Preparation method of phase change energy storage water-based polyurethane nanofiber membrane

Abstract

The application discloses a phase change energy storage water-based polyurethane nanofiber membrane and a preparation method thereof, and utilizes ultraviolet light crosslinking and lignin shell encapsulation to prepare lignin-based phase change microcapsules, and then the phase change microcapsules are used to prepare nanofiber membranes through electrospinning technology, and finally, the water-based polyurethane phase change fiber membrane with asymmetric wettability is constructed through low-temperature plasma technology. The lignin is self-assembled into nanoparticles, and ultraviolet light-induced free radical polymerization is used to form a polymer film, so that the encapsulation capacity for phase change materials is improved. The phase change microcapsules prepared by the method have high encapsulation efficiency and excellent phase change performance, the preparation process is green and environmentally friendly, and the process operation is simple, the temperature of the prepared phase change energy storage water-based polyurethane nanofiber membrane meets the temperature range of human comfort, the phase change energy storage water-based polyurethane nanofiber membrane has excellent temperature regulation and waterproof and moisture permeable performances, and has a good application prospect in the fields of intelligent temperature regulation and waterproof and air permeable functional textiles.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of functional membrane materials, and particularly relates to a phase change energy storage water-based polyurethane nanofiber membrane and a preparation method thereof. BACKGROUND

[0002] With the global warming trend significantly accelerating, extreme high temperature, severe cold, storm and other severe weather frequently occur, which poses a severe physiological challenge to people who work outdoors for a long time, such as construction workers, farmers, emergency personnel and outdoor athletes. High temperature can cause heatstroke, dehydration and other health problems, and long-term exposure to cold environment can cause hypothermia and even frostbite. Therefore, how to effectively protect the thermal comfort and health of outdoor workers has become a key field of functional textile research in recent years.

[0003] Traditional temperature control means, such as air conditioners, heaters, fans, etc., are mainly used for indoor environment, and outdoor workers cannot enjoy these conveniences. In addition, such devices consume a large amount of energy and do not meet the requirements of environmental protection and sustainable development. With the increasing attention to low-carbon economy and energy saving and environmental protection around the world, personal thermal management (PTM) has gradually become a key strategy to cope with extreme weather. PTM adjusts the temperature of the human body surface locally, rather than changing the temperature of the whole environment, to achieve more precise thermal management, which not only saves energy, but also improves the comfort and work efficiency of workers in severe environment.

[0004] In the study of PTM, the development of intelligent functional textiles has attracted particular attention. Such textiles, through the combination with phase change materials (PCM), can absorb or release heat, playing a role in automatically adjusting temperature. The thermal conductivity of traditional PCMs is limited, and leakage often occurs during phase transformation. The emergence of phase change microcapsules provides a solution to these problems. Phase change microcapsules contain two parts: PCM as the core and polymer or inorganic shell wrapping PCM. In the traditional method of preparing phase change microcapsules, a polymer is often used to wrap a phase change emulsion (W / O), which is composed of an aqueous phase and an oil phase. The oil phase is PCM material, and the aqueous phase contains a polymer shell material wrapping PCM. However, the emulsion has a tendency to separate under natural conditions, so a large amount of surfactant and emulsifier is needed to stabilize the emulsion. The instability of the phase change emulsion can lead to low encapsulation efficiency of the phase change microcapsules. Polyurethane can be used as a textile coating and is often used to encapsulate phase change materials. CN202411192924 discloses a preparation method of low-temperature phase change microcapsules. Polyurethane is used as the shell material, and low-temperature phase change material is used as the core material. In-situ polymerization is used to uniformly coat the polyurethane material on the surface of the core material to obtain the low-temperature phase change microcapsules. The prepared microcapsules have good temperature regulation ability, water resistance, and mechanical properties. However, the in-situ polymerization has low encapsulation efficiency, and the phase change material is prone to leakage. Ultraviolet light-induced polyurethane radical polymerization has fast curing speed, short time, and high encapsulation efficiency. At the same time, lignin can be used as a surfactant and insoluble shell, and can self-assemble into nanoparticles under acidic conditions. Adding lignin as a shell material to the emulsion system forms a W / O / O double-phase emulsion, which can effectively encapsulate phase change materials. Double encapsulation of polyurethane combined with lignin shell can effectively prevent leakage of phase change materials.

[0005] In addition to temperature regulation, outdoor workers often face the problem of excessive sweat discharge in high-temperature environments. If sweat cannot be discharged in time, it will make the skin surface wet and cold, affecting the comfort of the human body and even causing skin problems. Therefore, intelligent textiles also need to have good air permeability and sweat-wicking function to ensure that the skin can remain dry. In recent years, fiber materials with asymmetric wettability have gradually attracted attention. Such materials build hydrophilic and hydrophobic structures on both sides of the fiber membrane, with the hydrophilic side in contact with the skin. When the human body produces sweat, it can achieve one-way water transfer, helping to quickly discharge sweat and keep the inside dry, improving the comfort of wearing.

[0006] Electrospinning technology has shown great potential in the development of personal thermal management intelligent textiles. Nanofiber membranes prepared by electrospinning technology have high specific surface area and good pore structure, which can not only be combined with phase change materials to achieve temperature regulation function, but also can enhance the sweat-wicking and moisture permeability of textiles by regulating the surface wettability. In addition, functionalization of fiber membranes using electrospinning technology according to the use requirements not only enables the material to have excellent mechanical properties, but also meets the needs of human wear. However, most of the existing electrospinning technologies rely on organic solvents such as tetrahydrofuran (THF), N,N-dimethylformamide (DMF), trifluoroacetic acid (TFA), dichloromethane (DCM), etc. These solvents will volatilize and leak during preparation and use, causing environmental pollution and endangering human health. Therefore, the development of environmentally friendly electrospinning process has become a hot research topic. CN116988225A discloses a preparation method and application of a double-layer phase change composite fiber membrane. By using N,N-dimethylformamide to dissolve polyacrylonitrile and adding carbon nanotubes, a composite phase change fiber membrane is prepared by electrospinning method. On this basis, a polyvinylidene fluoride layer is further constructed by electrospinning method, and a double-layer phase change fiber membrane is successfully prepared. However, this method uses a large amount of organic solvent N,N-dimethylformamide during preparation, which will cause environmental pollution and endanger human health. In addition, the outermost polyvinylidene fluoride layer will have a negative impact on the thermal conductivity of the inner phase change fiber membrane.

