Preparation method of Chinese yam mucoprotein anti-drag hydrogel

Abstract

The invention discloses a preparation method of Chinese yam mucin anti-drag hydrogel. The preparation method comprises the following steps: crushing Chinese yam blocks and deionized water to obtain a Chinese yam mucus mixture; centrifuging, standing and layering, extracting supernate, and filtering to obtain a plant extracting solution; purifying by adopting a reverse osmosis method, and air-drying to obtain Chinese yam mucoprotein; the preparation method comprises the following steps: adding gelatin into a PBS solution, heating and stirring, then adding N, N-dimethylformamide and methacrylic anhydride, heating and stirring, dialyzing, and freeze-drying to obtain a gelatin derivative grafted with carbon-carbon double bonds; the preparation method comprises the following steps: adding a gelatin derivative into deionized water, heating and stirring, adding Chinese yam mucoprotein, N, N '-methylene bisacrylamide and ammonium persulfate, stirring, centrifugally defoaming, and drying to obtain the Chinese yam mucoprotein drag-reducing hydrogel. According to the preparation method of the Chinese yam mucoprotein anti-drag hydrogel, Chinese yam mucoprotein macromolecular chains are connected into a network structure by using N, N '-methylene bisacrylamide molecules, so that water-soluble Chinese yam mucoprotein is prevented from being dissolved and lost in a water body, and long-term lubrication and anti-drag are realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of surface engineering and relates to a preparation method of yam mucin drag-reducing hydrogel. BACKGROUND

[0002] In the field of ocean, when the ship and submarine sail, the turbulent boundary layer formed by the interaction between the ship body and the water flow makes the frictional resistance of the ship surface account for about 50% of the total resistance, and the frictional resistance of the underwater vehicle accounts for about 70% of the total resistance, which leads to huge energy loss and increased transportation cost. Reducing the frictional resistance can not only improve the ship speed and reduce the transportation cost, but also improve the fuel utilization rate, which is of great significance to resource saving and development of ocean science and technology.

[0003] When the ship sails, it generally encounters three kinds of resistance: wave-making resistance, pressure difference resistance and frictional resistance. The wave-making resistance is mainly a problem encountered during high-speed water surface sailing, and improving the design of the vehicle can reduce the wave-making resistance; designing the vehicle into a streamlined shape can reduce the pressure difference resistance (the pressure difference between the head and tail of the vehicle when it moves); the frictional resistance comes from the interaction between the vehicle and the surrounding water flow. For general ships, the frictional resistance accounts for about 70-80% of the total resistance. Therefore, reducing the surface friction is crucial for the overall underwater drag reduction. The underwater drag reduction through the super-lubricating coating technology is an effective solution.

[0004] The main component of the current lubricating coating, the lubricating drag-reducing agent, is mostly made by chemical synthesis method, which generally has problems such as complicated production, easy decomposition and inconvenience for use. In order to solve the above problems, the project group has carried out in-depth research on a new type of natural drag-reducing agent, yam mucin, and prepared a natural and environmentally friendly drag-reducing hydrogel by adding yam mucin into the super-lubricating hydrogel. SUMMARY

[0005] The purpose of the application is to provide a preparation method of yam mucin drag-reducing hydrogel, which uses N,N'-methylenebisacrylamide molecules to connect the yam mucin macromolecular chains into a network structure, prevents the water-soluble yam mucin from dissolving and losing in water, and realizes long-term lubrication and drag reduction.

[0006] The technical scheme adopted by the application is a preparation method of yam mucin drag-reducing hydrogel, and the steps are as follows: Step 1, peeling and cutting the yam, mixing and crushing the yam pieces with deionized water to obtain a yam mucilage mixture; Step 2, after centrifuging the yam mucilage mixture, extracting the supernatant after standing and layering; Step 3, filtering the supernatant to obtain a plant extract; Step 4, purifying the plant extract by reverse osmosis, and obtaining yam mucin after air drying; Step 5: gelatin is added into PBS solution, heated and stirred once, then N,N-dimethylformamide and methacrylic anhydride are added in turn, heated and stirred twice; Step 6: the reaction product of step 5 is loaded into a dialysis bag for dialysis, freeze-dried to obtain a gelatin derivative grafted with carbon-carbon double bonds; Step 7: the gelatin derivative is weighed and added into deionized water, heated and stirred, then a certain amount of yam mucin, N,N'-methylene bisacrylamide and ammonium persulfate are added and stirred uniformly; Step 8: the solution of step 7 is centrifuged to remove bubbles, and dried to obtain a yam mucin drag-reducing hydrogel.

