Microsphere particles and preparation method thereof, polyurethane foam and preparation method thereof

Abstract

The present application discloses a silver-phase microsphere particle, a preparation method thereof, a polyurethane foam and a preparation method thereof. The preparation method of the silver-phase microsphere particle includes: respectively providing a polymer film-forming agent solution, a silver ion solution and a precipitant solution; mixing the polymer film-forming agent solution and the silver ion solution to obtain a mixed solution; adding the precipitant solution to the mixed solution to form silver-phase microsphere particles, and a polymer protective film is coated on the surface of the silver-phase microsphere particles. The polymer protective film can be dissolved when encountering a compatible solvent to release silver compounds. The silver-phase microsphere particles obtained by the above method are coated with a polymer protective film on their surfaces. The polyurethane foam prepared by using the above silver-phase microsphere particles avoids the problem of cell blockage.

Description

Technical Field

[0001] The present application relates to the technical field of polyurethane foam preparation, and particularly relates to a microsphere particle, a preparation method thereof, a polyurethane foam and a preparation method thereof. Background Art

[0002] Polyurethane foam generally uses isocyanate and polyether as main raw materials, and under the action of various additives such as foaming agents, catalysts, and flame retardants, it is mixed by special equipment and sprayed and foamed into a polymer. At present, hydrophilic polyurethane soft foam is often used in the medical care industry. For example, polyurethane foam dressings, negative pressure drainage dressings, etc. are all used for the care of acute and chronic wounds, can absorb wound exudate, and maintain a moist healing environment for the wound, thereby promoting wound healing. Preventing infection or reducing infection during wound healing is a very important link. Especially for chronic wounds, there is basically an infection to form a bacterial biofilm, which makes the wound always in the inflammatory period, inhibits the proliferation of granulation, and thus slows down the healing speed. Therefore, it is particularly important to add antibacterial agents to polyurethane foam dressings.

[0003] Antibacterial polyurethane foam dressings generally use silver ion compounds, nano silver, iodine series, cationic surfactants, etc. as antibacterial components. These antibacterial components are all soluble in water or can be solubilized in wound exudate. In the prior art, the dip coating method is often used to load antibacterial agents on polyurethane foam, and the coating agent or adhesive usually blocks the pores of the polyurethane foam, thereby affecting the performance of the polyurethane foam itself in absorbing wound exudate. Summary of the Invention

[0004] The present application mainly provides a silver-phase microsphere particle, a preparation method thereof, a polyurethane foam and a preparation method thereof to solve the problem that the pores of polyurethane foam in the prior art are blocked by coating agents or adhesives.

[0005] To solve the above technical problems, the first technical solution adopted by the present application is: to provide a preparation method of silver-phase microsphere particles, including:

[0006] Respectively provide a polymer film-forming agent solution, a silver ion solution and a precipitating agent solution;

[0007] Mix the polymer film-forming agent solution and the silver ion solution to obtain a mixed solution;

[0008] Add the precipitating agent solution to the mixed solution to form silver-phase microsphere particles. A polymer protective film is coated on the surface of the silver-phase microsphere particles, and the polymer protective film can be dissolved when encountering a compatible solvent to release silver compounds.

[0009] Among them, the method further includes: providing a film-forming aid solution, where the film-forming aid is used to assist the polymer film-forming agent to form the polymer protective film on the surface of the silver-phase microsphere particles, and the film-forming aid includes a polymer;

[0010] Mix the film-forming aid solution, the polymer film-forming agent solution, and the silver ion solution to obtain the mixed solution.

[0011] Among them, the step of mixing the film-forming aid solution, the polymer film-forming agent solution, and the silver ion solution to obtain the mixed solution includes:

[0012] Add the film-forming aid solution to the silver ion solution in batches to form a first mixed solution;

[0013] Add the polymer film-forming agent solution to the first mixed solution to form the mixed solution.

[0014] Among them, the step of adding the film-forming aid solution to the silver ion solution in batches to form a first mixed solution includes:

[0015] Add the first film-forming aid solution to the silver ion solution and stir for 0.5 - 3 h to form a second mixed solution;

[0016] Add the second film-forming aid solution to the second mixed solution and stir for 0.5 - 3 h to form the first mixed solution; the components of the first film-forming aid and the second film-forming aid are the same or different.

[0017] Among them, the mass fraction of the solute in the film-forming aid solution is 0.005 - 8%.

[0018] Among them, the molecular weight of the film-forming aid is 1000 - 1000000 Da.

[0019] Among them, the film-forming aid includes one or more of polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, and polyvinyl alcohol.

[0020] Among them, the film-forming aid includes polyvinyl alcohol, and the degree of alcoholysis of the polyvinyl alcohol is 88 - 92%.

[0021] Among them, the step of adding the precipitant solution to the mixed solution to form silver-phase microsphere particles includes:

[0022] Drop the precipitant solution into the stirred mixed solution at a rate of 1 - 50 mL / min and stir for 0.5 - 2 h to form the silver-phase microsphere particle solution.

[0023] Among them, the silver ion solution includes one or more of silver nitrate solution, silver sulfate solution, silver acetate solution, and silver ammonia solution.

[0024] Among them, the mass fraction of the solute in the silver ion solution is 0.01 - 5%.

[0025] Among them, the mass fraction of the solute in the polymer film-forming agent solution is 0.05 - 10%.

[0026] Among them, the molecular weight of the polymer film-forming agent is 1000 - 1000000 Da.

[0027] Among them, the polymer film-forming agent includes one or more of polyvinyl alcohol, highly substituted hydroxypropyl cellulose, and polybutylene terephthalate.

[0028] Among them, the polymer film-forming agent includes polyvinyl alcohol, and the degree of alcoholysis of the polyvinyl alcohol is 92 - 99%.

[0029] Among them, the solute in the precipitant solution is an inorganic soluble salt, and the mass fraction of the solute in the precipitant solution is 0.01 - 5%.

[0030] Among them, the anions of the inorganic soluble salt include one or more of chloride ions, carbonate ions, sulfate ions, hydroxide ions, and oxalate ions; the cations of the inorganic soluble salt include one or more of sodium ions, potassium ions, calcium ions, and magnesium ions.

[0031] To solve the above technical problems, the second technical solution adopted by this application is: to provide a silver-phase microsphere particle, the surface of the silver-phase microsphere particle is coated with a polymer protective film, and the polymer protective film can be dissolved when encountering a compatible solvent to release silver compounds.