[0007] Waterborne polyurethane has the characteristics of non-toxic and environmental protection, and is suitable for preparing PTM coating. However, the surface tension of water is high, the conductivity is high, and the evaporation rate is slow, so using water as a solvent can easily lead to uneven thickness of nanofibers prepared by electrospinning. At present, in order to prepare a waterproof and moisture-permeable membrane using waterborne polyurethane as raw material by electrospinning process, some preparation process difficulties still need to be overcome. In order to solve the environmental pollution of organic solvents in traditional electrospinning process and the process problems of waterborne polyurethane spinning in electrospinning, the present application uses waterborne polyurethane (WPU) instead of organic solvent, improves the spinning process, reduces the surface tension of water and improves the conductivity of the spinning solution, develops a green and environmentally friendly electrospinning process for the production of human thermal management phase change textiles. Further, through plasma surface modification technology, the hydrophobic performance of the fiber membrane is improved, and asymmetric wettability is realized, so as to meet the special needs of outdoor workers in extreme weather. SUMMARY

[0008] The purpose of the present application is to provide a phase change energy storage waterborne polyurethane nanofiber membrane and a preparation method thereof.

[0009] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0010] A preparation method of a phase change energy storage aqueous polyurethane nanofiber membrane, comprising the following steps:

[0011] (1) Preparing a lignin-based phase change microcapsule: 1 part of alkali lignin is added into 50-100 parts of sodium hydroxide, and then 2-5 parts of a phase change material is added, and emulsified for 3-10 minutes to obtain an emulsion; 1-3 parts of 1,6-hexanediol diacrylate, 1 part of Span 80 and 1 part of a photoinitiator are mixed and then added into the emulsion, and emulsified for another 3-10 minutes; the pH of the solution is adjusted to 2-3, and then the solution is irradiated with ultraviolet light for 15 minutes; finally, the lignin-based phase change microcapsule powder is obtained through spray drying; the wavelength of the ultraviolet light is 365 nm, and the intensity is 2000 mW / cm 2 ;

[0012] (2) Preparing a spinning solution: an organosilicon-modified aqueous polyurethane emulsion, an aqueous thickening agent, the lignin-based phase change microcapsule powder, a surfactant and an electrolyte are mixed and ultrasonically dispersed, and then uniformly stirred at room temperature to obtain the spinning solution;

[0013] (3) Preparing a phase change fiber membrane: the spinning solution is injected into an electrostatic spinning injector, and a nanofiber membrane is obtained through electrostatic spinning, and then the phase change fiber membrane is obtained through drying;

[0014] (4) Hydrophobic modification of the phase change fiber membrane: the low-temperature plasma technology is used to perform hydrophobic modification on one side of the phase change fiber membrane.

[0015] Further, in step (1), the phase change material is one or more of polyethylene glycol, paraffin, dodecanol and octadecane; the addition amount of the phase change microcapsule powder is 10-25% of the total mass of the organosilicon-modified aqueous polyurethane emulsion and the aqueous thickening agent; and the photoinitiator is one or more of 2-hydroxy-2-methylpropyl phenone, acryloyl carboxylic acid diester, trimethyl benzoyl-diphenyl phosphine oxide and 2,4-diethyl thioxanthone.

[0016] Further, in step (2), the organosilicon-modified aqueous polyurethane emulsion is one or more of a vinyl triethoxysilane-modified aqueous polyurethane emulsion, a vinyl trimethoxysilane-modified aqueous polyurethane emulsion, a γ-glycidyl ether oxypropyl trimethoxysilane-modified aqueous polyurethane emulsion and a γ-aminopropyl methyl diethoxysilane-modified aqueous polyurethane emulsion; and the solid content of the organosilicon-modified aqueous polyurethane emulsion is 30-50%.

[0017] Further, in step (2), the aqueous thickening agent is one or more of polyvinyl alcohol, sodium alginate, sodium carboxymethyl cellulose, polyacrylic acid sodium and polyvinyl pyrrolidone; the mass fraction of the aqueous thickening agent is 10-20%; and the mass ratio of the organosilicon-modified aqueous polyurethane emulsion to the aqueous thickening agent is 1:1.

[0018] Further, the surface active agent in step (2) is one or more of sodium dodecyl benzene sulfonate, polysorbate, glycerol fatty acid ester, polyethylene glycol sulfate ester; the added amount of the surface active agent is 0.05-0.1% of the total mass of the silicone-modified waterborne polyurethane emulsion and the waterborne thickening agent.

[0019] Further, the electrolyte in step (2) is one or more of sodium chloride, sodium bisulfite, hydrogen chloride, acetic acid; the added amount of the electrolyte is 0.05-0.1% of the total mass of the silicone-modified waterborne polyurethane emulsion and the waterborne thickening agent.

[0020] Further, the electrospinning parameters in step (3) are as follows: positive high voltage 15-17kV, negative high voltage -1.5kV, spinning distance 15-20cm, advancing speed 0.5mm / h, receiving drum rotating speed 60-100r / min, and the receiver is a silicon oil paper-covered drum; the spinning environment temperature is 25-30℃, and the humidity is 30-50%.

[0021] Further, the gas for low-temperature plasma hydrophobic modification in step (4) is one of carbon tetrafluoride, tetrafluoroethylene, sulfur hexafluoride, and trimethylfluorosilane; the low-temperature plasma modification power is 50-75W, and the modification time is 5-10min.

[0022] A phase change energy storage waterborne polyurethane phase change fiber film prepared by the above preparation method, wherein the phase change temperature of the phase change energy storage waterborne polyurethane phase change fiber film is 13.5-28.5℃, the phase change enthalpy is 18.0-65.5J / g, the water droplet contact angle of the hydrophobic side of the plasma-modified phase change fiber film is 140-160°, the moisture permeation amount is 1300-2500g / m 2 ·d, the tensile strength is 6.5-11.5MPa, and the elongation at break is 255-330%.

[0023] The application further provides the application of the above phase change energy storage waterborne polyurethane phase change fiber film in functional textiles.

[0024] The present application takes organic silicon modified waterborne polyurethane as raw material, first prepares lignin-based phase change microcapsules by lignin self-assembly and ultraviolet crosslinking, introduces HDDA as a third phase into lignin-based water phase and PCM oil phase, regulates the interfacial tension relationship between the three phases, forms a double emulsion with lignin as shell and PCM as core, and crosslinks the emulsion with core-shell structure by ultraviolet curing to form phase change microcapsules with dense polymer film on the outside, simultaneously realizes the encapsulation of phase change materials by using the self-assembly performance of lignin under acidic conditions, and prepares lignin-based phase change microcapsules with high encapsulation rate and excellent phase change performance.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] (1) The shell monomers formed by the double emulsion template are crosslinked by ultraviolet light induced radical polymerization to form a polymer film to encapsulate the phase change material, and lignin-based phase change microcapsules are formed by using lignin self-assembly. The lignin-based phase change microcapsules are prepared by using lignin self-assembly and ultraviolet crosslinking technology to encapsulate the phase change material, which has high encapsulation efficiency and is not easy to leak, and also realizes the resource utilization and high value of lignin.