[0007] The application is also characterized in that: In step 1, the mass ratio of yam to deionized water is 1:1-1:2.

[0008] In step 2, the centrifugation is performed by a centrifuge at a speed of 3000-5000 rpm for 10-15 min, and the standing time is 20-30 min. In step 3, the supernatant is filtered by a microporous filter membrane with a pore size of 0.8 μm.

[0009] In step 5, the mass of gelatin is 1-6 g, the volume of PBS solution is 20-200 mL, the volume of N,N-dimethylformamide is 100-130 mL, and the volume of methacrylic anhydride is 4-8 mL.

[0010] In step 5, the first heating temperature is 30-50℃, and the stirring time is 0.5-1 h; the second heating temperature is 40-50℃, and the stirring time is 2-4 h.

[0011] In step 6, the molecular weight cut-off of the dialysis bag is 10000, and the dialysis time is 2-4 d, and the dialysis solution is replaced every 10-15 h.

[0012] In step 7, the mass of gelatin derivative is 0.5-5 g, and the volume of deionized water is 10-50 mL. The heating temperature is 40-60℃, and the stirring time is 0.5-1 h.

[0013] In step 7, the mass of yam mucin is 20-100 mg, the mass ratio of N,N'-methylene bisacrylamide to yam mucin is 1:100-5:100, and the mass ratio of ammonium persulfate to yam mucin is 1:100-3:100.

[0014] In step 8, the centrifugation is performed by a centrifuge at a speed of 5000-8000 rpm for 5-10 min, and the drying is performed by an oven for 4-6 h.

[0015] The beneficial effects of the present application are: The yam mucin drag-reducing hydrogel preparation method of the present application adopts reverse osmosis to obtain yam mucin, uses N,N'-methylene bisacrylamide molecules to covalently graft water-soluble super-lubricating yam mucin macromolecules onto gelatin macromolecular chains with carbon-carbon double bonds, prevents water-soluble yam mucin from dissolving and losing in water, and prepares yam mucin hydrogel with lubricating and drag-reducing functions; thereby solving the problem of yam mucin dissolving and losing in water. The water-soluble yam mucin is directly extracted from yam stock solution, has a pure natural formula, good stability, safety and environmental protection, and has a good application prospect in the field of drag reduction of ships and other vehicles. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The nuclear magnetic resonance spectrum of the yam mucin drag-reducing hydrogel of the present application example 1 is shown in the figure. Figure 2 The infrared spectrum comparison figure of the yam mucin drag-reducing hydrogel of the present application example 1 with gelatin and yam mucin protein is shown in the figure. DETAILED DESCRIPTION

[0017] The present application will be described in detail below in combination with the drawings and specific embodiments.

[0018] The yam mucin drag-reducing hydrogel preparation method of the present application has the following steps: Step 1: peel fresh yam and cut it into small pieces, put the yam pieces and deionized water into a juicer at a mass ratio of 1:1-1:2, and stir and crush to obtain a yam mucilage mixture; Step 2: centrifuge the mucilage mixture of step 1 in a centrifuge at a speed of 3000-5000 rpm for 10-15 minutes. Let the solution stand for 20-30 minutes, and extract the transparent liquid in the upper layer of the solution, referred to as supernatant, after the solution is stratified; Step 3: filter the supernatant of step 2 using a microporous filter membrane with a pore size of 0.8 μm to obtain a plant extract; Step 4: purify the plant extract of step 3 by reverse osmosis to remove water and anthocyanins, and obtain yam mucin MC after air drying; The main component of the existing lubricating coating, a lubricating drag-reducing agent, is generally made by chemical synthesis method, which has the problems of complicated preparation, easy decomposition and inconvenience for use. The water-soluble yam mucin used in the present application is directly extracted from yam stock solution, has a pure natural formula, simple process, good stability, safety and environmental protection.

