Copolymer for imitating folium sennae coating and preparation process thereof

Abstract

The invention discloses a copolymer imitating a folium sennae coating and a preparation process, and the synthesis process of the copolymer comprises the following steps: a, obtaining methyl methacrylate, butyl methacrylate and azodiisobutyronitrile to obtain a product A; b, a mixed solvent is obtained, the mixed solvent comprises methylbenzene, isopropanol and acetone, and a product B is obtained; c, sequentially adding a part of the product A and a part of the product B into a container with a reflux device, filling the container with a protective gas atmosphere, and stirring for reaction at the temperature of 50-60 DEG C to obtain a product C; d, uniformly mixing the residual product A and the residual product B, dropwise adding the mixture into the product C, reacting for 2-3 hours, and taking a reaction product to obtain a product D; and e, feeding the product D into a sealed container, sealing for 20-30 hours, taking out, standing, sealing the product, and cleaning with ethanol to obtain a finished product of the copolymer. The super-hydrophobic coating disclosed by the invention has the advantages of no marine pollution, good super-hydrophobicity, good mechanical property, high bonding strength with a base material and high biological removal rate.

Description

Technical Field

[0001] The present invention relates to a copolymer with a senna leaf-like coating and a preparation process thereof. Background Art

[0002] The ocean covers about 71% of the Earth's area, and there are many marine organisms in its vast waters. According to big data statistics, there are currently more than 200,000 known organisms in the ocean, among which there are as many as more than 5,000 recorded marine fouling organisms.

[0003] Marine biofouling is the unnecessary accumulation and growth of biomolecules, microorganisms, organisms, and plants on the surface of objects, dynamically deteriorating their surface functions over a relatively long time scale. Its essence is the accumulation and growth of biomolecules and organisms on the surface of objects, which usually damages the related functions of the surface, such as the corrosion of metal substrates, the increase in the frictional resistance of the object surface, etc. This kind of biofouling causes serious harm and economic losses to the marine industry every year.

[0004] Due to the expansion of human activities in the marine industry, the intensification of marine environmental pollution has led to an increasingly obvious "eutrophication" phenomenon, which has resulted in the accelerated reproduction of fouling biomolecules and organisms. The reproductive weight of related fouling organisms in the ocean expands at a rate of 8.2% per year. The expansion of research also warns that the bioadhesion in different sea areas will also cause environmental problems such as the invasion of alien species, which not only poses a potential threat to the ecological environment of the invaded sea area, but also leads to energy consumption for humans to deal with related threats, thereby indirectly increasing the emissions of greenhouse gases and polluting exhaust gases.

[0005] To study the increase in energy consumption caused by marine fouling, it is necessary to first understand the formation process of marine biofouling. There are more than 4,000 fouling organisms in the vast ocean, and more than half of the related organisms are concentrated along the coastline and in ports. Generally, fouling organisms can be divided into: microorganisms such as bacteria, diatoms, and spores, and common macroscopic organisms such as barnacles, oysters, bryozoans, mussels, and algae. Eventually, a macroscopic biofouling with a huge weight, a large number of biological weights, a high frictional resistance, and difficult to remove is formed on the hull surface. These difficult-to-remove macroscopic fouling organisms result in a large amount of fuel consumption and greenhouse gas emissions in the marine / maritime industry every year.

[0006] Currently, for the problem of marine biofouling, it is mainly prevented by setting an antifouling coating on the surface of the object. The antifouling coating will gradually secrete an antifouling agent to prevent the fouling of the object by marine organisms. However, while the antifouling agent inhibits fouling organisms, it will also enter the marine water body, causing pollution to the ocean. Summary of the Invention

[0007] The object of the present invention is to provide a copolymer with a mimetic senna leaf coating and a preparation process. The present invention has the advantages of not causing marine pollution, good superhydrophobicity, good mechanical properties, high adhesion strength with the substrate, and high biological removal rate.

