and electrospinning can enhance the binding force, but they require high-temperature and high-pressure equipment (>300 °C) and introduce perfluoroalkyl substances, posing a risk of bioaccumulation. Therefore, it has become an urgent need to develop a chemically bonded superhydrophobic coating material with both high mechanical strength and environmental friendliness. Summary of the Invention

[0004] The first object of the present invention is to provide a bio-based superhydrophobic UV curable coating to solve at least one of the above technical problems.

[0005] The second object of the present invention is to provide a preparation method of the bio-based superhydrophobic UV curable coating to solve at least one of the above technical problems.

[0006] The third object of the present invention is to provide the application of the bio-based superhydrophobic UV curable coating in the surface treatment of substrates to solve at least one of the above technical problems.

[0007] According to the first aspect of the present invention, a bio-based superhydrophobic ultraviolet (UV) curable coating is provided, which is prepared from the following raw materials in parts by weight: 33 - 66 parts of vegetable oil-based reactive monomer, 20 - 45 parts of polythiol, 20 - 45 parts of modified cellulose, 15 - 150 parts of organic solvent, and 1 - 5 parts of photoinitiator;

[0008] Among them, the vegetable oil-based reactive monomer is prepared from epoxy vegetable oil, unsaturated organic compound and Lewis acid catalyst, and the unsaturated organic compound contains a hydroxyl group and a carbon-carbon double bond at the end of the molecular chain.

[0009] The bio-based UV curable coating of the present invention uses a vegetable oil-based reactive monomer, polythiol, and modified cellulose as raw materials, effectively introducing biomass resources into the UV curable coating, which is green and environmentally friendly. The three can form a three-dimensional interpenetrating network covalent crosslinking to construct a chemically bonded surface microstructure. The obtained bio-based superhydrophobic UV curable coating not only has superhydrophobic properties but also excellent wear resistance.

[0010] In some embodiments, the vegetable oil-based reactive monomer is prepared by the following steps:

[0011] (1) Dissolve epoxy vegetable oil and unsaturated organic compound in acetone to obtain solution A;

[0012] (2) Dissolve Lewis acid catalyst in acetone to obtain solution B;

[0013] (3) Slowly drop solution B into solution A and stir for 6 - 16 h to obtain the product.

[0014] In some embodiments, in step (1), solution A is obtained by dissolving epoxy vegetable oil and unsaturated organic compound in acetone and stirring for 5 - 10 min.

[0015] In some embodiments, in step (2), solution B is obtained by dissolving Lewis acid catalyst in acetone and stirring for 5 - 10 min.

[0016] In some embodiments, the epoxy vegetable oil is selected from at least one of epoxy soybean oil, epoxy castor oil, and epoxy linseed oil.

[0017] In some embodiments, the unsaturated organic compound is selected from at least one of unsaturated alcohols, unsaturated ethers, and unsaturated esters.

[0018] In some embodiments, the unsaturated alcohol is a C4 - C7 straight-chain or branched-chain fatty alcohol containing 1 - 2 carbon-carbon double bonds and 1 hydroxyl group; preferably, the unsaturated alcohol is selected from at least one of 3-buten-1-ol, methallyl alcohol, and 1,6-heptadien-4-ol.

[0019] In some embodiments, the unsaturated ether is an organic compound having an allyl ether and a hydroxyl group; preferably, the unsaturated ether is selected from at least one of glycerol-α,α'-diallyl ether and pentaerythritol triallyl ether.

[0020] In some embodiments, the unsaturated ester is an organic compound having an acrylate and a hydroxyl group; preferably, the unsaturated ester is pentaerythritol triacrylate.

[0021] In some embodiments, the Lewis acid catalyst is a boron trifluoride complex; preferably, the Lewis acid catalyst is selected from at least one of boron trifluoride diethyl etherate, boron trifluoride dimethyl etherate, and boron trifluoride dibutyl etherate.

[0022] In some embodiments, the mass ratio of the epoxy vegetable oil to the unsaturated organic compound is 2.5:(0.9 - 1.4).

[0023] In some embodiments, the dosage of the Lewis acid catalyst is 0.9% - 1.5% of the total mass of the epoxy vegetable oil and the unsaturated organic compound; preferably, the dosage of the Lewis acid catalyst is 1% of the total mass of the epoxy vegetable oil and the unsaturated organic compound.

[0024] In some embodiments, the modified cellulose is prepared from cellulose and a terminal double bond-containing silane through the following steps:

[0025] (1) Disperse the cellulose in an organic solvent and stir for 5 - 20 min in a nitrogen atmosphere to obtain a cellulose suspension;

[0026] (2) Slowly add 5 - 20 mL of the terminal double bond-containing silane to the cellulose suspension and stir for 2 - 12 h to obtain the product.

[0027] In some embodiments, the organic solvent is selected from at least one of tetrahydrofuran, acetone, cyclohexane, ethyl acetate, and ethanol.

[0028] In some embodiments, the terminal double bond-containing silane is selected from at least one of 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, vinyltriethoxysilane, methacryloxypropyltris(trimethylsiloxy)silane, (3-acryloxypropyl)tris(trimethylsiloxy)silane, 2-(methacryloxy)ethyl[3-(triethoxysilyl)propyl]carbamate, and trichlorovinylsilane.

[0029] In some other embodiments, the modified cellulose is prepared from cellulose and a terminal double bond-containing acyl chloride through the following steps:

[0030] (1) Disperse cellulose in N,N-dimethylacetamide, centrifuge, disperse the supernatant obtained after centrifugation in acetone, centrifuge for the second time, and disperse the supernatant obtained after the second centrifugation in N,N-dimethylacetamide to obtain an N,N-dimethylacetamide dispersion containing cellulose;

[0031] (2) Add 5 - 20 mL of pyridine and 3 - 20 mL of acyl chloride with terminal double bond to the N,N-dimethylacetamide dispersion containing cellulose, and reflux and heat with stirring at 60 - 90 °C for 0.5 - 3 h to obtain the product.