[0019] Step 5: 1-6 g of gelatin is weighed and added to 20-200 mL of a phosphate buffered saline (PBS) solution, heated to 30-50 DEG C at one time, stirred for 0.5-1 h, and then 100-130 mL of N,N-dimethylformamide and 4-8 mL of methacrylic anhydride are added in sequence, heated to 40-50 DEG C at two times, and stirred for 2-4 h; Step 6: The reaction product of step 5 is loaded into a dialysis bag with a molecular weight cut-off of 10000, dialyzed for 2-4 d, the dialysate is replaced every 10-15 h, and then freeze-drying is performed to obtain a gelatin derivative grafted with carbon-carbon double bonds, namely GelMA; Step 7: 0.5-5 g of GelMA is weighed and added to 10-50 mL of deionized water, heated to 40-60 DEG C, stirred for 0.5-1 h, and then 20-100 mg of the yam mucin MC of step 4, a certain amount of N,N'-methylenebisacrylamide and a certain amount of ammonium persulfate are added in sequence, and stirred for 0.5-1 h; The mass ratio of N,N'-methylenebisacrylamide to yam mucin MC is 1:100 to 5:100.

[0020] The mass ratio of ammonium persulfate to yam mucin MC is 1:100 to 3:100.

[0021] Step 8: The solution of step 7 is centrifuged to remove bubbles in a centrifuge at a speed of 5000-8000 rpm for 5-10 min, then poured into a polytetrafluoroethylene mold with a size of 10 cm x 10 cm x 2 mm, and placed in an oven at 60-80 DEG C for heat treatment for 4-6 h to obtain a yam mucin drag-reducing hydrogel (MC-GelMA3) with drag-reducing function.

[0022] The current lubricating drag-reducing agent is generally added into the hydrogel by simple mechanical mixing, and the lubricating drag-reducing agent is prone to loss during use, resulting in a decrease or even failure of the drag-reducing performance of the hydrogel. The yam mucin drag-reducing hydrogel preparation method of the present application uses a reverse osmosis method to obtain yam mucin, and uses N,N'-methylenebisacrylamide molecules to covalently graft the water-soluble super-lubricating yam mucin macromolecule to the gelatin macromolecular chain with carbon-carbon double bonds, to obtain a network structure with strong binding force, prevent the water-soluble yam mucin from dissolving and losing in water, and prepare a yam mucin hydrogel with lubricating and drag-reducing functions; thereby solving the problem of the dissolution and loss of yam mucin in water; and the prepared yam mucin drag-reducing hydrogel has the advantages of long service life, stable and continuous effect, and good application prospect in the field of drag reduction of ships and other vehicles.

[0023] Example 1 The specific process of the yam mucin drag-reducing hydrogel preparation method of the present application is as follows: Step 1: peel fresh yam and cut into small pieces, put 500g yam pieces and 500ml deionized water into a juicer and stir to obtain a yam mucilage mixture; Step 2: put the mucilage mixture of step 1 into a centrifuge and centrifuge at 4000 rpm for 13 minutes. Let the solution stand for 25 minutes, the heavy particles will precipitate at the bottom, after the solution is stratified, extract the transparent liquid in the upper layer of the solution, simply called supernatant, which is a viscous liquid rich in mucin and polysaccharide; Step 3: filter the supernatant of step 2 with a microporous filter membrane with a pore size of 0.8 μm to further filter out particles and obtain a plant extract; Step 4: purify the plant extract of step 3 by reverse osmosis to remove water and anthocyanins, and dry to obtain yam mucin (MC); Step 5: weigh 3.5g gelatin, add to 110mL PBS solution, heat to 40℃, stir for 0.8h, then add 120mL N,N-dimethylformamide and 6mL methacrylic anhydride in sequence, heat to 45℃, stir for 3h; Step 6: put the reaction product of step 5 into a dialysis bag with a molecular weight cut-off of 10000, dialyze for 3d, replace the dialysate every 13h, and freeze-dry to obtain a gelatin derivative grafted with carbon-carbon double bonds (GelMA); The water-soluble super-lubricating yam mucin is covalently grafted onto the macromolecular chain of gelatin with carbon-carbon double bonds to prevent the water-soluble super-lubricating yam mucin from dissolving and losing in water, and to achieve the purpose of long-term lubrication and drag reduction.

