A self-generating zwitterionic organosilicon polyurea and methods of making and using the same

Abstract

The application provides a self-generating zwitterionic organic silicon polyurea, a preparation method and application thereof, and the self-generating zwitterionic organic silicon polyurea comprises structural units derived from a double-end carboxyl-functionalized poly self-generating zwitterionic polymer, double-amino-terminated organic silicon and isocyanate. The application introduces urea bonds and zwitterionic precursors containing fluorocarbon groups into organic silicon, and the obtained self-generating zwitterionic organic silicon polyurea is used as marine antifouling paint, and the paint is endowed with excellent bonding performance, self-healing performance, static antifouling performance, low simulated barnacle removal strength and water absorption.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to an organosilicon polyurea containing self-generated zwitterions, its preparation method, and its application. Background Technology

[0002] Silicone-based antifouling coatings offer advantages such as low surface free energy, minimal surface roughness, low glass transition temperature, and low elastic modulus, making them commonly used in dirt-removing coatings. The interfacial bond between biomass and the silicone coating surface is weak, allowing attached biomass to be easily removed by mechanical cleaning or the water shear forces generated during ship navigation. However, traditional silicone-based antifouling materials suffer from drawbacks such as low mechanical strength, weak adhesion to the substrate, poor static antifouling ability, and lack of self-healing capabilities, thus limiting their widespread application.

[0003] Numerous studies have explored modifications using various methods. For instance, Liu et al. developed a PDMS-based polyurea with soft PDMS segments and hard 1,6-hexanediamine segments. This coating exhibited an adhesion strength as high as 2 MPa, significantly improving the adhesion performance of the silicone coating and imparting self-healing properties. However, it still lacked static antifouling capabilities. Dundua et al. introduced zwitterionic polymers into the PDMS matrix to enhance its static antifouling ability and demonstrated lower protein adsorption. However, the surface free energy (SFE) of PDMS was low, while that of the zwitterionic polymer was high, causing the latter to be trapped within the matrix and unable to fully exert its antifouling ability. Simultaneously, zwitterions increased the hydrophilicity of the silicone, affecting the swelling ratio and modulus of the coating, thereby impairing the silicone's dirt-releasing ability and reducing mechanical properties. Furthermore, the incompatibility between highly polar zwitterionic materials and other nonpolar building blocks led to phase segregation, which also compromised mechanical properties.

[0004] Therefore, developing silicone coatings with good adhesion, static antifouling properties, self-healing ability, and low swelling rate is an urgent problem to be solved. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides an organosilicon polyurea containing self-generated zwitterions and its preparation method. This invention introduces urea bonds and zwitterionic precursors containing fluorocarbon groups into organosilicon, resulting in an organosilicon polyurea containing self-generated zwitterions. As a marine antifouling coating, this coating possesses excellent adhesion, self-healing properties, static antifouling properties, and low water absorption.

[0006] Firstly, one of the objectives of this invention is to provide an organosilicon polyurea containing self-generated zwitterions.

[0007] Specifically, the organosilicon polyurea containing self-generated zwitterions is derived from bi-terminated carboxyl-functionalized polyself-generated zwitterion polymer structural units, bi-amino-terminated organosilicon structural units, and isocyanate structural units.

[0008] The general structural formula of the above-mentioned organosilicon polyurea is as follows:

[0009]

[0010] In the above general structural formula, the curved portion represents an alkyl group; the alkyl group is selected from one or a combination of straight-chain, branched, and cyclic alkyl groups containing 1 to 20 carbon atoms, preferably from one or a combination of straight-chain, branched, and cyclic alkyl groups containing 3 to 10 carbon atoms; m = 12 to 35, preferably m = 25 to 32; n = 1 to 5, preferably n = 2 to 3; x = 1 to 10, preferably x = 1 to 5, more preferably x = 1 to 3.

[0011] Preferably, the molecular weight of the organosilicon polyurea containing self-generated zwitterions is greater than 10000 g·mol⁻¹. -1 The preferred concentration is 12000–18000 g·mol⁻¹. -1 .

[0012] Preferably, the mass percentage of the double-terminated carboxyl-functionalized zwitterionic polymer in the organosilicon polyurea containing zwitterionic groups is 5-40%; more preferably 10-30%; and particularly preferably 15-20%.

[0013] It is worth mentioning that this invention uses a poly-self-generating zwitterionic polymer with dual-terminated carboxyl groups as the functional monomer and a diamino-terminated organosilicon and isocyanate as the matrix monomers. Urea bonds and zwitterionic precursors containing fluorocarbon groups are introduced into the organosilicon. Urea bonds can form a large number of hydrogen bonds, giving the organosilicon coating excellent adhesion properties and self-healing properties. The zwitterionic precursors containing fluorocarbon groups have low surface free energy and can migrate to the surface during coating film formation. In seawater environment, they hydrolyze into zwitterions to improve the static antifouling ability of the coating. At the same time, the zwitterionic precursors located in the coating matrix will not undergo hydrolysis, so they will not cause changes in matrix swelling ratio and modulus caused by traditional zwitterions, resulting in a low water absorption rate of the coating matrix.

[0014] Furthermore, the polyzombie polymer with dual-terminated carboxyl groups is a homopolymer, in which the middle segment of the molecular chain consists of zombie structural units containing fluorocarbon groups and trithiocarbon structural units, and the two ends of the molecular chain are capped by carboxyl groups. Its general structural formula is as follows:

[0015]

[0016] In the above general structural formula, the curved portion is one or a combination of straight-chain or branched alkyl groups containing 1 to 5 carbon atoms, preferably one or a combination of straight-chain or branched alkyl groups containing 2 to 3 carbon atoms, more preferably one or a combination of ethyl, propyl, and isopropyl; n = 1 to 5, preferably n = 2 to 3.

[0017] It is worth mentioning that the bi-terminated carboxyl-functionalized zwitterionic homopolymer provided by this invention can improve the static antifouling performance of the coating while maintaining certain mechanical properties when introduced into polyurea.

[0018] Furthermore, the bi-terminated carboxyl-functionalized zwitterionic polymers are derived from acrylate compounds and trithiocarbonate compounds containing fluorocarbon groups.