[0032] In some embodiments, in step (1), a centrifuge is used to disperse cellulose in N,N-dimethylacetamide, acetone, and N,N-dimethylacetamide solution.

[0033] In some embodiments, the acyl chloride with terminal double bond is selected from at least one of 10-undecenoyl chloride, but-3-enoyl chloride, allyl oxalyl chloride, and diallylcarbamoyl chloride.

[0034] In some embodiments, cellulose is selected from at least one of α-cellulose, microcrystalline cellulose, cellulose microfibrils, cellulose nanofibers, cellulose nanocrystals, and micro-nano cellulose extracted from straw.

[0035] In some embodiments, the dosage of the modified cellulose is 9% - 40% of the total mass of the vegetable oil-based active monomer, polythiol, modified cellulose, and photoinitiator.

[0036] In some embodiments, the photoinitiator is selected from at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, α,α-dimethoxy-α-phenylacetophenone, ethyl 2,4,6-trimethylbenzoyl phenylphosphinate, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 1-hydroxycyclohexyl phenyl ketone, and diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate.

[0037] In some embodiments, the polythiol is selected from at least one of ethylene glycol bis(3-mercaptopropionate), 1,4-butanediol bis(mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(mercaptoacetate), pentaerythritol tetra(3-mercaptopropionate), and dipentaerythritol hexa(3-mercaptopropionate).

[0038] According to the second aspect of the present invention, a preparation method of a bio-based superhydrophobic ultraviolet curable coating is provided, including the following steps: Mix a vegetable oil-based active monomer, polythiol, modified cellulose, organic solvent, and photoinitiator to obtain the product.

[0039] The preparation method of the bio-based superhydrophobic UV-curable coating of the present invention is simple. The vegetable oil-based reactive monomer has a double bond structure, and the polyhydric thiol can crosslink with the vegetable oil-based reactive monomer and cellulose under UV curing conditions to achieve efficient curing of the coating without oxygen inhibition polymerization.

[0040] According to the third aspect of the present invention, there is provided an application of the bio-based superhydrophobic UV-curable coating in the surface treatment of substrates.

[0041] The bio-based superhydrophobic UV-curable coating of the present invention can be coated on the surface of a substrate and form a superhydrophobic coating with self-cleaning behavior on the surface of the substrate through UV curing.

[0042] In some embodiments, the substrates include iron products, plastic products, glass products, wood products and paper.

[0043] The beneficial effects of the present invention are as follows:

[0044] (1) Aiming at the technical bottleneck that the physical adsorption micro-nano structure of the traditional superhydrophobic coating is easy to fall off, the bio-based superhydrophobic UV-curable coating of the present invention selects vegetable oil-based reactive monomers, polyhydric thiols and cellulose as raw materials. When curing into a film, the three-dimensional interpenetrating network covalent crosslinking of the vegetable oil-based reactive monomer, polyhydric thiol and cellulose in the coating constructs a chemically bonded surface micro-structure. Through wear resistance tests, it shows that the water contact angle of the coating still remains >150° after 50 cycles, realizing the long-term retention of superhydrophobic performance;

[0045] (2) The present invention adopts a thiol-ene click chemistry curing system. Through the double bond functionalization design of the ends of epoxy vegetable oil and cellulose molecules, and in cooperation with polyhydric thiols as multi-functional thiol crosslinking agents, efficient curing of the coating without oxygen inhibition polymerization is achieved under UV light irradiation;

[0046] (3) The superhydrophobic UV-curable coating of the present invention, with vegetable oil-based reactive monomers and cellulose prepared from epoxy vegetable oil as the main raw materials, can effectively apply biomass resources to UV-curable coatings, reduce the use of petroleum-based acrylic resins, play a positive role in protecting the environment, and also increase the added value of biomass resources. Description of the Drawings

[0047] Figure 1 It is a schematic diagram of the synthesis route of the vegetable oil-based reactive monomer of the present invention;

[0048] Figure 2 It is the Fourier transform infrared spectrogram of α-cellulose and modified cellulose of the present invention;

[0049] Figure 3 It is the Fourier transform infrared spectrogram of epoxy soybean oil and vegetable oil-based reactive monomer of the present invention;

[0050] Figure 4 The surface morphology of the coatings prepared from the bio-based superhydrophobic UV-curable coatings of Examples 1-2 of the present invention and the bio-based UV-curable coatings of Comparative Examples 1-3;

[0051] Figure 5 The water contact angles of the coatings prepared from the bio-based superhydrophobic UV-curable coatings of Examples 1-2 of the present invention and the bio-based UV-curable coatings of Comparative Examples 1-6;

[0052] Figure 6 The self-cleaning effect of the superhydrophobic coating prepared from the bio-based superhydrophobic UV-curable coating of Example 1 of the present invention. Detailed implementation manners

[0053] The present invention will be further described in detail below with reference to the accompanying drawings, but the implementation manners of the present invention are not limited thereto. The raw materials and reagents involved in the following examples are all commercially available.

[0054] Figure 1 It is a schematic diagram of the synthesis route of the vegetable oil-based reactive monomer of the present invention. Epoxidized soybean oil and 3-buten-1-ol undergo a nucleophilic substitution reaction under the action of a Lewis acid catalyst to obtain soybean oil-based allyl ether. Specifically, the Lewis acid catalyst interacts with the epoxy groups of epoxidized soybean oil to open the epoxy groups, and the alcohol hydroxyl group (-OH) of 3-buten-1-ol attacks the epoxidized soybean oil after ring opening, and the oxygen atom of the alcohol hydroxyl group forms a new C-O bond with the carbon atom after the epoxy group is opened.