[0027] (2) The present application takes organic silicon waterborne polyurethane as raw material, lignin-based phase change microcapsules as phase change material, uses water-based thickening agent, surfactant and electrolyte to improve the spinnability of water-based spinning solution, and prepares nanofiber membrane by electrospinning process, which solves the solvent pollution problem caused by traditional electrospinning.

[0028] (3) The nanofiber membrane is hydrophobically modified by plasma technology to give it asymmetric wettability and one-way wetting function. The plasma modification technology is used instead of fluorine-containing emulsion hydrophobic modification to avoid fluoride pollution, reduce pollution and harm to the environment and human body during preparation. The prepared nanofiber is fine and uniform, has good heat storage and release performance, strong thermal stability, and good air permeability, and has great application potential in the field of PTM intelligent temperature regulating textiles. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The scanning electron microscope (SEM) and the heat flow-temperature change curve (DSC) images of the lignin-based phase change microcapsules prepared in Example 1.

[0030] Figure 2 Scanning electron microscope images (SEM) of the phase change energy storage nanofiber membranes prepared for Example 1 (b) and Comparative Example 1 (a).

[0031] Figure 3 Tensile stress-Tensile strain curves of the phase change energy storage nanofiber membranes prepared for Example 1 and Comparative Example 1 (without adding thickening agent, electrolyte, surfactant).

[0032] Figure 4 Heat flow-temperature change curves (DSC) of the endothermic and exothermic sections of the phase change energy storage nanofiber membranes prepared for Example 1 and Comparative Example 2 (without adding phase change microcapsules).

[0033] Figure 5 Water drop contact angle (WCA) comparison chart of the phase change energy storage nanofiber membranes prepared for Example 1, Example 2 and Comparative Example 3 (unmodified).

[0034] Figure 6 X-ray photoelectron spectroscopy (XPS) of the phase change energy storage nanofiber membranes prepared for Example 1, Example 2 and Comparative Example 3 (unmodified). DETAILED DESCRIPTION

[0035] The raw materials used in the following examples listed in the present application are described as follows:

[0036] Alkaline lignin was purchased from Merck Group, Germany (CAS No. 8068-05-1), and silicone-modified waterborne polyurethane emulsion was purchased from Guangzhou Dolphin New Material Co., Ltd.

[0037] The encapsulation efficiency (E p ) of the phase change microcapsules involved in the following examples listed in the present application was calculated by the following formula:

[0038]

[0039] Wherein, E c is the PCMs content of the phase change microcapsules, ΔH m0 and ΔH c0 are the melting enthalpy and crystallization enthalpy of pure PCMs, respectively, ΔH m0 and ΔH c0 are the melting enthalpy and crystallization enthalpy of the phase change microcapsules, respectively, and φPCMs is the theoretical mass fraction of PCMs in the phase change microcapsules.

[0040] The retention rate (E r ) after 100 cycles of cold and hot cycles (0℃-50℃-0℃) was calculated by the following formula:

[0041]

[0042] wherein ΔH0and ΔH t are the phase transition enthalpy of the phase change microcapsule before and after 100 cycles of cold and hot cycles, respectively.

[0043] Example 1

[0044] (1) Preparation of lignin-based phase change microcapsule: 1 g of alkali lignin was added to 50 g of NaOH, 3.5 g of dodecanol (DD) was added at 60 °C, and the emulsion was obtained by homogenizing in a homogenizer at 10000 rpm / min for 3 min; 1 g of 1,6-hexanediol diacrylate (HDDA), 1 g of Span 80 and 1 g of 2-hydroxy-2-methylpropiophenone (HMPP) were mixed and added to the above emulsion, and then homogenized in a homogenizer at 10000 rpm / min for 3 min, and the pH was adjusted to 2-3 using 0.1 mol / L hydrochloric acid solution, then it was transferred to a magnetic stirrer, stirred at 400 rpm / min, and irradiated with a UV lamp (wavelength 365 nm, intensity 2000 mW / cm 2 , the distance between the light source and the emulsion was 10 cm) for 15 min to crosslink HDDA, and finally the phase change microcapsule powder was obtained by spray drying at 150 °C.

[0045] (2) Preparation of spinning solution: 3 g of polyvinyl alcohol powder (PVA, Mn=100000) was added to 17 g of deionized water, and stirred uniformly at 80 °C for 2 h to obtain a 15% PVA solution, and then left to stand at room temperature. 12.5 g of vinyltriethoxysilane modified waterborne polyurethane emulsion (WPU, solid content 50%) was mixed with 12.5 g of PVA solution (WPU / PVA=1:1, wt%), and stirred uniformly at room temperature for 12 h to obtain 25 g of WPU / PVA solution. 10 g of deionized water, 0.025 g of sodium dodecylbenzenesulfonate (SDBS), 0.025 g of sodium chloride (NaCl) and 5.0 g of phase change microcapsule powder were added and ultrasonically dispersed for 30 min, then stirred at 1000 rpm / min at 80 °C for 40 min, then 25 g of WPU / PVA solution was added while hot, and stirred for 1 h to obtain the spinning emulsion.

[0046] (3) Preparation of phase change fiber membrane: phase change energy storage waterborne polyurethane nanofiber membrane was prepared by emulsion electrospinning technology, the spinning emulsion was transferred to a 10 mL needle tube, and the needle with a specification of 17G was used to spin for 8h. The specific spinning parameters are as follows: positive high voltage: 17kV, negative high voltage: -1.5kV, spinning distance: 20cm, liquid inlet speed: 0.5mm / h, receiving drum rotating speed: 80r / min, receiver is silicone oil paper; spinning environment temperature: 25℃, humidity: 45%. After spinning, the fiber membrane was transferred to a 35℃ vacuum drying oven, and dried for 24h to obtain the required phase change fiber membrane.

[0047] (4) Hydrophobic modified phase change fiber membrane: the phase change energy storage waterborne polyurethane nanofiber membrane was placed in a low temperature plasma equipment, placed on a glass flat plate, vacuumed to a vacuum degree of 1×10 -6 Pa, and C2F4 gas was introduced when the instrument was stable, and the surface of the nanofiber membrane was hydrophobically modified. The parameter settings of the plasma equipment are as follows: modification power is 75W, and time is 10min.

[0048] The phase change enthalpy of the phase change microcapsule prepared according to the above steps is 176.5J / g, the encapsulation efficiency is 99.0%, and the phase change enthalpy of the phase change microcapsule after 100 times of cold and hot cycle is 174.7J / g, the retention rate is 99.0%, the contact angle of the phase change energy storage waterborne polyurethane nanofiber membrane is 160°, the crystallization enthalpy is 38.3J / g, the crystallization temperature is 13.5℃, the melting enthalpy is 43.3J / g, the melting temperature is 27.5℃, the water pressure resistance is 14.5kPa, the moisture permeation amount is 2500g / m 2 ·d, the elongation at break is 310%, and the tensile strength is 10.5MPa.

