An antibacterial powder coating based on environmentally friendly biomass and its preparation method

Abstract

This invention relates to the field of antibacterial powder coating technology, and discloses an antibacterial powder coating based on environmentally friendly biomass and its preparation method. This environmentally friendly biomass-based antibacterial powder coating includes the following raw materials: hydroxyl polyester resin, biomass antibacterial complex, waterproof and corrosion-resistant additives, polyisocyanate curing agent, organotin catalyst, benzoin, antioxidant, ultraviolet absorber, and leveling agent. This invention solves the problems of poor environmental friendliness and short-lasting antibacterial effect caused by directly adding chemical antibacterial agents to ordinary powder coatings, as well as the problems of ordinary powder coatings having poor corrosion resistance and waterproof performance, weak adhesion, and difficulty in meeting the application needs of multiple fields, by adding biomass antibacterial complex and waterproof and corrosion-resistant additives during the antibacterial powder preparation process.

Description

Technical Field

[0001] This invention relates to the field of antibacterial powder coating technology, specifically to an antibacterial powder coating based on environmentally friendly biomass and its preparation method. Background Technology

[0002] With the continuous development of modern industrial technology, while bringing countless conveniences to people, it has also brought many environmental problems. In order to uphold the concept of sustainable development, environmental protection has become an unavoidable issue in the development of industrial technology. As one of the most widely used products in industrial development at present, coatings are applied in a variety of fields. However, traditional coatings mostly use organic solvents as diluents. During use, organic solvents are easy to volatilize and cause air pollution, which does not meet the requirements for environmental protection. Powder coatings are a solid system coatings that do not contain organic solvents, so they do not cause air pollution. Moreover, the oversprayed coatings can be recycled and reused, which can effectively reduce the waste of raw materials and conform to the green and environmentally friendly industrial concept.

[0003] However, ordinary powder coatings have poor adhesion to substrates and are prone to peeling off after prolonged use. They also have limited waterproofing properties and lack antibacterial and corrosion-resistant capabilities, making it difficult to meet the needs of special industries such as medical, shipbuilding, and chemical industries. This severely limits the application areas of powder coatings. Therefore, when using powder coatings, people often make improvements. For example, patent CN109439095B discloses a weather-resistant antibacterial powder coating and its preparation method. This method improves the antibacterial properties of powder coatings by selecting epoxy-modified acrylic resin and polyester resin with suitable functionality and acid value as the matrix components of the powder coating, adding quaternary phosphonium salt as an antibacterial additive, and selecting and adjusting the amount of each component to make the prepared powder coating have strong weather resistance and antibacterial ability. Although this patent enhances the antibacterial properties of powder coatings and expands their application areas, it does not improve their waterproof and corrosion-resistant properties. Furthermore, the use of quaternary phosphonium salts as an antibacterial agent in this powder coating is a chemical antibacterial agent that can have adverse environmental effects and may lead to bacterial resistance with prolonged use, making it difficult to maintain its antibacterial effect for an extended period and affecting the lifespan of the powder coating. Summary of the Invention

[0004] The purpose of this invention is to provide an antibacterial powder coating based on environmentally friendly biomass and its preparation method, which solves the following technical problems: (1) Adding chemical antibacterial agents directly to ordinary powder coatings is not environmentally friendly and can easily cause bacteria to develop drug resistance, resulting in a short antibacterial effect; (2) Ordinary powder coatings generally have poor corrosion resistance and waterproof performance, and weak adhesion, making it difficult to meet the needs of multiple fields.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] An antibacterial powder coating based on environmentally friendly biomass comprises the following raw materials in parts by weight: 70-90 parts hydroxyl polyester resin, 5-8 parts biomass antibacterial compound, 8-10 parts waterproof and corrosion-resistant additives, 10-12 parts polyisocyanate curing agent, 1-2 parts organotin catalyst, 0.5-1 part benzoin, 1.5-2 parts antioxidant, 1-2 parts ultraviolet absorber, and 0.5-2 parts leveling agent.