[0055] It should be noted that this synthesis route is only one of the implementation manners of the present invention. Unsaturated organic compounds containing hydroxyl groups and carbon-carbon double bond structures at the ends of molecular chains can react with epoxidized vegetable oils to obtain vegetable oil-based reactive monomers. Specifically, the unsaturated organic compounds can be unsaturated alcohols, unsaturated ethers or unsaturated esters. Among them, the epoxidized vegetable oil can be selected from at least one of epoxidized soybean oil, epoxidized castor oil, and epoxidized linseed oil; the unsaturated alcohol can be a C4-C7 straight-chain or branched-chain fatty alcohol containing 1-2 carbon-carbon double bonds and 1 hydroxyl group, such as 3-buten-1-ol, methallyl alcohol, 1,6-heptadien-4-ol; the unsaturated ether can be an allyl ether structure, such as glycerol-α,α'-diallyl ether, pentaerythritol triallyl ether; the unsaturated ester can be an allyl ester structure, such as pentaerythritol triacrylate. The Lewis acid catalyst can be a boron trifluoride complex, such as boron trifluoride diethyl ether, boron trifluoride dimethyl ether, boron trifluoride dibutyl ether.

[0056] Example 1

[0057] This example provides a preparation method of a bio-based superhydrophobic UV-curable coating, including the following steps:

[0058] (1) Preparation of modified cellulose: Using the solvent exchange method, 1 g of α-cellulose was dispersed in N,N-dimethylacetamide, centrifuged with a centrifuge. The supernatant obtained after centrifugation was dispersed in acetone and centrifuged again with a centrifuge. The supernatant obtained after centrifugation was dispersed in N,N-dimethylacetamide, and 8.9 mL of pyridine and 8.0 mL of 10-undecenoyl chloride were added, followed by reflux heating and stirring at 80 °C for 1 h to obtain modified cellulose;

[0059] (2) Preparation of vegetable oil-based reactive monomer: 50 g of epoxy soybean oil and 18 g of 3-buten-1-ol were dissolved in 50 g of acetone, and stirred at room temperature for 5 min to obtain solution A; 0.68 g of catalyst boron trifluoride diethyl ether was dissolved in 20 g of acetone, and stirred at room temperature for 5 min to obtain solution B; solution B was slowly dropped into solution A, and stirring was continued for 8 h to obtain the vegetable oil-based reactive monomer;

[0060] (3) Preparation of bio-based superhydrophobic UV-curable coating: 4.96 g of vegetable oil-based reactive monomer and 2.38 g of pentaerythritol tetra(mercaptoacetate) were dissolved in 30 mL of tetrahydrofuran solution, and stirred for 10 min; then 3.14 g of modified cellulose was added, and stirring was continued for 10 min; finally, 0.52 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone was added, and stirring was carried out in the dark for 5 min. A bio-based superhydrophobic UV-curable coating was obtained.

[0061] The α-cellulose and modified cellulose were characterized by infrared spectroscopy using a Thermo Fisher Nicolet iS10 Fourier transform infrared spectrometer, and the results are as Figure 2 shown. It can be seen from Figure 2 that new characteristic peaks appeared after the modification of α-cellulose with 10-undecenoyl chloride. The characteristic peak at 3077 cm -1 was attributed to the C═C stretching vibration on 10-undecenoyl chloride; the characteristic peak at 1742 cm -1 was attributed to the C═O stretching vibration; the characteristic peaks at 2925 cm -1 and 2857 cm -1 belonged to CH3 and CH2 respectively; while the characteristic peaks at 1639 cm -1 and 908 cm -1 were attributed to the blue shift of the C═C stretching vibration and the ═C-H deformation vibration respectively. In addition, the appearance of the C-Cl stretching vibration peak was not observed at 725 cm -1 in the infrared spectrum of the modified cellulose, indicating that 10-undecenoyl chloride reacted completely with α-cellulose. The above results fully demonstrate that α-cellulose was successfully modified after being treated with 10-undecenoyl chloride to obtain modified cellulose containing terminal double bonds.

[0062] The infrared spectra of epoxidized soybean oil and vegetable oil-based reactive monomers were characterized using a Thermo Fisher Nicolet iS10 Fourier transform infrared spectrometer, and the results are as Figure 3 shown. It can be seen from Figure 3 that after the reaction of epoxidized soybean oil with 3-buten-1-ol, the epoxy peaks at 823 cm -1 and 843 cm -1 disappeared, and a stronger hydroxyl peak appeared at 3475 cm -1 . This is because a small amount of hydroxyl groups were generated by the ring-opening of epoxidized soybean oil. After the ring-opening reaction was completed, the vegetable oil-based reactive monomer obtained had a large number of hydroxyl groups. It can also be observed that a new characteristic peak appeared at 1638 cm -1 for the vegetable oil-based reactive monomer, which is attributed to the C=C stretching vibration peak of 3-buten-1-ol. The above results indicate that the ring-opening reaction of epoxidized soybean oil has been completed, and the double bond of 3-buten-1-ol has been successfully grafted onto epoxidized soybean oil, and the obtained vegetable oil-based reactive monomer is soybean oil-based allyl ether.

[0063] Example 2

[0064] This example provides a method for preparing a bio-based superhydrophobic ultraviolet curable coating, which includes the following steps:

[0065] (1) Preparation of modified cellulose: Using the solvent exchange method, 1 g of α-cellulose was dispersed in N,N-dimethylacetamide, centrifuged with a centrifuge, the supernatant obtained after centrifugation was dispersed in acetone, centrifuged again with a centrifuge, the supernatant obtained after centrifugation was dispersed in N,N-dimethylacetamide, and then 8.9 mL of pyridine and 8.0 mL of 10-undecenoyl chloride were added, and the mixture was refluxed and stirred at 80 °C for 1 h to obtain modified cellulose;

[0066] (2) Preparation of vegetable oil-based reactive monomer: 50 g of epoxidized soybean oil and 18 g of 3-buten-1-ol were dissolved in 50 g of acetone, and stirred at room temperature for 5 min to obtain solution A; 0.68 g of boron trifluoride diethyl etherate catalyst was dissolved in 20 g of acetone, and stirred at room temperature for 5 min to obtain solution B; solution B was slowly added dropwise to solution A, and stirring was continued for 8 h to obtain the vegetable oil-based reactive monomer;

[0067] (3) Preparation of bio-based ultraviolet curable coating: 4.96 g of vegetable oil-based reactive monomer and 2.38 g of pentaerythritol tetra(mercaptoacetate) were dissolved in 40 mL of tetrahydrofuran solution, and stirred for 10 min; then 4.89 g of modified cellulose was added, and stirring was continued for 10 min; finally, 0.61 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone was added, and stirring was carried out in the dark for 5 min. A bio-based superhydrophobic ultraviolet curable coating was obtained.