[0049] Example 2

[0050] (1) Preparation of lignin-based phase change microcapsule: 1g of alkali lignin was added to 50g of NaOH, 3.5g of dodecanol (DD) was added at 60℃, and the emulsion was homogenized in a homogenizer at 10000 rpm / min for 3min; 1g of 1,6-hexanediol diacrylate (HDDA), 1g of Span80 and 1g of 2-hydroxy-2-methylpropiophenone (HMPP) were mixed and added to the above emulsion, and then homogenized in a homogenizer at 10000 rpm / min for 3min, 0.1mol / L hydrochloric acid solution was used to adjust the pH to 2~3, then it was transferred to a magnetic stirrer, stirred at 400rpm / min, and irradiated with a UV lamp (wavelength 365nm, intensity 2000mW / cm 2 , the distance between the light source and the emulsion was 10cm) for 15min to crosslink HDDA, and finally the phase change microcapsule powder was obtained by spray drying at 150℃.

[0051] (2) Preparation of the spinning solution: 3 g of polyvinyl alcohol powder (PVA, Mn = 100000) was added to 17 g of deionized water, and stirred uniformly at 80°C for 2 h to obtain a 15% PVA solution, which was left to stand at room temperature for use. 12.5 g of vinyl triethoxysilane modified waterborne polyurethane emulsion (WPU, solid content 50%) was mixed with 12.5 g of PVA solution (WPU / PVA = 1:1, wt%), and stirred uniformly at room temperature for 12 h to obtain 25 g of WPU / PVA solution. 10 g of deionized water was weighed, and 0.025 g of sodium dodecyl benzene sulfonate (SDBS), 0.025 g of sodium chloride (NaCl) and 5.0 g of phase change microcapsule powder were added, and ultrasonically dispersed for 30 min, and then stirred at 80°C at 1000 rpm / min for 40 min, and then 25 g of WPU / PVA solution was added while hot, and stirred for 1 h to obtain the spinning emulsion.

[0052] (3) Preparation of the phase change fiber membrane: the phase change energy storage waterborne polyurethane nanofiber membrane was prepared by the emulsion electrospinning technology, the spinning emulsion was transferred to a 10 mL needle tube, and the spinning was performed for 8 h using a needle with a specification of 17G. The specific spinning parameters were as follows: positive high voltage: 17 kV, negative high voltage: -1.5 kV, spinning distance: 20 cm, liquid feeding speed: 0.5 mm / h, receiving roller rotating speed: 80 r / min, and the receiver was silicone oil paper; the spinning environment temperature was 25°C, and the humidity was 45%. After the spinning was completed, the fiber membrane was transferred to a 35°C vacuum drying oven, and dried for 24 h to obtain the required phase change fiber membrane.

[0053] (4) Hydrophobic modification of the phase change fiber membrane: the phase change energy storage waterborne polyurethane nanofiber membrane was placed in a low temperature plasma device, placed on a glass flat plate, vacuumed to a vacuum degree of 1 x 10 -6 Pa, CF4 gas was introduced when the instrument was stable, and the surface of the nanofiber membrane was hydrophobically modified, and the parameter settings of the plasma device were as follows: modification power was 50 W, and the time was 10 min.

[0054] The phase change enthalpy of the phase change microcapsule prepared according to the above steps was 176.2 J / g, the encapsulation efficiency was 99.0%, the phase change enthalpy of the phase change microcapsule after 100 times of cold and hot cycles was 174.9 J / g, the retention rate was 99.0%, the contact angle of the phase change energy storage waterborne polyurethane nanofiber membrane was 153°, the crystallization enthalpy was 38.2 J / g, the crystallization temperature was 13.4°C, the melting enthalpy was 43.5 J / g, the melting temperature was 27.4°C, the water pressure resistance was 11.5 kPa, the moisture permeation amount was 2300 g / m 2 ·d, the elongation at break was 300%, and the tensile strength was 10.1 MPa.

[0055] Example 3

[0056] (1) Preparation of lignin-based phase change microcapsules: 1 g of alkali lignin was added to 60 g of NaOH, 3 g of polyethylene glycol (PEG, Mn=5000) was added at 60°C, and emulsified in a homogenizer at 10000 rpm / min for 3 min to obtain an emulsion. 3 g of 1,6-hexanediol diacrylate (HDDA), 1 g of Span 80 and 1 g of acryloyl carboxylic acid diester (AA) were mixed and added to the above emulsion, and then homogenized in a homogenizer at 10000 rpm / min for 3 min. 0.1 mol / L hydrochloric acid solution was used to adjust the pH to 2-3, and then it was transferred to a magnetic stirrer, stirred at 400 rpm / min, and irradiated with a UV lamp (wavelength 365 nm, intensity 2000 mW / cm 2 , the distance between the light source and the emulsion was 10 cm) for 15 min to crosslink HDDA. Finally, the phase change microcapsule powder was obtained by spray drying at 150°C.

[0057] (2) Preparation of spinning solution: 4 g of polyvinylpyrrolidone powder (PVP, Mn=125000) was added to 16 g of deionized water, and stirred uniformly at 80°C for 2 h to obtain a 20% PVP solution. 12.5 g of vinyltrimethoxysilane organosilicon modified WPU emulsion (solid content 30%) was mixed with 12.5 g of PVP solution (WPU / PVP=1:1, wt%), and stirred uniformly at room temperature for 12 h to obtain 25 g of WPU / PVP solution. 10 g of deionized water, 0.025 g of polysorbate (PS), 0.0125 g of sodium bisulfite (NAHSO3) and 3.75 g of phase change microcapsule powder were added, and ultrasonic dispersion was performed for 30 min. Then, 25 g of WPU / PVA solution was added while stirring at 80°C and 1000 rpm / min for 40 min, and then stirring was continued for 1 h to obtain the spinning emulsion.

[0058] (3) Preparation of phase change fiber membrane: The phase change energy storage waterborne polyurethane nanofiber membrane was prepared by emulsion electrospinning technology. The spinning emulsion was transferred to a 10 mL needle tube, and the spinning was performed for 8 h using a needle with a specification of 17G. The specific spinning parameters were as follows: positive high voltage: 16 kV, negative high voltage: -1.5 kV, spinning distance: 15 cm, liquid feeding speed: 0.5 mm / h, receiving drum rotating speed: 90 r / min, and the receiver was silicone oil paper. The spinning environment temperature was 30°C, and the humidity was 40%. After the spinning was completed, the fiber membrane was transferred to a 35°C vacuum drying oven, and dried for 24 h to obtain the required phase change fiber membrane.

