BE1028623A1 - METHOD OF SYNTHETING A FUNCTIONAL GEL FOR SURFACE MODIFICATION OF ARTIFICIAL GRASS FIBERS - Google Patents

Abstract

The present disclosure belongs to the technical field of modification of polymeric materials and applications thereof and relates to a method for synthesizing a functional gel for the surface modification of artificial turf fibers. The present disclosure provides a gel containing dopamine functional groups that can be applied to commonly used polyethylene (PE) synthetic fibers. The gel coat thus formed has improved adhesion to PE fibers and can reversibly adsorb and release water, imparting good self-cooling property, dirt resistance and self-cleaning property to the surface of PE fibers.

Description

| ‚ BE2021/5582

METHOD OF SYNTHETING A FUNCTIONAL GEL FOR THE SURFACE MODIFICATION OF ARTIFICIAL GRASS FIBERS TECHNICAL AREA

[01] The present disclosure belongs to the technical field of modifying polymeric materials and applications thereof, and relates to a method for synthesizing a functional gel for surface modification of artificial turf fibers.

BACKGROUND ART

[02] Artificial turf has experienced a boom in development in recent years. Because of the advantages of safety and environmental friendliness, convenient maintenance, all-weather capability, etc., artificial grass can be widely used for various landscape and sports applications such as soccer, tennis and golf. With further research on artificial turf, it has been found that compared to natural turf, artificial turf is more likely to absorb heat under the sunlight, resulting in a high surface temperature that is increased by about 30°C to 40°C. As a result, the risk of heat stroke is greatly increased and people's safety is compromised.

[03] An extremely hydrophilic gel having a three-dimensional network structure has stability and flexibility and elasticity as a solid, and is capable of absorbing water to swell rapidly and retain a large amount of water without dissolving in the swollen state. The gel system has been widely used in the fields of plant water retention agents, slow-release fertilizers for crops, medical supplies (physical cooling), etc. due to the excellent water retention ability of its three-dimensional network structure.

[04] At present, polyethylene (PE) material is most widely used in the production of artificial grass fibers because of its flexibility, good impact resistance and low cost. However, the surface of fibers made from a PE polymer is hydrophobic because there is no polar group in the chain structure of the PE polymer. Thus, in order to coat the surface with a traditional gel, the PE fibers should first undergo hydrophilic modification, resulting in more steps.

EXECUTIVE SUMMARY

[05] The present disclosure provides a method for synthesizing a functional gel for the surface modification of artificial grass fibers to solve the problem of more steps of gel application due to the hydrophobicity of the traditional PE

; BE2021/5582 to loosen artificial grass fibers.

[06] Dopamine methacrylamide (DMA) is synthesized by a method that includes the following steps:

[07] (1) Dissolving sodium tetraborate decahydrate and sodium bicarbonate in a specified molar ratio in deionized water, bubbling nitrogen to degas for 20 minutes, then adding dopamine hydrochloride and stirring thoroughly;

[08] (2) adding a solution of methacrylic anhydride in tetrahydrofuran (THF) dropwise to the mixed aqueous solution;

[09] (3) preparing an aqueous sodium hydroxide solution at a specified concentration to adjust the pH of the mixed solution in step (2), and then bubbling nitrogen into the reaction mixture at room temperature;

[10] (4) obtaining a white slurry after completion of the reaction, washing the white slurry with 50 mL of ethyl acetate, followed by filtration and acidification with 6 mol/L HCl to pH=2; and

[11] (5) Based on 100 mL of deionized water in step (1), extracting the organic layer in the solution with 50 mL of ethyl acetate three times, concentrating using a rotary evaporator, and adding the organic layer dropwise to 250 mL of n-hexane for the Allow to settle followed by filtration and vacuum drying to give the brown solid product. The specific addition amounts of the different substances can be adjusted in such a ratio.

[12] The functional monomer DMA can be prepared according to the following reaction formula: no” = SON À 3 L m7 sr YT a 8 2 ï

[13] Further, in step (1), a molar ratio of sodium tetraborate decahydrate to sodium bicarbonate may be 1:1.8. Based on 100 mL of deionized water, 14 g total of sodium tetraborate decahydrate and sodium bicarbonate and 0.026 moles of dopamine hydrochloride can be added. The specific addition amounts of the

; BE2021/5582 different substances can be adjusted in such a ratio.