[0068] Example 3

[0069] This embodiment provides a method for preparing a bio-based superhydrophobic ultraviolet curable coating, which includes the following steps:

[0070] (1) Preparation of modified cellulose: Using the solvent exchange method, disperse 1 g of α-cellulose in N,N-dimethylacetamide, centrifuge with a centrifuge, disperse the supernatant obtained after centrifugation in acetone, centrifuge again with a centrifuge, disperse the supernatant obtained after centrifugation in N,N-dimethylacetamide, then add 5.0 mL of pyridine and 3.0 mL of 10-undecenoyl chloride, and reflux and heat with stirring at 60 °C for 0.5 h to obtain modified cellulose;

[0071] (2) Preparation of vegetable oil-based reactive monomer: Dissolve 50 g of epoxidized soybean oil and 18 g of 3-buten-1-ol in 50 g of acetone, stir at room temperature for 5 min to obtain solution A; dissolve 0.68 g of catalyst boron trifluoride diethyl ether in 20 g of acetone, stir at room temperature for 5 min to obtain solution B; slowly drop solution B into solution A, and continue to stir for 6 h to obtain the vegetable oil-based reactive monomer;

[0072] (3) Preparation of bio-based superhydrophobic ultraviolet curable coating: Dissolve 4.96 g of vegetable oil-based reactive monomer and 2.38 g of pentaerythritol tetra(mercaptoacetate) in 20 mL of tetrahydrofuran solution, stir for 10 min; then add 0.82 g of modified cellulose and continue to stir for 10 min; finally add 0.4 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone, and stir in the dark for 5 min. To obtain the bio-based superhydrophobic ultraviolet curable coating.

[0073] Example 4

[0074] This embodiment provides a method for preparing a bio-based superhydrophobic ultraviolet curable coating, which includes the following steps:

[0075] (1) Preparation of modified cellulose: Using the solvent exchange method, disperse 1 g of α-cellulose in N,N-dimethylacetamide, centrifuge with a centrifuge, disperse the supernatant obtained after centrifugation in acetone, centrifuge again with a centrifuge, disperse the supernatant obtained after centrifugation in N,N-dimethylacetamide, then add 20.0 mL of pyridine and 20.0 mL of 10-undecenoyl chloride, and reflux and heat with stirring at 90 °C for 3 h to obtain modified cellulose;

[0076] (2) Preparation of vegetable oil-based reactive monomer: Dissolve 50 g of epoxidized soybean oil and 18 g of 3-buten-1-ol in 50 g of acetone, stir at room temperature for 10 min to obtain solution A; dissolve 0.68 g of catalyst boron trifluoride diethyl ether in 20 g of acetone, stir at room temperature for 5 min to obtain solution B; slowly drop solution B into solution A, and continue to stir for 16 h to obtain the vegetable oil-based reactive monomer;

[0077] (3) Preparation of bio-based superhydrophobic UV-curable coating: Dissolve 4.96 g of vegetable oil-based reactive monomer and 2.38 g of pentaerythritol tetrakis(mercaptoacetate) in 40 mL of tetrahydrofuran solution, and stir for 10 min; then add 4.89 g of modified cellulose and continue stirring for 10 min; finally, add 0.61 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone and stir in the dark for 5 min. The bio-based superhydrophobic UV-curable coating is obtained.

[0078] Comparative Example 1

[0079] This example provides a preparation method of a bio-based UV-curable coating, which includes the following steps:

[0080] (1) Preparation of modified cellulose: Using the solvent exchange method, disperse 1 g of α-cellulose in N,N-dimethylacetamide, centrifuge with a centrifuge, disperse the supernatant obtained after centrifugation in acetone, centrifuge again with a centrifuge, disperse the supernatant obtained after centrifugation in N,N-dimethylacetamide, then add 8.9 mL of pyridine and 8.0 mL of 10-undecenoyl chloride, and reflux and stir at 80 °C for 1 h to obtain modified cellulose;

[0081] (2) Preparation of vegetable oil-based reactive monomer: Dissolve 50 g of epoxidized soybean oil and 18 g of 3-buten-1-ol in 50 g of acetone, and stir at room temperature for 5 min to obtain Solution A; dissolve 0.68 g of catalyst boron trifluoride diethyl etherate in 20 g of acetone, and stir at room temperature for 5 min to obtain Solution B; slowly drop Solution B into Solution A and continue stirring for 8 h to obtain the vegetable oil-based reactive monomer;

[0082] (3) Preparation of bio-based UV-curable coating: Dissolve 4.96 g of vegetable oil-based reactive monomer and 2.38 g of pentaerythritol tetrakis(mercaptoacetate) in 20 mL of tetrahydrofuran solution (17.78 g), and stir for 10 min; then add 0.82 g of modified cellulose and continue stirring for 10 min; finally, add 0.4 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone and stir in the dark for 5 min. The bio-based UV-curable coating is obtained.