[0059] (4) Hydrophobic modification of phase change fiber membrane: The phase change energy storage waterborne polyurethane nanofiber membrane was placed in a low temperature plasma device, placed on a glass flat plate, and vacuumed to a vacuum degree of 1×10 -6Pa, CF4 gas was passed into the instrument when it was stable, and the surface of the nanofiber membrane was hydrophobically modified. The parameters of the plasma equipment were set as follows: modification power was 50 W, and time was 5 min.

[0060] The phase change enthalpy of the phase change microcapsules prepared according to the above steps was 202.3 J / g, the encapsulation efficiency was 98.0%, the phase change enthalpy of the phase change microcapsules after 100 cold and hot cycles was 200.3 J / g, the retention rate was 99.0%, the contact angle of the phase change energy storage waterborne polyurethane nanofiber membrane was 142°, the crystallization enthalpy was 25.5 J / g, the crystallization temperature was 24.0℃, the melting enthalpy was 34.0 J / g, the melting temperature was 37.2℃, the water pressure resistance was 10.5 kPa, and the moisture permeation amount was 1300 g / m 2 ·d, the elongation at break was 305%, and the tensile strength was 8.2 MPa.

[0061] Example 4

[0062] (1) Preparation of lignin-based phase change microcapsules: 1 g of alkali lignin was added to 70 g of NaOH, 4 g of paraffin (PW) was added at 60℃, and emulsification was carried out in a homogenizer at 10000 rpm / min for 3 min to obtain an emulsion, 2 g of 1,6-hexanediol diacrylate (HDDA), 1 g of Span80 and 1 g of trimethylbenzoyl-diphenyl phosphine oxide (TPO) were mixed and added to the above emulsion, and then homogenized in a homogenizer at 10000 rpm / min for 3 min, 0.1 mol / L hydrochloric acid solution was used to adjust the pH to 2-3, then it was transferred to a magnetic stirrer, stirred at 400 rpm / min, and irradiated with a UV lamp (wavelength 365 nm, intensity 2000 mW / cm 2 , the distance between the light source and the emulsion was 10 cm) for 15 min to crosslink HDDA, and finally phase change microcapsule powder was obtained by spray drying at 150℃.

[0063] (2) Preparation of the spinning solution: 2 g of sodium alginate (SA, Mn=85000) powder was added to 18 g of deionized water, and stirred uniformly at 80 °C for 2 h to obtain a 10% SA solution, which was left to stand at room temperature for use. 12.5 g of γ-glycidoxypropyltrimethoxysilane organically modified WPU emulsion (solid content 35%) was weighed and mixed with 12.5 g of SA solution (WPU / SA = 1:1, wt%), and stirred uniformly at room temperature for 12 h to obtain 25 g of WPU / SA solution. 10 g of deionized water was weighed, and 0.0125 g of fatty acid glyceride (TG), 0.025 g of hydrogen chloride (HCl) and 5.0 g of phase change microcapsule powder were added, and ultrasonic dispersion was performed for 30 min, followed by stirring at 1000 rpm / min at 80 °C for 40 min, and then 25 g of WPU / PVA solution was added while hot, and stirring was continued for 1 h to obtain the spinning emulsion.

[0064] (3) Preparation of the phase change fiber membrane: the phase change energy storage waterborne polyurethane nanofiber membrane was prepared by the emulsion electrospinning technology, the spinning emulsion was transferred to a 10 mL needle tube, and the spinning was performed for 8 h using a needle with a specification of 17G. The specific spinning parameters were as follows: positive high voltage: 15 kV, negative high voltage: -1.5 kV, spinning distance: 15 cm, liquid feeding speed: 0.5 mm / h, receiving drum rotating speed: 70 r / min, and the receiver was silicone oil paper; the spinning environment temperature: 25 °C, and humidity: 45%. After the spinning was completed, the fiber membrane was transferred to a 35 °C vacuum drying oven, and was dried for 24 h to obtain the required phase change fiber membrane.

[0065] (4) Hydrophobic modification of the phase change fiber membrane: the phase change energy storage waterborne polyurethane nanofiber membrane was placed in a low temperature plasma device, and was placed on a glass flat plate, and was vacuumed to a vacuum degree of 1×10 -6 Pa, SF6 gas was introduced when the instrument was stable, the surface of the nanofiber membrane was subjected to hydrophobic modification, and the parameter settings of the plasma device were as follows: modification power: 75 W, and time: 10 min.

[0066] The phase change enthalpy of the phase change microcapsule prepared according to the above steps was 163.2 J / g, the encapsulation efficiency was 99.0%, the phase change enthalpy of the phase change microcapsule after 100 times of cold and hot cycles was 160.0 J / g, the retention rate was 98.0%, the contact angle of the phase change energy storage waterborne polyurethane nanofiber membrane was 150°, the crystallization enthalpy was 40.2 J / g, the crystallization temperature was 24.5 °C, the melting enthalpy was 49.5 J / g, the melting temperature was 42.0 °C, the water pressure resistance was 12.2 kPa, the moisture permeation amount was 1650 g / m 2 ·d, the elongation at break was 280%, and the tensile strength was 7.5 MPa.

[0067] Example 5

[0068] (1) Preparation of lignin-based phase change microcapsules: 1 g of alkali lignin was added to 100 g of NaOH, 5 g of octadecane (ODE) was added at 60 °C, and emulsification was carried out in a homogenizer at 10,000 rpm / min for 3 min to obtain an emulsion. 3 g of 1,6-hexanediol diacrylate (HDDA), 1 g of Span 80 and 1 g of 2,4-diethylthioxanthone (DETX) were mixed and added to the above emulsion, and homogenization was continued in the homogenizer at 10,000 rpm / min for 3 min. The pH was adjusted to 2-3 using 0.1 mol / L hydrochloric acid solution, and then it was transferred to a magnetic stirrer, which was stirred at 400 rpm / min while being irradiated with a UV lamp (wavelength 365 nm, intensity 2000 mW / cm 2 , the distance between the light source and the emulsion was 10 cm) for 15 min to crosslink HDDA. Finally, phase change microcapsule powder was obtained by spray drying at 150 °C.

