Inflatable foot drop corrective shoe and preparation method thereof

Abstract

The invention relates to the field of medical auxiliary equipment, in particular to an inflatable foot drop corrective shoe and a preparation method thereof.The inflatable foot drop corrective shoe is prepared from, by mass, 75-80 parts of modified polyurethane rubber, 6-8 parts of a modified chain extender, 10-12 parts of modified chitosan microspheres, 5-7 parts of modified nano-silicon dioxide and the like. Through dynamic cross-linked network design, multi-stage antibacterial function integration and gradient mechanical regulation and control technologies, compared with the prior art, synergistic breakthrough of damage self-repairing, long-acting antibacterial protection and bionic comfortable supporting is achieved. An innovative material system can actively respond to a foot microenvironment, airtight stability is maintained under repeated mechanical stress, meanwhile, the infection risk is reduced through a molecular-level hydrophilic-antibacterial bifunctional interface, and the wearing safety and rehabilitation suitability are remarkably improved. The foot care solution is suitable for the field of chronic disease foot care and has wide clinical application prospects.

Description

Technical Field

[0001] This invention relates to the field of medical assistive devices, and more particularly to an inflatable foot drop correction shoe and its manufacturing method. Background Technology

[0002] Foot drop refers to the dysfunction of ankle dorsiflexion caused by nerve damage or muscle lesions. Patients drag their toes when walking, are prone to falling, and have abnormal gait. Inflatable foot drop correction shoes, as a type of dynamic ankle and foot orthosis, dynamically adjust the angle of the foot through air pressure and are a key auxiliary device in rehabilitation medicine.

[0003] In existing technologies, traditional thermoplastic polyurethane airbags lack a dynamic repair mechanism. The microcracks generated by repeated inflation and deflation will continue to expand, causing the pressure maintenance to fail at night. This forces patients to frequently inflate the airbags. Furthermore, when rigid orthotics come into contact with the foot microenvironment where sweat accumulates, the lack of functional treatment on the material surface not only causes pressure sores but also fosters the growth of microorganisms. In addition, single-modulus materials cannot adapt to the biomechanical characteristics of the foot's gradient load. Insufficient forefoot support weakens toe grip, while heel overload exacerbates heel pain.

[0004] Therefore, based on the relevant technologies mentioned above, there is an urgent need to develop an inflatable foot drop correction shoe and its manufacturing method. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide an inflatable foot drop correction shoe and its preparation method, so as to solve the problems of functional failure, poor antibacterial properties and single modulus in the prior art.

[0006] To achieve the above objectives, the present invention provides an inflatable foot drop correction shoe and a method for preparing the same.

[0007] An inflatable foot drop correction shoe is composed of the following components in parts by weight: 75-80 parts modified polyurethane rubber, 6-8 parts modified chain extender, 10-12 parts modified chitosan microspheres, 5-7 parts modified nano silica, 3-5 parts polyethylene glycol, 5-7 parts modified nano zinc oxide, and 0.5-1 parts antioxidant.

[0008] Preferably, the modified polyurethane rubber is prepared using the following steps:

[0009] Step A1: Under a nitrogen atmosphere, polytetrahydrofuran ether diol is added to a reaction vessel, heated to 100-120℃, reacted for 1-3 hours, cooled to 70-90℃, 4,4'-diphenylmethane diisocyanate and catalyst dibutyltin dilaurate are added, and the mixture is stirred for 80-100 minutes. Once the reaction is complete, the prepolymer is obtained.

[0010] Step A2: Under a nitrogen atmosphere, place the prepolymer into a reactor, heat to 50-70℃, add 1,4-butanediol, react for 100-140 min, after the reaction is complete, reduce the pressure to -0.098 MPa, degas for 25-35 min, pour and cure, extract and dry to obtain modified polyurethane rubber.

[0011] The mass ratio of polytetrahydrofuran ether diol, 4,4'-diphenylmethane diisocyanate to catalyst is 1:0.53-0.55:0.0003-0.0005;

[0012] The mass ratio of the prepolymer to 1,4-butanediol is 1:0.6-0.7.

[0013] Preferably, the preparation steps of the modified chain extender are as follows:

[0014] Under a nitrogen atmosphere, 4-aminophenol was added to anhydrous tetrahydrofuran solution, heated to 20-30℃, stirred for 20-40 min, cooled to 0-5℃, triethylamine was added, disulfur dichloride was added, the temperature was raised to 6-10℃, the reaction was carried out for 2-4 h, and then the temperature was raised to 20-30℃, the reaction was carried out for 3-5 h. After the reaction was completed, the mixture was filtered, washed, purified and dried to obtain the modified chain extender.

[0015] The dynamic disulfide bonds in the modified chain extender repair microscopic damage through bond energy recombination during repeated inflation of the airbag. At the same time, the modified chitosan microspheres contain hexamethylene diisocyanate repair agent microcapsules. When the airbag is punctured, the isocyanate groups are released and react with the hydroxyl and amino groups of the polyurethane matrix to form a polyurea crosslinking network, which seals macroscopic cracks and thus improves its airtightness.

[0016] The mass ratio of 4-aminophenol, triethylamine, and disulfur dichloride is 1:0.3-0.32:0.93-0.95.

[0017] Preferably, the modified chitosan microspheres are prepared using the following steps:

[0018] Step B1: Add chitosan to 1% acetic acid solution, heat to 40-60℃, stir for 1-3 hours, cool to 35-45℃, add glycidyltrimethylammonium chloride, add 0.1mol / L sodium hydroxide solution, adjust pH to 8-9, react for 5-7 hours, purify and dry to obtain quaternized chitosan.

[0019] Step B2: Add hexamethylene diisocyanate to liquid paraffin, stir and mix, add emulsifier Span-80, heat to 20-30℃, and ultrasonically disperse for 8-12 minutes to obtain the oil phase;

[0020] Step B3: Add quaternized chitosan and pentylene glycol to deionized water, stir to dissolve, add oil phase, heat to 30-40℃, spin at 9000-11000 rpm, emulsify for 5-8 min to obtain emulsion;

[0021] Step B4: Add the emulsion to a flask, heat to 50-70℃, add the crosslinking agent epichlorohydrin, add 5% sodium carbonate solution, adjust the pH to 7.5-8.5, stir the reaction for 2-4 hours, after the reaction is complete, centrifuge and wash, freeze dry to obtain modified chitosan microspheres.