[0007] Furthermore, the hydroxyl value of the hydroxyl polyester resin is 40-45 mg KOH / g.

[0008] Furthermore, the organotin catalyst is any one of dibutyltin dilaurate and stannous octoate; the antioxidant is any one of antioxidant 1010, antioxidant 2246, and antioxidant 1135; the ultraviolet absorber is any one of ultraviolet absorber UV-326, ultraviolet absorber UV-360, and ultraviolet absorber UV-329; and the leveling agent is an acrylate leveling agent.

[0009] Furthermore, the preparation of the biomass antibacterial complex includes the following steps:

[0010] ① Place chitosan in a 1-2% acetic acid solution and stir thoroughly to form a chitosan solution. Place sodium alginate in deionized water and stir thoroughly to obtain a sodium alginate solution.

[0011] ② Place mesoporous titanium dioxide and berberine in anhydrous ethanol, ultrasonically disperse for 15-20 min, stir at 300-350 r / min for 10-12 h, let stand for 3-5 h, filter and collect the product to obtain mesoporous titanium dioxide-supported berberine.

[0012] ③ Mix sodium alginate solution, Tween 80 and mesoporous titanium dioxide-loaded berberine evenly, emulsify using a high-pressure homogenizer for 5-6 min, add chitosan solution, stir for 8-10 h, cool to room temperature for 5-6 h, add 5-8% glutaraldehyde aqueous solution, freeze dry at -20 to -10℃ for 12-18 h, collect the product, and obtain the biomass antibacterial complex.

[0013] In this scheme, microcapsules with chitosan and sodium alginate as shells and mesoporous titanium dioxide loaded with berberine as the core material are prepared by complex coagulation. These microcapsules are then incorporated into the preparation process of antibacterial powder coatings. The multiple hydroxyl groups in the sodium alginate structure enhance the compatibility between the microcapsules and the powder coating matrix material, and improve the adhesion between the powder coating and the matrix material. By co-encapsulating the mesoporous titanium dioxide loaded with berberine with chitosan, the microcapsules are protected during the powder coating preparation process, preventing mechanical action and inactivation of the antibacterial active substance at high temperatures. Simultaneously, the berberine is released slowly, enhancing the antibacterial effect. On the one hand, the antibacterial effect of powder coatings is enhanced by the adsorption properties of chitosan, which disrupts bacterial cell membranes and produces an antibacterial effect through the adsorption properties of polycations. Berberine can inhibit bacterial enzyme systems and disrupt bacterial physiological activities, thereby inhibiting bacteria. Mesoporous titanium dioxide generates free radicals through photocatalytic oxidation, which destroys and inhibits the synthesis of microbial growth factors, thus achieving an antibacterial effect. Through the synergistic effect of two biomass antibacterial agents, chitosan and berberine, and the inorganic antibacterial agent mesoporous titanium dioxide, the broad-spectrum antibacterial properties of powder coatings can be significantly enhanced, forming multiple antibacterial barriers and greatly improving the antibacterial performance of powder coatings.

[0014] Furthermore, in step ②, the pore size of the mesoporous titanium dioxide is 5-12 nm.

[0015] Furthermore, in step ③, the working pressure of the high-pressure homogenizer is 25-30 MPa.

[0016] Furthermore, the preparation of the waterproof and corrosion-resistant additive includes the following steps:

[0017] (1) Place methyl hydrogen silicone oil in isopropanol, mix and stir thoroughly, then introduce nitrogen gas, add 2-(trifluoromethyl)acrylic acid and chloroplatinic acid, heat to 70-75℃ and react for 10-12h, remove the solvent by rotary evaporation and collect the product to obtain fluorinated silicone oil.