[0024] Step 7: weigh 3g GelMA of step 6, add to 20mL deionized water, heat to 50℃, stir for 0.8h, then add yam mucin (MC) 50mg, N,N'-methylene bisacrylamide 1.5mg and ammonium persulfate 1mg of step 4 in sequence, stir for 0.8h; Step 8: centrifuge the solution of step 7 to remove bubbles in a centrifuge at a speed of 7000 rpm for 7min, then pour into a polytetrafluoroethylene mold with specifications of 10cm x 10cm x 2mm, and put into a 65℃ oven for heat treatment for 4.5h to obtain a yam mucin drag reduction hydrogel (MC-GelMA3) with drag reduction function.

[0025] The principle of the application is: The water-soluble yam mucin is an excellent lubricating and drag-reducing material, but due to its excellent water solubility, it is easy to lose from the coating. The water-soluble super-lubricating yam mucin is covalently grafted onto the macromolecular chain of gelatin with carbon-carbon double bonds to prevent the water-soluble super-lubricating yam mucin from dissolving and losing in water, and to achieve the purpose of long-term lubrication and drag reduction.

[0026] Example 2 The preparation method of the yam mucin drag-reducing hydrogel of the present application is as follows: 1) Fresh yam is peeled and cut into small pieces, and 500 g of the yam pieces and 500 ml of deionized water are put into a juicer and stirred to obtain a yam mucilage mixture; 2) The mucilage mixture of 1) is put into a centrifuge and centrifuged at a speed of 3000 rpm for 15 minutes. The solution is left for 25 minutes until the solution is stratified, and the transparent liquid on the upper layer of the solution is extracted, which is referred to as supernatant; 3) The supernatant of 2) is filtered by using a microporous filter membrane with a pore size of 0.8 μm to obtain a plant extract; 4) The plant extract of 3) is purified by using a reverse osmosis method to remove water and anthocyanins, and dried to obtain yam mucin (MC); 5) 4 g of gelatin is weighed and added to 100 mL of PBS solution, heated to 40℃, and stirred for 1 h, and then 130 mL of N,N-dimethylformamide and 6 mL of methacrylic anhydride are added in sequence, and heated to 45℃ and stirred for 3 h; 6) The reaction product of 5) is loaded into a dialysis bag with a molecular weight cut-off of 10000, and dialyzed for 3 days, and the dialysis solution is replaced every 12 h, and then freeze-dried to obtain a gelatin derivative grafted with carbon-carbon double bonds (GelMA); 7) 0.5 g of GelMA of 6) is weighed and added to 10 mL of deionized water, heated to 45℃, and stirred for 0.5 h, and then 20 mg of yam mucin (MC) of 4), 0.2 mg of N,N'-methylenebisacrylamide, and 0.2 mg of ammonium persulfate are added in sequence, and stirred for 0.5 h; 8) The solution of 7) is centrifuged to remove bubbles (6000 rpm, 7 min), and then poured into a polytetrafluoroethylene mold (10 cm x 10 cm x 2 mm), and placed in a 60℃ oven for heat treatment for 6 h to obtain a yam mucin drag-reducing hydrogel with drag-reducing function.

[0027] Example 3 The preparation method of the yam mucin drag-reducing hydrogel of the present application is as follows: 1) Fresh yam is peeled and cut into small pieces, and 500 g of the yam pieces and 1000 ml of deionized water are put into a juicer and stirred to obtain a yam mucilage mixture; 2) The mucilage mixture of 1) is put into a centrifuge and centrifuged at a speed of 4000 rpm for 12 minutes. The solution is left for 30 minutes until the solution is stratified, and the transparent liquid on the upper layer of the solution is extracted, which is referred to as supernatant; 3) The supernatant of 2) is filtered by using a microporous filter membrane with a pore size of 0.8 μm to obtain a plant extract; 4): the plant extract of 3) is purified by reverse osmosis to remove water and anthocyanins, and dried to obtain the yam mucin (MC); 5): 6g of gelatin is weighed and added to 200mL of PBS solution, heated to 50°C, stirred for 1h, and then 130mL of N,N-dimethylformamide and 8mL of methacrylic anhydride are added in sequence, heated to 50°C, and stirred for 4h; 6): the reaction product of 5) is loaded into a dialysis bag with a molecular weight cut-off of 10000, dialyzed for 4d, and the dialysis solution is replaced every 15h, and then freeze-dried to obtain the gelatin derivative grafted with carbon-carbon double bonds (GelMA); 7): 1g of GelMA of 6) is weighed and added to 30mL of deionized water, heated to 45°C, stirred for 0.8h, and then 60mg of yam mucin (MC) of 4), 1.5mg of N,N'-methylene bisacrylamide, and 1.2mg of ammonium persulfate are added in sequence, and stirred for 0.8h; 8): the solution of 7) is centrifuged to remove bubbles (5000rpm, 10min), then poured into a polytetrafluoroethylene mold (10cmx10cmx2mm), and placed in a 70°C oven for heat treatment for 5h, to obtain the yam mucin drag-reducing hydrogel with drag-reducing function.