[0032] To solve the above technical problems, the third technical solution adopted by this application is: to provide a polyurethane foam, the polyurethane foam includes silver-phase microsphere particles, the surface of the silver-phase microsphere particles is coated with a polymer protective film, and the polymer protective film can be dissolved when encountering a compatible solvent to release silver compounds.

[0033] To solve the above technical problems, the fourth technical solution adopted by this application is: to provide a preparation method of a polyurethane foam, including: providing a silver-phase microsphere particle solution, and the silver-phase microsphere particles are prepared by using any one of the above silver-phase microsphere particle preparation methods;

[0034] Mixing the silver-phase microsphere particle solution with a surfactant solution to form a foaming phase;

[0035] Mix the foaming phase with the polyurethane prepolymer, and foam mold to obtain a polyurethane foam. The polyurethane foam includes silver-phase microsphere particles, and a polymer protective film is coated on the surface of the silver-phase microsphere particles. The polymer protective film can be dissolved when encountering a compatible solvent to release silver compounds.

[0036] Among them, the surfactant in the surfactant solution is a non-ionic surfactant.

[0037] Among them, the non-ionic surfactant includes at least two of long-chain fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, alkylphenol polyoxyethylene ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene-polyoxypropylene ether block copolymer, and sorbitan fatty acid ester.

[0038] Among them, the non-ionic surfactant includes polyoxyethylene sorbitan fatty acid ester, polyoxyethylene-polyoxypropylene ether block copolymer, and sorbitan fatty acid ester;

[0039] The preparation of the surfactant solution includes: adding polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester to a solvent, stirring for 0.5 - 1 h; then adding polyoxyethylene-polyoxypropylene ether block copolymer, stirring for 1 - 5 h, and cooling to 0 - 20 °C to form the surfactant solution.

[0040] Among them, the mass fraction of the solute in the surfactant solution is 0.001 - 10%.

[0041] Among them, the HLB value of the surfactant solution is 10 - 20.

[0042] Among them, the mass ratio of the silver-phase microsphere particle solution to the surfactant solution is 1:50 - 10:1.

[0043] Among them, the step of mixing the silver-phase microsphere particle solution with the surfactant solution to form a foaming phase includes:

[0044] Dripping the surfactant solution into the silver-phase microsphere particle solution under stirring at a speed of 1 - 25 mL / min, and stirring for 0.5 - 2 h, and cooling to 0 - 20 °C to form the foaming phase.

[0045] Among them, the step of mixing the foaming phase with the polyurethane prepolymer and foam molding to obtain a polyurethane foam includes:

[0046] Heat the polyurethane prepolymer to 20 - 45 °C;

[0047] Mix the foaming phase with the polyurethane prepolymer, and cure and mold at 20 - 45 °C for 2 - 10 min to form a prepolyurethane foam;

[0048] The pre-polyurethane foam is dried by infrared heating or microwave heating to form the polyurethane foam.

[0049] Among them, the polyurethane prepolymer includes a TDI polyether polyol prepolymer or an MDI polyether polyol prepolymer.

[0050] Among them, the mass ratio of the polyurethane prepolymer to the foaming phase is 1:2 - 2:1.

[0051] The beneficial effect of this application is: Different from the prior art, this application discloses a silver-phase microsphere particle and its preparation method, as well as a polyurethane foam and its preparation method. The preparation method of the silver-phase microsphere particle includes: separately providing a polymer film-forming agent solution, a silver ion solution, and a precipitant solution; mixing the polymer film-forming agent solution and the silver ion solution to obtain a mixed solution; adding the precipitant solution to the mixed solution to form silver-phase microsphere particles, and a polymer protective film is coated on the surface of the silver-phase microsphere particles. The polymer protective film can be dissolved when encountering a compatible solvent to release silver compounds. The silver-phase microsphere particles obtained by the above preparation method have a polymer protective film coated on their surface. The polyurethane foam prepared by using the above silver-phase microsphere particles avoids the problem of cell blockage. Description of the Drawings

[0052] In order to more clearly illustrate the technical solutions in the embodiments of this application 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 following drawings are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, where:

[0053] Figure 1 is a schematic flowchart of the first embodiment of the preparation method of the silver-phase microsphere particle provided by this application;

[0054] Figure 2 is a schematic flowchart of the second embodiment of the preparation method of the silver-phase microsphere particle provided by this application;

[0055] Figure 3 is a schematic flowchart of an embodiment of the preparation method of the polyurethane foam provided by this application;

[0056] Figure 4 is a schematic diagram of the component ratio of four experiments on the preparation of polyurethane foam;

[0057] Figure 5 is Figure 4 a schematic diagram of the silver ion release trend in the polyurethane foam obtained from the four experiments in

[0058] Figure 6 It is the scanning electron microscope image of the second polyurethane foam sample prepared in Experiment 2;

[0059] Figure 7 It is the microscope image of the third polyurethane foam sample prepared in Experiment 3;

[0060] Figure 8 It is the schematic diagram of the particle size distribution of the silver-phase microsphere particles prepared in Experiment 3. Specific Embodiments

[0061] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0062] The terms "first", "second", and "third" in the embodiments of the present application are only for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", and "third" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes unlisted steps or units, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0063] Referring to

[0064] Referring to Figure 1 , Figure 1 It is the schematic flowchart of the first embodiment of the method for preparing silver-phase microsphere particles provided by the present application.

[0065] The present application provides a method for preparing silver-phase microsphere particles. Through this preparation method, silver-phase microsphere particles can be prepared. The method for preparing silver-phase microsphere particles specifically includes the following steps:

[0066] S11: Provide a polymer film-forming agent solution, a silver ion solution, and a precipitating agent solution respectively.

[0067] Specifically, first provide a polymer film-forming agent solution. The solute in the polymer film-forming agent solution is a polymer film-forming agent with relatively high hydrophilicity. Among them, the mass fraction of the solute in the polymer film-forming agent solution is 0.05 - 10%, and the molecular weight of the polymer film-forming agent is 1000 - 1000000 Da. Optionally, the polymer film-forming agent can be one or more of polyvinyl alcohol (PVA), highly substituted hydroxypropyl cellulose (H-HPC), and polybutylene terephthalate. These polymer film-forming agents can be dissolved in certain solvents or water under certain conditions, and a dense film can be formed on the solid surface after the solvent is evaporated.