[0069] (2) Preparation of spinning solution: 3 g of carboxymethyl cellulose sodium (CMC-Na, Mn = 100,000) powder was added to 17 g of deionized water, and stirred uniformly at 80 °C for 2 h to obtain a 15% CMC-Na solution, which was left to stand at room temperature. 12.5 g of γ-aminopropylmethyldiethoxysilane organosilicon modified WPU emulsion (solid content 45%) was mixed with 12.5 g of CMC-Na solution (WPU / PVA = 1:1, wt%), and stirred uniformly at room temperature for 12 h to obtain 25 g of WPU / CMC-Na solution. 10 g of deionized water was weighed, 0.0125 g of polyethylene glycol sulfate (PEGS, Mn = 1500), 0.0125 g of acetic acid (CH3COOH) and 6.25 g of phase change microcapsule powder were added, and ultrasonic dispersion was carried out for 30 min. Then, 25 g of WPU / PVA solution was added while stirring at 80 °C and 1000 rpm / min for 40 min, and the stirring was continued for 1 h to obtain the spinning emulsion.

[0070] (3) Preparation of phase change fiber membrane: The phase change energy storage waterborne polyurethane nanofiber membrane was prepared by emulsion electrospinning technology. The spinning emulsion was transferred to a 10 mL needle tube, and a needle with a specification of 17G was used for spinning for 8 h. The specific spinning parameters are as follows: positive high voltage: 17 kV, negative high voltage: -1.5 kV, spinning distance: 20 cm, liquid feeding speed: 0.5 mm / h, receiving drum rotating speed: 100 r / min, receiver: silicone oil paper; spinning environment temperature: 30 °C, humidity: 40%. After spinning, the fiber membrane was transferred to a 35 °C vacuum drying oven, and dried for 24 h to obtain the required phase change fiber membrane.

[0071] (4) Hydrophobic modified phase change fiber membrane: the phase change energy storage waterborne polyurethane nanofiber membrane is placed in a low temperature plasma equipment, placed on a glass flat plate, vacuumized to a vacuum degree of 1 x 10 -6 Pa, (CH3)3SIF gas is introduced when the instrument is stable, the surface layer of the nanofiber membrane is hydrophobically modified, and the parameters of the plasma equipment are set as follows: the modification power is 75 W, and the time is 5 min.

[0072] The phase change enthalpy of the phase change microcapsule prepared according to the above steps is 242.6 J / g, the encapsulation efficiency is 99%, the phase change enthalpy of the phase change microcapsule after 100 cold and hot cycles is 240.2 J / g, the retention rate is 99%, the contact angle of the phase change energy storage waterborne polyurethane nanofiber membrane is 140°, the crystallization enthalpy is 52.5 J / g, the crystallization temperature is 15.0 ℃, the melting enthalpy is 65.5 J / g, the melting temperature is 28.5 ℃, the water pressure resistance is 11.5 kPa, and the moisture permeation amount is 1400 g / m 2 ·d, the elongation at break is 255%, and the tensile strength is 6.8 MPa.

[0073] Comparative Example 1

[0074] (1) Preparation of lignin-based phase change microcapsule: 1 g of alkali lignin is added to 50 g of NaOH, 3.5 g of dodecanol (DD) is added at 60 ℃, and homogenization emulsification is carried out in a homogenizer at 10000 rpm / min for 3 min to obtain an emulsion; 1 g of 1,6-hexanediol diacrylate (HDDA), 1 g of Span80 and 1 g of 2-hydroxy-2-methylpropiophenone (HMPP) are mixed and then added to the above emulsion, and homogenization is continued in the homogenizer at 10000 rpm / min for 3 min, 0.1 mol / L hydrochloric acid solution is used to adjust the pH to 2-3, then it is transferred to a magnetic stirrer, stirred at 400 rpm / min, and irradiated with a UV lamp (wavelength 365 nm, intensity 2000 mW / cm 2 , the distance between the light source and the emulsion is 10 cm) for 15 min to crosslink HDDA, and finally spray drying is carried out at 150 ℃ to obtain phase change microcapsule powder.

[0075] (2) Preparation of spinning solution: 25 g of vinyltrimethoxysilane organosilicon modified WPU emulsion is uniformly stirred at room temperature for 12 h, 10 g of deionized water is weighed, 5.0 g of phase change microcapsule powder is added, ultrasonic dispersion is carried out for 30 min, then stirring is carried out at 80 ℃ and 1000 rpm / min for 40 min, then 25 g of WPU / PVA solution is added while hot, and stirring is continued for 1 h to obtain a spinning emulsion.

[0076] (3) Preparation of phase change fiber membrane: phase change energy storage waterborne polyurethane nanofiber membrane was prepared by emulsion electrospinning technology, the spinning emulsion was transferred to a 10 mL needle tube, and the needle with a specification of 17G was used for spinning for 8h. The specific spinning parameters are as follows: positive high voltage: 17kV, negative high voltage: -1.5kV, spinning distance: 20cm, liquid inlet speed: 0.5mm / h, receiving drum rotating speed: 80r / min, receiver: silicone oil paper; spinning environment temperature: 25℃, humidity: 45%. After spinning, the fiber membrane was transferred to a 35℃ vacuum drying oven, and dried for 24h to obtain the required phase change fiber membrane.

[0077] (4) Hydrophobic modified phase change fiber membrane: the phase change energy storage waterborne polyurethane nanofiber membrane was placed in a low temperature plasma equipment, placed on a glass flat plate, vacuumed to a vacuum degree of 1×10 -6 Pa, and C2F4 gas was introduced when the instrument was stable, and the surface layer of the nanofiber membrane was hydrophobically modified. The parameter settings of the plasma equipment are as follows: modification power is 75W, and the time is 10min.

[0078] The phase change enthalpy of the phase change microcapsule prepared according to the above steps is 177.2J / g, the encapsulation efficiency is 99.4%, and the phase change enthalpy of the phase change microcapsule after 100 times of cold and hot cycle is 176.8J / g, the retention rate is 99.8%, the contact angle of the phase change energy storage waterborne polyurethane nanofiber membrane is 158°, the crystallization enthalpy is 38.5J / g, the crystallization temperature is 13.6℃, the melting enthalpy is 43.7J / g, the melting temperature is 27.1℃, the water pressure resistance is 14.5kPa, and the moisture permeation amount is 2450 / m 2 ·d, the elongation at break is 190%, and the tensile strength is 1.5MPa.

[0079] Comparative Example 2

[0080] (1) Preparation of spinning solution: 3g of polyvinyl alcohol powder (PVA, Mn=100000) was added to 17g of deionized water, and uniformly stirred at 80℃ for 2h to obtain a 15% PVA solution, and then left to stand at room temperature. 12.5g of vinyl triethoxysilane modified waterborne polyurethane emulsion (WPU, solid content is 50%) was mixed with 12.5g of PVA solution (WPU / PVA=1:1, wt%), and uniformly stirred at room temperature for 12h to obtain 25g of WPU / PVA solution. 10g of deionized water, 0.025g of sodium dodecylbenzenesulfonate (SDBS), 0.025g of sodium chloride (NaCl) and 5.0g of phase change microcapsule powder were added, and ultrasonically dispersed for 30min. Then, 25g of WPU / PVA solution was added while stirring at 1000rpm / min at 80℃ for 40min, and then continuously stirred for 1h to obtain the spinning emulsion.