[14] In step (2), 29.7 ml of the solution of 18% methacrylic anhydride in THF can be prepared.

[15] In step (3), the aqueous sodium hydroxide solution can be used to adjust the pH to greater than or equal to 8, preferably.

[16] A gel containing functional groups on dopamine is prepared by a method including the following steps:

[17] S1: Prepare a solution at normal temperature by adding 0.1 g of initiator and 30 ml of solvent to a 100 ml one-necked flask;

[18] S2: Adding a monomer A and a monomer B in different molar ratios according to different molecular weights, and magnetically stirring at normal temperature for 10 minutes until dissolved;

[19] 5$3: Attaching a T-piece to the single-neck flask, ensuring a vacuum has been drawn inside the flask, and injecting an inert gas into the mixed solution to remove oxygen; and

[20] S4: Initiating a polymerization reaction by heating the flask in a water bath, followed by isolating the polymerization product by allowing it to stand and cooling it naturally to room temperature, thereby obtaining the gel containing functional groups on dopamine.

[21] The gel containing functional groups on dopamine can be prepared according to the following reaction formula: => IT { = 27 5 no N se * a ae ed FAN 08 it

[22] Further, the initiator used in step S1 may be azodiisobutyronitrile.

[23] The solvent used in step S1 can be selected from the group consisting of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, etc.

[24] Further, the monomer A used in step S2 can be selected from DMA.

[25] Further, the monomer B used in step S2 can be selected from the group

\ BE2021/5582 consisting of acrylic acid, methacrylic acid, various vinyl alcohols and other hydrophilic double bond monomers such as glycidyl methacrylate.

[26] The molar ratio of monomer A to monomer B in step S2 can be 1:1, 1:2, 1:3, 3:1 or 2:1.

[27] Further, the protective gas used in step S3 may be one of nitrogen and helium.

[28] Preferably, the polymerization reaction in step S4 is carried out at a temperature of 75°C to 80°C for 24 hours.

[29] Specifically, step S3 may alternatively include vacuuming and injecting the protective gas for more than three times to reduce the influence of external gas such as oxygen on the experiment, thereby reducing by-products in the final product. The protective gas can generally be selected from nitrogen. A T-piece can also be used. The first end of the T-piece can be connected to a balloon (shielding gas) while the second end is connected to the single-neck flask and the third end is used for vacuuming and injecting the shielding gas. Specifically, the vacuuming can be performed by pumping away the air in the single-necked flask and the balloon first, and then the protective gas can be injected so that the balloon and the single-necked flask are full of protective gas. Freezing may be performed prior to vacuuming to reduce foreign gas solubility.

[30] A method of manufacturing a self-cooling artificial turf using the functional gel includes fixing purchased or manufactured artificial turf upside down, moving a side with the artificial turf fibers of the artificial turf through a container containing the functional gel at a speed of 3 - 20 m/min and allowing the functional gel to cool naturally to room temperature, thereby obtaining the self-cooling artificial turf.

[31] Compared to the prior art, the present disclosure has the following advantages:

[32] 1. The present disclosure provides a gel system containing functional groups on dopamine. Based on the high adhesion of dopamine, the novel gel thus obtained can be applied directly to the surface of PE for modification. The waste of resources is thus avoided.

[33] 2. The present disclosure provides a gel containing functional groups on dopamine that can be applied to commonly used PE artificial grass fibers. The gel coat thus formed has improved adhesion to PE fibers and can reversibly adsorb and release water, giving the surface of the PE fibers a good

) BE2021/5582 Confers self-cooling property, dirt resistance and self-cleaning property. Further, the formation of the functional coating on the surface of the PE fibers will effectively protect the PE fibers from active substances in the environment to reduce environmental stress cracking of PE.

[34] 3. A performance test on the synthesized gel showed this excellent flexibility and ease of curling and twisting of the gel and instantaneous recovery to the initial state after cessation of external force application, as shown in FIG. 1, which would be beneficial in improving the comfort of people playing on the turf and reducing injuries. In addition, as shown by the data, the gel has an elongation at break of up to 2500% and a tensile strength of up to 1MPa, thus it could effectively protect the artificial grass fibers and prolong the life of the artificial grass. The gel is able to absorb water and swell rapidly and retain a large amount of water without dissolving in the swollen state. It was found through a test that the gel had enormous water absorption (about 253 g/g) and could effectively reduce the temperature of the artificial turf.