[0018] (2) Place the fluorinated silicone oil in N,N-dimethylformamide, stir and mix thoroughly, add glycidyl furfury ether and catalyst, heat to 65-70℃ and react for 5-6 hours, remove the solvent by vacuum distillation, and collect the product to obtain the waterproof and corrosion-resistant additive.

[0019] In this scheme, under the action of chloroplatinic acid, the silane-hydrogen bonds in the hydrogen-containing silicone oil structure undergo an addition reaction with the active double bonds in the 2-(trifluoromethyl)acrylic acid structure to obtain fluorinated silicone oil. Then, under the action of a catalyst, the carboxyl groups in the fluorinated silicone oil structure undergo a ring-opening reaction with the epoxy groups in the glycidyl furfuryl ether structure to obtain a waterproof and corrosion-resistant additive containing multiple hydroxyl groups. This waterproof and corrosion-resistant additive has multiple hydroxyl groups in its structure, which can participate in the preparation process of powder coatings and have good compatibility with the powder coating matrix. Through the combination of organic fluorine and hydrogen-containing silicone oil, the surface energy of the powder coating can be effectively reduced, and the waterproof performance of the powder coating can be enhanced. At the same time, organic fluorine and furan groups can produce a synergistic effect, improving the corrosion resistance of the powder coating, expanding the application field of the powder coating, and enhancing the service life of the powder coating.

[0020] Further, in step (1), the hydrogen content of the methyl hydrogen silicone oil is 1.55-2.55%.

[0021] Further, in step (2), the catalyst is any one of tetrabutylammonium bromide, tetrabutylammonium chloride, and tetrabutylammonium hydroxide.

[0022] A method for preparing an antibacterial powder coating based on environmentally friendly biomass includes the following steps:

[0023] Step 1: Place the hydroxyl polyester resin, biomass antibacterial compound, waterproof and corrosion-resistant additives, polyisocyanate curing agent, organotin catalyst, benzoin, antioxidant, ultraviolet absorber, and leveling agent into a high-speed mixer, set the speed to 350-400 r / min, mix thoroughly for 0.5-1 h, and then discharge to obtain the mixture.

[0024] Step 2: Place the mixture in a twin-screw extruder, set the screw speed of the twin-screw extruder to 200-250 r / min, and the die temperature to 170-180℃. After melt extrusion, the mixture is pressed into sheets, cooled and crushed, then graded and ground by ACM, and passed through a 180-200 mesh sieve to obtain an antibacterial powder coating.

[0025] The beneficial effects of this invention are:

[0026] This invention incorporates a biomass antibacterial complex and waterproof and corrosion-resistant additives into the preparation process of powder coatings, resulting in a powder coating with a salt spray resistance of up to 2000 hours; an adhesion grade of 0; an antibacterial rate of up to 99.95%; and a water contact angle greater than 150°. It exhibits excellent corrosion resistance, adhesion, antibacterial effect, and waterproof capability, meeting the application requirements of various fields and providing long-lasting antibacterial effects.

[0027] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart illustrating the preparation process of the antibacterial powder of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The preparation of the composite biomass antibacterial additive and the waterproof and corrosion-resistant filler in the following embodiments and comparative examples of the present invention are shown below:

[0032] I. Preparation of Biomass Antibacterial Complex

[0033] ① Place 3g of chitosan in 30ml of 1% acetic acid solution and stir thoroughly to form a chitosan solution. Place 3.2g of sodium alginate in 35ml of deionized water and stir thoroughly to obtain a sodium alginate solution.

[0034] ② Place 2.5g of mesoporous titanium dioxide with a pore size of 5nm and 2g of berberine in 100ml of anhydrous ethanol, disperse by ultrasonication for 15min, stir at 300r / min for 10h, let stand for 3h, filter and collect the product to obtain mesoporous titanium dioxide loaded with berberine.

