Lignocellulose-based amphiphilic polymer, electrospun fiber film and preparation method thereof

Abstract

The invention relates to the technical field of material engineering, in particular to a lignocellulose-based amphiphilic polymer, an electrospun fiber film and a preparation method thereof. The preparation method comprises the following steps: pre-treating agricultural product processing byproducts by adopting a chemical method and / or a biological method to obtain lignocellulose; the method comprises the following steps: taking lignocellulose as a raw material, carrying out high-pressure homogenization treatment to obtain lignocellulose nanofibers, mixing the lignocellulose nanofibers, an aliphatic monomer and a catalyst, and carrying out high-temperature polymerization to obtain the lignocellulose-based amphiphilic polymer. The invention further provides a porous electrospun fiber film which is converted from a mixture of the lignocellulose-based amphiphilic polymer and the aliphatic polymer and has excellent mechanical strength, flexibility and biocompatibility, and the porous electrospun fiber film can be widely applied to the biomedical fields of wound dressing, tissue engineering and the like. And optimal regulation and control of material performance and efficient utilization of agricultural product processing byproducts are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of materials engineering, and particularly to lignocellulose-based amphiphilic polymers, electrospun fiber films and preparation methods thereof. Background Art

[0002] With the continuous and rapid economic growth, the level of agricultural modernization has been continuously improved, and agricultural product production and processing activities have become increasingly frequent, resulting in a year-on-year increase in the quantity of processing by-products such as potato residues, vines, straws, rice bran, rice husks, wheat bran, distiller's grains, etc. At present, agricultural product processing by-products are usually directly discarded, causing a large amount of resource waste and serious environmental pollution, which poses new challenges and opportunities for the comprehensive utilization of agricultural products and the development of circular economy.

[0003] Lignocellulose is the main component of agricultural product processing by-products and can be extracted through relatively simple separation methods. Lignocellulose exhibits great application potential in many aspects such as the food industry, pharmaceutical field, tissue engineering, etc. due to its characteristics such as wide sources, good biocompatibility, surface modifiability, degradability, and excellent thermal stability. Nevertheless, at present, lignocellulose still needs to be decomposed into cellulose, hemicellulose, and lignin to realize its utilization value. This decomposition process involves complex technical processes, resulting in high processing costs and the generation of new waste acid solutions, waste alkali solutions, etc., thereby affecting its overall utilization rate. However, directly using lignocellulose can reduce costs and waste, but as a hydrophilic material, its compatibility with hydrophobic materials is poor, resulting in uneven distribution in hydrophobic materials and unsatisfactory enhancement effects. By grafting hydrophobic polymers onto the active sites on the surface of lignocellulose, preparing amphiphilic polymers can solve the problem. Amphiphilic polymers are macromolecular compounds composed of hydrophilic parts and hydrophobic parts, and this structure enables amphiphilic polymers to have wide applications in many fields, especially in the biomedical field. For example, tissue engineering, bioimaging, drug delivery, and biosensing. Compared with other materials, lignocellulose polyester-based amphiphilic polymers have the advantages of easy availability, non-toxicity, low inflammation, and degradability, and thus have received extensive attention.

[0004] Therefore, in order to improve the utilization rate of agricultural processing byproducts and improve the economic value of lignocellulose-based materials, the development of the above-mentioned amphiphilic polymer has become one of the currently feasible methods. Invention CN104693426A discloses a method for lactic acid-modified cellulose nanofibers, in which lactic acid is grafted on the hydroxyl groups on the surface of cellulose nanofibers to prepare polylactic acid-cellulose nanofiber polymers. The material has good compatibility with polylactic acid, greatly improving the mechanical strength of polylactic acid materials. However, the method is based on cellulose nanofibers as raw materials, and high-concentration sulfuric acid needs to be used in the production process, and the waste liquid generated needs to be specially treated, which virtually increases the danger and cost of producing the material. The utilization of lignocellulose has always been a major problem in the art, and there is no method for directly utilizing lignocellulose as raw material to prepare amphiphilic polymers. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a lignocellulose-based amphiphilic polymer, an electrospun fiber film, and a preparation method and application thereof. The present invention uses agricultural product processing byproducts as raw materials, and uses chemical or biological methods to obtain lignocellulose; after shearing and homogenization, lignocellulose nanofibers are obtained; the lignocellulose nanofibers are mixed with aliphatic monomers and polymerized at high temperature to obtain lignocellulose-based amphiphilic polymers; finally, the lignocellulose nanofibers are mixed with aliphatic polymer solutions, and electrospun fiber films are prepared by electrostatic spinning technology.

[0006] In the first aspect, the present invention provides a method for preparing a lignocellulose-based amphiphilic polymer, comprising: pretreating agricultural product processing byproducts by chemical and / or biological methods to obtain lignocellulose; using the lignocellulose as a raw material, performing high-pressure homogenization treatment to obtain lignocellulose nanofibers; mixing the lignocellulose nanofibers, aliphatic monomers and a catalyst and performing high-temperature polymerization to obtain a lignocellulose-based amphiphilic polymer. In the present invention, lignocellulose is obtained by pretreating agricultural product processing byproducts, and the lignocellulose-based amphiphilic polymer obtained by high-pressure homogenization, high-temperature polymerization and the like with the lignocellulose raw material can well convert lignocellulose into nanofibers, and through high-temperature polymerization reaction with aliphatic monomers, the lignocellulose has better hydrophilicity and hydrophobicity while retaining its biocompatibility. The present invention not only improves the application value of lignocellulose, but also improves its compatibility with hydrophobic materials, and can broaden its application potential in the biomedical field.

[0007] Preferably, the pretreatment is α-amylase hydrolysis and / or hydrochloric acid hydrolysis. In the present invention, if the byproduct contains starch, α-amylase hydrolysis and hydrochloric acid hydrolysis are carried out successively, and if the byproduct does not contain starch, hydrochloric acid hydrolysis can be directly carried out.

[0008] Preferably, the pretreatment includes: mixing the mixed material of agricultural product processing by-products and water with α-amylase, centrifuging after enzymatic hydrolysis to obtain a precipitate; mixing the precipitate with hydrochloric acid, centrifuging after acid hydrolysis, washing with water and drying.

[0009] More preferably, the addition amount of the α-amylase is 5% - 10% of the volume of the mixed material; the enzymatic hydrolysis temperature is 90 - 100 °C, and the time is 0.5 - 2 h; the centrifugation speed after enzymatic hydrolysis is 6000 - 8000 g, and the time is 10 - 25 min.

[0010] More preferably, the mass ratio of the hydrochloric acid to the precipitate is 1:10 - 1:40; the concentration of the hydrochloric acid is 0.2% - 1.5%; the acid hydrolysis temperature is 75 - 90 °C, and the time is 15 - 60 min; the centrifugation speed after acid hydrolysis is 6000 - 8000 g, and the time is 10 - 25 min, washing with water until the pH value is 6 - 8, and the drying temperature is 45 - 75 °C, and the time is 8 - 12 h.