BRIEF DESCRIPTION OF THE DRAWINGS

[35] The FIG. 1 shows a functional gel made according to an example of the present disclosure.

[36] The FIG. 2 shows experimental figures of different types of artificial grass according to an example of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

[37] In order to make the objects, features, and advantages of the present disclosure more understandable, the present disclosure is further described below with reference to the accompanying drawings and specific examples. It should be noted that the examples in the application and features in the examples can be combined with each other in a non-contradictory situation.

[38] In the following description, many specific details are set forth in order to facilitate a thorough understanding of the present disclosure, but the present disclosure may be implemented in ways other than those described herein. Therefore, the present disclosure is not limited by the specific examples disclosed below.

[39] Unless otherwise noted, all components used in the examples are commercially available.

° BE2021/5582

[40] Example 1

[41] (1) Preparation of a functional dopamine monomer with a double bond.

[42] 10 g sodium tetraborate decahydrate and 4 g sodium bicarbonate were dissolved in 100 mL deionized water. Nitrogen was bubbled in for degassing for 20 minutes, followed by adding 5 g of dopamine hydrochloride and stirring fully. 4.7 ml of a solution of methacrylic anhydride in THF (25 ml) was added dropwise to the mixed aqueous solution. The pH was adjusted to greater than or equal to 8 using aqueous sodium hydroxide solution. The reaction mixture was stirred at room temperature with nitrogen sparging for 14 hours. The white slurry thus obtained was washed with 50 ml of ethyl acetate twice and then filtered, and the obtained aqueous solution was acidified to pH=2 with 6 mol/l HCl. The organic layer in the solution was extracted with 50 mL of ethyl acetate three times, concentrated using a rotary evaporator, then added dropwise to 250 mL of n-hexane to settle, and filtered and dried in vacuo to obtain a brown solid product.

[43] (2) Preparation of a gel containing functional groups of dopamine.

[44] The obtained monomer DMA and a monomer acrylic acid (AA) were subjected to solution phase free radical polymerization to prepare the gel containing functional groups of dopamine.

[45] Specifically, 0.1 g of azobisisobutyronitrile (AIBN) and 15 g of DMA and AA (in a 1:1 molar ratio) were dissolved in 30 mL of DMF in a 100 mL one-necked flask by magnetic stirring at room temperature for 10 minutes. Vacuuming was performed, and then nitrogen was injected and the mixture was allowed to react at 75°C for 24 hours. After the completion of the reaction, the product was allowed to naturally cool down to room temperature. Thus, a functional gel containing dopamine with a molecular weight of 10120 and a molecular weight distribution of 1.25 was obtained.

[46] (3) The production of artificial turf (this example provides a method of producing artificial turf, all steps being conventional steps of artificial turf production unless otherwise specified. Alternatively, the artificial turf can be purchased directly and then with the functional gel be coated.)

[47] A matrix resin and functional additives including an anti-ager, a plasticizer, and a leveling agent (commercially available, not limited in type) were added in an appropriate amount of about 1% by mass to the raw material with a high-speed mixer mixed. The mixture was then melted at 150°C and formed into a thin sheet

| BE2021/5582 extruded using a single screw extruder.

[48] The extruded sheet was introduced into water to cool and solidify. The thin film was slit into ribbons 50 µm thick and 30 mm wide (monofilaments were not slit). The tapes or monofilaments were elongated four times in their drawing direction in a drying oven at 80°C or in water at 100°C. The elongated ribbons or monofilaments were subjected to a 1% relaxation heat treatment at 80°C.

[49] A twisted yarn for the artificial turf was produced at a rate of 70 m/min with a twist controlled at 20/m. The artificial grass was knitted using a quilting process with a gauge of 0.5 inch and 108 + 10 loops per yard.

[50] The artificial turf fibers, which differed in type, color and quantity depending on the design, were quilted by a twisting and then knitted on a roll of prepared plastic base fabric using a knitting machine and knitting needles. Before knitting, the space between the rows of quilted fibers, the needle offset, the height of the fibers were adjusted. The fibers were of the same height so that the artificial turf surface was level.