[0035] ③ Mix 30 mL of sodium alginate solution, 2.8 g of Tween 80 and 5 g of mesoporous titanium dioxide-loaded berberine evenly, emulsify using a high-pressure homogenizer at a pressure of 25 MPa for 5 min, add 35 mL of chitosan solution, stir for 8 h, cool to room temperature for 5 h, add 5% glutaraldehyde aqueous solution, freeze dry at -20℃ for 12 h, collect the product, and obtain the biomass antibacterial complex.

[0036] A biomass antibacterial complex was obtained by encapsulating berberine-loaded mesoporous titanium dioxide in microcapsules using chitosan and sodium alginate as shells. The sodium alginate in the shells enhances the adhesion between the powder coating and the matrix material, and also enhances the compatibility between the biomass antibacterial complex and the powder coating matrix. This allows the biomass antibacterial complex to be uniformly dispersed in the powder matrix material. During the preparation of the powder coating, the biomass material berberine can be slowly released to achieve a long-lasting antibacterial effect. Furthermore, it has a synergistic effect with the biomass material chitosan and the inorganic antibacterial agent mesoporous titanium dioxide, jointly enhancing the antibacterial performance of the powder coating and prolonging the antibacterial effect.

[0037] II. Preparation of Waterproof and Corrosion-Resistant Additives

[0038] (1) Place 2.8g of methyl hydrogen silicone oil with a hydrogen content of 1.55% in 60ml of isopropanol, mix and stir thoroughly, then introduce nitrogen gas, add 3g of 2-(trifluoromethyl)acrylic acid and 0.02g of chloroplatinic acid, heat to 70℃ and react for 10h, remove the solvent by rotary evaporation and collect the product to obtain fluorinated silicone oil.

[0039] The content of carboxyl groups in fluorinated silicone oil was characterized by acid-base titration. 1 g of fluorinated silicone oil was placed in 50 ml of butanone solution, and 0.1 mol / L potassium hydroxide ethanol solution was added to excess. 0.2 ml of phenolphthalein indicator was added, and the mixture was thoroughly mixed. Titration was then performed using a 0.1 mol / L hydrochloric acid standard solution. Stirring was continued until the color disappeared, and titration continued until the color reappeared, until the color completely disappeared. A blank test was performed simultaneously, recording the mass of the excess potassium hydroxide ethanol solution consumed and the mass of the neutralized hydrochloric acid standard solution. The carboxyl group content was calculated using the following formula: Carboxyl group content = 45c(V-V0)×100% / M; where c is the concentration of the hydrochloric acid standard solution (mol / L); V is the volume of hydrochloric acid standard solution consumed in the sample (ml); V0 is the volume of hydrochloric acid standard solution consumed in the blank sample (ml); M is the mass of the sample (g); and 45 is the molar mass of the carboxyl group (g / mol). The calculated carboxyl content in the fluorinated silicone oil is 9.92%.

[0040] (2) Place 3.5g of fluorinated silicone oil in 80ml of N,N-dimethylformamide, stir and mix thoroughly, then add 3.2g of glycidyl furfural ether and 0.05g of tetrabutylammonium bromide, heat to 65℃ and react for 5h, remove the solvent by vacuum distillation, and collect the product to obtain the waterproof and corrosion-resistant additive.

[0041] The content of carboxyl groups in the waterproof and corrosion-resistant additive was characterized by acid-base titration. The specific steps are shown in step (1). The calculated content of carboxyl groups in the waterproof and corrosion-resistant additive was 1.23%, which was significantly lower than that in fluorinated silicone oil. This was due to the ring-opening reaction between the carboxyl groups in the fluorinated silicone oil structure and the epoxy groups in the glycidyl furfural ether structure.