[0022] Preferably, the mass ratio of chitosan to glycidyltrimethylammonium chloride in step B1 is 1:1.8-2.2;

[0023] In step B2, the mass ratio of hexamethylene diisocyanate, liquid paraffin, and emulsifier Span-80 is 1:24-26:0.12-0.13.

[0024] Preferably, the mass ratio of quaternized chitosan, pentanediol and oil phase in step B3 is 1:0.04-0.06:18-22;

[0025] The mass ratio of the emulsion to the crosslinking agent in step B4 is 1:0.02-0.03.

[0026] Preferably, the preparation steps of the modified nano-silica are as follows:

[0027] Step C1: Under a nitrogen atmosphere, add silane coupling agent KH-550 to a mixed solvent of anhydrous ethanol and deionized water, heat to 20-30℃, stir for 20-40 min, add glacial acetic acid, adjust the pH to 4.8-5.2, heat to 50-70℃, react for 50-70 min, and obtain hydrolysate;

[0028] Step C2: Under a nitrogen atmosphere, add silica to the hydrolysate, sonicate for 20-40 min, heat to 70-90℃, reflux for 5-7 h, after the reaction is complete, centrifuge, wash, and vacuum dry to obtain aminated silica;

[0029] Step C3: Under a nitrogen atmosphere, add aminated silica to N,N-dimethylformamide solvent and stir until homogeneous. Add acrylamine monomer and initiator azobisisobutyronitrile, and ultrasonically disperse for 10-20 min. Heat to 60-80℃ and stir for 7-9 h. Add crosslinking agent N,N'-methylenebisacrylamide and react for 1-3 h. Once the reaction is complete, cool to 20-30℃, centrifuge, wash, and dry to obtain modified nano silica.

[0030] The mass ratio of the silane coupling agent KH-550, anhydrous ethanol, and deionized water is 1:4.4-4.6:0.4-0.6.

[0031] The mass ratio of silica to hydrolysate is 1:7.4-7.6;

[0032] The mass ratio of the aminated silica, acrylamine monomer, initiator and crosslinking agent is 1:0.4-0.6:0.008-0.012:0.04-0.06.

[0033] Preferably, the modified nano zinc oxide preparation steps are as follows:

[0034] Step D1: Add zinc oxide powder to anhydrous ethanol, ultrasonically disperse for 20-40 min, add 3-aminopropyltriethoxysilane, heat to 60-70℃, reflux for 3-5 h, centrifuge and wash, vacuum dry to obtain the carrier;

[0035] Step D2: Add the carrier to deionized water, add silver nitrate, heat to 20-30℃, stir for 1-3 hours, add 0.1 mol / L sodium borohydride aqueous solution as reducing agent, stir for 50-70 minutes, add polyvinylpyrrolidone as dispersant, heat to 40-60℃, stir for 2-4 hours, add 1% glutaraldehyde aqueous solution, react for 50-70 minutes, after the reaction is complete, centrifuge, wash, and dry to obtain modified nano zinc oxide;

[0036] By modifying the surface of nano-zinc oxide and loading it with silver nanoparticles, contact disruption of microbial cell membranes is achieved. Furthermore, the cationic quaternary ammonium groups of quaternized chitosan microspheres adsorb negatively charged bacteria, thereby causing the solute inside the bacteria to leak out and achieving a bactericidal effect. At the same time, the chitosan microspheres slowly release silver ions in the sweat environment of the feet, which can form a charge synergistic effect with the chitosan quaternary ammonium salt, realizing a dual physical and chemical antibacterial pathway, avoiding the development of drug resistance in bacteria and improving bactericidal efficiency.

[0037] The mass ratio of zinc oxide powder to 3-aminopropyltriethoxysilane is 1:0.48-0.52;

[0038] The mass ratio of the carrier, silver nitrate, reducing agent, dispersant and glutaraldehyde aqueous solution is 1:0.04-0.06:0.0035-0.004:0.08-0.12:0.004-0.006.

[0039] A method for preparing an inflatable foot drop correction shoe, comprising the following steps:

[0040] Step S1: Under a nitrogen atmosphere, add the modified polyurethane rubber into a mixer, heat to 70-90℃, add the modified chain extender, modified chitosan microspheres, modified nano silica, modified nano zinc oxide, polyethylene glycol and antioxidant, mix for 10-20 minutes at a speed of 50-70 rpm to obtain the rubber compound.

[0041] Step S2: Add the modified polyurethane rubber into a mixer, heat it to 70-90℃, rotate it at 50-70 rpm, add the modified chain extender, modified nano silica, modified chitosan microspheres and antioxidant, react for 10-20 minutes, add it to a twin-screw extruder, water-cool and pelletize it, vacuum dry it to obtain masterbatch.

[0042] Step S3: Place the masterbatch into a double-layer co-extrusion blown film machine, add modified nano zinc oxide, heat to 150-160℃, and traction speed 7-9m / min to obtain the airbag inner liner.

[0043] Step S4: Add the rubber compound to the open mill, heat it to 60-80℃, perform 4-6 thin passes, put it into the mold, add the air bladder inner layer, heat it to 150-170℃, pressurize it to 14-16MPa, vulcanize for 15-25 minutes, after the reaction is complete, cool it down and let it stand, assemble and inflate it to obtain an inflatable foot drop correction shoe.

[0044] Polyurethane is plasticized and modified with polyethylene glycol to reduce its hardness. At the same time, a hydrated lubricating layer can be formed by grafting acrylamine onto the surface of nano-silica, reducing the coefficient of friction between the skin and the shoe. In addition, modified nano-zinc oxide co-crystallizes with the hard segments of polyurethane to improve local strength and enhance the rigidity of the outer layer. Furthermore, the modified silica can form a hydrogen bond network in the sweaty environment of the foot to capture water molecules and achieve intelligent sweat absorption.