[0019] Furthermore, the acrylate compound containing a fluorocarbon group is selected from TCBF, with the chemical name 2-((3-((2,3,4,5,5,5-hexafluoro-2,4-bis(trifluoromethyl)pentyl)oxy)-3-oxopropyl)(methyl)amino)ethyl acrylate, and its specific structural formula is as follows:

[0020]

[0021] Furthermore, the preparation method of acrylate compounds containing fluorocarbon groups (TCBF) includes the following steps:

[0022] Dodecyl fluoroheptyl acrylate (DFA) and methylaminoethanol were mixed and reacted at low temperature for a period of time. Tetrahydrofuran and triethylamine were then added, followed by the addition of a tetrahydrofuran solution of acyl chloride and the reaction continued at low temperature to obtain an acrylate compound containing a fluorocarbon group (TCBF).

[0023] Furthermore, the general structural formula of trithiocarbonates is as follows:

[0024]

[0025] In the above general structural formula, the curved portion is one or a combination of straight-chain or branched alkyl groups containing 1 to 5 carbon atoms, preferably one or a combination of straight-chain or branched alkyl groups containing 2 to 3 carbon atoms, and more preferably one or a combination of ethyl, propyl, and isopropyl.

[0026] For example, 2,2'-[thiocarbonyl(sulfur)]bis[2-methylpropionic acid] (TSMA) (Structural Formula I), 2-((((2-carboxyethyl)sulfur)carbonthio)sulfur)-2-methylpropionic acid (Structural Formula II), 3-(((1-carboxyethyl)thio)carbonylthio)thiopropionic acid (Structural Formula III), the specific structural formulas are as follows:

[0027]

[0028]

[0029] It is worth mentioning that trithiocarbonate compounds, as chain transfer agents, can control the reversible addition-fragmentation chain transfer polymerization of acrylate compounds containing fluorocarbon groups.

[0030] In a preferred embodiment of the present invention, the provided bi-terminated carboxyl-functionalized self-generating zwitterionic polymer is obtained by reversible addition-fragmentation chain transfer polymerization of a fluorocarbon-containing acrylate compound (TCBF) and a trithiocarbonate compound (TSMA), and its general structural formula is as follows:

[0031]

[0032] Furthermore, the degree of polymerization of the bi-terminated carboxyl-functionalized zwitterionic polymer is 3–10, preferably 4–6; the number-average molecular weight is 1300–5500 g·mol⁻¹. -1 Preferably, it is 2300–3500 g·mol⁻¹ -1 The polydispersity index is 1.15 to 1.30.

[0033] Furthermore, the diamino-terminated organosilicon is selected from amino-terminated polydimethylsiloxanes, whose general structural formula is as follows:

[0034]

[0035] In the above general structural formula, the curved portion is one or a combination of straight-chain and branched alkyl groups containing 1 to 5 carbon atoms, preferably one or a combination of ethyl and propyl groups.

[0036] Preferably, the amino-terminated polydimethylsiloxane has a number-average molecular weight of 1500–3500 g·mol⁻¹. -1 Preferably, it is 2000–2500 g·mol⁻¹ -1 .

[0037] Furthermore, the isocyanate is selected from one or a combination of isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), and dicyclohexylmethane diisocyanate (HMDI).

[0038] Secondly, another objective of this invention is to provide a method for preparing organosilicon polyurea containing self-generated zwitterions, which is one of the objectives of this invention.

[0039] Specifically, the method includes the following steps:

[0040] Step 1: Under the protection of an inert gas, acrylate compounds containing fluorocarbon groups and trithiocarbonate compounds are mixed and subjected to a reversible addition-fragmentation chain transfer polymerization reaction under photoinitiation to obtain a polyzombie polymer with dual-terminated carboxyl groups.

[0041] Step 2: Dissolve the diamino-terminated organosilicon and the bi-carboxyl-functionalized zwitterionic polymer in a solvent, add an amide condensing agent to react, remove the precipitate, and then add isocyanate to react again to obtain organosilicon polyurea containing zwitterions.

[0042] Furthermore, the method includes the following steps:

[0043] Step 1: Acrylic ester compounds containing fluorocarbon groups, trithiocarbonate compounds, and dioxane filtered through an alkaline alumina column are added to a Schlenk tube. The tube is degassed through three "freeze-pump-thaw" cycles, and then backfilled with nitrogen to atmospheric pressure. It is then placed in a photoreactor and polymerized under light. After the reaction, the resulting polymer is precipitated in hexane, then redissolved in tetrahydrofuran, and this process is repeated three times. Finally, the polymer is dried in a vacuum oven to remove the solvent, yielding a bi-terminated carboxyl-functionalized zwitterionic polymer.

[0044] Step 2: The diamino-terminated polydimethylsiloxane was vacuum dried to remove water and then added to a three-necked flask equipped with a magnetic induction chamber, a spherical condenser, a constant-pressure dropping funnel, and a nitrogen protection device. Subsequently, the vacuum-dried, carboxyl-terminated, self-generated zwitterionic polymer was dissolved in tetrahydrofuran, and an amide condensing agent was added for pre-activation at room temperature before being added to the flask. After the reaction was complete at room temperature, the precipitate was removed. Then, isocyanate dissolved in tetrahydrofuran was added dropwise to the three-necked flask to continue the reaction at room temperature. After the reaction was complete, an organosilicon polyurea solution containing self-generated zwitterions was obtained.

[0045] Furthermore, in step one, the polymerization reaction is carried out in a Schlenk tube; the wavelength of the light is 450 nm; the molar ratio of the fluorocarbon-containing acrylate compound and the trithiocarbonate compound is 2.2:1 to 16.5:1, preferably 5.5:1 to 11:1.

[0046] Furthermore, in step two, the molar ratio of the diamino-terminated organosilicon, the bicarboxyl-functionalized polyzwitterionic polymer, and the isocyanate is 10:0.5-8:0.5-12; preferably 10:1-5:5-9.

[0047] Furthermore, in step two, the amide condensing agent is selected from a combination of 4-dimethylaminopyridine (DMAP) and N,N'-dicyclohexylcarboimide (DCC), and its dosage is adjusted according to the amount of raw materials used.