[0068] In this embodiment, the solute in the polymer film-forming agent solution is polyvinyl alcohol (PVA), the solvent is water, and the degree of alcoholysis of polyvinyl alcohol is 92 - 99%. The polymer film-forming agent solution is formed by first mixing polyvinyl alcohol and water in a ratio of 5:95, then cooking in a high-temperature and high-pressure environment at 121°C until the polyvinyl alcohol is completely dissolved, and cooling the obtained solution.

[0069] The polymer film-forming agent is used to form a uniform film on the solid surface. The formed film has a strong adhesion ability to the solid surface and will not easily fall off from the solid surface. At the same time, the polymer film-forming agent has a strong capacity for accommodation and has sufficient capacity for other substances, and can ensure that the embedded substances will not penetrate out of the film during the drying or film-forming process. Moreover, the polymer film-forming agent has good stability and safety, will not be absorbed by the human body when contacting the human body, and is non-toxic and harmless to the human body.

[0070] Secondly, provide a silver ion solution. The silver ion solution is a solution obtained by dissolving a soluble silver salt. Specifically, the silver ion solution can include one or more of silver nitrate (AgNO 3 ) solution, silver sulfate (Ag 2 SO 4 ) solution, silver acetate (CH 3 COOAg) solution, and silver ammonia (Ag(NH)OH) solution. In this embodiment, the solvent in the silver ion solution is water, the solute is a soluble silver salt, the soluble silver salt is added to water, and stirred for 0.5 - 3 h. The soluble silver salt is fully dissolved to obtain a silver ion solution, and among them, the mass fraction of the solute in the silver ion solution is 0.01 - 5%.

[0071] Finally, provide a precipitating agent solution. The precipitating agent solution is a solution obtained by dissolving an inorganic soluble salt. Specifically, the anions of the inorganic soluble salt include chloride ions (Cl - ) and carbonate ions (CO 3 2-), sulfate ion (SO 4 2- ), hydroxide ion (OH - ), oxalate ion (C 2 O 4 2- ), and the corresponding cations also include sodium ions (Na + ), potassium ion (K + ), calcium ions (Ca 2+ ), magnesium ion (Mg 2+ ). In this embodiment, the solvent in the precipitant solution is water, and the solute is an inorganic soluble salt. The inorganic soluble salt is added to the water and stirred for 0.5-1h. The inorganic soluble salt is fully dissolved to obtain a precipitant solution, wherein the mass fraction of the solute in the precipitant solution is 0.01-5%.

[0072] It should be noted that, in the present embodiment, the solvents in the polymer film-forming agent solution, the silver ion solution and the precipitant solution are all water. In other embodiments, the solvents in the polymer film-forming agent solution, the silver ion solution and the precipitant solution may also be other substances, for example, the solvent in the above solutions may be ethanol, etc., and the polymer film-forming agent may also be other oil-soluble substances. In other embodiments, the solute in the precipitant solution may also be an organic compound, and the organic compound is used as a precipitant for silver ions to prepare the silver phase microsphere particles.

[0073] S12: Mixing the polymer film-forming agent solution and the silver ion solution to obtain a mixed solution.

[0074] Specifically, the polymer film-forming agent solution and the silver ion solution obtained through the above steps are mixed according to a certain proportion and stirred sufficiently to make them uniformly mixed, thereby obtaining a mixed solution of the polymer film-forming agent solution and the silver ion solution.

[0075] S13: adding the precipitant solution to the mixed solution to form silver phase microsphere particles, the surface of the silver phase microsphere particles is coated with a polymer protective film, and the polymer protective film can be dissolved when encountering a compatible solvent to release the silver compound.

[0076] Specifically, the precipitant solution prepared in step S11 is dripped into a mixed solution obtained by mixing the polymer film-forming agent solution and the silver ion solution under stirring at a rate of 1-50 mL / min, and stirred for 0.5-2 h, so that anions in the precipitant solution, such as chloride ions (Cl - ), carbonate ions (CO 3 2- ), sulfate ion (SO 4 2- ), hydroxide ion (OH -) Oxalate ions (C 2 O 4 2- ) etc. react fully with silver ions (Ag + ) in the silver ion solution of the mixed solution to form insoluble silver salt particles such as silver chloride (AgCl), silver carbonate (Ag 2 CO 3 ), silver sulfate (Ag 2 SO 4 ), silver hydroxide (AgOH), silver oxalate (Ag 2 C 2 O 4 ), etc., and then form silver phase microsphere particles.

[0077] The surface of the silver phase microsphere particles is coated with a layer of polymer protective film. In this embodiment, the polymer protective film is a film formed by the polymer film-forming agent in the polymer film-forming agent solution on the surface of the silver phase microsphere particles. It has a strong adhesion ability on the surface of the silver phase microsphere particles and will not fall off easily. Moreover, the polymer protective film formed on the surface of the silver phase microsphere particles can ensure that the encapsulated silver phase microsphere particles will not penetrate out of the polymer protective film during the drying or film-forming process. Only when the polymer protective film encounters a compatible solvent can it be dissolved. The polymer protective film is dissolved and damaged, and the silver phase microsphere particles embedded by the polymer protective film can release silver compounds.

[0078] In this embodiment, when the silver phase microsphere particles are applied to acute and chronic wound care, the polymer protective film on the surface of the silver phase microsphere particles comes into contact with the wound exudate. Due to the relatively high body temperature of the human body, the strongly hydrophilic polymer film-forming agent in the polymer protective film can be dissolved when it comes into contact with the wound exudate, so that the silver phase microsphere particles encapsulated by the polymer film-forming agent come into contact with the wound exudate and release silver compounds. The silver ions in the released silver compounds have antibacterial effects and can perform antibacterial treatment on the wound to avoid wound infection.

[0079] Compared with the prior art when preparing antibacterial polyurethane foam, where the antibacterial material is adsorbed by the encapsulant and then loaded on the polyurethane foam, which is likely to cause blockage of the pores of the polyurethane foam. In this application, the surface of the silver phase microsphere particles is coated with a polymer protective film. The particle size of the silver phase microsphere particles is relatively small, and the problem of blockage of the pores of the polyurethane foam is not easily generated, which is beneficial to improving the performance of the polyurethane foam.

[0080] Refer to Figure 2 , Figure 2 which is a schematic flow chart of the second embodiment of the preparation method of the silver phase microsphere particles provided by this application.