[0045] Preferably, the mass ratio of the modified polyurethane rubber, modified chain extender, modified chitosan microspheres, modified nano silica, modified nano zinc oxide, polyethylene glycol and antioxidant in step S1 is 1:0.085-0.095:0.13-0.15:0.07-0.08:0.07-0.08:0.05-0.052:0.009-0.01.

[0046] In step S2, the mass ratio of the modified polyurethane rubber, modified chain extender, modified nano silica, modified chitosan microspheres, and antioxidant is 1:0.085-0.095:0.07-0.08:0.13-0.15:0.009-0.01.

[0047] In step S3, the mass ratio of the masterbatch to the modified nano zinc oxide is 1:0.04-0.06;

[0048] The mass ratio of the adhesive material to the inner liner of the airbag in step S4 is 2.8-3.2:1.

[0049] The beneficial effects of this invention are:

[0050] This invention provides an inflatable foot drop corrective shoe and its manufacturing method. Through dynamic cross-linked network design, multi-level antibacterial function integration, and gradient mechanical regulation technology, this invention achieves a synergistic breakthrough in damage self-repair, long-lasting antibacterial protection, and biomimetic comfort support compared to existing technologies. Its innovative material system can actively respond to the foot microenvironment, maintaining airtight stability under repeated mechanical stress. Simultaneously, it reduces the risk of infection through a molecular-level hydrophilic-antibacterial dual-functional interface, significantly improving wearing safety and rehabilitation adaptability. It is suitable for the field of foot care for chronic diseases and has broad clinical application prospects. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0052] Example 1: The preparation steps of modified polyurethane rubber are as follows:

[0053] S1: Under a nitrogen atmosphere, 100g of polytetrahydrofuran ether diol was added to a reaction vessel, heated to 100℃, reacted for 3h, cooled to 70℃, and 53g of 4,4'-diphenylmethane diisocyanate and 0.03g of catalyst dibutyltin dilaurate were added. The mixture was stirred for 100min until the reaction was complete, and the prepolymer was obtained.

[0054] S2: Under a nitrogen atmosphere, 100g of prepolymer was placed in a reactor, heated to 50℃, and 60g of 1,4-butanediol was added. The reaction was carried out for 140min. After the reaction was completed, the pressure was reduced to -0.098MPa, degassing was performed for 25min, and the mixture was poured and cured. After extraction and drying, the modified polyurethane rubber was obtained.

[0055] Example 2: The preparation steps of modified polyurethane rubber are as follows:

[0056] S1: Under a nitrogen atmosphere, 100g of polytetrahydrofuran ether diol was added to a reaction vessel, heated to 110℃, reacted for 2h, cooled to 80℃, and 54g of 4,4'-diphenylmethane diisocyanate and 0.04g of catalyst dibutyltin dilaurate were added. The mixture was stirred for 90min until the reaction was complete, and the prepolymer was obtained.

[0057] S2: Under a nitrogen atmosphere, 100g of prepolymer was placed in a reactor, heated to 60℃, and 65g of 1,4-butanediol was added. The reaction was carried out for 120min. After the reaction was completed, the pressure was reduced to -0.098MPa, degassing was performed for 30min, and the mixture was poured and cured. After extraction and drying, the modified polyurethane rubber was obtained.

[0058] Example 3: The preparation steps of modified polyurethane rubber are as follows:

[0059] S1: Under a nitrogen atmosphere, 100g of polytetrahydrofuran ether diol was added to a reaction vessel, heated to 120℃, reacted for 1h, cooled to 90℃, and 55g of 4,4'-diphenylmethane diisocyanate and 0.05g of dibutyltin dilaurate catalyst were added. The mixture was stirred and reacted for 80min. The reaction was completed, and the prepolymer was obtained.

[0060] S2: Under a nitrogen atmosphere, 100g of prepolymer was placed in a reactor, heated to 70℃, and 70g of 1,4-butanediol was added. The reaction was carried out for 100min. After the reaction was completed, the pressure was reduced to -0.098MPa, degassing was performed for 35min, and the mixture was poured and cured. After extraction and drying, the modified polyurethane rubber was obtained.

[0061] Example 4: The preparation steps of the modified chain extender are as follows:

[0062] Under a nitrogen atmosphere, 100 g of 4-aminophenol was added to 200 mL of anhydrous tetrahydrofuran solution, heated to 20 °C, stirred for 40 min, cooled to 0 °C, 30 g of triethylamine and 93 g of disulfide dichloride were added, the temperature was raised to 10 °C, and the reaction was carried out for 2 h. The temperature was then raised to 20 °C and the reaction was carried out for 5 h. After the reaction was completed, the mixture was filtered, washed, purified and dried to obtain the modified chain extender.

[0063] Example 5: The preparation steps of the modified chain extender are as follows:

[0064] Under a nitrogen atmosphere, 100 g of 4-aminophenol was added to 200 mL of anhydrous tetrahydrofuran solution, heated to 25 °C, stirred for 30 min, cooled to 3 °C, 31 g of triethylamine was added, and 94 g of disulfide dichloride was added. The temperature was raised to 8 °C and reacted for 3 h. The temperature was then raised to 25 °C and reacted for 4 h. After the reaction was completed, the mixture was filtered, washed, purified, and dried to obtain the modified chain extender.

[0065] Example 6: The preparation steps of the modified chain extender are as follows:

[0066] Under a nitrogen atmosphere, 100 g of 4-aminophenol was added to 200 mL of anhydrous tetrahydrofuran solution, heated to 30 °C, stirred for 20 min, cooled to 5 °C, 32 g of triethylamine and 95 g of disulfide dichloride were added, the temperature was raised to 6 °C, and the reaction was carried out for 4 h. The temperature was then raised to 20 °C and the reaction was carried out for 5 h. After the reaction was completed, the mixture was filtered, washed, purified and dried to obtain the modified chain extender.

[0067] Example 7: The preparation steps of modified chitosan microspheres are as follows:

[0068] S1: Add 100g of chitosan to 200mL of 1% acetic acid solution, heat to 40℃, stir and react for 3h, cool to 35℃, add 180g of glycidyltrimethylammonium chloride, add 0.1mol / L sodium hydroxide solution, adjust pH to 8-9, react for 5h, purify and dry to obtain quaternized chitosan.