[0083] Comparative Example 2

[0084] This example provides a preparation method of a bio-based UV-curable coating, which includes the following steps:

[0085] (1) Preparation of modified cellulose: Using the solvent exchange method, 1 g of α-cellulose was dispersed in N,N-dimethylacetamide, centrifuged with a centrifuge. The supernatant obtained after centrifugation was dispersed in acetone and centrifuged again with a centrifuge. The supernatant obtained after centrifugation was dispersed in N,N-dimethylacetamide, and then 8.9 mL of pyridine and 8.0 mL of 10-undecenoyl chloride were added, and the mixture was refluxed and stirred at 80 °C for 1 h to obtain modified cellulose;

[0086] (2) Preparation of vegetable oil-based reactive monomer: 50 g of epoxidized soybean oil and 18 g of 3-buten-1-ol were dissolved in 50 g of acetone, and stirred at room temperature for 5 min to obtain solution A; 0.68 g of catalyst boron trifluoride diethyl ether was dissolved in 20 g of acetone, and stirred at room temperature for 5 min to obtain solution B; Solution B was slowly added dropwise to solution A, and stirring was continued for 8 h to obtain the vegetable oil-based reactive monomer;

[0087] (3) Preparation of bio-based UV-curable coating: 4.96 g of vegetable oil-based reactive monomer and 2.38 g of pentaerythritol tetra(mercaptoacetate) were dissolved in 20 mL of tetrahydrofuran solution, and stirred for 10 min; then 1.84 g of modified cellulose was added, and stirring was continued for 10 min; finally, 0.46 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone was added, and stirred in the dark for 5 min. A bio-based UV-curable coating was obtained.

[0088] Comparative Example 3

[0089] This comparative example provides a preparation method of a bio-based UV-curable coating, including the following steps:

[0090] (1) Preparation of vegetable oil-based reactive monomer: 50 g of epoxidized soybean oil and 18 g of 3-buten-1-ol were dissolved in 50 g of acetone, and stirred at room temperature for 5 min to obtain solution A; 0.68 g of catalyst boron trifluoride diethyl ether was dissolved in 20 g of acetone, and stirred at room temperature for 5 min to obtain solution B; Solution B was slowly added dropwise to solution A, and stirring was continued for 8 h to obtain the vegetable oil-based reactive monomer;

[0091] (2) Preparation of bio-based UV-curable coating: 4.96 g of vegetable oil-based reactive monomer and 2.38 g of pentaerythritol tetra(mercaptoacetate) were dissolved in 20 mL of tetrahydrofuran solution, and stirred for 10 min; then 0.37 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone was added, and stirred in the dark for 5 min. A bio-based UV-curable coating was obtained.

[0092] Comparative Example 4

[0093] This comparative example provides a preparation method of a bio-based UV-curable coating, including the following steps:

[0094] (1) Preparation of vegetable oil-based reactive monomer: Dissolve 50 g of epoxidized soybean oil and 18 g of 3-buten-1-ol in 50 g of acetone, and stir at room temperature for 5 min to obtain Solution A; dissolve 0.68 g of boron trifluoride ethyl etherate catalyst in 20 g of acetone, and stir at room temperature for 5 min to obtain Solution B; slowly drop Solution B into Solution A, and continue stirring for 8 h to obtain the vegetable oil-based reactive monomer;

[0095] (2) Preparation of bio-based hydrophobic UV-curable coating: Dissolve 4.96 g of vegetable oil-based reactive monomer and 2.38 g of pentaerythritol tetra(mercaptoacetate) in 20 mL of tetrahydrofuran solution, and stir for 10 min; then add 3.14 g of α-cellulose, and continue stirring for 10 min; finally add 0.37 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone, and stir in the dark for 5 min. Obtain the bio-based UV-curable coating.

[0096] Comparative Example 5

[0097] This comparative example provides a preparation method of a bio-based superhydrophobic UV-curable coating, including the following steps:

[0098] (1) Preparation of modified cellulose: Using the solvent exchange method, disperse 1 g of α-cellulose in N,N-dimethylacetamide, centrifuge with a centrifuge, disperse the supernatant obtained after centrifugation in acetone, centrifuge again with a centrifuge, disperse the supernatant obtained after centrifugation in N,N-dimethylacetamide, then add 8.9 mL of pyridine and 8.0 mL of 10-undecenoyl chloride, and reflux and heat with stirring at 80 °C for 1 h to obtain modified cellulose;

[0099] (2) Preparation of vegetable oil-based reactive monomer: Dissolve 50 g of epoxidized soybean oil and 18 g of 3-buten-1-ol in 50 g of acetone, and stir at room temperature for 5 min to obtain Solution A; dissolve 0.68 g of boron trifluoride ethyl etherate catalyst in 20 g of acetone, and stir at room temperature for 5 min to obtain Solution B; slowly drop Solution B into Solution A, and continue stirring for 8 h to obtain the vegetable oil-based reactive monomer;

[0100] (3) Preparation of bio-based superhydrophobic UV-curable coating: Dissolve 2.48 g of vegetable oil-based reactive monomer and 1.31 g of ethylene glycol bis(3-mercaptopropionate) in 30 mL of tetrahydrofuran solution, and stir for 10 min; then add 0.42 g of modified cellulose, and continue stirring for 10 min; finally add 0.21 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone, and stir in the dark for 5 min. Obtain the bio-based superhydrophobic UV-curable coating.

[0101] Comparative Example 6

[0102] This comparative example provides a preparation method of a bio-based superhydrophobic UV-curable coating, including the following steps:

[0103] (1) Preparation of modified cellulose: Using the solvent exchange method, 1 g of α-cellulose was dispersed in N,N-dimethylacetamide, centrifuged with a centrifuge. The supernatant obtained after centrifugation was dispersed in acetone, and then centrifuged again with a centrifuge. The supernatant obtained after centrifugation was dispersed in N,N-dimethylacetamide, and then 8.9 mL of pyridine and 8.0 mL of 10-undecenoyl chloride were added. It was refluxed and stirred at 80 °C for 1 h to obtain modified cellulose;

[0104] (2) Preparation of vegetable oil-based reactive monomer: 50 g of epoxidized soybean oil and 18 g of 3-buten-1-ol were dissolved in 50 g of acetone, and stirred at room temperature for 5 min, which was called solution A; 0.68 g of boron trifluoride ethyl ether catalyst was dissolved in 20 g of acetone, and stirred at room temperature for 5 min, which was called solution B; Solution B was slowly dropped into solution A, and stirring was continued for 8 h to obtain the vegetable oil-based reactive monomer;

[0105] (3) Preparation of bio-based superhydrophobic UV-curable coating: 3.72 g of vegetable oil-based reactive monomer and 2.19 g of trimethylolpropane tris(3-mercaptopropionate) were dissolved in 30 mL of tetrahydrofuran solution, and stirred for 10 min; Subsequently, 0.66 g of modified cellulose was added, and stirring was continued for 10 min; Finally, 0.32 g of photoinitiator α,α-dimethoxy-α-phenylacetophenone was added, and stirring was carried out in the dark for 5 min. A bio-based superhydrophobic UV-curable coating was obtained.