[0081] Figure 2 The preparation method of the silver phase microsphere particles provided Figure 1The difference in the preparation method of the provided silver-phase microsphere particles lies in that a film-forming aid solution is also used when preparing the mixed solution. In this embodiment, the preparation method of the silver-phase microsphere particles specifically includes the following steps:

[0082] S21: Provide a polymer film-forming agent solution, a silver ion solution, a film-forming aid solution, and a precipitating agent solution respectively.

[0083] Specifically, in this embodiment, the provided silver ion solution, polymer film-forming agent solution, and precipitating agent solution are the same as the silver ion solution, precipitating agent solution, and polymer film-forming agent solution provided in step S11 of the first embodiment of the preparation method of the silver-phase microsphere particles, and will not be elaborated here.

[0084] Different from the first embodiment of the preparation method of the silver-phase microsphere particles, in this embodiment, a film-forming aid solution is also provided. The solute in the film-forming aid solution is a hydrophilic polymer, that is, the film-forming aid is a hydrophilic polymer, and the film-forming aid is used to assist the polymer film-forming agent to form a polymer protective film on the surface of the silver-phase microsphere particles.

[0085] The hydrophilic polymer is a strongly hydrophilic polymer material, which can dissolve or swell in water to form an aqueous solution or a dispersion system, and is generally divided into three categories: cationic, anionic, and non-ionic polymers. The hydrophilic groups in water-soluble polymers not only endow them with water solubility, but also have chemical reaction functions, as well as various physical functions such as dispersion, flocculation, thickening, drag reduction, adhesion, film formation, gel formation, and chelation.

[0086] In this embodiment, the solvent in the film-forming aid solution is water, the solute is a hydrophilic polymer, and the hydrophilic polymer is a non-ionic polymer compound. Optionally, the film-forming aid includes one or more of polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), polyethylene oxide (PEO), and polyvinyl alcohol (PVA). When the film-forming aid includes polyvinyl alcohol, the degree of alcoholysis of the polyvinyl alcohol is 88-92%. The mass fraction of the solute in the film-forming aid solution is 0.005-8%, and the molecular weight of the film-forming aid is 1000-1000000 Da.

[0087] S22: Mix the polymer film-forming agent solution, the silver ion solution, and the film-forming aid solution to obtain a mixed solution.

[0088] Specifically, in this embodiment, the step of mixing the polymer film-forming agent solution, the silver ion solution, and the film-forming aid solution to obtain a mixed solution specifically includes:

[0089] S221: Add the film-forming aid solution to the silver ion solution in batches to form a first mixed solution.

[0090] Specifically, the step of adding the film-forming aid solution to the silver ion solution in batches to form a first mixed solution specifically includes:

[0091] S2211: Add the first film-forming aid solution to the silver ion solution and stir for 0.5 - 3 h to form a second mixed solution.

[0092] Specifically, add the first film-forming aid solution provided in step S21 to the provided silver ion solution, and stir well for 0.5 - 3 h to fully mix and homogenize the first film-forming aid solution and the silver ion solution, forming a second mixed solution.

[0093] S2212: Add the second film-forming aid solution to the second mixed solution and stir for 0.5 - 3 h to form a first mixed solution.

[0094] Specifically, add the second film-forming aid solution provided in step S21 to the second mixed solution prepared in step S2211, and stir for 0.5 - 3 h to fully mix and homogenize the second film-forming aid solution and the second mixed solution, forming a first mixed solution. Among them, the solutes in the first film-forming aid solution and the second film-forming aid solution can be the same or different, that is to say, the components of the hydrophilic polymers included in the first film-forming aid and the second film-forming aid can be the same or different.

[0095] S222: Add the polymer film-forming agent solution to the first mixed solution to form a mixed solution.

[0096] Specifically, in this embodiment, add the polymer film-forming agent solution provided in step S21 to the first mixed solution prepared in step S221, and stir for 0.5 - 5 h to fully mix and homogenize the polymer film-forming agent solution and the first mixed solution, forming a mixed solution.

[0097] S23: Add the precipitant solution to the mixed solution to form silver-phase microsphere particles, and a polymer protective film is coated on the surface of the silver-phase microsphere particles. The polymer protective film can be dissolved when encountering a compatible solvent to release silver compounds.

[0098] Specifically, in this embodiment, the provided precipitant solution is the same as the precipitant solution provided in the first embodiment of the preparation method of silver-phase microsphere particles, which will not be elaborated here. In this embodiment, the precipitant solution is dropped into the stirred mixed solution at a rate of 1 - 50 mL / min. The mixed solution is the mixed solution obtained by mixing the polymer film-forming agent solution, the silver ion solution and the film-forming aid solution prepared in step S22, and stir for 0.5 - 2 h to make the anions in the precipitant solution react fully with the silver ions in the mixed solution, forming silver chloride (AgCl), silver carbonate (Ag 2 CO 3 ), silver sulfate (Ag 2 SO 4 ), silver hydroxide (AgOH), silver oxalate (Ag 2 C2 O 4 ) and other insoluble silver salt particles, thereby forming silver phase microsphere particles.

[0099] In this embodiment, since the polymer film-forming agent and the film-forming aid, i.e., hydrophilic polymers, are highly compatible in water, they jointly form a protective layer on the surface of the silver phase microsphere particles, namely a polymer protective film. The polymer protective film coated on the surface of the silver phase microsphere particles will not dissolve in water at room temperature and its preparation environment, and can only be dissolved when it comes into contact with a compatible solvent. The polymer protective film coated on the surface of the silver phase microsphere particles is dissolved and damaged, and the silver phase microsphere particles embedded by the polymer protective film release silver compounds.

[0100] In this embodiment, by adjusting the ratio of the polymer film-forming agent and the film-forming aid in the mixed solution, the thickness and composition ratio of the polymer protective film formed on the surface of the silver phase microsphere particles can be adjusted. Specifically, the higher the proportion of the film-forming aid in the mixed solution, the higher the proportion of the film-forming aid in the formed polymer protective film. When the polymer protective film comes into contact with a compatible solvent, the dissolution rate of the polymer protective film is faster, that is, the rate of damage to the polymer protective film is faster, and the rate of release of silver ions from the encapsulated silver phase microsphere particles in contact with the compatible solvent is also faster, and the amount of released silver ions is also more. That is to say, in this embodiment, the controllable release of silver ions can be achieved by adjusting the ratio of the polymer film-forming agent and the film-forming aid.