[0011] In the present invention, through the pretreatment of enzymatic hydrolysis with α-amylase and acid hydrolysis with hydrochloric acid, the starch and lignin in agricultural product processing by-products can be effectively decomposed, and the availability of lignocellulose can be improved. Through parameter optimization, it helps to further expose the hydroxyl groups on the surface of lignocellulose, which is beneficial to the esterification reaction with aliphatic monomers, thus being more conducive to the preparation of lignocellulose-based amphiphilic polymers.

[0012] Preferably, the agricultural product processing by-products include one or more of potato residues, vines, straws, rice bran, rice husks, wheat bran, distiller's grains, bagasse, coconut shells, fruit peels, and fruit husks. In the present invention, other agricultural product processing by-products commonly used in the art can also be used as the types of agricultural product processing by-products adopted.

[0013] According to the preferred embodiment of the present invention, the pretreatment process is enzymatic hydrolysis with α-amylase and acid hydrolysis with hydrochloric acid. The enzymatic hydrolysis with α-amylase includes: after crushing the agricultural product processing by-products, mixing them with water according to a mass ratio of 1:20 - 1:60 to obtain a suspension, adding heat-resistant α-amylase at 5% - 10% of the volume of the suspension, mixing and then carrying out enzymatic hydrolysis at 90 - 100 °C for 0.5 - 2 h, and then centrifuging at 6000 - 8000 g for 10 - 25 min, respectively collecting the supernatant and the precipitate to obtain a sugar-rich liquid and dietary fiber; the acid hydrolysis with hydrochloric acid includes: dispersing the dietary fiber with a 0.2% - 1.5% hydrochloric acid solution according to a mass ratio of 1:10 - 1:40, carrying out acid hydrolysis at 75 - 90 °C for 15 - 60 min, and then centrifuging at 6000 - 8000 g for 10 - 25 min, respectively collecting the supernatant and the precipitate. Among them, the supernatant is subjected to alcohol precipitation to obtain pectin, and the precipitate is washed with water until the pH value is 6 - 8 and dried at 45 - 75 °C for 8 - 12 h to obtain lignocellulose.

[0014] Preferably, the high-pressure homogenization includes: mixing lignocellulose with water to obtain a lignocellulose suspension; shearing the lignocellulose suspension after suspension, and then performing high-pressure homogenization cycles and drying. In the present invention, high-pressure homogenization treatment can effectively disperse lignocellulose and convert it into nanoscale fibers, significantly increasing its surface area and reactivity, thereby providing better raw materials for subsequent polymerization reactions.

[0015] Preferably, the concentration of the lignocellulose suspension is 0.1% - 1.5%; the suspension time is 8 - 14 h; the shearing speed is 9000 - 12000 r / min, and the time is 30 - 90 s; the pressure of high-pressure homogenization is 30 - 60 MPa, and the number of high-pressure homogenization cycles is 3 - 9 times. By optimizing the treatment conditions, the structure of lignocellulose is more uniform, which helps to further enhance the product performance and stability.

[0016] According to a preferred embodiment of the present invention, the high-pressure homogenization includes: mixing lignocellulose with water, adjusting the concentration of the suspension to 0.1% - 1.5%, suspending the suspension for 8 - 14 h, and then shearing for 30 - 90 s at a speed of 9000 - 12000 r / min; thereafter, performing 3 - 9 high-pressure homogenization cycles under a pressure of 30 - 60 MPa, and drying to obtain lignocellulose nanofibers.

[0017] Preferably, the reaction temperature of the high-temperature polymerization is 105 - 150 °C, such as 110, 120, 125, 130, 135, 145 °C, etc., and the reaction time is 2 - 14 h, such as 3, 4, 6, 8, 10 h, etc. Preferably, the reaction temperature of the high-temperature polymerization is 120 - 130 °C, and the reaction time is 8 - 10 h.

[0018] More preferably, the ratio of the lignocellulose nanofibers to the aliphatic monomer is 1:10 - 1:80 w / v, and the aliphatic monomer is lactic acid and / or ε-caprolactone.

[0019] Preferably, a catalyst is added at 0.1% - 1% of the volume of the aliphatic monomer, and the catalyst is stannous octoate and / or diethyl zinc.

[0020] In the present invention, through the high-temperature polymerization reaction of lignocellulose nanofibers and aliphatic monomers, it is possible to promote the reaction between lignocellulose nanofibers and aliphatic monomers to form a stable amphiphilic polymer, improve the hydrophobicity and biocompatibility of lignocellulose, and the effect is better by optimizing and controlling the reaction temperature, time and catalyst concentration, and it is beneficial to achieve better combination of lignocellulose and aliphatic monomers and optimization of comprehensive performance.

[0021] According to a preferred embodiment of the present invention, the high-temperature polymerization includes: uniformly mixing lignocellulose nanofibers with aliphatic monomers (lactic acid and / or ε-caprolactone) at a material ratio of 1:10 to 1:80 (w / v), adding a catalyst (stannous octoate and / or diethyl zinc) accounting for 0.1% to 1% of the volume of the polymer monomer, and reacting at 100 to 150 °C for 2 to 14 h; then using four times the volume of dichloromethane to wash at a rotation speed of 300 r / min for 8 to 12 h; centrifuging at 4000 g for 15 min to collect the precipitate, and then washing the precipitate three times with dichloromethane, ethanol, and water respectively, centrifuging at 4000 g for 15 min, collecting the precipitate, and drying to obtain the lignocellulose-based amphiphilic polymer.

[0022] Preferably, it further includes washing and drying; preferably, dichloromethane with a volume 3 to 5 times that of the aliphatic monomer is used for washing, the washing rotation speed is 200 to 400 r / min, the washing time is 8 to 12 h, then centrifuging and washing the precipitate with dichloromethane, ethanol, and water respectively, then centrifuging and drying the precipitate to obtain the lignocellulose-based amphiphilic polymer; preferably, the rotation speed of the centrifugation is 3000 to 5000 g, and the time is 10 to 20 min.

[0023] In a second aspect, the present invention provides a lignocellulose-based amphiphilic polymer prepared by the preparation method of the above-mentioned lignocellulose-based amphiphilic polymer.

[0024] In a third aspect, the present invention provides a preparation method of an electrospun fiber film, including: mixing the above-mentioned lignocellulose-based amphiphilic polymer with an aliphatic polymer to prepare an electrospinning solution, and then performing electrospinning.

[0025] Preferably, the preparation of the electrospinning solution includes: mixing the lignocellulose-based amphiphilic polymer with an aliphatic polymer and adding a solvent for stirring.