[0081] (2) Preparation of phase change fiber membrane: phase change energy storage waterborne polyurethane nanofiber membrane was prepared by emulsion electrospinning technology, and the spinning emulsion was transferred to a 10 mL needle tube. A needle with a specification of 17G was used for spinning for 8 h. The specific spinning parameters are as follows: positive high voltage: 17 kV, negative high voltage: -1.5 kV, spinning distance: 20 cm, liquid inlet speed: 0.5 mm / h, receiving drum rotating speed: 80 r / min, and the receiver is silicone oil paper; the spinning environment temperature is 25°C, and the humidity is 40%. After spinning, the fiber membrane was transferred to a 35°C vacuum drying oven and dried for 24 h to obtain the required phase change fiber membrane.

[0082] (3) Hydrophobic modified phase change fiber membrane: the phase change energy storage waterborne polyurethane nanofiber membrane was placed in a low temperature plasma device, placed on a glass flat plate, and vacuumed to a vacuum degree of 1x10 -6 Pa. When the instrument is stable, CF4 gas is introduced, and the surface layer of the nanofiber membrane is hydrophobically modified. The parameter settings of the plasma device are as follows: modification power is 75 W, and time is 10 min.

[0083] The contact angle of the phase change energy storage waterborne polyurethane nanofiber membrane prepared according to the above steps is 155°, the water pressure resistance is 13.5 kPa, the moisture permeation amount is 2300 g / m 2 d, the elongation at break is 330%, and the tensile strength is 10.5 MPa.

[0084] Comparative Example 3

[0085] (1) Preparation of lignin-based phase change microcapsules: 1 g of alkali lignin was added to 50 g of NaOH, 3.5 g of dodecanol (DD) was added at 60°C, and the emulsion was homogenized in a homogenizer at 10000 rpm / min for 3 min; 1 g of 1,6-hexanediol diacrylate (HDDA), 1 g of Span80 and 1 g of 2-hydroxy-2-methylpropyl phenone (HMPP) were mixed and added to the above emulsion, and then homogenized in a homogenizer at 10000 rpm / min for 3 min. The pH was adjusted to 2-3 using 0.1 mol / L hydrochloric acid solution, and then transferred to a magnetic stirrer, stirred at 400 rpm / min, and irradiated with a UV lamp (wavelength 365 nm, intensity 2000 mW / cm 2 , the distance between the light source and the emulsion was 10 cm) for 15 min to crosslink HDDA. Finally, the phase change microcapsule powder was obtained by spray drying at 150°C.

[0086] (2) Preparation of spinning solution: 3 g of polyvinyl alcohol powder (PVA, Mn = 100000) was added to 17 g of deionized water, and stirred uniformly at 80 °C for 2 h to obtain a 15% PVA solution, which was left to stand at room temperature. 12.5 g of vinyl triethoxysilane modified waterborne polyurethane emulsion (WPU, solid content 50%) was mixed with 12.5 g of PVA solution (WPU / PVA = 1:1, wt%), and stirred uniformly at room temperature for 12 h to obtain 25 g of WPU / PVA solution. 10 g of deionized water, 0.025 g of sodium dodecylbenzenesulfonate (SDBS), 0.025 g of sodium chloride (NaCl), and 5.0 g of phase change microcapsule powder were ultrasonically dispersed for 30 min, and then stirred at 80 °C at 1000 rpm / min for 40 min. Then 25 g of WPU / PVA solution was added while hot, and stirring was continued for 1 h to obtain the spinning emulsion.

[0087] (3) Preparation of phase change fiber membrane: The phase change energy storage waterborne polyurethane nanofiber membrane was prepared by emulsion electrospinning technology. The spinning emulsion was transferred to a 10 mL needle tube, and a needle with a specification of 17G was used for spinning for 8 h. The specific spinning parameters are as follows: positive high voltage: 17 kV, negative high voltage: -1.5 kV, spinning distance: 20 cm, liquid feeding speed: 0.5 mm / h, receiving drum rotating speed: 80 r / min, receiver is silicone oil paper; spinning environment temperature: 25 °C, humidity: 45%. After spinning, the fiber membrane was transferred to a 35 °C vacuum drying oven, and dried for 24 h to obtain the required phase change fiber membrane.

[0088] The phase change enthalpy of the phase change microcapsule prepared according to the above steps is 175.4 J / g, the encapsulation efficiency is 99%, and the phase change enthalpy of the phase change microcapsule after 100 cycles of cold and hot cycles is 175.2 J / g, the retention rate is 99.9%, the contact angle of the phase change energy storage waterborne polyurethane nanofiber membrane is 122°, the crystallization enthalpy is 38.0 J / g, the crystallization temperature is 13.5 °C, the melting enthalpy is 43.8 J / g, the melting temperature is 26.0 °C, the water pressure resistance is 14.5 kPa, and the moisture permeation amount is 500 g / m 2 ·d, the elongation at break is 310%, and the tensile strength is 12.3 MPa.

[0089] Figure 1 For the scanning electron microscope (SEM) and the heat flow-temperature change curve (DSC) images of the lignin-based phase change microcapsule prepared in Example 1, it can be seen that the particle size of the phase change microcapsule is about 200 nm, and the alkali lignin effectively encapsulates the phase change material. The phase change enthalpy of the prepared phase change microcapsule can reach 171.86 J / g, showing good thermal stability and durability, and the encapsulation rate at different phase change temperatures is more than 99%.

[0090] Figure 2The scanning electron microscope (SEM) of the phase change energy storage waterborne polyurethane nanofiber membrane prepared by electrospinning of the spinning emulsion of Example 1 and Comparative Example 1 can be seen that when the spinning emulsion does not contain a water-based thickening agent, an electrolyte and a surfactant, due to the poor spinnability of the WPU, only fibers with a large number of spindle-shaped structures can be obtained after electrospinning, and the fiber morphology structure is poor, while the phase change fiber prepared by electrospinning of the emulsion added with a water-based thickening agent, an electrolyte and a surfactant has a smooth surface and excellent fiber morphology structure, which shows that the addition of a water-based thickening agent, an electrolyte and a surfactant can effectively improve the spinnability of the WPU emulsion and realize the effective wrapping of the WPU on the phase change material.

[0091] Figure 3 The tensile stress-tensile strain curve of the phase change energy storage waterborne polyurethane nanofiber membrane prepared by electrospinning of the spinning emulsion in Example 1 and Comparative Example 1 can be seen that the mechanical properties of the nanofiber membrane added with a water-based thickening agent, an electrolyte and a surfactant are significantly improved compared with those without the addition.