[51] The back of the artificial turf was then coated with a compounded latex. A butadiene styrene rubber was selected and applied to the backing to form a coating that further fixes the quilted synthetic fibers to the base fabric. The artificial grass, which has been dried at 145°C, has been perforated to prevent rainwater from accumulating on it. Then, the artificial turf was fixed upside down, and the side with the artificial turf fibers on the artificial turf was passed through a tank containing the functional gel at a speed of 3 m/min. After the gel was naturally cooled down to room temperature, a self-cooling artificial turf could be obtained.

[52] The artificial grass made with self-cooling PE artificial grass fibers in this example had to meet the following conditions: A three-layer structure including the artificial grass fibers, knitted base and primer, and crimped artificial grass fibers with a length of 50 mm, a density of 170 stitches and a diameter of about 100 µm, suitable for sports applications such as soccer. As tested, the water absorption of the artificial turf was 263 g/g, and in an outdoor environment at 35°C, the temperature of the artificial turf could be reduced by more than 5°C compared with a common PE artificial turf.

[53] Example 2

[54] (1) Preparation of functional dopamine monomer with double bond [SS] 10 g sodium tetraborate decahydrate and 4 g sodium bicarbonate were dissolved in 100 ml

; BE2021/5582 dissolved in ionized water. Nitrogen was bubbled in for degassing for 20 minutes, followed by adding 5 g of dopamine hydrochloride and stirring fully. 4.7 ml of a solution of methacrylic anhydride in THF (25 ml) was added dropwise to the mixed aqueous solution. The pH was adjusted to greater than or equal to 8 using aqueous sodium hydroxide solution. The reaction mixture was stirred at room temperature with nitrogen sparging for 14 hours. The white slurry thus obtained was washed with 50 ml of ethyl acetate twice and then filtered, the obtained aqueous solution was acidified to pH=2 with 6 mol/l HCl. The organic layer in the solution was extracted with 50 mL of ethyl acetate three times, concentrated using a rotary evaporator, then added dropwise to 250 mL of n-hexane to settle, and filtered and dried in vacuo to obtain a brown solid product.

[56] 2) Preparation of a gel containing functional groups of dopamine.

[57] The obtained monomer DMA and a monomer acrylic acid (AA) were subjected to solution-phase free radical polymerization to prepare the gel containing functional groups of dopamine.

[58] Specifically, 0.1 g of AIBN and 15 g of DMA and AA (in a 2:1 molar ratio) were dissolved in 30 mL of DMF in a 100 mL one-necked flask by magnetic stirring at room temperature for 10 minutes. Vacuuming was performed and nitrogen was injected, and the mixture was allowed to react at 75°C for 24 hours. After naturally cooling down to room temperature, a functional gel containing dopamine with a molecular weight of 9800 and a molecular weight distribution of 1.30 was obtained.

[59] The surface of the artificial grass fibers (commercially available) was coated with the gel containing functional groups of dopamine obtained in this example. The specifications of the artificial grass were as follows: a three-layer structure including the artificial grass fibers, knitted base and primer, and crimped artificial grass fibers with a length of 32mm, a density of 150 stitches and a diameter of about 100um, and the water absorption of the artificial grass of up to 223 g/g. The temperature was measured under sunlight and the results showed that compared with artificial grass not coated with the gel, the temperature of the artificial grass coated with the gel could be reduced by about 5°C.

[60] Example 3

[61] (1) Preparation of functional dopamine monomer with double bond

[62] 10 g sodium tetraborate decahydrate and 4 g sodium bicarbonate were dissolved in 100 ml

) BE2021/5582 dissolved in ionized water. Nitrogen was bubbled in for degassing for 20 minutes, followed by adding 5 g of dopamine hydrochloride and stirring fully. 4.7 ml of a solution of methacrylic anhydride in THF (25 ml) was added dropwise to the mixed aqueous solution. The pH was adjusted to greater than or equal to 8 using aqueous sodium hydroxide solution. The reaction mixture was stirred at room temperature with nitrogen sparging for 14 hours. The white slurry thus obtained was washed with 50 ml of ethyl acetate twice and then filtered, and the obtained aqueous solution was acidified to pH=2 with 6 mol/l HCl. The organic layer in the solution was extracted with 50 mL of ethyl acetate three times, concentrated using a rotary evaporator, then added dropwise to 250 mL of n-hexane to settle, and filtered and dried in vacuo to obtain a brown solid product.

[63] 2) Preparation of a gel containing functional groups of dopamine.

[64] The obtained monomer DMA and a monomer acrylic acid (AA) were subjected to solution phase free radical polymerization to prepare the gel containing functional groups of dopamine.