[0026] More preferably, the mass ratio of the lignocellulose-based amphiphilic polymer to the aliphatic polymer is 1 to 6:100, the solvent is dichloromethane, the concentration of the aliphatic polymer is 5% to 20% w / w, and the stirring rotation speed is 200 to 400 r / min.

[0027] Further preferably, the conditions for electrospinning include: the distance between the needle and the collector is 10 - 25 cm, the rotational speed of the collector is 150 - 450 r / min, the liquid supply rate is 0.2 - 2 mL / h, the voltage is 10 - 25 kV, the spinning time is 1 - 6 h, and it is preferably to use a 3 - 8 mL injection device; preferably, electrospinning is carried out for 4 ± 2 h under the conditions that the distance between the needle and the collector is 15 ± 2 cm, the rotational speed of the collector is 300 ± 20 r / min, the liquid supply rate is 0.6 ± 0.2 mL / h, and the voltage is 16 ± 5 kV.

[0028] In the present invention, through the adoption of specific electrospinning treatment, the lignocellulose-based amphiphilic polymer can better interact with the aliphatic polymer. By optimizing the conditions, it helps to enhance the interfacial bonding strength between the two, and further improve the mechanical strength and tensile properties of the thin film material, and electrospin a porous fiber thin film with higher mechanical strength, biocompatibility and other properties. The method provided by the present invention helps to improve the flexibility and stability of the material, and provides more excellent properties for its application in biomedical fields such as wound dressings and tissue engineering.

[0029] According to a preferred embodiment of the present invention, lignocellulose obtained by treating agricultural product processing by-products as raw materials is mixed with water, and after high-pressure homogenization and drying, lignocellulose nanofibers are obtained. Then it is mixed with an aliphatic monomer and a catalyst in a certain proportion and subjected to a grafting reaction under certain conditions, and after washing and drying, a lignocellulose-based amphiphilic polymer is obtained. By mixing the lignocellulose-based amphiphilic polymer with a hydrophobic polymer, an electrospun fiber membrane reinforced by amphiphilic lignocellulose is prepared through electrospinning technology. In a further preferred embodiment, the preparation method of the electrospun fiber membrane reinforced by amphiphilic lignocellulose includes: preparing an aliphatic polymer solution with a concentration of 5% - 20% (w / w), and adding a lignocellulose-based amphiphilic polymer according to 1% - 6% of the mass of the aliphatic polymer; using a 5 mL syringe, controlling the distance between the needle and the collector to be 10 - 25 cm, the rotational speed of the collector to be 150 - 450 r / min, the liquid supply rate to be 0.2 - 2 mL / h, the voltage to be 10 - 25 kV, and the spinning time to be 1 - 6 h, to obtain an electrospun fiber thin film reinforced by a lignocellulose-based amphiphilic polymer.

[0030] Fourthly, the present invention provides an electrospun fiber thin film prepared by the preparation method of the above electrospun fiber thin film.

[0031] Fifthly, the present invention provides the application of the above electrospun fiber thin film in biomedicine, preferably in wound dressings and tissue engineering, and more preferably in cell culture, wound healing dressings, tissue engineering scaffolds, wearable medical devices, and artificial intelligence skin.

[0032] The beneficial effects of the present invention are at least as follows: (1)The method adopted in the present invention is suitable for all agricultural product processing by-products rich in lignocellulose, laying a foundation for the full utilization of agricultural product processing by-products.

[0033] (2)Through high-pressure homogenization treatment, the present invention can, under certain homogenization pressure and number of cycles, rely on the sharp increase in the flow rate of the suspension when passing through a narrow gap under high pressure to form a shear force, breaking large-sized lignocellulose into smaller-sized lignocellulose nanofibers. Compared with lignocellulose, lignocellulose nanofibers have a higher specific surface area and can expose more hydroxyl sites on lignocellulose, creating conditions for subsequent modification with hydrophobic polymers.

[0034] (3)The preparation method of the amphiphilic polymer provided by the present invention initiates a polymerization reaction under certain temperature, time and the participation of an organometallic catalyst, connecting aliphatic monomers to the hydroxyl sites exposed on the surface of lignocellulose through an esterification reaction, and gradually converting aliphatic monomer molecules and lignocellulose into a polymer copolymer through the formation of new chemical bonds. The hydroxyl sites on the surface of the copolymer are replaced by hydrophobic polymers, resulting in a decrease in the polarity of the copolymer surface and an improvement in the interfacial compatibility of the sample, thereby realizing fine regulation of the molecular weight, degree of substitution, grafting ratio, morphology, mechanical properties, thermal stability, etc. of the polymer.

[0035] (4)Compared with other films prepared by methods such as hot pressing and solvent evaporation, the electrospun fiber film provided by the present invention has a porous structure, a higher specific surface area, good mechanical strength, flexibility and biocompatibility, can load drugs, nanoparticles, bioactive molecules, etc., and is suitable for biomedical fields such as wound dressings and tissue engineering scaffolds. By adjusting electrospinning parameters, the diameter of the fibers and the size of the membrane pores can be controlled, thereby producing fiber membranes with different morphologies (such as disordered, oriented, multi-layer structures), and these morphologies can further affect the performance of the membrane, thus adapting to different application requirements. In addition, compared with the electrospun fiber film prepared only with lignocellulose, the electrospun fiber film described in the present invention adds an amphiphilic copolymer, and the hydrophobic segments contained in the copolymer can entangle with the molecular chains of the hydrophobic polymer, and this structure can enhance the interfacial bonding strength between the two, thereby effectively transferring stress and greatly improving the mechanical strength and tensile properties of the film material. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 This is a process flow diagram for the preparation of a lignocellulose-based amphiphilic polymer and an electrospun fiber film provided by an embodiment of the present invention.

[0038] Figure 2 This is a microscopic structure diagram before and after the preparation of the lignocellulose-based amphiphilic polymer provided by an embodiment of the present invention. Detailed implementation manners

[0039] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0040] In the ranges disclosed in the present invention, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0041] For those not specifying specific techniques or conditions in the embodiments of the present invention, they shall be carried out according to the techniques or conditions described in the literature in the field or according to the product specifications. For those devices, instruments, reagents, etc. not indicating the manufacturer, they are all conventional products that can be obtained through regular channels. The experimental reagents and raw materials involved are all commercially available products, and the reagents are all analytical pure products.

[0042] As a preferred embodiment of the present invention, the preparation method of the lignocellulose-based amphiphilic polymer and the electrospun fiber film is as Figure 1 shown, and the steps are as follows: (1) Suspend the crushed agricultural product processing by-products in water at a mass ratio of 1:25 to 1:50, add 5% to 8% by volume of heat-resistant α-amylase, react in a water bath at 92 to 98 °C for 1 to 2 h, and then centrifuge at 6500 to 8000 g for 15 to 20 min to collect the precipitate.