[0042] Under the action of chloroplatinic acid, hydrogen-containing silicone oil undergoes a hydrosilylation reaction with 2-(trifluoromethyl)acrylic acid to obtain fluorinated silicone oil. Then, it undergoes a ring-opening reaction with glycidyl furfuryl ether to obtain a waterproof and corrosion-resistant additive. The ring-opening reaction between fluorinated silicone oil and glycidyl furfuryl ether can introduce multiple hydroxyl groups, allowing the waterproof and corrosion-resistant additive to participate in the preparation process of powder coatings, thereby enhancing the compatibility of the waterproof and corrosion-resistant additive in the matrix. The combination of organic fluorine and hydrogen-containing silicone oil can enhance the waterproof ability of the powder coating. At the same time, the introduction of organic fluorine can also have a synergistic effect with the furan group in the glycidyl furfuryl ether structure, enhancing the corrosion resistance of the powder coating.

[0043] Example 1

[0044] Preparation of powder coatings

[0045] Step 1: Place 70g of hydroxyl polyester resin with a hydroxyl value of 40mgKOH / g, 5g of biomass antibacterial compound, 8g of waterproof and corrosion-resistant additive, 10g of polyisocyanate curing agent, 1g of dibutyltin dilaurate, 0.5g of benzoin, 1.5g of antioxidant 1010, 1g of ultraviolet absorber UV-326, and 0.5g of acrylic leveling agent into a high-speed mixer, set the speed to 350r / min, mix thoroughly for 0.5h, and then discharge to obtain the mixture.

[0046] Step 2: Place the mixture in a twin-screw extruder, set the screw speed of the twin-screw extruder to 200 r / min, and the die temperature to 170℃. After melt extrusion, the mixture is pressed into sheets, cooled and crushed, then graded and ground by ACM, and passed through a 180-mesh sieve to obtain powder coating.

[0047] Example 2

[0048] Preparation of powder coatings

[0049] Step 1: Place 80g of hydroxyl polyester resin with a hydroxyl value of 42mgKOH / g, 6g of biomass antibacterial compound, 9g of waterproof and corrosion-resistant additive, 11g of polyisocyanate curing agent, 1.5g of dibutyltin dilaurate, 0.8g of benzoin, 1g of antioxidant 2246, 1.5g of ultraviolet absorber UV-360, and 1g of acrylic leveling agent into a high-speed mixer. Set the speed to 380r / min and mix thoroughly for 0.8h before discharging to obtain the mixture.

[0050] Step 2: Place the mixture in a twin-screw extruder, set the screw speed of the twin-screw extruder to 240 r / min and the die temperature to 175℃, melt extrude and then press into sheets. After cooling and crushing, the mixture is graded and ground by ACM and then passed through a 190-mesh sieve to obtain powder coating.

[0051] Example 3

[0052] Preparation of powder coatings

[0053] Step 1: Place 90g of hydroxyl polyester resin with a hydroxyl value of 45mgKOH / g, 8g of biomass antibacterial compound, 10g of waterproof and corrosion-resistant additive, 11g of polyisocyanate curing agent, 2g of stannous octoate, 1g of benzoin, 2g of antioxidant 1135, 2g of ultraviolet absorber UV-329, and 2g of acrylate leveling agent into a high-speed mixer, set the speed to 400r / min, mix thoroughly for 1 hour, and then discharge to obtain the mixture.

[0054] Step 2: Place the mixture in a twin-screw extruder, set the screw speed of the twin-screw extruder to 250 r / min and the die temperature to 180℃, melt extrude and then press into sheets. After cooling and crushing, the mixture is graded and ground by ACM and then passed through a 200-mesh sieve to obtain powder coating.

[0055] Comparative Example 1

[0056] Preparation of powder coatings

[0057] Step 1: Place 80g of hydroxyl polyester resin with a hydroxyl value of 42mgKOH / g, 9g of waterproof and corrosion-resistant additive, 11g of polyisocyanate curing agent, 1.5g of dibutyltin dilaurate, 0.8g of benzoin, 1g of antioxidant 2246, 1.5g of ultraviolet absorber UV-360, and 1g of acrylic leveling agent into a high-speed mixer, set the speed to 380r / min, mix thoroughly for 0.8h, and then discharge to obtain the mixture.