[65] Specifically, 0.1 g of AIBN and 15 g of DMA and methacrylic acid (in a 2:1 molar ratio) were dissolved in 30 mL of DMF in a 100 mL one-necked flask by magnetic stirring at room temperature for 10 minutes. Vacuuming was performed and nitrogen was injected, and the mixture was allowed to react at 75°C for 24 hours. After naturally cooling down to room temperature, a functional gel containing dopamine with a molecular weight of 8930 and a molecular weight distribution of 1.15 was obtained.

[66] The surface of the artificial grass fibers was coated with the gel containing functional groups of dopamine obtained in this example. The specifications of the artificial grass were as follows: A three-layer structure including the artificial grass fibers, knitted base and primer, and mixed crimped and straight artificial grass fibers with a length of 32mm, a density of 200 stitches and a diameter of about 100um, suitable for sports applications, such as tennis, and a water absorption of the artificial turf of up to 189 g/g. The temperature was measured under sunlight, and the results showed that compared with artificial grass not coated with the gel, the temperature of the artificial grass coated with the gel could be reduced by about 4°C.

[67] Example 4

[68] (1) Preparation of functional dopamine monomer with double bond

“BE2021/5582

[69] 10 g of sodium tetraborate decahydrate and 4 g of sodium bicarbonate were dissolved in 100 mL of deionized water. Nitrogen was bubbled in for degassing for 20 minutes, followed by adding 5 g of dopamine hydrochloride and stirring fully. 4.7 ml of a solution of methacrylic anhydride in THF (25 ml) was added dropwise to the mixed aqueous solution. The pH was adjusted to greater than or equal to 8 using aqueous sodium hydroxide solution. The reaction mixture was stirred at room temperature with nitrogen sparging for 14 hours. The white slurry thus obtained was washed with 50 ml of ethyl acetate twice and then filtered, and the obtained aqueous solution was acidified to pH=2 with 6 mol/l HCl. The organic layer in the solution was extracted with 50 mL of ethyl acetate three times, concentrated using a rotary evaporator, then added dropwise to 250 mL of n-hexane to settle, and filtered and dried in vacuo to obtain a brown solid product.

[70] 2) Preparation of a gel containing dopamine functional groups.

[71] The obtained monomer DMA and a monomer acrylic acid (AA) were subjected to solution phase free radical polymerization to prepare the gel containing functional groups of dopamine.

[72] Specifically, 0.1 g of AIBN and 15 g of DMA and methacrylic acid (in a 1:1 molar ratio) were dissolved in 30 mL of DMF in a 100 mL one-necked flask by magnetic stirring at room temperature for 10 minutes. Vacuuming was performed and nitrogen was injected, and the mixture was allowed to react at 75°C for 24 hours. After naturally cooling down to room temperature, a functional gel containing dopamine with a molecular weight of 11,000 and a molecular weight distribution of 1.27 was obtained.

[73] The surface of the artificial grass fibers was coated with the gel containing functional groups of dopamine obtained in this example. The specifications of the artificial grass were as follows: artificial grass fibers, knitted base and primer, mixed crimped and straight artificial grass fibers with a length of 12mm, a density of 212 stitches and a diameter of about 50um, suitable for sports applications, such as basketball and swimming, and landscape applications , and a water absorption of up to 225 g/g. In an outdoor environment at 35°C, the temperature of this artificial grass could be reduced by about 4°C compared with a common PE artificial grass.

[74] The gels obtained in Examples 1 to 4 were subjected to other tests, with the resulting data being shown below.

" BE2021/5582 Item Elongation at Break % Tensile Strength Mpa Water Absorption LT TE (EE

[75] As shown in FIG. 1, a property test was conducted on the gel synthesized in Example 1, and the results showed that the gel has excellent flexibility, can be easily crimped and twisted, and can be immediately restored to the original state upon release of external forces which would be beneficial in improving the comfort of people playing on the artificial turf and reducing injuries.

[76] Self-cleaning experiment

[77] The procedure of the experiment was as follows: the artificial turf dipped in the functional gel obtained in Example 1 and the artificial turf not dipped in the functional gel were put into an equal area which was not was less than 0.5 square meters, cut and then placed in the open ground. The surfaces of the artificial turf immersed in the functional gel and the artificial turf not immersed in the functional gel were observed after natural exposure for one week.