[0043] (2) Mix the precipitate from step (1) with 1% hydrochloric acid solution at a mass ratio of 1:15 to 1:30, treat it at 80 - 90 °C for 20 - 50 min, then centrifuge at 6500 - 8000 g for 10 - 20 min to remove the supernatant and collect the precipitate; wash the precipitate with deionized water until the pH value reaches 6 - 7, and dry it at 45 - 60 °C for 8 - 10 h to obtain lignocellulose. Preferably, when the agricultural product processing by - product does not contain starch, step (1) can be omitted and step (2) can be directly carried out.

[0044] (3) Mix the lignocellulose obtained in step (2) with deionized water to obtain a suspension with a concentration of 0.2% - 1.0%, stir it overnight at 300 r / min, then shear it at 10000 - 12000 r / min for 40 - 80 s, and carry out 3 - 8 high - pressure homogenization cycles at 35 - 55 Mpa. After drying, lignocellulose nanofibers are obtained.

[0045] (4) Mix the lignocellulose nanofibers obtained in step (3) with aliphatic monomers at a mass (g): volume (mL) ratio of 1:20 to 1:70, add a catalyst at 0.2% - 0.8% of the volume of the aliphatic monomer, mix evenly, and react at 0.01 - 0.06 MPa, 300 r / min and 100 - 140 °C for 4 - 14 h, then cool to room temperature.

[0046] (5) Add dichloromethane with a volume 4 times that of the aliphatic monomer to the sample cooled in step (4), wash it at 300 r / min for 8 - 12 h, and centrifuge at 4000 g for 15 min to collect the precipitate.

[0047] (6) Wash the precipitate in step (5) three times with dichloromethane, ethanol and water respectively, centrifuge at 4000 g for 15 min, collect the precipitate, and after drying, obtain lignocellulose - based amphiphilic polymers.

[0048] (7) Mix the lignocellulose - based amphiphilic polymers obtained in step (6) with aliphatic polymer particles at a ratio of 1% - 5% (w / w), stir evenly with dichloromethane at 300 r / min to form an electrospinning solution.

[0049] (8) Add the electrospinning solution in step (7) into a syringe, and use an electrospinning device to spin at a distance of 10 - 20 cm from the needle to the collector, a collector rotation speed of 200 - 400 r / min, a feeding speed of 0.4 - 1.6 mL / h, and a voltage of 10 - 20 kV for 3 - 5 h to obtain an electrospun fiber membrane.

[0050] As a preferred embodiment of the present invention, the method for preparing the lignocellulose-based amphiphilic polymer and the electrospun fiber film is as follows: (1) The pulverized agricultural product processing by-products are suspended in water at a mass ratio of 1:30 to 1:40, 6% to 7% by volume of heat-resistant α-amylase is added, and the reaction is carried out in a water bath at 95 to 97 °C for 1.5 to 2 h. Then, centrifugation is carried out at 7000 to 8000 g for 15 to 20 min, and the precipitate is collected.

[0051] (2) The precipitate from step (1) is mixed with 1% hydrochloric acid solution at a mass ratio of 1:20 to 1:30, and treated at 85 to 90 °C for 30 to 40 min. Then, centrifugation is carried out at 7000 to 8000 r / min for 15 to 20 min, the supernatant is removed, and the precipitate is collected; the precipitate is washed with deionized water until the pH value is 6 to 7, and dried at 50 to 65 °C for 8 to 10 h to obtain lignocellulose.

[0052] (3) The lignocellulose obtained in step (2) is mixed with deionized water to obtain a suspension with a concentration of 0.5% to 1.0%, stirred overnight at 300 r / min, then sheared at 11000 to 12000 r / min for 50 to 70 s, and subjected to 4 to 6 high-pressure homogenization cycles at 40 to 50 Mpa. After drying, lignocellulose nanofibers are obtained.

[0053] (4) The lignocellulose nanofibers obtained in step (3) are mixed with aliphatic monomers at a mass (g): volume (mL) ratio of 1:30 to 1:60, 0.5% to 0.6% of the volume of the aliphatic monomers is added as a catalyst, and the mixture is stirred evenly and reacted at 0.01 - 0.05 MPa, 300 r / min and 120 - 130 °C for 4 to 8 h, and then cooled to room temperature.

[0054] (5) Dichloromethane with a volume 4 times that of the aliphatic monomers is added to the sample cooled in step (4), and washed at 300 r / min for 10 to 12 h, and centrifuged at 4000 r / min for 15 min to collect the precipitate.

[0055] (6) The precipitate in step (5) is washed three times with dichloromethane, ethanol and water respectively, centrifuged at 4000 g for 15 min, the precipitate is collected, and after drying, a lignocellulose-based amphiphilic polymer is obtained; (7) The lignocellulose-based amphiphilic polymer obtained in step (6) is mixed with aliphatic polymer particles at a ratio of 2% to 4% such as 3% (w / w), and stirred evenly at 300 r / min using dichloromethane to form an electrospinning solution.

[0056] (8) Add the electrospinning solution in step (7) into a syringe, and use an electrospinning device to spin for 3 - 4 h under the conditions of a distance of 15 - 20 cm from the needle to the collector, a collector rotation speed of 250 - 350 r / min, a liquid supply speed of 0.5 - 1.5 mL / h, and a voltage of 15 - 20 kV to obtain an electrospun fiber film.

[0057] Example 1 This example provides a lignocellulose-based amphiphilic polymer, an electrospun fiber film, and a preparation method thereof. As Figure 1 shown, the steps are as follows: (1) Suspend sweet potato residue in water at a mass ratio of 1:30, add heat-resistant α-amylase with a volume ratio of 6%, react in a 95 °C water bath for 1.5 h, then centrifuge at 7500 g for 15 min, and collect the precipitate.

[0058] (2) Mix the precipitate in step (1) with 1% hydrochloric acid solution at a mass ratio of 1:20, treat at 85 °C for 30 min, then centrifuge at 7500 g for 15 min, remove the supernatant, and collect the precipitate; wash the precipitate with deionized water until the pH value is 7, and dry at 65 °C for 8 h to obtain (sweet potato) lignocellulose.

[0059] (3) Mix the sweet potato lignocellulose obtained in step (2) with deionized water to obtain a suspension with a concentration of 0.5%, stir overnight at 300 r / min, then shear at 12000 r / min for 60 s, and perform 6 high-pressure homogenization cycles at 50 Mpa, and freeze-dry to obtain lignocellulose nanofibers.

[0060] (4) Mix the lignocellulose nanofibers obtained in step (3) with ε-caprolactone at a mass (g): volume (mL) ratio of 1:60, add stannous octanoate as a catalyst at 0.6% of the volume of ε-caprolactone, mix evenly, and react at 0.02 Mpa, 300 r / min, and 120 °C for 8 h, and then cool to room temperature.

[0061] (5) Add dichloromethane with a volume 4 times that of ε-caprolactone to the sample cooled in step (4), wash at 300 r / min for 12 h, and then centrifuge at 4000 g for 15 min to collect the precipitate.