[0058] Step 2: Place the mixture in a twin-screw extruder, set the screw speed of the twin-screw extruder to 240 r / min and the die temperature to 175℃, melt extrude and then press into sheets. After cooling and crushing, the mixture is graded and ground by ACM and then passed through a 190-mesh sieve to obtain powder coating.

[0059] Comparative Example 2

[0060] Preparation of powder coatings

[0061] Step 1: Place 80g of hydroxyl polyester resin with a hydroxyl value of 42mgKOH / g, 6g of biomass antibacterial compound, 11g of polyisocyanate curing agent, 1.5g of dibutyltin dilaurate, 0.8g of benzoin, 1g of antioxidant 2246, 1.5g of ultraviolet absorber UV-360, and 1g of acrylate leveling agent into a high-speed mixer, set the speed to 380r / min, mix thoroughly for 0.8h, and then discharge to obtain the mixture.

[0062] Step 2: Place the mixture in a twin-screw extruder, set the screw speed of the twin-screw extruder to 240 r / min and the die temperature to 175℃, melt extrude and then press into sheets. After cooling and crushing, the mixture is graded and ground by ACM and then passed through a 190-mesh sieve to obtain powder coating.

[0063] Comparative Example 3

[0064] Preparation of powder coatings

[0065] Step 1: Place 80g of hydroxyl polyester resin with a hydroxyl value of 42mgKOH / g, 11g of polyisocyanate curing agent, 1.5g of dibutyltin dilaurate, 0.8g of benzoin, 1g of antioxidant 2246, 1.5g of ultraviolet absorber UV-360, and 1g of acrylic leveling agent into a high-speed mixer, set the speed to 380r / min, mix thoroughly for 0.8h, and then discharge to obtain the mixture.

[0066] Step 2: Place the mixture in a twin-screw extruder, set the screw speed of the twin-screw extruder to 240 r / min and the die temperature to 175℃, melt extrude and then press into sheets. After cooling and crushing, the mixture is graded and ground by ACM and then passed through a 190-mesh sieve to obtain powder coating.

[0067] Comparative Example 4

[0068] Preparation of powder coatings

[0069] Step 1: Place 80g of hydroxyl polyester resin with a hydroxyl value of 42mgKOH / g, 6g of biomass antibacterial compound, 9g of fluorinated silicone oil, 11g of polyisocyanate curing agent, 1.5g of dibutyltin dilaurate, 0.8g of benzoin, 1g of antioxidant 2246, 1.5g of ultraviolet absorber UV-360, and 1g of acrylate leveling agent into a high-speed mixer, set the speed to 380r / min, mix thoroughly for 0.8h, and then discharge to obtain the mixture.

[0070] Step 2: Place the mixture in a twin-screw extruder, set the screw speed of the twin-screw extruder to 240 r / min and the die temperature to 175℃, melt extrude and then press into sheets. After cooling and crushing, the mixture is graded and ground by ACM and then passed through a 190-mesh sieve to obtain powder coating.

[0071] Performance testing

[0072] The powder coatings prepared in Examples 1-3 and Comparative Examples 1-4 were electrostatically sprayed onto steel plates meeting specifications. The coating thickness was controlled at 60-70 μm. After curing at 80℃ for 1 hour, the samples were used as samples. The salt spray resistance of the samples was tested according to standard GB / T1771-2007; the adhesion grade of the samples was tested according to standard GB / T1727-2021; the antibacterial rate of the samples was calculated according to standard GB / T21866-2008; and the water contact angle of the samples was tested using a JC2000D2G contact angle tester to determine the waterproof performance of the samples. The specific test results are shown in the table below:

[0073]

[0074]