[0101] In this embodiment, when the prepared silver phase microsphere particles are used for clinical care such as acute and chronic wound care, the polymer protective film on the surface of the silver phase microsphere particles comes into contact with the wound exudate. Due to the relatively high body temperature, the film-forming aid in the polymer protective film, i.e., hydrophilic polymer, dissolves when in contact with the wound exudate in a high-temperature environment, causing the polymer protective film to be damaged. The silver phase microsphere particles embedded by the polymer protective film come into contact with the wound exudate and release antibacterial silver ions to perform antibacterial treatment on the wound and prevent wound infection. By adjusting the ratio of the polymer film-forming agent and the film-forming aid, the controllable release of silver ions is achieved, enabling silver ions to be continuously and stably released onto the wound surface, thereby providing excellent antibacterial performance.

[0102] In other embodiments, the solvent in the silver phase microsphere particle solution can also be other substances, such as ethanol, etc. The polymer film-forming agent can also be an oil-soluble substance, and the film-forming aid is a polymer that can be dissolved in both water and ethanol. The polymer film-forming agent and the film-forming aid jointly wrap the silver phase microsphere particles to form a polymer protective film.

[0103] Refer to Figure 3 , Figure 3 which is a schematic flowchart of an embodiment of the preparation method of the polyurethane foam provided by this application.

[0104] The present application provides a method for preparing a polyurethane foam, and a polyurethane foam can be prepared by this method. The steps of the method for preparing the polyurethane foam provided by the present application specifically include:

[0105] S31: Provide a silver-phase microsphere particle solution.

[0106] Specifically, the silver-phase microsphere particle solution is prepared by the method for preparing silver-phase microsphere particles provided by the present application. Specifically refer to the first embodiment or the second embodiment of the method for preparing silver-phase microsphere particles. The silver-phase microsphere particle solution prepared by using the first embodiment or the second embodiment of the method for preparing silver-phase microsphere particles can be used to prepare a polyurethane foam. Exemplarily, in this embodiment, the silver-phase microsphere particle solution prepared in the second embodiment of the method for preparing silver-phase microsphere particles is taken as an example for introduction. The prepared silver-phase microsphere particles are the same as those in the second embodiment of the method for preparing silver-phase microsphere particles, and will not be described in detail.

[0107] S32: Mix the silver-phase microsphere particle solution with a surfactant solution to form a foaming phase.

[0108] Specifically, the surfactant solution is prepared by adding a surfactant to a solvent. In this embodiment, the solvent in the surfactant solution is water, and the solute is a non-ionic surfactant. The non-ionic surfactant can avoid the destruction of the polymer protective film on the surface of the silver-phase microsphere particles caused by the charge carried by the active groups. The mass fraction of the solute in the surfactant solution is 0.001-10%, and the HLB value of the surfactant solution is 10-20.

[0109] Optionally, the non-ionic surfactant may include at least two of long-chain fatty alcohol polyoxyethylene ethers (Brij), fatty acid polyoxyethylene esters (Myrij), alkylphenol polyoxyethylene ethers (Triton), polyoxyethylene sorbitan fatty acid esters (Tween), polyoxyethylene-polyoxypropylene block copolymers (Poloxamer), sorbitan fatty acid esters (Span). In this embodiment, the surfactant includes polyoxyethylene sorbitan fatty acid ester, polyoxyethylene-polyoxypropylene block copolymer, and sorbitan fatty acid ester.

[0110] Specifically, in this embodiment, the steps for preparing the surfactant solution include: adding polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester into water, and stirring for 0.5 - 1 h to fully dissolve the polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester in water; then adding a polyoxyethylene-polyoxypropylene ether block copolymer into the obtained solution, and stirring for 1 - 5 h to fully dissolve the surfactant in water, and then cooling the dissolved solution to 0 - 20 °C to obtain the surfactant solution. It can be understood that in this embodiment, after dissolving the polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester in water first, due to the strong water solubility of the polyoxyethylene sorbitan fatty acid ester, the solution has a certain surface tension, and then adding the polyoxyethylene-polyoxypropylene ether block copolymer can promote the dissolution of the polyoxyethylene-polyoxypropylene ether block copolymer.

[0111] In this embodiment, the silver-phase microsphere particle solution and the surfactant solution are mixed according to a mass ratio of 1:50 - 10:1. Preferably, the mass ratio of the silver-phase microsphere particle solution to the surfactant solution is 1:5 - 10:1, and more preferably, the mass ratio of the silver-phase microsphere particle solution to the surfactant solution is 1:1 - 5:1. Specifically, the steps for mixing the silver-phase microsphere particle solution and the surfactant solution to form a foaming phase specifically include:

[0112] Dripping the prepared surfactant solution into the silver-phase microsphere particle solution under stirring at a rate of 1 - 25 mL / min, and stirring for 0.5 - 2 h to make the silver-phase microsphere particle solution and the surfactant solution uniformly mixed, and then cooling to 0 - 20 °C to form a foamed aqueous phase.

[0113] It can be understood that the surfactant is beneficial to the foaming in the process of preparing the polyurethane foam, making the prepared polyurethane foam have uniform pores and good softness and hardness. At the same time, it can also provide an appropriate surface tension for the silver-phase microsphere particles wrapped by the polymer protective film to improve the stability of the silver-phase microsphere particles dispersed in the solution, and can prevent the polyurethane fibers from completely embedding the wrapped silver-phase microsphere particles. In this embodiment, controlling the HLB value of the surfactant solution between 10 - 20 can stably disperse the silver-phase microsphere particles in the foamed aqueous phase.

[0114] In other embodiments, the solvent in the silver-phase microsphere particle solution can also be other substances, such as ethanol, etc., the polymer film-forming agent can also be an oil-soluble substance, and the film-forming aid is a polymer that can be dissolved in both water and ethanol. The silver-phase microsphere particles are wrapped by the polymer film-forming agent and the film-forming aid together. Select a suitable surfactant to disperse the silver-phase microsphere particle solution in the foaming phase or the polyurethane prepolymer for foaming.

[0115] S33: Mix the foaming phase with the polyurethane prepolymer and foam-mold to obtain polyurethane foam.

[0116] Specifically, in this embodiment, the polyurethane prepolymer includes a TDI polyether polyol prepolymer or an MDI polyether polyol prepolymer. The mass ratio of the polyurethane prepolymer to the foaming phase is 1:2 - 2:1.

[0117] In this embodiment, the steps of mixing the foaming phase with the polyurethane prepolymer and foam-molding to obtain polyurethane foam specifically include:

[0118] S331: Heat the polyurethane prepolymer to 20 - 45 °C.