[0048] It is worth mentioning that, by changing the molecular weight of the diamino-terminated polydimethylsiloxane, the degree of polymerization and content of the bi-terminated carboxyl-functionalized zwitterionic polymer, the present invention can prepare different organosilicon polyureas containing zwitterions.

[0049] Finally, a third objective of the present invention is to provide the application of organosilicon polyurea containing self-generated zwitterions, which is one of the objectives of the present invention.

[0050] One of the objectives of this invention is to provide an organosilicon polyurea containing self-generating zwitterions that exhibits good adhesion to the substrate and static antifouling properties; at the same time, it has certain self-healing properties and low water absorption, making it suitable for use in marine antifouling coatings.

[0051] Furthermore, the method for using the organosilicon polyurea containing self-generated zwitterions as a coating, one of the objectives of this invention, is as follows:

[0052] The prepared organosilicon polyurea solution or reaction solution containing self-generated zwitterions is coated onto the surface of an object (such as a ship hull). After the solvent is removed (such as by evaporation or drying), a coating is obtained.

[0053] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0054] This invention utilizes RAFT polymerization to functionalize self-generated zwitterions containing fluorocarbon groups at both ends with carboxyl groups, introducing them into an organosilicon polyurea system. The urea bonds can form numerous hydrogen bonds, significantly improving the adhesion of organosilicon to glass fiber reinforced epoxy resin boards. Simultaneously, it endows the organosilicon with room temperature self-healing properties, achieving a self-healing efficiency of 28-40% after 24 hours at room temperature. It also retains the advantage of low surface free energy of organosilicon, approaching the simulated barnacle removal strength of unmodified PDMS. Because the introduced self-generated zwitterions containing fluorocarbon groups have low surface free energy, they can migrate to the coating surface during film formation, reducing the proportion trapped in the substrate. These migrating zwitterions hydrolyze into zwitterions in seawater, improving the static antifouling ability of the coating. The zwitterions located in the substrate do not undergo hydrolysis, thus preventing changes in the substrate swelling ratio and modulus, resulting in low water absorption. Attached Figure Description

[0055] Figure 1 These are schematic diagrams illustrating the reactions for preparing bi-terminated carboxyl-functionalized polyzombie polymers as described in Examples 5-7 of this invention.

[0056] Figure 2 The 1H NMR spectrum of the polyzombie polymer with dual-terminal carboxyl functionalization prepared in Example 5 of this invention;

[0057] Figure 3The above are the 1H NMR spectra of the bi-terminated carboxyl-functionalized zwitterionic polymer prepared in Example 5 of this invention before and after hydrolysis.

[0058] Figure 4 The gel permeation test spectra of the bi-terminated carboxyl-functionalized polyzwitterionic polymers prepared in Examples 5-7 of this invention are shown.

[0059] Figure 5 The flowchart shows the reaction process for preparing organosilicon polyurea containing self-generated zwitterions in Example 8 of the present invention.

[0060] Figure 6 The gel permeation test spectra of the polymer raw materials, reaction intermediates, and products used in the preparation of organosilicon polyurea containing self-generated zwitterions in Example 9 of the present invention are shown.

[0061] Figure 7 The stress-strain curves are shown for the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-11 and Comparative Example 1 of this invention.

[0062] Figure 8 The image shows the intensity of removing simulated barnacles on the organosilicon polyurea coating containing self-generated zwitterions prepared and hydrolyzed in Examples 8-11 and Comparative Example 1 of this invention.

[0063] Figure 9 The graphs show the water contact angle of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 of this invention as a function of time in artificial seawater.

[0064] Figure 10 Infrared comparison images of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 of this invention before and after hydrolysis;

[0065] Figure 11 The graph shows the change in water absorption rate over time after hydrolysis of the organosilicon polyurea coating containing self-generated zwitterions prepared in Examples 8-10 of this invention.

[0066] Figure 12 The bonding strength diagrams of the organosilicon polyurea coating containing self-generated zwitterions prepared in Examples 8-10 of the present invention on glass fiber reinforced epoxy resin boards are shown.

[0067] Figure 13 The stress-strain comparison curves of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 of the present invention before and after self-healing are shown.

[0068] Figure 14 These are laser confocal scanning micrographs of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 of this invention after hydrolysis.

[0069] Figure 15The graph shows the relative sedimentation rates of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 of this invention after hydrolysis. Detailed Implementation

[0070] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0071] In the following examples and comparative examples, the raw materials were all commercially available products, as listed in Table 1:

[0072] Table 1:

[0073]

[0074]

[0075] Example 1

[0076] This embodiment illustrates the preparation of the trithiocarbonate compound 2,2'-[thiocarbonyl(sulfur)]bis[2-methylpropionic acid] (TSMA). The specific preparation method is as follows:

[0077] Under nitrogen atmosphere, carbon disulfide (27.4 g, 0.36 mol), chloroform (107.5 g, 0.9 mol), acetone (52.3 g, 0.9 mol), and tetrabutylammonium hydrogen sulfate (2.41 g, 7.1 mmol) were mixed with 120 mL of petroleum ether and added to a 2 L round-bottom flask, which was then cooled with water. Sodium hydroxide solution (50% wt) (201.6 g, 2.52 mol) was added dropwise over 90 minutes, and the mixture was stirred overnight while maintaining the temperature below 25 °C. After dissolving the solid in 900 mL of water, 120 mL of concentrated hydrochloric acid was added to acidify the aqueous layer, and the mixture was stirred for 30 minutes under nitrogen purging. The solid product was filtered and thoroughly washed with water, dried to constant weight, and 41.3 g of the mud-colored product was collected.

[0078] The mixture was stirred in toluene / acetone (v / v = 4 / 1) and further purified to obtain a yellow crystalline solid product.