[0008] The technical solution of the present invention: A copolymer with a mimetic senna leaf coating, the synthesis process of the copolymer includes the following steps,

[0009] a. Obtain methyl methacrylate, butyl methacrylate and azobisisobutyronitrile, and the mass ratio of methyl methacrylate, butyl methacrylate and azobisisobutyronitrile is (50 - 70):(20 - 40):(5 - 15) to obtain Product A;

[0010] b. Obtain a mixed solvent, the mixed solvent includes toluene, isopropanol and acetone, and the mass ratio of toluene, isopropanol and acetone is (2 - 4):(0.5 - 1.5):(5 - 7) to obtain Product B, and the mass ratio of Product A and Product B is 1:(5 - 20);

[0011] c. Add a part of Product A and a part of Product B to a container with a reflux device in sequence, the container is filled with a protective gas atmosphere, and stir and react at a temperature of 50 - 60 °C for 0.5 - 1.5 h to obtain Product C;

[0012] d. Mix the remaining Product A and the remaining Product B evenly and then drop them into Product C, react for 2 - 3 h, take the reaction product to obtain Product D;

[0013] e. Product D enters a sealed container, is sealed at a temperature of 20 - 30 °C for 20 - 30 h, then taken out and the sealed product is left standing, washed with ethanol to obtain the finished product of the copolymer.

[0014] In the aforementioned copolymer with a mimetic senna leaf coating, in step a, the mass ratio of methyl methacrylate, butyl methacrylate and azobisisobutyronitrile is 60:30:10; in step b, the mass ratio of toluene, isopropanol and acetone is 3:1:6, and the mass ratio of Product A and Product B is 1:10.

[0015] In the aforementioned copolymer with a mimetic senna leaf coating, in step c, add 50% of Product A and 50% of Product B to the container, stir and react at a temperature of 55 °C for 1 h; in step d, seal at a temperature of 25 °C for 24 h; in step e, after sealing at a temperature of 25 °C for 24 h, take out and leave the sealed product standing, wash with ethanol at least three times to remove unreacted monomers and impurities, and after the ethanol volatilizes, obtain the finished product of the copolymer.

[0016] The aforementioned preparation process of the mimetic senna leaf coating includes the following steps,

[0017] f. Take epoxy resin and amine curing agent, mix them evenly to obtain a mixture. After degassing the mixture, place it in a petri dish. Take the senna leaves that have been cleaned and dried, place them upright or upside down on the mixture until the mixture cures, then remove the senna leaves to obtain a bionic mold.

[0018] g. Take xylene and the copolymer described in claim 1, stir the xylene and the copolymer evenly to obtain Product G.

[0019] h. Add benzyl silicone oil and 2-hydroxyethyl methacrylate phosphate to Product G, stir evenly to obtain a coating.

[0020] i. Coat the coating on the bionic mold, and after the coating cures, obtain the finished product with a coating imitating the senna leaf.

[0021] In the preparation process of the aforementioned coating imitating the senna leaf, in step f, the model of the epoxy resin is E51, the amine curing agent is 1,3-cyclohexanedimethylamine, and the ratio of the epoxy resin to the amine curing agent is 5:1.

[0022] In the preparation process of the aforementioned coating imitating the senna leaf, in step f, the senna leaves are repeatedly rinsed alternately with ethanol and deionized water to remove the dirt on the surface of the senna leaves.

[0023] In the preparation process of the aforementioned coating imitating the senna leaf, in step f, the curing temperature of the mixture is 20 - 30 °C, and the curing time is 10 - 14 h.

[0024] In the preparation process of the aforementioned coating imitating the senna leaf, in step f, the senna leaves on the cured mixture are treated with 84 disinfectant solution to remove the senna leaves from the mixture, and the mixture after removing the senna leaves is washed with deionized water to obtain a bionic mold.

[0025] In the preparation process of the aforementioned coating imitating the senna leaf, in step g, the xylene and the copolymer are in equal mass parts.

[0026] In the preparation process of the aforementioned coating imitating the senna leaf, in step h, the ratio of the copolymer, benzyl silicone oil and 2-hydroxyethyl methacrylate phosphate in Product G is (80 - 120):(2 - 10):(1 - 4).