[0119] S332: Mix the foaming phase with the polyurethane prepolymer and cure and mold at 20 - 45 °C for 2 - 10 min to form pre-polyurethane foam.

[0120] Specifically, the foamed water phase prepared in step S32 and the heated polyurethane prepolymer are mixed evenly and coated by a foaming device, and then cured and molded in a curing device at 20 - 45 °C for 2 - 10 min to form pre-polyurethane foam.

[0121] S333: Dry the pre-polyurethane foam by infrared heating or microwave heating to form polyurethane foam.

[0122] Specifically, the pre-polyurethane foam prepared in step S332 is dried by an infrared heating or microwave heating device to finally obtain polyurethane foam.

[0123] The polyurethane foam prepared by the above method has uniform and delicate pores and strong hydrophilicity, solving the problems of pore blockage, increased foam hardness, reduced comfort, and antibacterial components being embedded in polyurethane fibers during the foaming process of polyurethane foam in the prior art.

[0124] Furthermore, using Figure 2 the silver-phase microsphere particles prepared in the second embodiment of the preparation method of the silver-phase microsphere particles shown, and then using the above polyurethane foam preparation method to prepare polyurethane foam, which is a controllable silver-release antibacterial polyurethane foam, can achieve stable and continuous release of silver ions in the polyurethane foam, providing excellent antibacterial properties, further solving the problem of non-adjustable silver ion release in polyurethane foam in the prior art, avoiding the problems that the antibacterial agent in the polyurethane foam is deeply buried in the polyurethane fibers and difficult to release, and the antibacterial agent completely precipitates from the polyurethane foam and releases too fast, resulting in all the antibacterial agent being released onto the wound surface and damaging the normal cells on the wound surface, which is not conducive to wound healing, and improving the antibacterial properties of the polyurethane foam.

[0125] To detect the various properties of the prepared polyurethane foam, the inventors of this application conducted four different experiments, namely Experiment 1, Experiment 2, Experiment 3, and Experiment 4. The following will provide specific introductions to the four different experiments.

[0126] Refer to Figure 4 , Figure 4 which is a schematic diagram of the component ratios of four experiments for preparing polyurethane foam.

[0127] The inventors of this application conducted Experiment 1 according to the component ratio of Experiment 1 in Figure 4 . The specific steps of Experiment 1 are as follows:

[0128] S001: Add silver sulfate to water, stir at 1000 rpm for 1 h, then add PVA 1799, stir at 1000 rpm for 1 h, add calcium chloride solution at a rate of 2 mL / min, and cool to 10 °C.

[0129] S002: Heat the TDI prepolymer to 30 °C, and mix it evenly with the solution in step S001 through a foaming device, coat it with a thickness of about 3 mm, cure at a temperature of 30 °C for 5 min, and dry it with microwave for 3 min to obtain the first polyurethane foam.

[0130] See Figure 4 , the inventors of this application conducted Experiment 2 according to the component ratio of Experiment 2 in Figure 4 . The specific steps of Experiment 2 are as follows:

[0131] S011: Add silver sulfate to water, stir at 200 rpm for 2 h, add PEG3000, PVA1799, and PVA1788 sequentially at intervals of 1 h, stir at a speed of 500 rpm, then add sodium chloride solution at a rate of 2 mL / min, and cool to 10 °C.

[0132] S012: Add Span-60, Poloxamer-F188, and Poloxamer-L61 to water sequentially at intervals of 0.5 h, stir at a speed of 500 rpm, and cool to 10 °C.

[0133] S013: Drop the solution in step S012 into the solution in step S011 at a rate of 5 mL / min, and stir at 300 rpm for 1 h, and cool to 5 °C.

[0134] S014: Heat the TDI prepolymer to 35 °C, and mix it evenly with the solution in step S013 through a foaming device, coat it with a thickness of about 3 mm, cure at a temperature of 35 °C for 5 min, and dry it with microwave for 3 min to obtain the second polyurethane foam.

[0135] See Figure 4, the inventors of the present application carried out Experiment 3 according to the component ratio of Experiment 3 in Figure 4 . The specific steps of Experiment 3 are as follows:

[0136] S021: Add silver nitrate to water, stir at 200 rpm for 1 h, add PVP, PEO, and PVA1799 sequentially at intervals of 1 h, stir at a speed of 400 rpm, then add sodium chloride solution at a speed of 1 mL / min, and cool to 10 °C.

[0137] S022: Add Span-20, Myrij 52, and Poloxamer-L61 to water sequentially at intervals of 0.5 h, stir at a speed of 500 rpm, and cool to 5 °C.

[0138] S023: Drop the solution of step S022 into the solution of step S021 at a speed of 2 mL / min, stir at 300 rpm for 1 h, and cool to 5 °C.

[0139] S024: Heat the TDI prepolymer to 40 °C, mix it evenly with the solution of step S023 through a foaming device, coat it to a thickness of about 3 mm, cure at a temperature of 32 °C for 6 min, and dry it with microwave for 4 min to obtain the third polyurethane foam.

[0140] See Figure 4 , the inventors of the present application carried out Experiment 3 according to the component ratio of Experiment 4 in Figure 4 . The specific steps of Experiment 4 are as follows:

[0141] S031: Add silver nitrate to water, stir at 200 rpm for 1 h, add PEG3000 and H-HPC sequentially at intervals of 1 h, stir at a speed of 500 rpm, then add sodium carbonate solution at a speed of 2 mL / min, and cool to 10 °C.

[0142] S032: Add Tween-20 and Triton X-100 to water sequentially at intervals of 0.5 h, stir at a speed of 500 rpm, and cool to 5 °C.

[0143] S033: Drop the solution of step S032 into the solution of step S031 at a speed of 2 mL / min, stir at 300 rpm for 1 h, and cool to 5 °C.

[0144] S034: Heat the MDI prepolymer to 30 °C, mix it evenly with the solution of step S033 through a foaming device, coat it to a thickness of about 3 mm, cure at a temperature of 30 °C for 6 min, and dry it with microwave for 3 min to obtain the fourth polyurethane foam.

[0145] Refer to Figure 5 ,Figure 5 Yes Figure 4 Schematic diagram of the silver ion release trend in the polyurethane foam obtained from four experiments.

[0146] Based on the above four different experiments, the inventors of the present application detected and analyzed the polyurethane foams prepared by different polyurethane preparation methods and steps in the four different experiments, detected the silver ion release amounts in four different polyurethane foams, and obtained the silver ion release trend as Figure 5 shown.