[0062] (6) Wash the precipitate in step (5) three times with dichloromethane, ethanol, and water respectively, centrifuge at 4000 g for 15 min, collect the precipitate, and freeze-dry to obtain a lignocellulose-based amphiphilic polymer.

[0063] (7) Mix the lignocellulose-based amphiphilic polymer obtained in step (6) with polycaprolactone particles at a mass ratio of 3% (w / w), and stir evenly with dichloromethane at a rotation speed of 300 r / min to prepare an electrospinning solution with a polycaprolactone mass concentration of 18% (w / w).

[0064] (8) Add the electrospinning solution in step (7) to a syringe, and use an electrospinning device to spin for 4 h under the conditions of a distance of 15 cm from the needle to the collector, a collector rotation speed of 300 r / min, a feeding speed of 0.6 mL / h, and a voltage of 16 kV to obtain an electrospun fiber film.

[0065] Example 2 This example provides a lignocellulose-based amphiphilic polymer, an electrospun fiber film, and a preparation method thereof, which are carried out according to the following steps: (1) Suspend sweet potato residue in water at a mass ratio of 1:30, add heat-resistant α-amylase with a volume ratio of 6%, react in a 95 °C water bath for 1.5 h, and then centrifuge at 7500 g for 15 min to collect the precipitate.

[0066] (2) Mix the precipitate in step (1) with 1% hydrochloric acid solution at a mass ratio of 1:20, treat it at 85 °C for 30 min, then centrifuge at 7500 g for 15 min, remove the supernatant, and collect the precipitate; wash the precipitate with deionized water until the pH value is 7, and dry it at 65 °C for 8 h to obtain sweet potato lignocellulose.

[0067] (3) Mix the sweet potato lignocellulose obtained in step (2) with deionized water to obtain a suspension with a concentration of 0.5%, stir overnight at 300 r / min, then shear at 12000 r / min for 60 s, and perform 6 high-pressure homogenization cycles at 50 Mpa, and freeze-dry to obtain lignocellulose nanofibers.

[0068] (4) Mix the lignocellulose nanofibers obtained in step (3) with ε-caprolactone at a mass (g) to volume (mL) ratio of 1:60, add stannous octanoate as a catalyst at 0.6% of the volume of ε-caprolactone, mix evenly, and react at 0.02 Mpa, 300 r / min, and 130 °C for 8 h, and then cool to room temperature.

[0069] (5) Add dichloromethane with a volume 4 times that of ε-caprolactone to the sample cooled in step (4), wash it at 300 r / min for 12 h, and then centrifuge at 4000 g for 15 min to collect the precipitate.

[0070] (6) Wash the precipitate in step (5) three times with dichloromethane, ethanol, and water respectively, centrifuge at 4000 g for 15 min, collect the precipitate, and obtain the lignocellulose-based amphiphilic polymer after freeze-drying.

[0071] (7) Mix the lignocellulose-based amphiphilic polymer obtained in step (6) with polycaprolactone particles at a mass ratio of 4% (w / w), stir evenly with dichloromethane at a rotation speed of 300 r / min, and prepare an electrospinning solution with a polycaprolactone mass concentration of 15% (w / w).

[0072] (8) Add the electrospinning solution in step (7) to a syringe, and use an electrospinning device to spin for 4 h under the conditions of a distance of 15 cm from the needle to the collector, a collector rotation speed of 350 r / min, a feeding speed of 0.8 mL / h, and a voltage of 16 kV to obtain an electrospun fiber membrane.

[0073] Example 3 This example provides a lignocellulose-based amphiphilic polymer, an electrospun fiber membrane, and a preparation method thereof, which are carried out according to the following steps: (1) Suspend potato residues in water at a mass ratio of 1:30, add heat-resistant α-amylase with a volume ratio of 6%, react in a water bath at 95 °C for 1.5 h, and then centrifuge at 7500 g for 15 min to collect the precipitate.

[0074] (2) Mix the precipitate in step (1) with 1% hydrochloric acid solution at a mass ratio of 1:20, treat at 85 °C for 30 min, then centrifuge at 7500 g for 15 min, remove the supernatant, and collect the precipitate; wash the precipitate with deionized water to a pH value of 7, and dry at 65 °C for 8 h to obtain potato lignocellulose.

[0075] (3) Mix the potato lignocellulose obtained in step (2) with deionized water to obtain a suspension with a concentration of 0.5%, stir overnight at 300 r / min, then shear at 12000 r / min for 60 s, and perform 6 high-pressure homogenization cycles at 50 Mpa, and obtain lignocellulose nanofibers after freeze-drying.

[0076] (4) Mix the lignocellulose nanofibers obtained in step (3) with lactic acid at a mass (g): volume (mL) ratio of 1:50, add stannous octoate as a catalyst at 0.6% of the lactic acid volume, mix evenly, and react at 0.01 Mpa, 300 r / min, and 120 °C for 10 h, and then cool to room temperature.

[0077] (5) Add dichloromethane with a volume 4 times that of lactic acid to the sample cooled in step (4), wash it at 300 r / min for 12 h, and then centrifuge at 4000 g for 15 min to collect the precipitate.

[0078] (6) Wash the precipitate in step (5) three times with dichloromethane, ethanol, and water respectively, centrifuge at 4000 g for 15 min, collect the precipitate, and obtain the lignocellulose-based amphiphilic polymer after freeze-drying.

[0079] (7) Mix the lignocellulose-based amphiphilic polymer obtained in step (6) with polylactic acid particles at a mass ratio of 4% (w / w), stir evenly with dichloromethane at a rotation speed of 300 r / min, and prepare an electrospinning solution with a polylactic acid mass concentration of 12% (w / w).

[0080] (8) Add the electrospinning solution in step (7) to a syringe, and use an electrospinning device to spin for 3 h under the conditions of a distance of 15 cm from the needle to the collector, a collector rotation speed of 300 r / min, a feeding speed of 0.6 mL / h, and a voltage of 18 kV to obtain an electrospun fiber film.

[0081] Example 4 This example provides a lignocellulose-based amphiphilic polymer, an electrospun fiber film, and a preparation method thereof, which are carried out according to the following steps: (1) Suspend the crushed potato residue in water at a mass ratio of 1:30, add heat-resistant α-amylase with a volume ratio of 6%, react in a water bath at 95 °C for 1.5 h, and then centrifuge at 7500 g for 15 min to collect the precipitate.

[0082] (2) Mix the precipitate in step (1) with a 1% hydrochloric acid solution at a mass ratio of 1:20, treat it at 85 °C for 30 min, and then centrifuge at 7500 g for 15 min to remove the supernatant and collect the precipitate; wash the precipitate with deionized water until the pH value is 7, and dry it at 65 °C for 8 h to obtain potato lignocellulose.