[0079] Example 2

[0080] This embodiment illustrates the preparation of the trithiocarbonate compound 2-((((2-carboxyethyl)thio)carbonthio)thio)-2-methylpropionic acid. The specific preparation method is as follows:

[0081] In a 250 mL round-bottom flask equipped with a magnetic stir bar, 10.6 g (0.1 mol) of 3-mercaptopropionic acid, 100 mL of deionized water, and 16.0 g (0.2 mol) of 50 wt% NaOH solution were added. After stirring for 0.5 h, 6.0 mL (0.1 mol) of carbon disulfide was added dropwise, and the resulting yellow solution was stirred overnight at 25 °C. Then, 29.9 g (0.25 mol) of chloroform and 16.8 g (0.3 mol) of acetone were added, followed by dropwise addition of 60.0 g (0.75 mol) of 50 wt% NaOH solution, and a small amount of tetrabutylammonium bisulfate was added to aid phase transfer. The mixture was stirred overnight at 25 °C. After the reaction was complete, the mixture was acidified with concentrated hydrochloric acid, and the product was then filtered to obtain a precipitate, which was washed with deionized water and dried to constant weight in a vacuum drying oven at 60 °C. The purified product was then recrystallized from acetone.

[0082] Example 3

[0083] This embodiment illustrates the preparation of the trithiocarbonate compound 3-(((1-carboxyethyl)thio)carbonylthio)thiopropionic acid. The specific preparation method is as follows:

[0084] In a 250 mL round-bottom flask equipped with a magnetic stir bar, 10.6 g (0.1 mol) of 3-mercaptopropionic acid, 100 mL of deionized water, and 16.0 g (0.2 mol) of 50 wt% NaOH solution were added. After stirring for 0.5 h, 6.0 mL (0.1 mol) of carbon disulfide was added dropwise, and the resulting yellow solution was stirred overnight at 25 °C. Subsequently, 15.3 g (0.1 mol) of 2-bromopropionic acid was added dropwise to the yellow solution, and the mixture was stirred overnight at 25 °C. The reaction mixture was acidified with concentrated hydrochloric acid, and the product was filtered to obtain a precipitate, which was washed with deionized water and then dried at 60 °C in a vacuum drying oven to constant weight to obtain a pure product.

[0085] Example 4

[0086] This embodiment illustrates the preparation of 2-((3-((2,3,4,5,5,5-hexafluoro-2,4-bis(trifluoromethyl)pentyl)oxy)-3-oxopropyl)(methyl)amino)ethyl acrylate (TCBF), an acrylate compound containing a fluorocarbon group. The specific preparation method is as follows:

[0087] Under ice-water bath conditions, 10.0 g of dodecafluoroheptyl acrylate (DFA) was added to a 100 mL three-necked flask equipped with a constant pressure dropping funnel and a magnetic stir bar, followed by the addition of 1.94 g of methylaminoethanol and reaction for 3 h. 45 mL of tetrahydrofuran (THF) and 2.62 g of triethylamine (TEA) were added to the reaction solution, and under ice-water bath conditions, 2.36 g of acrylate chloride dissolved in 15 mL of THF was added dropwise to a round-bottom flask under constant pressure dropping funnel, and the reaction continued for 3 h. The white precipitate was removed by filtration, the solvent was removed by rotary evaporation, the resulting liquid was dissolved in ethyl acetate, and extracted three times with saturated sodium chloride solution. The extracted liquid was dried with anhydrous sodium sulfate, filtered, rotary evaporated, and dried in a vacuum oven at 60 °C for 24 h to obtain a transparent oily product.

[0088] Example 5

[0089] This embodiment illustrates the preparation of a poly-self-generating zwitterionic polymer with dual-terminal carboxyl functionalization. The specific preparation method is as follows:

[0090] 13.5 mmol TCBF monomer, 2.44 mmol TSMA, and 14 ml of dioxane filtered through an alkaline alumina column were added to a Schlenk tube. The tube was frozen using liquid nitrogen, degassed through three "freeze-pump-thaw" cycles, and then backfilled with nitrogen to atmospheric pressure. It was then placed in a photoreactor and polymerized at 450 nm for 8 h. After the reaction, the resulting polymer was precipitated in hexane and then redissolved in tetrahydrofuran. This process was repeated three times to remove unreacted monomers. The polymer was then dried in a vacuum oven at 60 °C for 24 h to remove the solvent, yielding a bivalently carboxyl-terminated poly(PTCBF). The degree of polymerization (DP) was calculated to be 5 based on the 1H NMR spectrum.

[0091] Figure 1 A schematic diagram of the reaction in this embodiment is shown.

[0092] Figure 2 The hydrogen nuclear magnetic resonance spectrum of the bi-terminated carboxyl-functionalized zwitterionic polymer prepared in this embodiment is shown.

[0093] Figure 3 The 1H NMR spectra of the bi-terminated carboxyl-functionalized zwitterionic polymer prepared in this embodiment are shown before and after hydrolysis.

[0094] Depend on Figure 2 It can be seen that the present invention has prepared a poly-self-generating zwitterionic polymer (PTCBF) with dual-terminal carboxyl functionalization.

[0095] Depend on Figure 3It can be seen that the h and g peaks disappeared after hydrolysis, indicating that the ester bond connected to the fluorocarbon group successfully underwent hydrolysis to generate a zwitterion; while the b peak did not disappear, indicating that the ester bond far from the fluorocarbon group did not undergo hydrolysis, further confirming that a zwitterion can be generated.

[0096] Example 6

[0097] This embodiment illustrates the preparation of a poly-self-generating zwitterionic polymer with dual-terminal carboxyl functionalization. The specific preparation method is as follows:

[0098] 13.5 mmol TCBF monomer, 1.22 mmol TSMA, and 14 ml of dioxane filtered through an alkaline alumina column were added to a Schlenk tube. The tube was frozen using liquid nitrogen, degassed through three "freeze-pump-thaw" cycles, and then backfilled with nitrogen to atmospheric pressure. It was then placed in a photoreactor and polymerized at 450 nm for 8 h. After the reaction, the resulting polymer was precipitated in hexane and then redissolved in tetrahydrofuran. This process was repeated three times to remove unreacted monomers. The polymer was then dried in a vacuum oven at 60 °C for 24 h to remove the solvent, yielding a bi-terminated carboxyl-functionalized poly(self-generating zwitterionic polymer) (PTCBF) (DP = 10).