[0147] Specifically, referring to Figure 5 , the inventors of the present application analyzed the silver ion release trends in the four different polyurethane foams obtained by detection and found that no film-forming aid, i.e., hydrophilic polymer, was added in Experiment 1, and the silver ion release amount in the first polyurethane foam was very small; different proportions of polymer film-forming agents and film-forming aids were added in Experiment 2 and Experiment 3, and the second polyurethane foam and the third polyurethane foam in Experiment 2 and Experiment 3 could both control the stable release of silver ions and could control the total amount of silver ion release; no polymer film-forming agent was added in Experiment 4, and the silver ions in the fourth polyurethane foam were released rapidly and unstably.

[0148] By analyzing the experimental results of the above four different experiments, the inventors of the present application concluded that adding a polymer film-forming agent and a film-forming aid during the preparation process of the polyurethane foam is beneficial to realizing the stable release of silver ions in the polyurethane foam, and by adjusting the proportions of the polymer film-forming agent and the film-forming aid, the release rate and the total release amount of silver ions can be controlled, that is, it is verified that the polyurethane foam prepared by the preparation method of the polyurethane foam provided by the present application can perform controllable release of silver ions, so that the silver ions in the polyurethane foam can be released stably and continuously.

[0149] Refer to Figures 6 to 8 , Figure 6 which is the scanning electron microscope image of the second polyurethane foam sample prepared in Experiment 2, Figure 7 which is the microscope image of the third polyurethane foam sample prepared in Experiment 3, Figure 8 which is the schematic diagram of the particle size distribution of the silver phase microspheres prepared in Experiment 3.

[0150] See Figure 6 , the inventors of the present application respectively sampled the second polyurethane foam and the third polyurethane foam prepared in Experiment 2 and Experiment 3 above, scanned the second polyurethane foam sample by a scanning electron microscope (SEM), and obtained as Figure 6Scanning electron microscope image of the second polyurethane foam sample shown. The silver-phase microsphere particles in the second polyurethane foam sample are silver chloride microsphere particles wrapped by PVA, PEG, and PVP together. By analyzing the scanning electron microscope image of the second polyurethane foam sample, the inventor found that the silver chloride microsphere particles in Experiment 2 are spherical particles, and their size and shape are regular.

[0151] See Figure 7 , the inventor scanned and analyzed the third polyurethane foam sample with a microscope and obtained the microscope image of the third polyurethane foam sample as shown in Figure 7 . By analyzing the microscope image of the third polyurethane foam sample, the inventor found that the pores of the third polyurethane foam prepared with the component ratios in Experiment 3 are dense and uniform. See Figure 8 . The silver-phase microsphere particles in Experiment 3 are microsphere particles wrapped by PVA, PEG, and PVP together. The inventor further detected the particle size of the silver-phase microsphere particles in the silver-phase microsphere particle solution prepared with the component ratios in Experiment 3 and obtained the particle size distribution result of the silver-phase microsphere particles as shown in Figure 8 . By analyzing the particle size distribution result of the silver-phase microsphere particles obtained in Experiment 3, it was found that the particle size distribution of the silver-phase microsphere particles obtained in Experiment 3 is relatively narrow, that is, the particle size distribution of the silver-phase microsphere particles in Experiment 3 is relatively uniform, that is, the size and shape of the silver-phase microsphere particles prepared in Experiment 3 are relatively regular.

[0152] By analyzing the scanning electron microscope images and microscope images of the second polyurethane foam and the third polyurethane foam prepared in Experiment 2 and Experiment 3, as well as the particle size distribution result of the silver-phase microsphere particles prepared in Experiment 3, and combining the different component ratios in the preparation process of the polyurethane foam in Experiment 2 and Experiment 3, the inventor further concluded that adding a polymer film-forming agent and a film-forming aid during the preparation process of the polyurethane foam can effectively improve the performance such as the shape regularity of the silver-phase microsphere particles in the prepared polyurethane foam, realize the controllable release of silver ions in the polyurethane foam, and at the same time adding a non-ionic surfactant can further improve the pore uniformity and denseness of the polyurethane foam, and a polyurethane foam with excellent performance can be prepared, further verifying the effectiveness of the preparation method of the polyurethane foam provided in this application.

[0153] This application provides a silver-phase microsphere particle, which is composed of Figure 2 or Figure 3It is prepared by the preparation method of the silver-phase microsphere particles shown, which will not be elaborated here. A polymer protective film is coated on the surface of the silver-phase microsphere particles. The polymer protective film can be dissolved when encountering a compatible solvent and can release silver compounds. When the silver-phase microsphere particles are applied to the care of acute and chronic wounds, the polymer protective film on the surface of the silver-phase microsphere particles dissolves when contacting the wound exudate, and the polymer protective film is damaged. At this time, the silver-phase microsphere particles wrapped by the polymer protective film will release silver compounds, and the silver compounds perform antibacterial treatment on the wound, thereby promoting the healing of the wound.

[0154] The present application also provides a polyurethane foam, which is prepared by Figure 3 the preparation method of the polyurethane foam shown, and the polyurethane foam includes the above-mentioned silver-phase microsphere particles, which will not be elaborated here.

[0155] The above are only the embodiments of the present application, and do not limit the patent scope of the present application accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present application by the same token.

Claims

1. A method for preparing silver-phase microsphere particles, characterized in that, comprising: providing a polymer film-forming agent solution, a silver ion solution, a film-forming aid solution and a precipitating agent solution respectively; mixing the film-forming aid solution, the polymer film-forming agent solution and the silver ion solution to obtain a mixed solution; adding the precipitating agent solution to the mixed solution to form silver-phase microsphere particles, and a polymer protective film is coated on the surface of the silver-phase microsphere particles, and the polymer protective film can be dissolved when encountering a compatible solvent to release silver compounds; the film-forming aid includes one or more of polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, and polyvinyl alcohol with a degree of alcoholysis of 88-92%, and the polymer film-forming agent includes one or more of polyvinyl alcohol with a degree of alcoholysis of 99%, highly substituted hydroxypropyl cellulose, and polybutylene terephthalate; or, the film-forming aid includes one or more of polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, and polyvinyl alcohol with a degree of alcoholysis of 88%, and the polymer film-forming agent includes one or more of polyvinyl alcohol with a degree of alcoholysis of 92-99%, highly substituted hydroxypropyl cellulose, and polybutylene terephthalate; the film-forming aid is used to assist the polymer film-forming agent to form the polymer protective film on the surface of the silver-phase microsphere particles, and the film-forming aid and the polymer film-forming agent are jointly used to realize the controlled release of silver ions.