[0092] Figure 4 The heat flow-temperature change curve (DSC) of the endothermic and exothermic sections of the phase change energy storage waterborne polyurethane nanofiber membrane prepared in Example 1 and Comparative Example 2 can be seen that the fiber membrane without the addition of a phase change material does not have a peak on the DSC graph, while the nanofiber membrane added with 20% phase change microcapsules shows good heat storage and heat dissipation effect at about 25°C and has a high latent heat, which demonstrates its application potential in human body intelligent wearable textiles.

[0093] Figure 5 The water droplet contact angle graph (WCA) of the phase change energy storage waterborne polyurethane nanofiber membrane modified by different gas plasmas and not modified by plasma in Example 1, Example 2 and Comparative Example 3 can be seen that since the WPU and PVA contain a large number of hydrophilic groups, the water resistance of the waterborne polyurethane phase change fiber membrane with WPU / PVA as the fiber matrix is poor, while the side modified by plasma exhibits excellent water resistance, and the contact angle is greatly improved, reaching up to 160°, and the contact angle does not decrease significantly with the extension of time. The difference in hydrophilicity of the two sides of the fiber membrane gives the fiber membrane asymmetric wettability, which can play a role in directional transportation of water.

[0094] Figure 6For the X-ray photoelectron spectrograms (XPS) of the phase change energy storage waterborne polyurethane nanofiber membranes after different gas plasma modification in Example 1, Example 2 and Comparative Example 3 and without plasma modification, it can be seen that new F element appears in the element composition after plasma modification, and the proportion of fluorine element also changes accordingly with the change of modification gas and modification power, which shows that the plasma modification is successfully carried out on the surface of the nanofiber membrane.

[0095] The above merely illustrates the preferred embodiments of the present application, and any equivalent changes and modifications made within the scope of the present application should be included in the scope of the present application.

Claims

1. A method for preparing a phase change energy storage aqueous polyurethane nanofiber membrane, characterized by: Comprising the following steps: (1) Preparation of lignin-based phase change microcapsules: 1 part of alkali lignin is added into 50-100 parts of sodium hydroxide, then 2-5 parts of phase change material is added, and emulsification is carried out for 3-10 min to obtain an emulsion; 1-3 parts of 1,6-hexanediol diacrylate, 1 part of Span 80 and 1 part of a photoinitiator are mixed and then added into the above emulsion, and emulsification is continued for 3-10 min; the pH of the solution is adjusted to 2-3, and ultraviolet light irradiation is carried out for 15 min; finally, lignin-based phase change microcapsule powder is obtained by spray drying; the wavelength of the ultraviolet light is 365 nm, and the intensity is 2000 mW / cm 2 ; (2) Preparation of spinning solution: mix silicone-modified waterborne polyurethane emulsion, water-based thickening agent, lignin-based phase change microcapsule powder, surfactant and electrolyte, ultrasonic dispersion, then stir uniformly at room temperature to obtain spinning solution; (3) Preparation of phase change fiber membrane: inject the spinning solution into the electrospinning injector, electrospinning to obtain nanofiber membrane, and then obtain the phase change fiber membrane after drying; (4) Hydrophobic modification of phase change fiber membrane: use low-temperature plasma technology to hydrophobically modify one side of the phase change fiber membrane.

2. The method of claim 1, wherein: The phase change material in step (1) is one or more of polyethylene glycol, paraffin, dodecanol and octadecane; the addition amount of the phase change microcapsule powder is 10-25% of the total mass of the silicone-modified waterborne polyurethane emulsion and the water-based thickening agent; the photoinitiator is one or more of 2-hydroxy-2-methylbenzophenone, acryloyl carboxylic acid diester, trimethylbenzoyl-diphenyl phosphine oxide and 2,4-diethylthioxanthone.

3. The method of claim 1, wherein: The silicone-modified waterborne polyurethane emulsion in step (2) is one or more of vinyl triethoxysilane-modified waterborne polyurethane emulsion, vinyl trimethoxysilane-modified waterborne polyurethane emulsion, γ-glycidyl ether propyltrimethoxysilane-modified waterborne polyurethane emulsion and γ-aminopropyl methyl diethoxysilane-modified waterborne polyurethane emulsion; the solid content of the silicone-modified waterborne polyurethane emulsion is 30-50%.

4. The method of claim 1, wherein: The water-based thickening agent in step (2) is one or more of polyvinyl alcohol, sodium alginate, sodium carboxymethyl cellulose, polyacrylic acid sodium and polyvinyl pyrrolidone; the mass fraction of the water-based thickening agent is 10-20%; the mass ratio of the silicone-modified waterborne polyurethane emulsion to the water-based thickening agent is 1:

1.

5. The method of claim 1, wherein: The surfactant in step (2) is one or more of sodium dodecylbenzenesulfonate, polysorbate, glycerol fatty acid ester and polyethylene glycol sulfate fat; the addition amount of the surfactant is 0.05-0.1% of the total mass of the silicone-modified waterborne polyurethane emulsion and the water-based thickening agent.

6. The method of claim 1, wherein: The electrolyte in step (2) is one or more of sodium chloride, sodium bisulfite, hydrogen chloride and acetic acid; the addition amount of the electrolyte is 0.05-0.1% of the total mass of the silicone-modified waterborne polyurethane emulsion and the water-based thickening agent.

7. The method of claim 1, wherein: The electrospinning parameters in step (3) are as follows: positive high voltage 15-17 kV, negative high voltage -1.5 kV, spinning distance 15-20 cm, pushing speed 0.5 mm / h, receiving drum rotating speed 60-100 r / min, and the receiver is a silicone oil paper covered drum; the spinning environment temperature is 25-30℃, and the humidity is 30-50%.

8. The method of claim 1, wherein: The low-temperature plasma hydrophobic modification gas in step (4) is one of carbon tetrafluoride, tetrafluoroethylene, sulfur hexafluoride and trimethylfluorosilane; the low-temperature plasma modification power is 50-75 W, and the modification time is 5-10 min.

9. The phase change energy storage aqueous polyurethane phase change fiber membrane prepared by the method of any one of claims 1-8, characterized in that: The phase change temperature of the phase change energy storage aqueous polyurethane phase change fiber film is 13.5~28.5℃, the phase change enthalpy is 18.0~65.5J / g, the water drop contact angle of the hydrophobic side of the plasma modified phase change fiber film is 140~160°, and the moisture permeation amount is 1300~2500g / m 2 ·d, the tensile strength is 6.5~11.5MPa, and the elongation at break is 255~330%.

10. Application of the phase change energy storage waterborne polyurethane phase change fiber membrane according to claim 9 in functional textiles.

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