[0099] Example 7

[0100] This embodiment illustrates the preparation of a poly-self-generating zwitterionic polymer with dual-terminal carboxyl functionalization. The specific preparation method is as follows:

[0101] 13.5 mmol TCBF monomer, 6.1 mmol TSMA, and 14 ml of dioxane filtered through an alkaline alumina column were added to a Schlenk tube. The tube was frozen using liquid nitrogen, degassed through three "freeze-pump-thaw" cycles, and then backfilled with nitrogen to atmospheric pressure. It was then placed in a photoreactor and polymerized at 450 nm for 8 hours. After the reaction, the resulting polymer was precipitated in hexane and then redissolved in tetrahydrofuran. This process was repeated three times to remove unreacted monomers. The polymer was then dried in a vacuum oven at 60 °C for 24 hours to remove the solvent, yielding a bivalently carboxyl-terminated poly(zwitterionic) polymer (PTCBF) (DP = 2).

[0102] Figure 4 Gel permeation chromatograms of the bi-terminated carboxyl-functionalized poly(self-generating zwitterionic polymer) PTCBF prepared in Examples 5-7 are shown.

[0103] Depend on Figure 4 The molecular weights and dispersion indices of the polymers provided in Examples 5-7 are shown in Table 2.

[0104] Table 2:

[0105] Example Mn (obtained via GPC) PDI 5 <![CDATA[2940g·mol -1 ]]> 1.295 6 <![CDATA[5000g·mol -1 ]]> 1.294 7 <![CDATA[1650g·mol -1 ]]> 1.17

[0106] As shown in Table 2, the molecular weight increases with the increase of the feed ratio, which proves that PTCBF was obtained. At the same time, with the increase of the feed ratio, the GPC peak position shifts to the left and has a lower polydispersity index, which proves that the degree of polymerization increases with the increase of the feed ratio, and proves that the reaction is a reversible addition-fragmentation chain transfer polymerization.

[0107] Example 8

[0108] This embodiment illustrates the preparation of an organosilicon polyurea coating containing self-generated zwitterions. The specific preparation method is as follows:

[0109] 0.832 mmol ART-PDMS (Mn = 2500 g·mol⁻¹) -1 After vacuum drying at 110°C for 2 hours, the solution was added to a 100 mL three-necked flask equipped with a magnetic induction chamber, a spherical condenser, a constant-pressure dropping funnel, and a nitrogen protection device. 0.087 mmol of PTCBF (DP=5) prepared in Example 5 was dissolved in 5 mL of tetrahydrofuran, and 0.017 mmol of DMAP and 0.182 mmol of DCC were added. After pre-activation at 25°C for 0.5 hours, the solution was added to the flask. The reaction was maintained at 25°C for 3 hours, and the resulting precipitate was removed. Then, 0.819 mmol of isophorone diisocyanate (IPDI) was dissolved in 5 mL of tetrahydrofuran and added dropwise to the three-necked flask. The reaction was continued at 25°C for 3 hours. After the reaction, the reaction solution was poured into a polytetrafluoroethylene mold, left at room temperature for 12 hours, and then cured in a vacuum oven at 60°C for 24 hours to obtain a coating named PTCBF-PU2500-5-10 with a molecular weight of 15600 g·mol⁻¹. -1 .

[0110] In the above coating, the mass fraction of the dual-terminated carboxyl-functionalized zwitterionic polymer is 10% wt.

[0111] Figure 5 A flowchart illustrating the reaction process in this embodiment is shown.

[0112] Example 9

[0113] This embodiment illustrates the preparation of an organosilicon polyurea coating containing self-generated zwitterions. The specific preparation method is as follows:

[0114] 0.748 mmol ART-PDMS (Mn = 2500 g·mol⁻¹) -1After vacuum drying at 110°C for 2 hours, the solution was added to a 100 mL three-necked flask equipped with a magnetic induction chamber, a spherical condenser, a constant-pressure dropping funnel, and a nitrogen protection device. 0.175 mmol of PTCBF (DP=5) prepared in Example 5 was dissolved in 5 mL of tetrahydrofuran, and 0.035 mmol of DMAP and 0.367 mmol of DCC were added. After pre-activation at 25°C for 0.5 hours, the solution was added to the flask. The reaction was maintained at 25°C for 3 hours, and the resulting precipitate was removed. Then, 0.630 mmol of isophorone diisocyanate (IPDI) was dissolved in 5 mL of tetrahydrofuran and added dropwise to the three-necked flask. The reaction was continued at 25°C for 3 hours. After the reaction, the reaction solution was poured into a polytetrafluoroethylene mold, left at room temperature for 12 hours, and then cured in a vacuum oven at 60°C for 24 hours to obtain a coating named PTCBF-PU2500-5-20 with a molecular weight of 15400 g·mol⁻¹. -1 .

[0115] In the above coating, the mass fraction of the double-ended carboxyl-functionalized zwitterionic polymer is 20% wt.

[0116] Figure 6 The gel permeation test spectra of the polymer raw materials, intermediates, and products used in the preparation of organosilicon polyurea containing self-generated zwitterions in this embodiment are shown.

[0117] Depend on Figure 6 It can be seen that the GPC elution positions of the intermediates and final products generated during the preparation process are shifted to the left compared with the GPC elution positions of the raw materials, which proves that the molecular weight of the intermediates and final products increases, indicating that the reaction has occurred successfully.

[0118] Example 10

[0119] This embodiment illustrates the preparation of an organosilicon polyurea coating containing self-generated zwitterions. The specific preparation method is as follows:

[0120] 0.664 mmol ART-PDMS (Mn = 2500 g·mol⁻¹) -1After vacuum drying at 110°C for 2 hours, the solution was added to a 100 mL three-necked flask equipped with a magnetic induction valve, a spherical condenser, a constant-pressure dropping funnel, and a nitrogen protection device. 0.262 mmol of PTCBF (DP=5) prepared in Example 5 was dissolved in 5 mL of tetrahydrofuran, and 0.052 mmol of DMAP and 0.550 mmol of DCC were added. After pre-activation at 25°C for 0.5 hours, the solution was added to the flask. The reaction was maintained at 25°C for 3 hours, and the resulting precipitate was removed. Then, 0.442 mmol of isophorone diisocyanate (IPDI) was dissolved in 5 mL of tetrahydrofuran and added dropwise to the three-necked flask. The reaction was continued at 25°C for 3 hours. After the reaction, the reaction solution was poured into a polytetrafluoroethylene mold, left at room temperature for 12 hours, and then cured in a vacuum oven at 60°C for 24 hours to obtain a coating named PTCBF-PU2500-5-30 with a molecular weight of 15800 g·mol⁻¹. -1 .