[0069] S2: Add 100g of hexamethylene diisocyanate to 2400g of liquid paraffin, stir and mix, add 12g of emulsifier Span-80, heat to 20℃, and ultrasonically disperse for 12min to obtain the oil phase;

[0070] S3: Add 100g of quaternized chitosan and 4g of pentanediol to 200mL of deionized water, stir to dissolve, add 180g of oil phase, heat to 30℃, spin at 11000rpm, emulsify for 5min to obtain emulsion.

[0071] S4: Add 100g of emulsion to a flask, heat to 50℃, add 2g of crosslinking agent epichlorohydrin, add 5% sodium carbonate solution, adjust pH to 7.5-8.5, stir and react for 4h. After the reaction is complete, centrifuge, wash, and freeze dry to obtain modified chitosan microspheres.

[0072] Example 8: The preparation steps of modified chitosan microspheres are as follows:

[0073] S1: Add 100g of chitosan to 200mL of 1% acetic acid solution, heat to 50℃, stir for 2h, cool to 40℃, add 200g of glycidyltrimethylammonium chloride, add 0.1mol / L sodium hydroxide solution, adjust pH to 8-9, react for 6h, purify and dry to obtain quaternized chitosan.

[0074] S2: Add 100g of hexamethylene diisocyanate to 2500g of liquid paraffin, stir and mix, add 12.5g of emulsifier Span-80, heat to 25℃, and ultrasonically disperse for 10min to obtain the oil phase;

[0075] S3: Add 100g of quaternized chitosan and 5g of pentanediol to 200mL of deionized water, stir to dissolve, add 2000g of oil phase, heat to 35℃, spin at 10000rpm, emulsify for 6min to obtain emulsion.

[0076] S4: Add 100g of emulsion to a flask, heat to 60℃, add 2.5g of crosslinking agent epichlorohydrin, add 5% sodium carbonate solution, adjust pH to 7.5-8.5, stir and react for 3h. After the reaction is complete, centrifuge, wash, freeze dry to obtain modified chitosan microspheres.

[0077] Example 9: The preparation steps of modified chitosan microspheres are as follows:

[0078] S1: Add 100g of chitosan to 200mL of 1% acetic acid solution, heat to 60℃, stir and react for 1h, cool to 45℃, add 220g of glycidyltrimethylammonium chloride, add 0.1mol / L sodium hydroxide solution, adjust pH to 8-9, react for 5h, purify and dry to obtain quaternized chitosan.

[0079] S2: Add 100g of hexamethylene diisocyanate to 2600g of liquid paraffin, stir and mix, add 13g of emulsifier Span-80, heat to 30℃, and ultrasonically disperse for 8min to obtain the oil phase;

[0080] S3: Add 100g of quaternized chitosan and 6g of pentanediol to 200mL of deionized water, stir to dissolve, add 2200g of oil phase, heat to 40℃, spin at 9000rpm, emulsify for 8min to obtain emulsion.

[0081] S4: Add 100g of emulsion to a flask, heat to 70℃, add 3g of crosslinking agent epichlorohydrin, add 5% sodium carbonate solution, adjust pH to 7.5-8.5, stir and react for 2h. After the reaction is complete, centrifuge, wash, and freeze dry to obtain modified chitosan microspheres.

[0082] Example 10: The preparation steps of modified nano-silica are as follows:

[0083] S1: Under a nitrogen atmosphere, 100g of silane coupling agent KH-550 was added to a mixed solvent of 440g of anhydrous ethanol and 40g of deionized water. The mixture was heated to 20°C and stirred for 40min. Glacial acetic acid was added to adjust the pH to 4.8-5.2. The mixture was then heated to 50°C and stirred for 70min to obtain a hydrolysate.

[0084] S2: Under a nitrogen atmosphere, 100g of silica was added to 740g of hydrolysate, ultrasonically dispersed for 20min, heated to 90℃, and refluxed for 5h. After the reaction was completed, the silica was centrifuged, washed, and vacuum dried to obtain aminated silica.

[0085] S3: Under a nitrogen atmosphere, 100g of aminated silica was added to 200mL of N,N-dimethylformamide solvent and stirred until homogeneous. Then, 40g of acrylamine monomer and 0.8g of initiator azobisisobutyronitrile were added, and the mixture was ultrasonically dispersed for 10min. The temperature was raised to 80℃ and stirred for 7h. Then, 4g of crosslinking agent N,N'-methylenebisacrylamide was added and the mixture was reacted for 1h. After the reaction was completed, the temperature was lowered to 30℃, and the mixture was centrifuged, washed, and dried to obtain modified nano silica.

[0086] Example 11: The preparation steps of modified nano-silica are as follows:

[0087] S1: Under a nitrogen atmosphere, 100g of silane coupling agent KH-550 was added to a mixed solvent of 450g of anhydrous ethanol and 50g of deionized water. The mixture was heated to 25°C and stirred for 30min. Glacial acetic acid was added to adjust the pH to 4.8-5.2. The mixture was then heated to 60°C and stirred for 60min to obtain a hydrolysate.

[0088] S2: Under a nitrogen atmosphere, 100g of silica was added to 750g of hydrolysate, ultrasonically dispersed for 30min, heated to 80℃, and refluxed for 6h. After the reaction was completed, the silica was centrifuged, washed, and vacuum dried to obtain aminated silica.

[0089] S3: Under a nitrogen atmosphere, 100g of aminated silica was added to 200mL of N,N-dimethylformamide solvent and stirred until homogeneous. Then, 50g of acrylamine monomer and 1g of initiator azobisisobutyronitrile were added and ultrasonically dispersed for 15min. The temperature was raised to 70℃ and stirred for 8h. Then, 5g of crosslinking agent N,N'-methylenebisacrylamide was added and reacted for 2h. After the reaction was completed, the temperature was lowered to 25℃, centrifuged, washed, and dried to obtain modified nano silica.