[0028] Example 4 The preparation method of the yam mucin drag-reducing hydrogel of the present application has the following specific process: 1): fresh yam is peeled and cut into small pieces, and 700g of the yam pieces and 700ml of deionized water are put into a juicer and stirred to obtain a yam mucilage mixture; 2): the mucilage mixture of 1) is placed in a centrifuge and centrifuged at a speed of 5000rpm for 10 minutes. The solution is left still for 20 minutes, and then the transparent liquid on the upper layer of the solution, referred to as supernatant, is extracted; 3): the supernatant of 2) is filtered by a microporous filter membrane with a pore size of 0.8μm to obtain a plant extract; 4): the plant extract of 3) is purified by reverse osmosis to remove water and anthocyanins, and dried to obtain the yam mucin (MC); 5): 1g of gelatin is weighed and added to 20mL of PBS solution, heated to 30°C, stirred for 0.5h, and then 100mL of N,N-dimethylformamide and 4mL of methacrylic anhydride are added in sequence, heated to 40°C, and stirred for 2h; 6): the reaction product of 5) is loaded into a dialysis bag with a molecular weight cut-off of 10000, dialyzed for 2d, and the dialysis solution is replaced every 10h, and then freeze-dried to obtain the gelatin derivative grafted with carbon-carbon double bonds (GelMA); 7): 5 g of GelMA from step 6) was weighed into 50 mL of deionized water, heated to 60°C, stirred for 1 h, and then 100 mg of yam mucin (MC) from step 4), 5 mg of N,N'-methylenebisacrylamide and 3 mg of ammonium persulfate were sequentially added, stirred for 1 h; 8): The solution from 7) was centrifuged to remove bubbles (8000 rpm, 5 min), then poured into a polytetrafluoroethylene mold (10 cm x 10 cm x 2 mm), and placed in an 80°C oven for heat treatment for 4 h to obtain a yam mucin drag-reducing hydrogel with drag-reducing function.

[0029] Example 5 The yam mucin drag-reducing hydrogel preparation method of the present application has the following specific process: Step 1: Fresh yam was peeled and cut into small pieces, and 500 g of yam pieces and 750 mL of deionized water were put into a juicer and stirred to obtain a yam mucilage mixture; Step 2: The mucilage mixture from step 1) was placed in a centrifuge and centrifuged at a speed of 3500 rpm for 13 minutes. The solution was allowed to stand for 25 minutes, and the heavy particles would settle at the bottom. After the solution was layered, the transparent liquid on the top of the solution was extracted, which was referred to as supernatant, and was a viscous liquid rich in mucin and polysaccharides; Step 3: The supernatant from step 2 was filtered through a microporous filter membrane with a pore size of 0.8 μm to further filter out particles and obtain a plant extract; Step 4: The plant extract from step 3 was purified by reverse osmosis to remove water and anthocyanins, and yam mucin (MC) was obtained after air drying; Step 5: 3 g of gelatin was weighed into 110 mL of PBS solution, heated to 40°C, stirred for 0.6 h, and then 110 mL of N,N-dimethylformamide, 5 mL of methacrylic anhydride were sequentially added, heated to 45°C, and stirred for 3 h; Step 6: The reaction product from step 5) was loaded into a dialysis bag with a molecular weight cut-off of 10000, dialyzed for 3 days, and the dialysis solution was replaced every 13 h. After freeze-drying, a gelatin derivative grafted with carbon-carbon double bonds (GelMA) was obtained; The water-soluble super-lubricating yam mucin is covalently grafted onto the macromolecular chains of gelatin with carbon-carbon double bonds, preventing the water-soluble super-lubricating yam mucin from dissolving and losing in water, and achieving the purpose of long-term lubrication and drag reduction.