[0121] In the above coating, the mass fraction of the double-ended carboxyl-functionalized zwitterionic polymer is 30% wt.

[0122] Example 11

[0123] This embodiment illustrates the preparation of an organosilicon polyurea coating containing self-generated zwitterions. The specific preparation method is as follows:

[0124] 0.433 mmol ART-PDMS (Mn = 2500 g·mol⁻¹) -1 After vacuum drying at 110°C for 2 hours, the solution was added to a 100 mL three-necked flask equipped with a magnetic induction device, a spherical condenser, a constant pressure dropping funnel, and a nitrogen protection device. 0.092 mmol of PTCBF (DP=10) prepared in Example 6 was dissolved in 10 mL of tetrahydrofuran, and 0.018 mmol of DMAP and 0.193 mmol of DCC were added. After pre-activation at 25°C for 0.5 hours, the solution was added to the flask. The reaction was maintained at 25°C for 3 hours, and the resulting precipitate was removed. Then, 0.375 mmol of isophorone diisocyanate (IPDI) was dissolved in 10 mL of tetrahydrofuran and added dropwise to the three-necked flask. The reaction was continued at 25°C for 3 hours. After the reaction was completed, the reaction solution was poured into a polytetrafluoroethylene mold, placed at room temperature for 12 hours, and then cured in a vacuum oven at 60°C for 24 hours to obtain a coating named PTCBF-PU2500-10-20.

[0125] In the above coating, the mass fraction of the double-ended carboxyl-functionalized zwitterionic polymer is 20% wt.

[0126] Comparative Example 1

[0127] This embodiment illustrates the preparation of an organosilicon polyurea coating containing self-generated zwitterions. The specific preparation method is as follows:

[0128] 1.66 mmol ART-PDMS (Mn = 1000 g·mol⁻¹) -1 After vacuum drying at 110°C for 2 hours, the solution was added to a 100 mL three-necked flask equipped with a magnetic induction device, a spherical condenser, a constant pressure dropping funnel, and a nitrogen protection device. 0.175 mmol of PTCBF (DP=5) prepared in Example 5 was dissolved in 5 mL of tetrahydrofuran, and 0.035 mmol of DMAP and 0.367 mmol of DCC were added. After pre-activation at 25°C for 0.5 hours, the solution was added to the flask. The reaction was maintained at 25°C for 3 hours, and the resulting precipitate was removed. Then, 1.633 mmol of isophorone diisocyanate (IPDI) was dissolved in 5 mL of tetrahydrofuran and added dropwise to the three-necked flask. The reaction was continued at 25°C for 3 hours. After the reaction was completed, the reaction solution was poured into a polytetrafluoroethylene mold, placed at room temperature for 12 hours, and then cured in a vacuum oven at 60°C for 24 hours to obtain a coating named PTCBF-PU1000-5-20.

[0129] In the above coating, the mass fraction of the dual-terminated carboxyl-functionalized zwitterionic polymer is 20% wt.

[0130] Comparative Example 2

[0131] This embodiment illustrates the preparation of an organosilicon polyurea coating containing self-generated zwitterions. The specific preparation method is as follows:

[0132] 0.764 mmol ART-PDMS (Mn = 2500 g·mol⁻¹) -1 After vacuum drying at 110°C for 2 hours, the solution was added to a 100 mL three-necked flask equipped with a spherical condenser, a constant pressure dropping funnel, and a nitrogen protection device. 0.381 mmol of PTCBF (DP=2) prepared in Example 7 was dissolved in 5 mL of tetrahydrofuran, and 0.076 mmol of DMAP and 0.800 mmol of DCC were added. After pre-activation at 25°C for 0.5 hours, the solution was added to the flask. The reaction was maintained at 25°C for 3 hours, and the resulting precipitate was removed. Then, 0.421 mmol of isophorone diisocyanate (IPDI) was dissolved in 5 mL of tetrahydrofuran and added dropwise to the three-necked flask. The reaction was continued at 25°C for 3 hours. After the reaction was completed, the reaction solution was poured into a polytetrafluoroethylene mold, placed at room temperature for 12 hours, and then cured in a vacuum oven at 60°C for 24 hours to obtain a coating named PTCBF-PU2500-2-20.

[0133] In the above coating, the mass fraction of the double-ended carboxyl-functionalized zwitterionic polymer is 20% wt.

[0134] Figure 7The stress-strain curves of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-11 and Comparative Example 1 are shown.

[0135] Depend on Figure 7 It can be seen that the coatings prepared in Examples 8-11 and Comparative Example 1 all have good mechanical properties. However, the organosilicon polyurea containing self-generated zwitterions prepared in Comparative Example 2 cannot be used as a coating because its mechanical strength is too low to form a film. When preparing organosilicon polyurea containing self-generated zwitterions in Comparative Example 2, PTCBF (DP=2) obtained in Example 7 was used to modify the polyurea. Due to its low degree of polymerization and low molecular weight, when the content of PTCBF in the polyurea reaches 20%wt, a large amount of PTCBF is required. The mechanical strength of the polyurea coating mainly depends on the hydrogen bonds formed by urea bonds. Increasing the amount of PTCBF will react with more amino groups to form amide bonds, reducing the content of urea bonds. Therefore, its mechanical strength is low and it cannot be used as a coating.

[0136] Figure 8 The strength of removing simulated barnacles on organosilicon polyurea coatings containing self-generated zwitterions prepared and hydrolyzed in Examples 8-11 and Comparative Example 1 is shown.