[0106] Test Example 1

[0107] In this test example, the bio-based UV-curable coatings prepared in Example 1, Example 2 and Comparative Examples 1-3 were respectively prepared into coatings, and the surface morphologies of the coatings were observed respectively to study the influence of the addition of modified cellulose on the surface morphology of the coatings.

[0108] The preparation method of the coating was to spray the bio-based UV-curable coatings prepared in Examples 1-2 and Comparative Examples 1-3 on the glass surface with a spray gun at a pressure of 0.2 MPa, and irradiate with a UV lamp with a wavelength of 365 nm for 10 min to obtain.

[0109] Observation was carried out using a ZEISS EVO18 scanning electron microscope. Before observation, gold was plated on the surface of the coating. The observation results of the surface morphology are as Figure 4 shown. From Figure 4It can be seen that the surface of the coating in Comparative Example 3 is smooth and without protrusions. This is because no cellulose was introduced in Comparative Example 3 to increase the roughness of the coating surface. Due to the introduction of modified cellulose, protrusions can be observed on the surfaces of the coatings obtained in Example 1, Example 2, Comparative Example 1, and Comparative Example 2. Among them, 0.82 g and 1.84 g of modified cellulose were respectively added to the coatings in Example 3 and Example 4, and there are fewer micro-nano rods with protrusions on the surfaces of their coatings. 3.14 g and 4.19 g of modified cellulose were respectively added to the coatings in Example 1 and Example 2. It can be observed that the protrusions on the surfaces of the prepared coatings are relatively dense, indicating that the difference in the addition amount of modified cellulose will affect the surface morphology of the coating. As the content of modified cellulose increases, the protrusion density on the coating surface increases and the roughness increases.

[0110] Test Example 2

[0111] In this test example, the bio-based UV-curable coatings prepared in Examples 1-2 and Comparative Examples 1-6 were respectively made into coatings, and the surface morphologies of the coatings were observed respectively to study the influence of the addition of modified cellulose on the surface morphology of the coatings.

[0112] The preparation method of the coating is as follows: The bio-based UV-curable coatings prepared in Examples 1-2 and Comparative Examples 1-6 were respectively sprayed on the glass surface with a spray gun at a pressure of 0.2 MPa, and irradiated with a UV lamp with a wavelength of 365 nm for 10 min to obtain the coatings.

[0113] The water contact angles of the coatings prepared in Examples 1-2 and Comparative Examples 1-6 were measured using a Shanghai Zhongchen JC2000C1 contact angle measuring instrument, and the results are as Figure 5 shown in Table 1.

[0114] Table 1 Results of water contact angle measurement

[0115]

[0116] From Figure 5As can be seen from Table 1, the water contact angle of the coating without cellulose added is only 62°, and the measurement result is the lowest. This is because there are no two factors with superhydrophobicity on the coating surface: surface roughness and low surface energy. The water contact angle of the coating surface made of the coating containing 28.94 wt% α-cellulose is 92°, indicating that the coating has a hydrophobic effect. This is the hydrophobicity given to the coating surface by the combination of the properties of the raw materials themselves and the roughness provided by cellulose. The water contact angle of the coating surface made of the coating containing 9.58 wt% modified cellulose is 75°. At this time, the coating surface has hydrophilicity. When the content of modified cellulose in the coating increases to 19.09 wt%, the water contact angle of the coating surface increases to 137°. At this time, the coating shows hydrophobicity. This is because as the content of modified cellulose increases, not only more low-surface-energy nanoparticles are introduced onto the coating surface, but also the roughness increases. When the content of modified cellulose is 28.55 wt% and 38.08 wt%, the water contact angle of the coating surface reaches more than 160°, indicating that the coating has superhydrophobicity. By comparing the water contact angle measurement results of Example 1, Example 2, Comparative Example 1 and Comparative Example 2, it can be found that the increase in the content of modified cellulose in the coating can change the surface properties of the coating and endow the coating surface with superhydrophobic behavior.

[0117] By comparing the water contact angle measurement results of Example 1 and Comparative Example 4, it is found that after the raw material of the coating is replaced from α-cellulose to modified cellulose, the water contact angle increases from 92° to 165°, and the coating changes from hydrophobic to superhydrophobic. This is because the introduction of modified cellulose can endow the coating surface with superhydrophobic behavior. Specifically, there is a hydrophobic long carbon chain in the 10-undecenoyl chloride structure. Introducing 10-undecenoyl chloride into cellulose changes the wettability of cellulose, and the modified cellulose obtained by modification changes from superhydrophilic to superhydrophobic. The water contact angle measurement results of Comparative Example 3 and Comparative Example 4 are both greater than 160°, indicating that the polyvalent thiol with a thiol functionality of 2-4 can form a crosslinked network through the thiol-ene click reaction between the thiol and the vegetable oil-based reactive monomer, thereby changing the surface wettability of the coating.

[0118] Test Example 3

[0119] In this test example, the coatings prepared from the bio-based superhydrophobic UV-curable coatings of Example 1, Comparative Example 5 and Comparative Example 6 were subjected to wear resistance tests to study the influence of the selection of polyvalent thiols on the wear resistance of the coatings.

[0120] The coating preparation method is as follows: The bio-based superhydrophobic UV-curable coatings of Example 1, Comparative Example 5 and Comparative Example 6 were respectively sprayed on the glass surface with a spray gun at a pressure of 0.2 MPa and irradiated with a UV lamp with a wavelength of 365 nm for 10 min to obtain the coatings.