[0090] Example 12: The preparation steps of modified nano-silica are as follows:

[0091] S1: Under a nitrogen atmosphere, 100g of silane coupling agent KH-550 was added to a mixed solvent of 460g of anhydrous ethanol and 60g of deionized water. The mixture was heated to 30°C and stirred for 20min. Glacial acetic acid was added to adjust the pH to 4.8-5.2. The mixture was then heated to 70°C and stirred for 50min to obtain a hydrolysate.

[0092] S2: Under a nitrogen atmosphere, 100g of silica was added to 760g of hydrolysate, ultrasonically dispersed for 40min, heated to 70℃, refluxed for 7h, and after the reaction was completed, the silica was centrifuged, washed, and vacuum dried to obtain aminated silica.

[0093] S3: Under a nitrogen atmosphere, 100g of aminated silica was added to 200mL of N,N-dimethylformamide solvent and stirred until homogeneous. Then, 60g of acrylamine monomer and 1.2g of initiator azobisisobutyronitrile were added, and the mixture was ultrasonically dispersed for 20min. The temperature was raised to 60℃ and stirred for 9h. Then, 6g of crosslinking agent N,N'-methylenebisacrylamide was added and the reaction was carried out for 1h. After the reaction was completed, the temperature was lowered to 30℃, and the mixture was centrifuged, washed, and dried to obtain modified nano silica.

[0094] Example 13: The preparation steps of modified nano zinc oxide are as follows:

[0095] S1: Add 100g of zinc oxide powder to 200mL of anhydrous ethanol, sonicate for 20min, add 480g of 3-aminopropyltriethoxysilane, heat to 70℃, reflux for 3h, centrifuge, wash, and vacuum dry to obtain the carrier.

[0096] S2: Add 100g of the carrier to 200mL of deionized water, add 4g of silver nitrate, heat to 20℃, stir for 3h, add 0.35g of reducing agent 0.1mol / L sodium borohydride aqueous solution, stir for 50min, add 8g of dispersant polyvinylpyrrolidone, heat to 60℃, stir for 2h, then add 0.4g of 1% glutaraldehyde aqueous solution, react for 50min, the reaction is complete, centrifuge, wash, and dry to obtain modified nano zinc oxide.

[0097] Example 14: The preparation steps of modified nano zinc oxide are as follows:

[0098] S1: Add 100g of zinc oxide powder to 200mL of anhydrous ethanol, sonicate for 30min, add 50g of 3-aminopropyltriethoxysilane, heat to 65℃, reflux for 4h, centrifuge, wash, and vacuum dry to obtain the carrier.

[0099] S2: Add 100g of the carrier to 200mL of deionized water, add 5g of silver nitrate, heat to 25℃, stir for 2h, add 0.38g of reducing agent 0.1mol / L sodium borohydride aqueous solution, stir for 60min, add 10g of dispersant polyvinylpyrrolidone, heat to 50℃, stir for 3h, then add 0.5g of 1% glutaraldehyde aqueous solution, react for 60min, the reaction is complete, centrifuge, wash, and dry to obtain modified nano zinc oxide.

[0100] Example 15: The preparation steps of modified nano zinc oxide are as follows:

[0101] S1: Add 100g of zinc oxide powder to 200mL of anhydrous ethanol, sonicate for 40min, add 52g of 3-aminopropyltriethoxysilane, heat to 60℃, reflux for 5h, centrifuge, wash, and vacuum dry to obtain the carrier.

[0102] S2: Add 100g of the carrier to 200mL of deionized water, add 6g of silver nitrate, heat to 30℃, stir for 1h, add 0.4g of reducing agent 0.1mol / L sodium borohydride aqueous solution, stir for 70min, add 12g of dispersant polyvinylpyrrolidone, heat to 40℃, stir for 4h, add 0.6g of 1% glutaraldehyde aqueous solution, react for 50min, the reaction is complete, centrifuge, wash, and dry to obtain modified nano zinc oxide.

[0103] Example 16: A method for preparing an inflatable foot drop correction shoe

[0104] S1: Under a nitrogen atmosphere, 100g of modified polyurethane rubber was added to a mixer, heated to 70℃, and 8.5g of modified chain extender, 13g of modified chitosan microspheres, 7g of modified nano silica, 7g of modified nano zinc oxide, 5g of polyethylene glycol and 0.9g of antioxidant were added. The mixture was then mixed for 20 minutes at a speed of 50 rpm to obtain the rubber compound.

[0105] S2: Add 100g of modified polyurethane rubber to a mixer, heat to 70℃, rotate at 70rpm, add 8.5g of modified chain extender, 7g of modified nano silica, 13g of modified chitosan microspheres and 0.9g of antioxidant, react for 10min, add to a twin-screw extruder, water-cool and pelletize, vacuum dry to obtain masterbatch;

[0106] S3: Put 100g of masterbatch into a double-layer co-extrusion blown film machine, add 4g of modified nano zinc oxide, heat to 150℃, and traction speed 9m / min to obtain the airbag inner liner.

[0107] S4: Add 28g of rubber compound to the open mill, heat to 60℃, perform 6 thin passes, put it into the mold, add 10g of air bladder inner layer, heat to 150℃, pressurize to 16MPa, vulcanize for 15min, the reaction is complete, cool down and let stand, assemble and inflate to obtain an inflatable foot drop correction shoe.

[0108] Example 17: A method for preparing an inflatable foot drop correction shoe

[0109] S1: Under a nitrogen atmosphere, 100g of modified polyurethane rubber was added to a mixer, heated to 80℃, and 9g of modified chain extender, 14g of modified chitosan microspheres, 7.5g of modified nano silica, 7.5g of modified nano zinc oxide, 5.1g of polyethylene glycol and 0.95g of antioxidant were added. The mixture was then mixed for 15 minutes at a speed of 60 rpm to obtain the rubber compound.

[0110] S2: Add 100g of modified polyurethane rubber to a mixer, heat to 80℃, rotate at 60rpm, add 9g of modified chain extender, 7.5g of modified nano silica, 14g of modified chitosan microspheres and 0.95g of antioxidant, react for 15min, add to a twin-screw extruder, water-cool and pelletize, vacuum dry to obtain masterbatch;

[0111] S3: Put 100g of masterbatch into a double-layer co-extrusion blown film machine, add 5g of modified nano zinc oxide, heat to 155℃, and traction speed 8m / min to obtain the airbag inner liner.