[0027] Compared with the prior art, the copolymer of the present invention is obtained through a free radical reaction. The prepared copolymer is incorporated with non-reactive benzyl silicone oil and cured to obtain a coating for antifouling. There is no antifouling agent in the coating, which will not cause marine pollution. The surface properties of the coating formed by this coating are consistent with those of the existing polydimethylsiloxane (PDMS) elastomer, ensuring good superhydrophobicity. The copolymer enhances the mechanical properties of the coating. More importantly, there is a high adhesion strength between the prepared coating and the substrates (including aluminum plates and steel plates), and the pull-off strength value is greater than 1.6 MPa.

[0028] In addition, a coating imitating senna leaves with a higher reduction degree is obtained through a bio-template method, and three microstructural units of convex polyhedra, jujube pit shapes, and conical rod shapes are obtained. Among them, the conical rod-shaped structure can be regarded as two parts: a cylinder and a sphere. There is almost no attachment of Navicula on the conical rod-shaped structure, showing extremely outstanding antifouling performance. For this coating, it still has excellent antifouling performance after 30 days of exposure time, and the biological fouling removal rate exceeds 92%.

[0029] In summary, the present invention has the advantages of not causing marine pollution, good superhydrophobicity, good mechanical properties, high adhesion strength with substrates, and high biological removal rate. Detailed implementation mode

[0030] The present invention will be further described below in conjunction with embodiments, but it is not used as a basis for limiting the present invention.

[0031] Embodiment 1: A copolymer of a coating imitating senna leaves. The synthesis process of the copolymer includes the following steps.

[0032] a. Obtain methyl methacrylate, butyl methacrylate, and azobisisobutyronitrile. The mass ratio of methyl methacrylate, butyl methacrylate, and azobisisobutyronitrile is 60:30:10 to obtain Product A.

[0033] b. Obtain a mixed solvent. The mixed solvent includes toluene, isopropanol, and acetone. The mass ratio of toluene, isopropanol, and acetone is 3:1:6 to obtain Product B. The mass ratio of Product A and Product B is 1:5.

[0034] c. Add 50% by mass of Product A and 50% by mass of Product B to a 500 mL four-neck round-bottom flask with a reflux device in sequence. The inside of the flask is filled with a nitrogen atmosphere, and the mixture is stirred and reacted at a temperature of 55°C for 1 h to obtain Product C.

[0035] d. Mix the remaining Product A and the remaining Product B evenly, and gradually add them dropwise to Product C within 30 min using an LSP022B micro-injection pump, and react for 2.5 h. Take the reaction product to obtain Product D.

[0036] e. The D product was transferred to a stoppered Erlenmeyer flask and sealed at 25 °C for 24 h. Then, the sealed product was taken out and allowed to stand. The product was washed with ethanol at least three times to remove unreacted monomers and impurities. After the ethanol was filtered and volatilized, the resulting white gel substance was the acrylic acid-MQ silicone resin (AMQ) synthesized in Example 1, i.e., the finished product of the copolymer.

[0037] Example 2: Preparation process of the senna leaf-like coating, including the following steps,

[0038] f. Take 25 g of epoxy resin and 5 g of amine curing agent. The type of the epoxy resin is E51, and the amine curing agent is 1,3-cyclohexanedimethanamine. Mix them evenly to obtain a mixture. After degassing the mixture in a vacuum dryer, pour it into a sterile disposable petri dish.

[0039] Take senna leaves and rinse them with ethanol and deionized water alternately three times to remove the dirt on the surface of the senna leaves. After drying the senna leaves, place them upright or upside down on the mixture, and carry out a curing reaction at 25 °C for 12 hours.

[0040] Treat the senna leaves on the cured mixture with 84 disinfectant solution (sodium hypochlorite, effective chlorine content is 5.5 - 6.5 wt%) to remove the senna leaves from the mixture, and wash the mixture after removing the senna leaves with deionized water to obtain a bionic mold.

[0041] g. Take xylene and the copolymer obtained in Example 1, with equal mass of xylene and the copolymer. Put the xylene and the copolymer into a sealed reagent bottle and stir evenly with a magnetic stirrer at a stirring speed of 200 rpm / min and a stirring temperature of 50 °C to obtain Product G.