[0121] Wear resistance test: The reciprocating friction test was used to simulate the wear situation of the coating during daily use. A 100 g weight was pressed on the surface of the coating, and 600-grit sandpaper was selected as the friction medium to move back and forth on the coating surface for polishing. Each 20 cm of friction was recorded as 1 reciprocating friction. The water contact angle of the coating surface was measured using a Shanghai Zhongchen JC2000C1 contact angle measuring instrument, and the measurement was taken three times and the average value of the results was taken.

[0122] The wear resistance test results are shown in Table 2. As can be seen from Table 2, the coating obtained by curing the bio-based superhydrophobic UV-curable coating of Example 1 was subjected to 50 reciprocating frictions, and the water contact angle on the coating surface was as high as 153.4 ± 1.1°, still showing superhydrophobicity. This is because pentaerythritol tetra(mercaptoacetate) in the coating of Example 1 is a tetra-thiol, which undergoes a thiol-ene click chemical reaction with the double bonds of the vegetable oil-based active monomer and modified cellulose to carry out three-dimensional interpenetrating network covalent crosslinking of the vegetable oil-based active monomer, poly-thiol and modified cellulose, resulting in a coating with high crosslinking degree and excellent wear resistance. The change in the crosslinking degree of the coating will have a certain impact on the wear resistance of the coating, manifested as a decrease in the crosslinking degree of the coating and a weakening of the intermolecular binding strength of the coating, thereby affecting its wear resistance. In the bio-based superhydrophobic UV-curable coating of Comparative Example 5, ethylene glycol bis(3-mercaptopropionate) is a di-thiol. After the coating obtained by curing into a film was subjected to 400 cm of reciprocating friction, it lost its superhydrophobic behavior; in the bio-based superhydrophobic UV-curable coating of Comparative Example 6, trimethylolpropane tris(3-mercaptopropionate) is a tri-thiol. After the coating obtained by curing into a film was subjected to more than 600 cm of reciprocating friction, it lost its superhydrophobic behavior. By comparing the water contact angle measurement results of different coatings after reciprocating friction in Table 2, it can be found that although the water contact angles on the surfaces of the coatings of Example 1, Comparative Example 5 and Comparative Example 6 all reached 160° before the reciprocating friction started, the coatings of Comparative Example 5 and Comparative Example 6 lost their superhydrophobic behavior after reciprocating friction, attributed to the fact that the number of thiols combined with the vegetable oil-based active monomer and modified cellulose in the coatings of Comparative Example 5 and Comparative Example 6 is lower than that of the coating of Example 1, and the crosslinking degree of the coating obtained by curing into a film is lower than that of the coating obtained by curing the coating of Comparative Example 5 into a film.

[0123] Table 2 Wear resistance test results

[0124] Coating 0 cm(°) 200 cm(°) 400 cm(°) 600 cm(°) 800 cm(°) 1000 cm(°) Example 1 165.3±1.2 162.5±2.0 160.1±1.5 159.7±3.2 155.6±0.2 153.4±1.1 Comparative Example 5 160.5±2.5 152.3±2.7 150.6±3.3 141.5±2.6 134.7±2.1 130.8±1.6 Comparative Example 6 163.4±1.3 157.6±3.4 155.4±2.7 153.2±1.7 146.8±0.7 137.6±1.9

[0125] Test Example 4

[0126] In this test example, the bio-based superhydrophobic UV-curable coating of Example 1 was prepared into a sample for self-cleaning test to study the potential of the coating's self-cleaning behavior in practical applications.

[0127] Sample preparation: The bio-based superhydrophobic UV-curable coating prepared in Example 1 was sprayed on the glass surface with a spray gun at a pressure of 0.2 MPa and irradiated with a UV lamp with a wavelength of 365 nm for 10 min to obtain the coating.

[0128] The self-cleaning behavior is a demonstration to verify the practical application potential of the superhydrophobic surface. First, the sample was tilted to an angle of about 20° with the horizontal plane to form a slope on the sample surface. Silica particles were randomly scattered on the sample surface, and then water droplets were continuously dropped from the upper part of the slope. The process is as Figure 6 shown.

[0129] As Figure 6 can be seen, after the silica particles were scattered, the silica particles remained on the sample surface. After the water droplets were flushed, the water droplets rolled along the slope and carried the particles away when they encountered the silica particles. Finally, it was observed that no particles remained on the sample surface. The above process shows that the coating of the bio-based superhydrophobic UV-curable coating has self-cleaning behavior. This self-cleaning behavior benefits from the superhydrophobicity of the coating surface. Due to the low surface energy, the coating surface is prevented from being wetted by water droplets. The water droplets cannot spread out on the coating surface and still maintain a spherical shape. Coupled with the microscopic structure of the surface, the actual contact area between the water droplets and the surface is very small. Therefore, the water droplets roll down along the slope by gravity and carry away the solid pollutant particles to complete the self-cleaning behavior. The test results show that the self-cleaning behavior of the bio-based superhydrophobic UV-curable coating of the present invention has application potential in the surface treatment of substrates. Specifically, the bio-based superhydrophobic UV-curable coating can be coated on the substrate surface and then cured by UV light to form a superhydrophobic coating on the substrate surface, and the pollutant particles on the substrate surface are carried away by the self-cleaning behavior of the coating.

[0130] In summary, the technical effects of the present invention are as follows:

[0131] (1) To solve the technical problem that the traditional superhydrophobic coating is prone to structural collapse, the preparation raw materials of the bio-based superhydrophobic UV-curable coating of the present invention are selected as cellulose, vegetable oil-based active monomers and polyhydric thiols. The three are covalently crosslinked to form a three-dimensional interpenetrating network structure during the UV curing process, thereby constructing a chemically bonded surface microstructure with excellent wear resistance. The cured coating has excellent wear resistance and still maintains superhydrophobic performance after 1000 cm of reciprocating friction;

[0132] (2) The present invention uses epoxy vegetable oil and cellulose as raw materials, which are green and environmentally friendly. The molecular terminals of epoxy vegetable oil and cellulose are respectively designed with double-bond functional groups. Epoxy vegetable oil reacts with unsaturated organic compounds containing hydroxyl groups and carbon-carbon double bonds at the molecular chain terminals. Cellulose is modified with acyl chloride containing terminal double bonds or silane containing terminal double bonds to obtain vegetable oil-based active monomers and modified cellulose with double-bond structures respectively. The vegetable oil-based active monomers and modified cellulose undergo thiol-ene click reactions through double bonds with polyvalent thiols in ultraviolet curing to achieve highly efficient curing without oxygen inhibition polymerization.