[0083] (3) Mix the potato lignocellulose obtained in step (2) with deionized water to obtain a suspension with a concentration of 0.5%, stir overnight at 300 r / min, then shear at 12000 r / min for 60 s, and perform 6 high-pressure homogenization cycles at 50 Mpa, and obtain lignocellulose nanofibers after freeze-drying.

[0084] (4) Mix the lignocellulose nanofibers obtained in step (3) with lactic acid at a mass (g): volume (mL) ratio of 1:60, add stannous octoate as a catalyst at 0.4% of the volume of lactic acid, mix well, and react at 0.02 Mpa, 300 r / min, and 120 °C for 8 h, then cool to room temperature.

[0085] (5) Add dichloromethane with a volume 4 times that of lactic acid to the sample cooled in step (4), wash it at 300 r / min for 12 h, and then centrifuge it at 4000 g for 15 min to collect the precipitate.

[0086] (6) Wash the precipitate in step (5) three times with dichloromethane, ethanol, and water respectively, centrifuge it at 4000 g for 15 min, collect the precipitate, and obtain the lignocellulose-based amphiphilic polymer after freeze-drying.

[0087] (7) Mix the lignocellulose-based amphiphilic polymer obtained in step (6) with polylactic acid particles at a mass ratio of 2% (w / w), stir evenly with dichloromethane at a rotation speed of 300 r / min, and prepare an electrospinning solution with a polylactic acid mass concentration of 9% (w / w).

[0088] (8) Add the electrospinning solution in step (7) to a syringe, and use an electrospinning device to spin for 4 h under the conditions of a distance of 15 cm from the needle to the collector, a collector rotation speed of 200 r / min, a feeding speed of 0.5 mL / h, and a voltage of 15 kV to obtain an electrospun fiber film.

[0089] Example 5 (1) Suspend potato residues in water at a mass ratio of 1:30, add heat-resistant α-amylase with a volume ratio of 6%, react in a 95 °C water bath for 1.5 h, and then centrifuge at 7500 g for 15 min to collect the precipitate.

[0090] (2) Mix the precipitate in step (1) with 1% hydrochloric acid solution at a mass ratio of 1:20, treat it at 85 °C for 30 min, then centrifuge at 7500 g for 15 min, remove the supernatant, and collect the precipitate; wash the precipitate with deionized water until the pH value is 7, and dry it at 65 °C for 8 h to obtain sweet potato lignocellulose.

[0091] (3) Mix the sweet potato lignocellulose obtained in step (2) with deionized water to obtain a suspension with a concentration of 0.5%, stir it overnight at 300 r / min, then shear it at 12000 r / min for 60 s, and perform 6 high-pressure homogenization cycles at 50 Mpa, and obtain lignocellulose nanofibers after freeze-drying.

[0092] (4) Mix the lignocellulose nanofibers obtained in step (3) with ε-caprolactone at a mass (g): volume (mL) ratio of 1:40. Add stannous octanoate as a catalyst at 0.4% of the volume of ε-caprolactone. After mixing evenly, react at 0.02 Mpa, 300 r / min and 100 °C for 8 h, and then cool to room temperature.

[0093] (5) Add dichloromethane with a volume 4 times that of ε-caprolactone to the sample cooled in step (4). Wash it at 300 r / min for 12 h, and then centrifuge at 4000 g for 15 min to collect the precipitate.

[0094] (6) Wash the precipitate in step (5) three times with dichloromethane, ethanol and water respectively. Centrifuge at 4000 g for 15 min, collect the precipitate, and obtain the lignocellulose-based amphiphilic polymer after freeze-drying.

[0095] (7) Mix the lignocellulose-based amphiphilic polymer obtained in step (6) with polycaprolactone particles at a mass ratio of 2% (w / w). Stir evenly with dichloromethane at a rotation speed of 300 r / min to prepare an electrospinning solution with a polycaprolactone mass concentration of 9% (w / w).

[0096] (8) Add the electrospinning solution in step (7) to a syringe. Use an electrospinning device to spin for 4 h under the conditions of a distance of 15 cm from the needle to the collector, a collector rotation speed of 350 r / min, a feeding speed of 0.8 mL / h, and a voltage of 16 kV to obtain an electrospun fiber film.

[0097] Example 6 (1) Suspend potato residues in water at a mass ratio of 1:30. Add heat-resistant α-amylase at a volume ratio of 6%. React in a 95 °C water bath for 1.5 h, and then centrifuge at 7500 g for 15 min to collect the precipitate.

[0098] (2) Mix the precipitate in step (1) with 1% hydrochloric acid solution at a mass ratio of 1:20. Treat it at 85 °C for 30 min, and then centrifuge at 7500 g for 15 min to remove the supernatant and collect the precipitate. Wash the precipitate with deionized water until the pH value is 7, and dry it at 65 °C for 8 h to obtain sweet potato lignocellulose.

[0099] (3) Mix the sweet potato lignocellulose obtained in step (2) with deionized water to obtain a suspension with a concentration of 0.5%. Stir it overnight at 300 r / min, then shear it at 12000 r / min for 60 s, and perform 6 high-pressure homogenization cycles at 50 Mpa. After freeze-drying, obtain lignocellulose nanofibers.

[0100] (4) Mix the lignocellulose nanofibers obtained in step (3) with lactic acid at a mass (g): volume (mL) ratio of 1:70. Add stannous octoate as a catalyst at 0.2% of the volume of lactic acid. After mixing evenly, react at 0.02 Mpa, 300 r / min and 120 °C for 4 h, and then cool to room temperature.

[0101] (5) Add dichloromethane with a volume 4 times that of lactic acid to the sample cooled in step (4), wash at 300 r / min for 12 h, and then centrifuge at 4000 g for 15 min to collect the precipitate.

[0102] (6) Wash the precipitate in step (5) three times with dichloromethane, ethanol and water respectively, centrifuge at 4000 g for 15 min, collect the precipitate, and obtain the lignocellulose-based amphiphilic polymer after freeze-drying.

[0103] (7) Mix the lignocellulose-based amphiphilic polymer obtained in step (6) with polycaprolactone particles at a mass ratio of 3% (w / w), stir evenly with dichloromethane at a rotation speed of 300 r / min, and prepare an electrospinning solution with a mass concentration of poly(lactic acid) of 18% (w / w).

[0104] (8) Add the electrospinning solution in step (7) to a syringe, and use an electrospinning device to spin for 4 h under the conditions of a distance of 15 cm from the needle to the collector, a collector rotation speed of 350 r / min, a feeding rate of 0.8 mL / h, and a voltage of 16 kV to obtain an electrospun fiber film.

[0105] Example 7 (1) Suspend potato residue in water at a mass ratio of 1:30, add heat-resistant α-amylase with a volume ratio of 6%, react in a 95 °C water bath for 1.5 h, and then centrifuge at 7500 g for 15 min to collect the precipitate.