[0042] h. Add 2-hydroxyethyl methacrylate phosphate to Product G and stir evenly. The ratio of the copolymer, benzyl silicone oil and 2-hydroxyethyl methacrylate phosphate in Product G is (80 - 120):(2 - 10):(1 - 4), and the preferred ratio of the copolymer, benzyl silicone oil and 2-hydroxyethyl methacrylate phosphate is 100:6:2.5 to obtain a coating.

[0043] i. Coat the coating on the bionic mold. After the coating is cured, the finished product of the senna leaf-like coating is obtained, and the finished product is in the form of a film.

[0044] Swelling test:

[0045] Immerse the prepared film sample with a size of 20×20×5 mm 3 (weight m 0 ) in sterilized seawater. After 14 days, take out the film and rinse it with tap water to remove the adsorbed crystal salts. Then, soak the water on the film surface with filter paper and weigh it (weight mt). The volume swelling rate of the film can be calculated by Equation 1

[0046] Formula 1:

[0047] In formula 1, Ws is the volume expansion rate, and ρ is the density of the film. The density of seawater ρ1 is about 1g / cm 3 .

[0048] Mechanical properties test:

[0049] Refer to ISO15184-1998 standard, use QHA hand-push pencil hardness tester loaded with 750g weight to evaluate the pencil hardness of the coating. The judgment standard is that the number of coating damages with pencils with a certain hardness mark does not exceed one-fifth. The definition of coating damage is as follows: there are visible scratches or cracks on the surface of the film; material has been removed from the film.

[0050] Biofilm Adhesion Test:

[0051] The antifouling performance of the coating was evaluated by the marine bacterial biofilm adhesion test. Six samples of each coating were painted on tinplate and immersed in 800mL fresh seawater (Yellow Sea, China) for 24 hours. Among them, three samples were gently rinsed with sterile deionized water to remove unsettled bacteria; the remaining samples were rinsed with sterile deionized water at 0.1MPa for 120s using a CB8LC high-pressure water gun, and then all samples were placed in a QNCJ-LED clean bench for drying and dehydration.

[0052] After the samples were dried naturally, 6 samples were dyed with 0.5 wt % crystal violet solution for 15 min, and then the dyed samples were taken out and dried, and then each sample was immersed in 45 mL of 36 wt % acetic acid solution and extracted for 10 min.

[0053] The extracted supernatant was placed in a quartz cuvette with an optical path of 1 cm, and the absorption intensity (OD590) at 590 nm was measured using a UV spectrophotometer to analyze the amount of biofilm adhesion on the coating surface.

[0054] The removal rate R of adherent fouling organisms was calculated by formula 2. Da and Db represent the OD590 values ​​of the rinse sample and the flush sample, respectively.

[0055] Formula (2):

[0056] Before the biofilm adhesion test, it is necessary to ensure that the upper and lower surfaces of the tinplate are coated with the preparation coating to ensure that seawater will not corrode the exposed tinplate. In addition, for experimental samples immersed in seawater for a long time, it is necessary to use ultraviolet germicidal lamps for regular sterilization (15min / day). For the biofilm adhesion test, the sample measured after curing for 8h is the sample at the exposure time of 0 days, and the sample measured after immersion in seawater for 30 days is the sample at the exposure time of 30 days.

[0057] Four samples were taken, the first one was recorded as AMQ bionic structure, that is, the sample of the senna leaf imitation coating obtained in Example 2; the second one was recorded as AMQ without bionic structure, that is, on the basis of Example 2, the coating was not applied on the bionic mold, but was directly applied to a smooth substance and cured to obtain the sample; the third one was recorded as PDMS bionic structure, that is, the sample obtained by applying the existing PDMS coating to the bionic mold and curing it; the fourth one was recorded as PDMS without bionic structure, that is, the sample obtained by directly applying the existing PDMS coating to a smooth substance and curing it.