[0133] (3) The bio-based superhydrophobic ultraviolet curable coating of the present invention is coated on the surface of a substrate, and a coating with self-cleaning behavior is formed on the surface of the substrate through ultraviolet curing, and solid pollutant particles on the surface of the substrate can be removed through self-cleaning.

[0134] The above are only some embodiments of the present invention. For those of ordinary skill in the art, without departing from the inventive concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. Bio-based superhydrophobic UV-curable coating, characterized in that, It is prepared from the following raw materials in parts by weight: 33-66 parts of vegetable oil-based active monomer, 20-45 parts of polyhydric thiol, 20-45 parts of modified cellulose, 15-150 parts of organic solvent, and 1-5 parts of photoinitiator; Among them, the vegetable oil-based active monomer is prepared from epoxy vegetable oil, unsaturated organic compound and Lewis acid catalyst, and the unsaturated organic compound contains hydroxyl group and carbon-carbon double bond at the end of the molecular chain.

2. The bio-based superhydrophobic UV-curable coating according to claim 1, wherein The vegetable oil-based active monomer is prepared from epoxy vegetable oil, unsaturated organic compound and Lewis acid catalyst through the following steps: (1) Dissolve epoxy vegetable oil and unsaturated organic compound in an organic solvent to obtain solution A; (2) Dissolve Lewis acid catalyst in an organic solvent to obtain solution B; (3) Slowly drop solution B into solution A and stir for 6-16 h to obtain the product.

3. The bio-based superhydrophobic ultraviolet curable coating according to claim 1 or 2, characterized in that, The epoxy vegetable oil is selected from at least one of epoxy soybean oil, epoxy castor oil, and epoxy linseed oil; The unsaturated organic compound is selected from at least one of unsaturated alcohol, unsaturated ether, and unsaturated ester; the unsaturated alcohol is selected from at least one of 3-buten-1-ol, methallyl alcohol, and 1,6-heptadiene-4-ol; the unsaturated ether is selected from at least one of glycerol-α,α'-diallyl ether and pentaerythritol triallyl ether; the unsaturated ester is pentaerythritol triacrylate; The Lewis acid catalyst is selected from at least one of boron trifluoride ethyl ether, boron trifluoride dimethyl ether, and boron trifluoride dibutyl ether.

4. The bio-based superhydrophobic UV-curable coating according to claim 3, wherein The mass ratio of epoxy vegetable oil to unsaturated organic compound is 2.5:(0.9-1.4); the dosage of Lewis acid catalyst is 0.9%-1.5% of the total mass of epoxy vegetable oil and unsaturated organic compound.

5. The bio-based superhydrophobic ultraviolet curable coating according to claim 1, wherein The modified cellulose is prepared from cellulose and terminal double bond-containing silane through the following steps: (1) Disperse cellulose in an organic solvent and stir for 5-20 min in a nitrogen atmosphere to obtain a cellulose suspension; (2) Slowly add 5-20 mL of terminal double bond-containing silane to the cellulose suspension and stir for 2-12 h to obtain the product. The terminal double bond-containing silane is selected from at least one of 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, vinyltriethoxysilane, methacryloxypropyltris(trimethylsiloxy)silane, (3-acryloxypropyl)tris(trimethylsiloxy)silane, 2-(methacryloxy)ethyl[3-(triethoxysilyl)propyl]carbamate, and trichlorovinylsilane.

6. The bio-based superhydrophobic UV-curable coating according to claim 1, wherein The modified cellulose is prepared from cellulose and terminal double bond-containing acyl chloride through the following steps: (1) Disperse cellulose in N,N-dimethylacetamide, centrifuge, disperse the supernatant obtained after centrifugation in acetone, centrifuge for the second time, and disperse the supernatant obtained after the second centrifugation in N,N-dimethylacetamide to obtain an N,N-dimethylacetamide dispersion containing cellulose; (2) Add 5-20 mL of pyridine and 3-20 mL of terminal double bond-containing acyl chloride to the N,N-dimethylacetamide dispersion containing cellulose, and reflux and heat and stir at 60-90 °C for 0.5-3 h to obtain the product. The acyl chloride containing a terminal double bond is selected from at least one of 10-undecenoyl chloride, 3-butenoyl chloride, monoallyl oxalyl chloride, and diallylcarbamoyl chloride.

7. The bio-based superhydrophobic UV curable coating according to claim 6, wherein, The cellulose is selected from at least one of α-cellulose, microcrystalline cellulose, cellulose microfibrils, cellulose nanofibers, cellulose nanocrystals, and micro-nano cellulose extracted from straw; the dosage of the modified cellulose is 9%-40% of the total mass of the vegetable oil-based active monomer, polythiol, modified cellulose, and photoinitiator.

8. The bio-based superhydrophobic UV-curable coating according to claim 1, characterized in that, The polythiol is selected from at least one of ethylene glycol bis(3-mercaptopropionate), 1,4-butanediol bis(mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(mercaptoacetate), pentaerythritol tetra(3-mercaptopropionate), and dipentaerythritol hexa(3-mercaptopropionate).

9. The preparation method of the bio-based superhydrophobic ultraviolet curable coating according to any one of claims 1-8, characterized in that, It includes the following steps: Mix the vegetable oil-based active monomer, polythiol, modified cellulose, organic solvent, and photoinitiator to obtain the product.

10. Use of the bio-based superhydrophobic UV-curable coating according to any one of claims 1-8, characterized in that, The application is the application of the bio-based superhydrophobic ultraviolet curable coating in the surface treatment of substrates.

Images