[0075] As shown in the table above, the samples prepared in Examples 1-3 and Comparative Examples 1-4 all exhibit excellent corrosion resistance, adhesion, antibacterial effect, and waterproofing. The sample prepared in Comparative Example 1 did not contain a biomass antibacterial compound, resulting in poor antibacterial effect and moderate adhesion. However, due to the addition of waterproof and corrosion-resistant additives, this sample has strong corrosion resistance and excellent waterproofing. The sample prepared in Comparative Example 2 did not contain any waterproof and corrosion-resistant additives, resulting in poor waterproofing and corrosion resistance. However, due to the addition of... The sample prepared in Comparative Example 3 contained a biomass antibacterial complex, resulting in excellent antibacterial effect and good adhesion. In Comparative Example 4, neither a biomass antibacterial complex nor waterproof and corrosion-resistant additives were added, leading to poor corrosion resistance, adhesion, antibacterial effect, and waterproofing. Comparative Example 4 contained both a biomass antibacterial complex and fluorinated silicone oil, exhibiting excellent antibacterial performance and good adhesion. However, its waterproofing and corrosion resistance were inferior to the examples, likely due to the lack of glycidyl furfural ether modification of the fluorinated silicone oil.

[0076] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0077] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the inventive concept, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing an antibacterial powder coating based on environmentally friendly biomass, characterized in that, Includes the following steps: Step 1: Place 70g of hydroxyl polyester resin with a hydroxyl value of 40mgKOH / g, 5g of biomass antibacterial compound, 8g of waterproof and corrosion-resistant additive, 10g of polyisocyanate curing agent, 1g of dibutyltin dilaurate, 0.5g of benzoin, 1.5g of antioxidant 1010, 1g of ultraviolet absorber UV-326, and 0.5g of acrylic leveling agent into a high-speed mixer, set the speed to 350r / min, mix thoroughly for 0.5h, and then discharge to obtain the mixture. Step 2: Place the mixture in a twin-screw extruder, set the screw speed of the twin-screw extruder to 200 r / min, the die temperature to 170℃, melt extrusion, then press into sheets, cool and crush, then classify and grind through ACM, and pass through a 180-mesh sieve to obtain powder coating. Preparation of the aforementioned biomass antibacterial complex: ① Place 3g of chitosan in 30ml of 1% acetic acid solution and stir thoroughly to form a chitosan solution. Place 3.2g of sodium alginate in 35ml of deionized water and stir thoroughly to obtain a sodium alginate solution. ② Place 2.5g of mesoporous titanium dioxide with a pore size of 5nm and 2g of berberine in 100ml of anhydrous ethanol, disperse by ultrasonication for 15min, stir at 300r / min for 10h, let stand for 3h, filter and collect the product to obtain mesoporous titanium dioxide loaded with berberine. ③ Mix 30ml sodium alginate solution, 2.8g Tween 80 and 5g mesoporous titanium dioxide-loaded berberine evenly, emulsify at 25MPa for 5min using a high-pressure homogenizer, add 35ml chitosan solution, stir for 8h, cool to room temperature for 5h, add 5% glutaraldehyde aqueous solution, freeze dry at -20℃ for 12h, collect the product, and obtain biomass antibacterial complex; Preparation of the aforementioned waterproof and corrosion-resistant additive: (1) 2.8g of methyl hydrogen silicone oil with a hydrogen content of 1.55% was placed in 60ml of isopropanol, mixed and stirred thoroughly, and nitrogen gas was introduced. 3g of 2-(trifluoromethyl)acrylic acid and 0.02g of chloroplatinic acid were added, the temperature was raised to 70℃ and reacted for 10h. The solvent was removed by rotary evaporation and the product was collected to obtain fluorinated silicone oil. (2) Place 3.5g of fluorinated silicone oil in 80ml of N,N-dimethylformamide, stir and mix thoroughly, then add 3.2g of glycidyl furfural ether and 0.05g of tetrabutylammonium bromide, heat to 65℃ and react for 5h, remove the solvent by vacuum distillation, and collect the product to obtain the waterproof and corrosion resistant additive.

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