2. The method for preparing silver-phase microsphere particles according to claim 1, characterized in that, the step of mixing the film-forming aid solution, the polymer film-forming agent solution and the silver ion solution to obtain the mixed solution includes: adding the film-forming aid solution to the silver ion solution in batches to form a first mixed solution; adding the polymer film-forming agent solution to the first mixed solution to form the mixed solution.

3. The method for preparing silver-phase microsphere particles according to claim 2, characterized in that, the step of adding the film-forming aid solution to the silver ion solution in batches to form a first mixed solution includes: adding a first film-forming aid solution to the silver ion solution and stirring for 0.5-3 h to form a second mixed solution; adding a second film-forming aid solution to the second mixed solution and stirring for 0.5-3 h to form the first mixed solution; the components of the first film-forming aid and the second film-forming aid are the same or different.

4. The method for preparing silver-phase microsphere particles according to claim 1, characterized in that, the mass fraction of the solute in the film-forming aid solution is 0.005-8%.

5. The method for preparing silver-phase microsphere particles according to claim 1, characterized in that, the molecular weight of the film-forming aid is 1000-1000000 Da.

6. The method for preparing silver-phase microsphere particles according to claim 1, characterized in that, the step of adding the precipitating agent solution to the mixed solution to form silver-phase microsphere particles includes: dropping the precipitating agent solution into the mixed solution under stirring at a speed of 1-50 mL / min and stirring for 0.5-2 h to form the silver-phase microsphere particle solution.

7. The preparation method of the silver-phase microsphere particles according to claim 1, characterized in that, the silver ion solution includes one or more of silver nitrate solution, silver sulfate solution, silver acetate solution and silver ammonia solution.

8. The preparation method of the silver-phase microsphere particles according to claim 1, characterized in that, the mass fraction of the solute in the silver ion solution is 0.01-5%.

9. The preparation method of the silver-phase microsphere particles according to claim 1, characterized in that, the mass fraction of the solute in the polymer film-forming agent solution is 0.05-10%.

10. The preparation method of the silver-phase microsphere particles according to claim 1, characterized in that, the molecular weight of the polymer film-forming agent is 1000-1000000 Da.

11. The preparation method of the silver-phase microsphere particles according to claim 1, characterized in that, the solute in the precipitating agent solution is an inorganic soluble salt, and the mass fraction of the solute in the precipitating agent solution is 0.01-5%.

12. The preparation method of the silver-phase microsphere particles according to claim 11, characterized in that, the anions of the inorganic soluble salt include one or more of chloride ions, carbonate ions, sulfate ions, hydroxide ions, oxalate ions; the cations of the inorganic soluble salt include one or more of sodium ions, potassium ions, calcium ions, magnesium ions.

13. A silver-phase microsphere particle, characterized in that, the silver-phase microsphere particle is made by using the preparation method of the silver-phase microsphere particles according to any one of claims 1-12.

14. A preparation method of a polyurethane foam, characterized in that, comprising: providing a silver-phase microsphere particle solution, the silver-phase microsphere particle is made by using the preparation method of the silver-phase microsphere particles according to any one of claims 1-12; mixing the silver-phase microsphere particle solution with a surfactant solution to form a foaming phase; mixing the foaming phase with a polyurethane prepolymer, and foaming and molding to obtain a polyurethane foam, the polyurethane foam includes silver-phase microsphere particles, and a polymer protective film is coated on the surface of the silver-phase microsphere particles, and the polymer protective film can be dissolved when encountering a compatible solvent to release silver compounds.

15. The preparation method of the polyurethane foam according to claim 14, characterized in that, the surfactant in the surfactant solution is a non-ionic surfactant.

16. The preparation method of the polyurethane foam according to claim 15, characterized in that, the non-ionic surfactant includes at least two of long-chain fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, alkylphenol polyoxyethylene ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene-polyoxypropylene block copolymer, sorbitan fatty acid ester.

17. The preparation method of the polyurethane foam according to claim 16, characterized in that, the non-ionic surfactant includes polyoxyethylene sorbitan fatty acid ester, polyoxyethylene-polyoxypropylene block copolymer, sorbitan fatty acid ester; the preparation of the surfactant solution includes: Add polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester into the solvent, and stir for 0.5 - 1 h; then add polyoxyethylene polyoxypropylene ether block copolymer, stir for 1 - 5 h, and cool to 0 - 20 °C to form the surfactant solution.

18. The method for preparing a polyurethane foam according to claim 14, characterized in that, the mass fraction of the solute in the surfactant solution is 0.001 - 10%.

19. The method for preparing a polyurethane foam according to claim 14, characterized in that, the HLB value of the surfactant solution is 10 - 20.

20. The method for preparing a polyurethane foam according to claim 14, characterized in that, the mass ratio of the silver-phase microsphere particle solution to the surfactant solution is 1:50 - 10:

1.

21. The method for preparing a polyurethane foam according to claim 14, characterized in that, the step of mixing the silver-phase microsphere particle solution and the surfactant solution to form a foaming phase includes: dropping the surfactant solution into the silver-phase microsphere particle solution under stirring at a rate of 1 - 25 mL / min, and stirring for 0.5 - 2 h, and cooling to 0 - 20 °C to form the foaming phase.

22. The method for preparing a polyurethane foam according to claim 14, characterized in that, the step of mixing the foaming phase and the polyurethane prepolymer and foaming and molding to obtain the polyurethane foam includes: heating the polyurethane prepolymer to 20 - 45 °C; mixing the foaming phase and the polyurethane prepolymer, and curing and molding at 20 - 45 °C for 2 - 10 min to form a pre-polyurethane foam; drying the pre-polyurethane foam by infrared heating or microwave heating to form the polyurethane foam.

23. The method for preparing a polyurethane foam according to claim 14, characterized in that, the polyurethane prepolymer includes a TDI polyether polyol prepolymer or an MDI polyether polyol prepolymer.

24. The method for preparing a polyurethane foam according to claim 14, characterized in that, the mass ratio of the polyurethane prepolymer to the foaming phase is 1:2 - 2:

1.

25. A polyurethane foam, characterized in that, the polyurethane foam is prepared by using the method for preparing a polyurethane foam according to any one of claims 14 - 24.

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