[0112] S4: Add 30g of rubber material to the open mill, heat to 70℃, perform 5 thin passes, put it into the mold, add 10g of air bladder inner layer, heat to 160℃, pressurize to 15MPa, vulcanize for 20min, the reaction is complete, cool down and let stand, assemble and inflate to obtain an inflatable foot drop correction shoe.

[0113] Example 18: A method for preparing an inflatable foot drop correction shoe

[0114] S1: Under a nitrogen atmosphere, 100g of modified polyurethane rubber was added to a mixer, heated to 90℃, and 9.5g of modified chain extender, 15g of modified chitosan microspheres, 8g of modified nano silica, 8g of modified nano zinc oxide, 5.2g of polyethylene glycol and 1g of antioxidant were added. The mixture was then mixed for 10 minutes at a speed of 70 rpm to obtain the rubber compound.

[0115] S2: Add 100g of modified polyurethane rubber to a mixer, heat to 90℃, rotate at 50rpm, add 9.5g of modified chain extender, 8g of modified nano silica, 15g of modified chitosan microspheres and 1g of antioxidant, react for 20min, add to a twin-screw extruder, water-cool and pelletize, vacuum dry to obtain masterbatch;

[0116] S3: Put 100g of masterbatch into a double-layer co-extrusion blown film machine, add 6g of modified nano zinc oxide, heat to 160℃, and traction speed 7m / min to obtain the airbag inner liner.

[0117] S4: Add 32g of rubber material to the open mill, heat to 80℃, perform 4 thin passes, put it into the mold, add 10g of air bladder inner layer, heat to 170℃, pressurize to 14MPa, vulcanize for 25min, the reaction is complete, cool down and let stand, assemble and inflate to obtain an inflatable foot drop correction shoe.

[0118] Comparative Example 1:

[0119] Compared with Example 1, this comparative example did not add modified chitosan microspheres and modified nano zinc oxide during the preparation of the inflatable foot drop correction shoe. Instead, an equal amount of silicone rubber was added. All other steps and parameters were the same, and will not be repeated here. The final inflatable foot drop correction shoe was obtained.

[0120] Comparative Example 2:

[0121] Compared with Example 1, this comparative example only replaces the "modified chain extender" with "ethylenediamine chain extender". All other steps and parameters are the same, and will not be repeated here. The final result is an inflatable foot drop correction shoe.

[0122] Comparative Example 3

[0123] Compared with Example 1, this comparative example only replaces "modified polyurethane rubber" with "polyurethane rubber". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, an inflatable foot drop correction shoe is obtained.

[0124] Comparative Example 4

[0125] This comparative example differs from Example 1 only in that "modified nano silica" is replaced with "nano silica". All other steps and parameters are the same, and will not be repeated here. The final result is an inflatable foot drop correction shoe.

[0126] Performance testing:

[0127] Air tightness test:

[0128] The VAC-V1 gas permeation analyzer was used in accordance with the GB / T7755.2-2019 testing standard.

[0129] 1. Take the airbag inner liner from Examples 16-18 and Comparative Examples 1-4 respectively, cut it into a diameter of 100mm and a thickness of 0.30±0.02mm, and pre-make a through hole with a diameter of 1mm in the middle of the sample.

[0130] 2. Clamp the sample in the test chamber of the VAC-V1 gas permeation instrument, fill it with 20 kPa compressed air, heat it to 23±2℃, and record the gas leakage amount Q0 over 24 hours, in mL / min.

[0131] 3. Place the damaged sample in a 60℃ constant temperature chamber and let it stand for 2 hours. Repeat the above steps and test the leakage amount Q1 after repair.

[0132] 4. Formula for calculating airtightness: .

[0133] Self-healing test:

[0134] The test was conducted using an Instron-5969 universal testing machine, in accordance with ISO 37:2017 "Determination of tensile stress-strain properties of vulcanized or thermoplastic rubber".

[0135] 1. Take the airbag inner liner from Examples 16-18 and Comparative Examples 1-4 respectively, cut them into dumbbell-shaped specimens, put them into a testing machine, tensile speed 500 mm / min, and record the original tensile strength σ0 (MPa) and elongation at break ε0 (%).

[0136] 2. Cut a 10mm long and 0.5mm deep slit in the center of the sample. Place the damaged sample in a 60℃ constant temperature chamber and let it stand for 2 hours. Repeat the above steps and measure the tensile strength σ1 and elongation ε1 after repair.

[0137] 3. Self-repair efficiency calculation formula:

[0138]

[0139]

[0140] Table 1

[0141] project Leakage rate decreased (%) Strength recovery rate (%) Deformation recovery rate (%) Example 16 92.5 89.7 91.2 Example 17 94.1 91.3 92.8 Example 18 93.0 90.5 91.9 Comparative Example 1 15.2 18.6 22.3 Comparative Example 2 41.7 53.9 49.8 Comparative Example 3 33.5 47.1 42.6 Comparative Example 4 38.9 51.4 48.3

[0142] Antibacterial performance test:

[0143] According to the ISO 20743:2021 standard "Determination of antimicrobial activity of antimicrobial finished textile products", the Biolog microbial growth analyzer was used, and the test strains were Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922).

[0144] 1. Take the inner bladder layer of the airbag from Examples 16-18 and Comparative Examples 1-4 respectively, cut it into 25×25mm pieces, and sterilize it under ultraviolet light for 30 minutes;

[0145] 2. Take the activated Staphylococcus aureus and Escherichia coli, and dilute them with physiological saline to a concentration of 1×10⁻⁶. 5 CFU / mL;

[0146] 3. Immerse the sample in 10 mL of bacterial solution, heat to 37℃±1℃, rotate at 120 rpm, and contact for 24 h. Remove the sample, remove excess bacterial solution, and then place the sample in 10 mL of PBS solution containing 0.5% sodium thiosulfate. Shake for 5 min, take 0.1 mL of the eluent and spread it evenly on a nutrient agar plate. Set up a blank control group and spread an equal amount of bacterial solution directly on the plate. Place the plate in an incubator, heat to 37℃, and let stand for 48 h. Count the colonies.