[0137] Depend on Figure 8 It can be seen that the coating prepared in Comparative Example 1 requires the highest strength to remove the simulated barnacles, while the coating prepared in Example 10 requires a strength of 0.25 MPa, which is very close to the 0.2 MPa required for PDMS. This is because the ART-PDMS used in Comparative Example 1 has a lower molecular weight, which leads to the formation of more urea bonds. Urea bonds, as polar groups, increase the surface free energy of the coating and also form hydrogen bonds with the surface of the simulated barnacles, increasing the removal strength. The coatings prepared in Examples 8 to 10 require progressively lower strength to remove the simulated barnacles. This is because the PTCBF content in the coatings of Examples 8 to 10 increases sequentially, replacing some urea bonds with amide bonds, reducing the urea bond content, lowering the surface free energy of the coating, and forming fewer hydrogen bonds, which is beneficial for the removal of the simulated barnacles. At the same time, the increase in PTCBF content also reduces the elastic modulus of the coating surface (from...). Figure 7 It can be seen that a lower surface elastic modulus is more conducive to the removal of simulated barnacles; while the strength required for the coating prepared in Example 11 to remove simulated barnacles is higher than that in Example 9, because the PTCBF used in Example 11 has a high degree of polymerization, which will produce more obvious microphase separation when forming the coating, resulting in an increase in surface roughness. The increase in surface roughness is not conducive to the removal of simulated barnacles, so the removal strength of simulated barnacles is slightly increased.

[0138] Figure 9 The graphs showing the water contact angle of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 in artificial seawater as a function of time are shown.

[0139] Depend on Figure 9 It can be seen that the water contact angle of the coatings prepared in Examples 8 to 10 gradually decreases in artificial seawater and tends to stabilize after 3 days, proving that the self-generated zwitterions in the coating successfully hydrolyze to produce zwitterions, and the hydrolysis is complete after 3 days. Furthermore, as the content of PTCBF in Examples 8 to 10 increases, the decrease in hydrolysis contact angle becomes more obvious. However, even the water contact angle after complete hydrolysis in Example 10 is greater than 100°, proving that it has a lower surface free energy, which is more conducive to the release of fouling.

[0140] Figure 10 Infrared comparison images of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 before and after hydrolysis are shown.

[0141] Depend on Figure 10 It can be seen that the organosilicon polyurea coatings prepared in Examples 8-10, after hydrolysis, are located at 1640 cm⁻¹. -1 The decrease in peak intensity at 1560 cm⁻¹ confirms the hydrolysis of the ester bond, and the decrease in peak intensity becomes more significant with increasing PTCBF content. -1 The increase in peak strength proves that COO - The generation of zwitterions leads to the formation of amphoteric ions, and the peak intensity increases more significantly with the increase of PTCBF content. The generated zwitterions can improve the static antifouling ability of the coating.

[0142] Figure 11 The curves showing the water absorption rate of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 after hydrolysis are shown as a function of time.

[0143] Depend on Figure 11 It can be seen that the water absorption rate of the coatings prepared in Examples 8-10 stabilized after 4 days after hydrolysis. Even the water absorption rate of the coating containing 30 wt% PTCBF was not high, only 10%. This is because the water absorption rate of the coating after hydrolysis is related to the PTCBF content. The zwitterions generated after PTCBF hydrolysis have a strong hydration effect. Therefore, as the PTCBF content increases, the water absorption rate of the coating gradually increases. However, since most of the zwitterions are on the surface of the coating, the self-generated zwitterions in the matrix will not undergo hydrolysis, thus preventing the matrix from swelling. This effectively prevents serious water absorption problems and keeps the coating with a low water absorption rate.

[0144] Figure 12 The diagram shows the bonding strength of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 on glass fiber reinforced epoxy resin boards.

[0145] Depend on Figure 12It can be seen that the coatings prepared in Examples 8-10 all exhibit a bonding strength greater than 1 MPa on the glass fiber reinforced epoxy resin board, and can be used as antifouling coatings. In the coatings prepared in Examples 8-10, the urea bonds interact with the epoxy resin board, improving the bonding strength of the coating and enabling it to meet the requirements of marine antifouling coatings.

[0146] Figure 13 The stress-strain curves of the organosilicon polyurea coatings containing self-generated zwitterions prepared in Examples 8-10 before and after self-healing are shown.

[0147] Depend on Figure 13 It can be seen that the coatings prepared in Examples 8-10 possess certain room-temperature self-healing properties. On one hand, the introduction of zwitterionic precursors containing fluorocarbon groups into the coatings results in a lower elastic modulus, making chain segment migration easier at room temperature and thus enhancing the coating's self-healing ability. On the other hand, the presence of an appropriate amount of urea bonds in the coatings allows for the reconstruction of sufficient hydrogen bonds for self-healing, maintaining good self-healing performance.

[0148] The self-healing efficiency of the coatings prepared in Examples 8 to 10 after 24 hours is shown in Table 3. The self-healing efficiency is calculated as (fracture strength of the self-healed sample / fracture strength of the original sample) * 100%.

[0149] Table 3:

[0150] Example Self-repair efficiency 8 28％ 9 36％ 10 30％

[0151] Figure 14 The images show laser confocal scanning micrographs of Pseudomonas aeruginosa deposited on PDMS coatings and organosilicon polyurea coatings containing self-generating zwitterions prepared in Examples 8-10.

[0152] Figure 15 The relative sedimentation rates of Pseudomonas aeruginosa on PDMS coatings and organosilicone urea coatings containing self-generated zwitterions prepared in Examples 8-10 are shown.

[0153] Depend on Figure 14 and 15 It is evident that the coatings prepared in Examples 8-10, due to the presence of zwitterions, exhibit strong hydration, forming a hydration layer on the coating surface that hinders bacterial adhesion, thus demonstrating excellent antibacterial adhesion properties. The presence of zwitterions significantly enhances the antibacterial adhesion properties of the coatings prepared in Examples 8-10 after hydrolysis, and this performance further increases with increasing PTCBF content. Examples 9 and 10 achieved antibacterial adhesion rates of 92% and 93%, respectively, demonstrating excellent antibacterial adhesion properties and good static antifouling capabilities.

[0154] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A self-generating zwitterionic organosilicon polyurea comprising structural units derived from a double end carboxyl functionalized poly self-generating zwitterionic polymer, a double amino terminated organosilicon and isocyanate structural units; the self-generating zwitterionic organosilicon polyurea has the following general structure: wherein the curved part represents an alkyl group; m = 12-35, n = 1-5, x = 1-10.