[0106] (2) Mix the precipitate in step (1) with 1% hydrochloric acid solution at a mass ratio of 1:20, treat at 85 °C for 30 min, and then centrifuge at 7500 g for 15 min to remove the supernatant and collect the precipitate; wash the precipitate with deionized water until the pH value is 7, and dry at 65 °C for 8 h to obtain sweet potato lignocellulose.

[0107] (3) Mix the sweet potato lignocellulose obtained in step (2) with deionized water to obtain a suspension with a concentration of 0.5%, stir overnight at 300 r / min, then shear at 12000 r / min for 60 s, and perform 6 high-pressure homogenization cycles at 50 Mpa. After freeze-drying, lignocellulose nanofibers are obtained.

[0108] (4) Mix the lignocellulose nanofibers obtained in step (3) with ε-caprolactone at a mass (g): volume (mL) ratio of 1:30, add stannous octoate as a catalyst at 1.0% of the volume of ε-caprolactone. After mixing evenly, react at 0.02 Mpa, 300 r / min and 110 °C for 6 h, and then cool to room temperature.

[0109] (5) Add dichloromethane with a volume 4 times that of ε-caprolactone to the sample cooled in step (4), wash it at 300 r / min for 12 h, and then centrifuge at 4000 g for 15 min to collect the precipitate.

[0110] (6) Wash the precipitate in step (5) three times with dichloromethane, ethanol and water respectively, centrifuge at 4000 g for 15 min, collect the precipitate, and obtain the lignocellulose-based amphiphilic polymer after freeze-drying.

[0111] (7) Mix the lignocellulose-based amphiphilic polymer obtained in step (6) with polycaprolactone particles at a mass ratio of 3% (w / w), stir evenly with dichloromethane at a rotation speed of 300 r / min, and prepare an electrospinning solution with a polycaprolactone mass concentration of 18% (w / w).

[0112] (8) Add the electrospinning solution in step (7) to a syringe, and use an electrospinning device to spin for 4 h under the conditions of a distance of 15 cm from the needle to the collector, a collector rotation speed of 350 r / min, a feeding speed of 0.8 mL / h, and a voltage of 16 kV to obtain an electrospun fiber film.

[0113] Example 8 (1) Suspend potato residues in water at a mass ratio of 1:30, add heat-resistant α-amylase with a volume ratio of 6%, react in a 95 °C water bath for 1.5 h, and then centrifuge at 7500 g for 15 min to collect the precipitate.

[0114] (2) Mix the precipitate in step (1) with 1% hydrochloric acid solution at a mass ratio of 1:20, treat it at 85 °C for 30 min, and then centrifuge at 7500 g for 15 min to remove the supernatant and collect the precipitate; wash the precipitate with deionized water until the pH value is 7, and dry it at 65 °C for 8 h to obtain sweet potato lignocellulose.

[0115] (3) Mix the sweet potato lignocellulose obtained in step (2) with deionized water to obtain a suspension with a concentration of 0.5%, stir it overnight at 300 r / min, then shear it at 12000 r / min for 60 s, and perform 6 high-pressure homogenization cycles at 50 Mpa, and obtain lignocellulose nanofibers after freeze-drying.

[0116] (4) Mix the lignocellulose nanofibers obtained in step (3) with lactic acid at a mass (g): volume (mL) ratio of 1:50, add stannous octoate as a catalyst at 0.6% of the lactic acid volume. After mixing evenly, react at 0.02 Mpa, 300 r / min and 140 °C for 12 h, and then cool to room temperature.

[0117] (5) Add dichloromethane with a volume 4 times that of lactic acid to the sample cooled in step (4), wash it at 300 r / min for 12 h, and then centrifuge at 4000 g for 15 min to collect the precipitate.

[0118] (6) Wash the precipitate in step (5) three times with dichloromethane, ethanol and water respectively, centrifuge at 4000 g for 15 min, collect the precipitate, and obtain the lignocellulose-based amphiphilic polymer after freeze-drying.

[0119] (7) Mix the lignocellulose-based amphiphilic polymer obtained in step (6) with polycaprolactone particles at a mass ratio of 3% (w / w), stir evenly with dichloromethane at a rotation speed of 300 r / min, and prepare an electrospinning solution with a polylactic acid mass concentration of 18% (w / w).

[0120] (8) Add the electrospinning solution in step (7) to a syringe, and use an electrospinning device to spin for 4 h under the conditions of a distance of 15 cm from the needle to the collector, a collector rotation speed of 350 r / min, a feeding speed of 0.8 mL / h, and a voltage of 16 kV to obtain an electrospun fiber film.

[0121] Comparative Example 1 The difference between this comparative example and Example 1 is that: without using the lignocellulose-based amphiphilic polymer, directly use lignocellulose nanofibers to replace the lignocellulose-based amphiphilic polymer to prepare the electrospun fiber film.

[0122] Comparative Example 2 The difference between this comparative example and Example 1 is that: without using lignocellulose nanofibers, directly use lignocellulose to replace lignocellulose nanofibers for the polymerization reaction.

[0123] Comparative Example 3 The difference between this comparative example and Example 1 is that: the temperature of the polymerization reaction in step (4) is 100 °C.

[0124] Comparative Example 4 The difference between this comparative example and Example 1 is that: no catalyst is added during the polymerization reaction.

[0125] Experimental Example 1: Hydroxyl Substitution Degree and Grafting Ratio of Lignocellulose-based Amphiphilic Polymers In this experimental example, the substitution degree and grafting ratio of hydroxyl groups on glucose in the lignocellulose-based amphiphilic polymers in Examples 1-8 and Comparative Examples 1-4 were measured and analyzed: The sample was dissolved in dimethyl sulfoxide-D6 (DMSO-d6), and the 1 1H NMR spectrum of the sample was measured using a Bruker 400 M NMR spectrometer with tetramethylsilane (TMS) as the internal standard.

[0126] The hydroxyl substitution degree was calculated from the 1H NMR spectrum results, and the formula is as follows: DS: Hydroxyl substitution degree on lignocellulose nanofibers; I a' : Signal intensity at a'; H 4： Signal intensity at H4; I b' : Signal intensity at b'; : Total signal intensity at OH2, OH3 and OH6.

[0127] The grafting ratio was calculated from the 1H NMR spectrum results, and the formula is as follows: MS: Molar substitution degree; : Sum of signal intensities at a' and a; H4: Signal intensity at H4; W: Grafting ratio; 114 is the molecular weight of caprolactone; 72 is the molecular weight of lactic acid; 162 is the molecular weight of glucose unit.

[0128] Table 1 Hydroxyl Substitution Degree and Grafting Ratio of Lignocellulose Nanofibers

[0129] Note: DS: Hydroxyl substitution degree on lignocellulose nanofibers; W: Grafting ratio; -: Not detected.