[0147] 4. Formula for calculating antibacterial rate:

[0148] A: Average CFU count in the blank control group; B: Average CFU count in the sample contact group.

[0149] Table 2

[0150] project Staphylococcus aureus inhibition rate (%) Escherichia coli inhibition rate (%) Example 16 99.8 99.5 Example 17 99.9 99.7 Example 18 99.7 99.6 Comparative Example 1 22.1 19.8 Comparative Example 2 98.5 98.3 Comparative Example 3 96.7 95.9 Comparative Example 4 97.2 96.4

[0151] Tensile property test:

[0152] The Zwick Z010 tensile testing machine was used in accordance with the ISO 527-3:2018 testing standard.

[0153] 1. Take the inner lining of the airbag from Examples 16-18 and Comparative Examples 1-4 respectively, and cut dumbbell-shaped samples with a total length ≥150mm, a gauge length width of 6.0±0.1mm, and a thickness of 0.30±0.02mm;

[0154] 2. Place the specimen in the testing machine with a clamp spacing of 75 mm, a tensile speed of 500 mm / min, a preload force of 0.1 N, and start until fracture, recording the maximum tensile force F. max (N) and gauge length L at fracture b (mm);

[0155] 3. Tensile strength σ t (MPa): A0: Initial cross-sectional area of ​​the sample, mm 2 A0 = width × thickness;

[0156] 4. Elongation at break ε b (%) L0: Original gauge length 50mm.

[0157] Tear strength test:

[0158] The Zwick Z010 tensile testing machine was used in accordance with the ISO 34-1:2015 testing standard.

[0159] 1. Take the airbag inner liner from Examples 16-18 and Comparative Examples 1-4 respectively, and cut out right-angled samples without cuts, with a length of 100mm, a width of 25mm, and a thickness of 0.30±0.02mm.

[0160] 2. Place the specimen in the tensile testing machine, with a tear angle of 90° and a tensile speed of 500 mm / min, and record the peak tear force F. tear (N);

[0161] 3. Data Analysis: Tear Strength Ts (kN / m): d: Sample thickness, mm.

[0162] Abrasion resistance test:

[0163] 1. Take the airbag inner liner from Examples 16-18 and Comparative Examples 1-4 respectively, cut a circular sample with a diameter of 100 mm, and make a hole with a diameter of 6.5 mm in the middle;

[0164] 2. Place the sample on the H22 rubber wheel, rotate at 60 rpm, pre-grind for 500 rpm to remove the surface layer, and then test for 5000 rpm. Measure the mass M0 and M1 (mg) before and after the test.

[0165] 3. Quality loss rate W loss (%) .

[0166] Table 3

[0167] project <![CDATA[σ t (MPa)]]> <![CDATA[ε b (%)]]> Ts (kN / m) <![CDATA[W loss (%)]]> Example 16 28.5 520 42.7 3.2 Example 17 29.8 538 44.1 2.9 Example 18 27.9 508 41.5 3.5 Comparative Example 1 16.3 285 24.6 12.7 Comparative Example 2 25.1 465 38.2 4.8 Comparative Example 3 18.7 320 28.3 9.6 Comparative Example 4 23.6 420 35.9 5.3

[0168] Data Analysis

[0169] As can be seen from Tables 1-3, the inflatable foot drop correction shoe prepared by the present invention has better airtight stability, self-repair efficiency, antibacterial properties and mechanical strength.

[0170] In contrast, Comparative Example 1, lacking the addition of modified chitosan microspheres and modified nano-zinc oxide, resulted in a leakage rate decrease of only 15.2%, an antibacterial rate of less than 25%, and a tensile strength reduction of 43%. This is because the modified chitosan microspheres contain hexamethylene diisocyanate (HDI) repair agent microcapsules. When the quaternized chitosan shell ruptures upon airbag puncture, the released HDI reacts with the -NH2 and -OH groups of the polyurethane matrix to form a polyurea cross-linking network, thus sealing the macroscopic cracks. Furthermore, the nano-silver loaded with modified nano-zinc oxide disrupts the microbial cell membrane through contact, and the quaternized chitosan causes bacterial solute leakage through cation adsorption. + The positive charge of the quaternary ammonium salt superimposed on the quaternary ammonium salt creates a charge synergy effect. In addition, silicone rubber has no antibacterial groups and its surface hydrophobicity promotes bacterial colonization. At the same time, the poor interfacial compatibility between silicone rubber and polyurethane matrix weakens the overall mechanical properties.

[0171] In Comparative Example 2, replacing the modified chain extender with ethylenediamine chain extender resulted in a strength recovery rate of 53.9% and a leakage rate decrease of only 41.7%. This is because the modified chain extender contains dynamic disulfide bonds (-SS-), whose bond energy is lower than that of covalent bonds. Under thermal excitation at 60℃, it can undergo recombination to achieve microcrack repair. In contrast, the ethylenediamine chain extender forms stable urea bonds, which have no dynamic responsiveness. Furthermore, the recombination of disulfide bonds can dissipate strain energy, while the rigid urea bond network is prone to stress concentration, which accelerates crack propagation. Therefore, its stress dissipation efficiency is reduced.

[0172] In Comparative Example 3, replacing the modified polyurethane rubber with polyurethane resulted in a 34% decrease in tensile strength and a 200% increase in wear rate. This is because the modified polyurethane can precisely control the hard segment content through the prepolymer method, forming a regular hydrogen bond array and providing a highly crystalline region. In contrast, the hard segments of ordinary polyurethane are randomly distributed, have low crystallinity, and cannot co-crystallize with ZnO nanoparticles, leading to a decrease in local support strength. In addition, the amino groups on the surface of the modified nano zinc oxide form coordination bonds with the carbonyl groups of the polyurethane hard segments, thereby constructing a "rigid island" structure. In contrast, the hard segments of ordinary polyurethane have poor dispersion, and ZnO agglomeration leads to stress concentration points.