[78] Result: As shown in FIG. As shown in Figure 2 (even more obvious contrast between the original images), the artificial turf that was immersed in the functional gel was apparently cleaner than the artificial turf that had not been immersed in the functional gel.

[79] Reason: The functional gel was applied on the surface of the artificial grass fibers to form a protective coating to effectively prevent infiltration and adhesion of dust, oil spills, etc.

[80] The foregoing are merely descriptions of preferred examples of the present disclosure and are not intended to limit the present disclosure in other forms. Alterations or modifications can be made to the disclosed technical content by anyone skilled in the art to come up with equivalent examples that can be applied in other fields. Any simple addition or equivalent changes and modifications made to the above examples according to the technical essence of the present disclosure without departing from the contents of the technical solutions of the present disclosure

| | BE2021/5582 should fall within the scope of the technical solutions of the present disclosure to be protected.

Claims (9)

N > BE2021/5582 PATENT CLAIMS Claims 1. A method for synthesizing a functional gel for surface modification of artificial turf fibers, comprising the following steps: S1: mixing an initiator with solvent a; S2: adding monomer A and monomer B and stirring to dissolve the monomers to obtain a mixture; S3: Injecting a protective gas after vacuuming; and S4: initiating a polymerization reaction by heating in a water bath, then isolating the polymerization product to stand and cool to room temperature, thereby obtaining a dopamine functional group-containing gel; wherein monomer A is dopamine methacrylamide. 2. A method for synthesizing a functional gel for surface modification of artificial turf fibers according to claim 1, wherein the dopamine methacrylamide is prepared by the following steps: (1) dissolving sodium tetraborate decahydrate and sodium bicarbonate in deionized water, bubbling nitrogen to degas, then adding dopamine - hydrochloride and complete stirring; (2) adding dropwise a solution of methacrylic anhydride in tetrahydrofuran (THF); (3) adding an alkaline solution to adjust the pH, then bubbling with nitrogen; (4) washing with ethyl acetate and filtering, followed by acidification; and (5) extracting an organic layer in the solution with ethyl acetate, concentrating and adding dropwise the organic layer to n-hexane for settling, followed by filtering and vacuum drying, thereby obtaining the dopamine methacrylamide. The method for synthesizing a functional gel for surface modification of artificial turf fibers according to claim 1, wherein the solvent used in step S1 is any one of the group consisting of N,N-dimethylformamide, N,N-dimethylacetamide and tetrahydrofuran while the initiator is azodiisobutyronitrile and the monomer B used in step S2 is a hydrophilic monomer having a double bond. 4. Method of synthesizing a functional gel for surface modification ' BE2021/5582 of artificial grass fibers according to claim 1, wherein the monomer B used in step S2 is any one of the group consisting of acrylic acid, methacrylic acid and vinyl alcohol. The method for synthesizing a functional gel for surface modification of artificial turf fibers according to claim 1, wherein the molar ratio of the monomer A to the monomer B is 1:3 to 3:1. The method for synthesizing a functional gel for surface modification of artificial turf fibers according to claim 1, wherein the protective gas used in step S3 is nitrogen or helium; and the polymerization reaction in step S4 occurs at a temperature of 75°C to 80°C for 24 hours. The method for synthesizing a functional gel for surface modification of artificial turf fibers according to claim 2, wherein in particular the step (1) comprises bubbling nitrogen for degassing for 15 to 25 minutes; step (4) comprises acidifying to pH 2 with 6 mol/L aqueous hydrochloric acid solution, wherein the molar ratio of sodium tetraborate decahydrate to sodium bicarbonate is 1:1.8; step (2) comprises preparing a solution of 17% methacrylic anhydride in THF; step (3) comprises adjusting the pH to greater than or equal to 8 with aqueous sodium hydroxide solution; and the step (5) comprises extracting the organic layer in the solution three times with ethyl acetate and concentrating it by using a rotary evaporator. 8. Use of the functional gel for the surface modification of artificial turf fibers according to any one of claims 1 - 7 in the production of turf fibers or (ready) turf. 9. A method for producing a self-cooling artificial turf, comprising: fixing artificial turf in an upside-down manner, passing the artificial turf from one side with turf fibers through a functional gel at a speed of 3 - 20 m/min, and allowing the functional gel to cool naturally Room temperature, giving the self-cooling artificial grass.