[0030] Step 7: 2.5 g of GelMA from step 6) was weighed into 25 mL of deionized water, heated to 50°C, stirred for 0.8 h, and then 50 mg of yam mucin (MC) from step 4), 1.5 mg of N,N'-methylenebisacrylamide and 1 mg of ammonium persulfate were sequentially added, stirred for 0.8 h; Step 8: The solution of step 7) is centrifuged to remove bubbles at a speed of 7000 rpm for 7 min, and then poured into a polytetrafluoroethylene mold with a size of 10 cm x 10 cm x 2 mm, and placed in an oven at 65 °C for heat treatment for 4.5 h to obtain the yam mucin drag-reducing hydrogel (MC-GelMA3) with drag-reducing function.

[0031] Example 6 The yam mucin drag-reducing hydrogel preparation method of the present application has the following specific process: Step 1: Fresh yam is peeled and cut into small pieces, and 500 g of yam pieces and 500 ml of deionized water are stirred and crushed in a juicer to obtain a yam mucilage mixture; Step 2: The mucilage mixture of step 1) is placed in a centrifuge and centrifuged at a speed of 5000 rpm for 13 minutes. The solution is left to stand for 25 minutes, and the heavy particles will precipitate at the bottom. After the solution is stratified, the transparent liquid in the upper layer of the solution, referred to as supernatant, is extracted, which is a viscous liquid rich in mucilage protein and polysaccharide; Step 3: The supernatant of step 2 is filtered through a microporous filter membrane with a pore size of 0.8 μm to further filter out particles to obtain a plant extract; Step 4: The plant extract of step 3) is purified by reverse osmosis to remove water and anthocyanins, and dried to obtain yam mucin (MC); Step 5: 5 g of gelatin is weighed and added to 180 mL of PBS solution, heated to 40 °C, and stirred for 0.8 h. Then 120 mL of N,N-dimethylformamide and 6 mL of methacrylic anhydride are added in sequence, heated to 45 °C, and stirred for 3 h; Step 6: The reaction product of step 5) is loaded into a dialysis bag with a molecular weight cut-off of 10000, dialyzed for 4 days, and the dialysis solution is replaced every 14 h. After freeze-drying, a gelatin derivative grafted with carbon-carbon double bonds (GelMA) is obtained. The water-soluble super-lubricating yam mucin is covalently grafted onto the macromolecular chains of gelatin with carbon-carbon double bonds to prevent the water-soluble super-lubricating yam mucin from dissolving and losing in water, and to achieve the purpose of long-term lubrication and drag reduction.

[0032] Step 7: 4 g of GelMA of step 6) is weighed and added to 40 mL of deionized water, heated to 50 °C, and stirred for 0.8 h. Then 80 mg of yam mucin (MC) of step 4), 4 mg of N,N'-methylenebisacrylamide, and 2.4 mg of ammonium persulfate are added in sequence, and stirred for 0.8 h; Step 8: The solution of step 7) was centrifuged to remove bubbles at a speed of 7000 rpm for 7 min, and then poured into a polytetrafluoroethylene mold with a size of 10 cm x 10 cm x 2 mm, and placed in a 65 °C oven for heat treatment for 4.5 h to obtain the yam mucin drag-reducing hydrogel (MC-GelMA3) with drag-reducing function.

[0033] The surface friction of the yam mucin drag-reducing hydrogel prepared in the above examples 1-6 is less than 0.8 N.

[0034] Figure 1 The nuclear magnetic resonance spectrum of the yam mucin drag-reducing hydrogel of example 1 shows two characteristic peaks of 1'2' on GelMA, which are characteristic hydrogen spectra of carbon-carbon double bonds (C=C), confirming that the methyl methacrylate anhydride is successfully grafted onto the gelatin (GelMA). The grafting rate of the carbon-carbon double bond is 73.58% by the ratio of the integral area.