[0058] The above four samples were subjected to the above swelling test, mechanical property test, and biofilm adhesion test, respectively, and the results were obtained as shown in Table 1 below:

[0059] Table 1

[0060]

Claims

1. A copolymer of senna-like coating, characterized in that: The synthesis process of the copolymer comprises the following steps: a. Obtain methyl methacrylate, butyl methacrylate and azobisisobutyronitrile, wherein the mass ratio of methyl methacrylate, butyl methacrylate and azobisisobutyronitrile is (50-70):(20-40):(5-15), and obtain product A; b. Obtain a mixed solvent, the mixed solvent includes toluene, isopropanol and acetone, the mass ratio of toluene, isopropanol and acetone is (2-4):(0.5-1.5):(5-7), and obtain product B, the mass ratio of product A to product B is 1:(5-20); c. Add a portion of product A and a portion of product B in sequence to a container with a reflux device, fill the container with a protective gas atmosphere, and stir the reaction at a temperature of 50-60°C for 0.5-1.5h to obtain product C; d. Mix the remaining product A and the remaining product B evenly and add them dropwise to product C. Let the mixture react for 2-3 hours and take the reaction product to obtain product D. e. Product D is placed in a sealed container, sealed at 20-30°C for 20-30 hours, then taken out and allowed to stand, and washed with ethanol to obtain the finished copolymer.

2. The copolymer of the senna-like coating according to claim 1, characterized in that: In the step a, the mass ratio of methyl methacrylate, butyl methacrylate and azobisisobutyronitrile is 60:30:10; in the step b, the mass ratio of toluene, isopropanol and acetone is 3:1:6, and the mass ratio of product A to product B is 1:

10.

3. The copolymer of the senna-like coating according to claim 1, characterized in that: In the step c, 50% of product A and 50% of product B are added into a container, and the mixture is stirred and reacted at a temperature of 55° C. for 1 hour; in the step d, the mixture is sealed at a temperature of 25° C. for 24 hours; in the step e, after being sealed at a temperature of 25° C. for 24 hours, the sealed product is taken out and allowed to stand, and is washed with ethanol for at least three times to remove unreacted monomers and impurities, and the finished copolymer is obtained after the ethanol is volatilized.

4. The process for preparing the senna-like coating according to any one of claims 1 to 3, characterized in that: The following steps are included: f. Take epoxy resin and amine curing agent, mix them evenly to obtain a mixture, degas the mixture and place it in a culture dish, take the cleaned and dried senna leaves, place them upright or inverted on the mixture until the mixture solidifies, remove the senna leaves, and obtain a bionic mold. g. Take xylene and the copolymer according to claim 1, stir the xylene and the copolymer evenly to obtain product G. h. Add phenylmethyl silicone oil and 2-hydroxyethyl methacrylate phosphate to product G and stir evenly to obtain the coating. i. Apply the coating to the bionic mold, and after the coating is cured, a finished product of the senna leaf-like coating is obtained.

5. The preparation process of the senna-like coating according to claim 4, characterized in that: In the step f, the epoxy resin is of model E51, the amine curing agent is 1,3-cyclohexanedimethylamine, and the ratio of the epoxy resin to the amine curing agent is 5:

1.

6. The preparation process of the senna-like coating according to claim 4, characterized in that: In the step f, the senna leaves are repeatedly and alternately rinsed with ethanol and deionized water to remove dirt on the surface of the senna leaves.

7. The preparation process of the senna-like coating according to claim 4, characterized in that: In the step f, the curing temperature of the mixture is 20-30° C., and the curing time is 10-14 hours.

8. The process for preparing the senna-like coating according to claim 4, characterized in that: In the step f, the senna leaves on the solidified mixture are treated with 84 eliminating liquid to remove the senna leaves from the mixture, and the mixture after the senna leaves are removed is washed with deionized water to obtain a bionic mold.

9. The process for preparing the senna-like coating according to claim 4, characterized in that: In the step g, the xylene and the copolymer are in equal parts by weight.

10. The process for preparing the senna-like coating according to claim 4, characterized in that: In the step h, the ratio of the copolymer, phenylmethyl silicone oil and 2-hydroxyethyl methacrylate phosphate in product G is (80-120):(2-10):(1-4).

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