2. The self-generating zwitterionic organosilicon polyurea of claim 1, wherein the alkyl group is selected from one or a combination of linear, branched, cyclic alkyl groups containing 1-20 carbon atoms. wherein, 3. The self-generating zwitterionic organosilicon polyurea of claim 1, wherein the alkyl group is selected from one or a combination of linear, branched, cyclic alkyl groups containing 3-10 carbon atoms.

2. The self-zwitterionic organosilicon polyurea of claim 1, wherein, 4. The self-generating zwitterionic organosilicon polyurea of claim 1, wherein m = 25-32, n = 2-3, x = 1-5.

3. The self-zwitterionic organosilicon polyurea of claim 2, wherein, 5. The self-generating zwitterionic organosilicon polyurea of claim 1, wherein the double end carboxyl functionalized poly self-generating zwitterionic polymer has a mass fraction of 5-40% in the self-generating zwitterionic organosilicon polyurea.

4. The self-zwitterionic organosilicon polyurea of claim 1, wherein, 6. The self-generating zwitterionic organosilicon polyurea of claim 5, wherein the double end carboxyl functionalized poly self-generating zwitterionic polymer has a mass fraction of 10-30% in the self-generating zwitterionic organosilicon polyurea.

5. The self-zwitterionic organosilicon polyurea of claim 4, wherein, x=1~3。 7. The self-generating zwitterionic organosilicon polyurea of claim 6, wherein the double end carboxyl functionalized poly self-generating zwitterionic polymer has a mass fraction of 15-20% in the self-generating zwitterionic organosilicon polyurea. The self-generating zwitterionic organosilicon polyurea has a molecular weight of greater than 10,000 g-mol -1 ; and / or, 8. The self-generating zwitterionic organosilicon polyurea of claim 7, wherein the double end carboxyl functionalized poly self-generating zwitterionic polymer is a homopolymer, the middle segment of the molecular chain is a self-generating zwitterionic structural unit containing a fluorocarbon group and a trithiocarbonic structural unit, and the two ends of the molecular chain are terminated by a carboxyl group, and the general structure is as follows:

9. The self-generating zwitterionic organosilicon polyurea of claim 8, wherein the curved part is one or a combination of linear, branched alkyl groups containing 1-5 carbon atoms; n = 1-5. The self-generating zwitterionic organosilicon polyurea has a molecular weight of 12000-18000 g / mol -1 ; and / or, 10. The self-generating zwitterionic organosilicon polyurea of claim 8, wherein the curved part is one or a combination of linear, branched alkyl groups containing 2-3 carbon atoms; n = 2-3.

11. The self-generating zwitterionic organosilicon polyurea of claim 8, wherein the double end carboxyl functionalized poly self-generating zwitterionic polymer is derived from a fluorocarbon-containing acrylate compound and a trithiocarbonic compound.

12. The self-generating zwitterionic organosilicon polyurea of claim 11, wherein the fluorocarbon-containing acrylate compound is selected from TCBF, and the structure is as follows:

9. The self-zwitterionic organosilicon polyurea of claim 1, wherein, 13. The self-generating zwitterionic organosilicon polyurea of claim 11, wherein the trithiocarbonic compound has the following general structure:

14. The self-generating zwitterionic organosilicon polyurea of claim 13, wherein the curved part in the general structure of the trithiocarbonic compound is one or a combination of linear, branched alkyl groups containing 1-5 carbon atoms.

10. The self-zwitterionic organosilicon polyurea of claim 9, wherein, 15. The self-generating zwitterionic organosilicon polyurea of claim 13, wherein the curved part is one or a combination of linear, branched alkyl groups containing 2-3 carbon atoms.

11. The self-zwitterionic organosilicon polyurea of claim 9, wherein, 16. The self-generating zwitterionic organosilicon polyurea of claim 13, wherein the curved part is one or a combination of ethyl, propyl, isopropyl.

17. The self-generating zwitterionic organosilicon polyurea of claim 1, wherein the double amino terminated organosilicon is selected from an amino terminated polydimethylsiloxane, and the general structure is as follows:

18. The self-generating zwitterionic organosilicon polyurea of claim 1, wherein the isocyanate is selected from one or a combination of isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate.

19. A method for preparing the self-generating zwitterionic organosilicon polyurea of any one of claims 1-18, comprising the following steps: ​ 12. The self-zwitterionic organosilicon polyurea of claim 11, wherein, ​ 13. The self-zwitterionic organosilicon polyurea of claim 11, wherein, ​ 14. The self-zwitterionic organosilicon polyurea of claim 9, wherein, The double-end carboxyl-functionalized polyzwitterionic polymer has a degree of polymerization of 3 to 10; a number average molecular weight of 1800 to 5500 g.mol -1 ; and a polydispersity index of 1.15 to 1.

30.

15. The self-zwitterionic organosilicon polyurea of claim 14, wherein, The double-end carboxyl-functionalized polyzwitterionic polymer has a degree of polymerization of 4-6 and a number average molecular weight of 2300-3500 g·mol -1 .

16. The self-zwitterionic organosilicon polyurea of claim 1, wherein, ​ wherein the curved portion is one or a combination of straight-chain, branched alkyl groups containing 1 to 5 carbon atoms; the number average molecular weight of the amino-terminated polydimethylsiloxane is 1500 to 3500 g·mol -1 .

17. The self-zwitterionic organosilicon polyurea of claim 16, wherein, The curve portion is one or a combination of ethyl, propyl; the number average molecular weight of the amino-terminated polydimethylsiloxane is 2000-2500 g·mol -1 .

18. The self-zwitterionic organosilicon polyurea of claim 1, wherein, ​ ​ Step one, under inert gas protection, mixing the acrylic ester compound containing fluorocarbon group and the trithiocarbonic acid ester compound, and performing reversible addition-fragmentation chain transfer polymerization under photo initiation to obtain a double-end carboxyl functionalized poly-zwitterion polymer; Step two, dissolving the double-amino-terminated silicone and the double-end carboxyl functionalized poly-zwitterion polymer in a solvent, adding an amide condensation agent to perform a reaction, removing the precipitate, and then adding an isocyanate to perform a reaction to obtain the self-zwitterionic silicone polyurea.

20. Use of the self-zwitterionic silicone polyurea according to any one of claims 1-18, wherein the polymer is used in marine antifouling coatings.

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