[0130] It can be found from Table 1 that the hydroxyl substitution degree and grafting ratio on lignocellulose nanofibers in the samples of Examples 1-8 are relatively high; in Comparative Example 1, since no polymerization reaction was carried out, the substitution degree and grafting ratio were not detected; while the hydroxyl substitution degree on lignocellulose nanofibers in Comparative Examples 2-4 is significantly lower than that in Examples 1-8. This is mainly because the specific surface area of lignocellulose without high-pressure homogenization is relatively small, and the number of hydroxyl groups exposed on the fiber surface is less, resulting in a decrease in the substitution degree and grafting ratio; in addition, a lower reaction temperature and the absence of a catalyst will reduce the polymerization reaction efficiency, thereby reducing the substitution degree and grafting ratio.

[0131] Experimental Example 2: Mechanical Strength of Electrospun Fiber Films Prepared from Lignocellulose-based Amphiphilic Polymers In this experimental example, the mechanical strength of the electrospun fiber films prepared in Examples 1-8 and Comparative Examples 1-4 was measured and analyzed: The mechanical strength of the electrospun fiber films was measured using a universal testing machine. The sample width was 15 mm, the length was 100 mm, and the stretching speed was 10 mm / min.

[0132] Table 2 Mechanical Strength of Electrospun Fiber Films

[0133] It can be found from Table 2 that the maximum stress and maximum strain that the samples of Examples 1-8 can withstand are relatively high, while the maximum stress and maximum strain that the samples in Comparative Examples 1-4 can withstand are much lower than those of the Examples. The sample in Example 1 has the highest maximum stress and maximum strain, which are 2.06 ± 0.12 MPa and 51.37 ± 0.16%, respectively; the sample in Comparative Example 1 has the lowest maximum stress and maximum strain because it has not undergone a polymerization reaction, which are 0.73 ± 0.05 MPa and 24.51 ± 0.29%, respectively. The increase in stress and strain reflects the improvement in aspects such as the interfacial compatibility between the lignocellulose-based amphiphilic polymer and the aliphatic polymer. The electrospun fiber film prepared using the lignocellulose-based amphiphilic polymer of the present invention enables the electrospun film of lignocellulose nanofibers modified with an aliphatic polymer to have higher maximum stress and maximum strain.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a lignocellulose-based amphiphilic polymer, characterized in that, Comprising: Pre-treating agricultural product processing by-products by chemical method and / or biological method to obtain lignocellulose; Using the lignocellulose as raw material, performing high-pressure homogenization treatment to obtain lignocellulose nanofibers, mixing the lignocellulose nanofibers, aliphatic monomers and a catalyst, and performing high-temperature polymerization to obtain a lignocellulose-based amphiphilic polymer.

2. The preparation method according to claim 1, wherein The pre-treatment is α-amylase enzymolysis and / or hydrochloric acid acidolysis; preferably, the pre-treatment includes: mixing a mixture of agricultural product processing by-products and water with α-amylase, centrifuging after enzymolysis to obtain a precipitate; mixing the precipitate with hydrochloric acid, centrifuging after acidolysis, washing with water and drying; Preferably, the addition amount of the α-amylase is 5% - 10% of the volume of the mixed material; the enzymolysis temperature is 90 - 100 °C, the time is 0.5 - 2 h; the centrifugation speed after enzymolysis is 6000 - 8000 g, and the time is 10 - 25 min; And / or, the mass ratio of the hydrochloric acid to the precipitate is 1:10 - 1:40; the concentration of the hydrochloric acid is 0.2% - 1.5%; the acidolysis temperature is 75 - 90 °C, the time is 15 - 60 min; the centrifugation speed after acidolysis is 6000 - 8000 g, the time is 10 - 25 min, washing with water until the pH value is 6 - 8, and the drying temperature is 45 - 75 °C, the time is 8 - 12 h; And / or, the agricultural product processing by-products include one or more of potato residue, vine, straw, rice bran, rice husk, bran, distillers' grains, bagasse, coconut shell, fruit peel, fruit shell.

3. The preparation method according to claim 1 or 2, characterized in that, The high-pressure homogenization includes: mixing lignocellulose with water to obtain a lignocellulose suspension; shearing the lignocellulose suspension after suspension, and then performing high-pressure homogenization cycle and drying; Preferably, the concentration of the lignocellulose suspension is 0.1% - 1.5%; the suspension time is 8 - 14 h; the shearing speed is 9000 - 12000 r / min, the time is 30 - 90 s; the pressure of high-pressure homogenization is 30 - 60 MPa, and the number of high-pressure homogenization cycles is 3 - 9 times.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The reaction temperature of the high-temperature polymerization is 100 - 150 °C, and the reaction time is 2 - 14 h; And / or, the ratio of the lignocellulose nanofibers to the aliphatic monomers is 1:10 - 1:80 w / v, and the aliphatic monomers are lactic acid and / or ε-caprolactone; Preferably, a catalyst is added in an amount of 0.1% - 1% of the volume of the aliphatic monomers, and the catalyst is stannous octoate and / or diethyl zinc.

5. The preparation method according to any one of claims 1-4, characterized in that, Also including washing and drying; preferably, washing is performed with dichloromethane which is 3 - 5 times the volume of the aliphatic monomers, the washing speed is 200 - 400 r / min, the washing time is 8 - 12 h, then centrifuging, and washing the precipitate with dichloromethane, ethanol and water respectively, then centrifuging and drying the precipitate; the centrifugation speed is preferably 3000 - 5000 g, and the time is 10 - 20 min.

6. A lignocellulose-based amphiphilic polymer, characterized in that, Prepared by the preparation method of the lignocellulose-based amphiphilic polymer according to any one of claims 1 - 5.

7. A method for preparing an electrospun fiber film, characterized in that, Comprising: Mix the amphiphilic polymer based on lignocellulose described in claim 6 with an aliphatic polymer and prepare an electrospinning solution, and then perform electrospinning.

8. The preparation method according to claim 7, wherein The preparation of the electrospinning solution includes: mixing the amphiphilic polymer based on lignocellulose with an aliphatic polymer, adding a solvent and stirring. Preferably, the mass ratio of the amphiphilic polymer based on lignocellulose to the aliphatic polymer is 1-6:100, the solvent is dichloromethane, the concentration of the aliphatic polymer is 5%-20% w / w, and the stirring speed is 200-400 r / min. And / or, the conditions for electrospinning include: the distance between the needle and the collector is 10-25 cm, the rotation speed of the collector is 150-450 r / min, the liquid supply speed is 0.2-2 mL / h, the voltage is 10-25 kV, the spinning time is 1-6 h, and preferably a 3-8 mL injection device is used.

9. An electrospun fiber film, characterized in that, Prepared by the preparation method of the electrospun fiber film described in claim 7 or 8.

10. Application of the electrospun fiber film described in claim 9 in biomedicine, preferably in wound dressings and tissue engineering.

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