[0035] Figure 2 The infrared spectrum of the yam mucin drag-reducing hydrogel of example 1 is compared with that of gelatin and the protein in yam mucilage, wherein the characteristic peak of the amide group is at 1650 cm -1 -1, and the absorption intensity of the yam mucin hydrogel (MC-GelMA3) sample is greater than that of gelatin (GelMA), indicating that the protein (MC) in yam mucilage is successfully grafted and cross-linked to GelMA; the absorption peak appearing at 1100 cm -1 -1 is generated by the stretching vibration of C-O, and the stretching vibration intensity of the yam mucin drag-reducing hydrogel (MC-GelMA3) sample of the present application is greater than that of gelatin (GelMA), indicating that the polysaccharide component in the mucilage is successfully grafted and cross-linked to gelatin (GelMA). The above results show that the yam mucin (MC) is successfully grafted and cross-linked to gelatin (GelMA).

Claims

1. A method for preparing yam mucin drag-reducing hydrogel, characterized in that, The steps are as follows: Step 1: Peel and cut the yam into chunks. Mix the yam chunks with deionized water and mash them to obtain a yam mucilage mixture. Step 2: After centrifuging the yam mucilage mixture, allow it to stand and separate into layers, then extract the supernatant. Step 3: Filter the supernatant to obtain the plant extract; Step 4: Purify the plant extract using reverse osmosis, and then air-dry it to obtain yam mucin; Step 5: Add gelatin to the PBS solution, heat and stir once, then add N,N-dimethylformamide and methacrylic anhydride in sequence, heat and stir a second time; Step 6: The reaction product from step 5 was placed in a dialysis bag for dialyzing and then freeze-dried to obtain a gelatin derivative grafted with carbon-carbon double bonds. Step 7: Weigh the gelatin derivative, add it to deionized water, heat and stir, then add a certain amount of yam mucin, N,N'-methylenebisacrylamide and ammonium persulfate, and stir evenly; Step 8: Centrifuge and degas the solution from Step 7, then dry it to obtain yam mucin drag-reducing hydrogel.

2. The method for preparing yam mucin drag-reducing hydrogel according to claim 1, characterized in that, In step 1, the mass ratio of the yam to deionized water is 1:1 to 1:

2.

3. The method for preparing yam mucin drag-reducing hydrogel according to claim 1, characterized in that, In step 2, the centrifugation is performed using a centrifuge with a rotation speed of 3000rpm-5000rpm and a centrifugation time of 10min-15min; the settling time is 20min-30min.

4. The method for preparing yam mucin drag-reducing hydrogel according to claim 1, characterized in that, In step 3, the supernatant is filtered using a microporous membrane with a pore size of 0.8 μm.

5. The method for preparing yam mucin drag-reducing hydrogel according to claim 1, characterized in that, In step 5, the gelatin weighs 1-6g, the PBS solution volume is 20-200mL, the N,N-dimethylformamide volume is 100-130mL, and the 4-8mL methacrylic anhydride volume is 4-8mL.

6. The method for preparing yam mucin drag-reducing hydrogel according to claim 1, characterized in that, In step 5, the first heating temperature is 30-50℃, and the stirring time is 0.5-1h; the second heating temperature is 40-50℃, and the stirring time is 2-4h.

7. The method for preparing yam mucin drag-reducing hydrogel according to claim 1, characterized in that, In step 6, the molecular weight cutoff of the dialysis bag is 10,000, the dialysis time is 2-4 days, and the dialysis solution is changed every 10-15 hours.

8. The method for preparing yam mucin drag-reducing hydrogel according to claim 1, characterized in that, In step 7, the mass of the gelatin derivative is 0.5-5g, and the volume of deionized water is 10-50mL; The heating temperature is 40-60℃, and the stirring time is 0.5-1h.

9. The method for preparing yam mucin drag-reducing hydrogel according to claim 1, characterized in that, In step 7, the mass of the yam mucin is 20-100 mg, the mass ratio of N,N'-methylenebisacrylamide to yam mucin is 1:100~5:100, and the mass ratio of ammonium persulfate to yam mucin is 1:100~3:

100.

10. The method for preparing yam mucin drag-reducing hydrogel according to claim 1, characterized in that, In step 8, the centrifugation equipment is a centrifuge with a speed of 5000-8000 rpm and a centrifugation time of 5-10 min. The drying operation is as follows: place it in an oven and dry it at a temperature of 60-80℃ for 4-6 hours.

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