[0173] Comparative Example 4 showed a 19% decrease in elongation at break and a 51% increase in wear rate after replacing modified nano-silica with nano-silica. This was attributed to the presence of primary amine groups in the polyacrylamide chains grafted onto the surface of the modified nano-silica, which protonated to -NH3 in the sweaty environment of the feet. + It captures water molecules through hydrogen bonds to form a 10-30nm thick hydration layer, while the silanol groups on the surface of ordinary silica are highly hydrophobic, increasing the coefficient of friction on the skin. In addition, polyacrylamide chains have good compatibility with polyurethane soft segments, while ordinary silica has poor compatibility with the matrix, leading to interfacial debonding and thus weakening the interfacial bonding force.

[0174] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

[0175] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An inflatable foot drop correction shoe, characterized in that, It is composed of the following components in parts by weight: 75-80 parts modified polyurethane rubber, 6-8 parts modified chain extender, 10-12 parts modified chitosan microspheres, 5-7 parts modified nano silica, 3-5 parts polyethylene glycol, 5-7 parts modified nano zinc oxide, and 0.5-1 parts antioxidant.

2. The inflatable foot drop correction shoe according to claim 1, characterized in that, The modified polyurethane rubber is prepared using the following steps: Step A1: Under a nitrogen atmosphere, polytetrahydrofuran ether diol is added to a reaction vessel, heated to 100-120℃, reacted for 1-3 hours, cooled to 70-90℃, 4,4'-diphenylmethane diisocyanate and catalyst dibutyltin dilaurate are added, and the mixture is stirred for 80-100 minutes. Once the reaction is complete, the prepolymer is obtained. Step A2: Under a nitrogen atmosphere, place the prepolymer into a reactor, heat to 50-70℃, add 1,4-butanediol, react for 100-140 min, after the reaction is complete, reduce the pressure to -0.098 MPa, degas for 25-35 min, pour and cure, extract and dry to obtain modified polyurethane rubber. The mass ratio of polytetrahydrofuran ether diol, 4,4'-diphenylmethane diisocyanate to catalyst is 1:0.53-0.55:0.0003-0.0005; The mass ratio of the prepolymer to 1,4-butanediol is 1:0.6-0.

7.

3. The inflatable foot drop correction shoe according to claim 1, characterized in that, The preparation steps of the modified chain extender are as follows: Under a nitrogen atmosphere, 4-aminophenol was added to anhydrous tetrahydrofuran solution, heated to 20-30℃, stirred for 20-40 min, cooled to 0-5℃, triethylamine was added, disulfur dichloride was added, the temperature was raised to 6-10℃, the reaction was carried out for 2-4 h, and then the temperature was raised to 20-30℃, the reaction was carried out for 3-5 h. After the reaction was completed, the mixture was filtered, washed, purified and dried to obtain the modified chain extender. The mass ratio of 4-aminophenol, triethylamine, and disulfur dichloride is 1:0.3-0.32:0.93-0.

95.

4. The inflatable foot drop correction shoe according to claim 1, characterized in that, The modified chitosan microspheres are prepared using the following steps: Step B1: Add chitosan to 1% acetic acid solution, heat to 40-60℃, stir for 1-3 hours, cool to 35-45℃, add glycidyltrimethylammonium chloride, add 0.1mol / L sodium hydroxide solution, adjust pH to 8-9, react for 5-7 hours, purify and dry to obtain quaternized chitosan. Step B2: Add hexamethylene diisocyanate to liquid paraffin, stir and mix, add emulsifier Span-80, heat to 20-30℃, and ultrasonically disperse for 8-12 minutes to obtain the oil phase; Step B3: Add quaternized chitosan and pentylene glycol to deionized water, stir to dissolve, add oil phase, heat to 30-40℃, spin at 9000-11000 rpm, emulsify for 5-8 minutes to obtain emulsion; Step B4: Add the emulsion to a flask, heat to 50-70℃, add the crosslinking agent epichlorohydrin, add 5% sodium carbonate solution, adjust the pH to 7.5-8.5, stir the reaction for 2-4 hours, after the reaction is complete, centrifuge and wash, freeze dry to obtain modified chitosan microspheres.

5. An inflatable foot drop correction shoe according to claim 4, characterized in that, The mass ratio of chitosan to glycidyltrimethylammonium chloride in step B1 is 1:1.8-2.2; The mass ratio of hexamethylene diisocyanate, liquid paraffin and emulsifier Span-80 in step B2 is 1:24-26:0.12-0.

13.

6. An inflatable foot drop correction shoe according to claim 4, characterized in that, In step B3, the mass ratio of quaternized chitosan, pentylene glycol, and oil phase is 1:0.04-0.06:18-22. The mass ratio of the emulsion to the crosslinking agent in step B4 is 1:0.02-0.

03.

7. An inflatable foot drop correction shoe according to claim 1, characterized in that, The preparation steps of the modified nano-silica are as follows: Step C1: Under a nitrogen atmosphere, add silane coupling agent KH-550 to a mixed solvent of anhydrous ethanol and deionized water, heat to 20-30℃, stir for 20-40 min, add glacial acetic acid, adjust the pH to 4.8-5.2, heat to 50-70℃, react for 50-70 min, and obtain hydrolysate; Step C2: Under a nitrogen atmosphere, add silica to the hydrolysate, sonicate for 20-40 min, heat to 70-90℃, reflux for 5-7 h, after the reaction is complete, centrifuge, wash, and vacuum dry to obtain aminated silica; Step C3: Under a nitrogen atmosphere, add aminated silica to N,N-dimethylformamide solvent and stir until homogeneous. Add acrylamine monomer and initiator azobisisobutyronitrile, and ultrasonically disperse for 10-20 min. Heat to 60-80℃ and stir for 7-9 h. Add crosslinking agent N,N'-methylenebisacrylamide and react for 1-3 h. Once the reaction is complete, cool to 20-30℃, centrifuge, wash, and dry to obtain modified nano silica. The mass ratio of the silane coupling agent KH-550, anhydrous ethanol, and deionized water is 1:4.4-4.6:0.4-0.

6. The mass ratio of silica to hydrolysate is 1:7.4-7.6; The mass ratio of the aminated silica, acrylamine monomer, initiator and crosslinking agent is 1:0.4-0.6:0.008-0.012:0.04-0.

06.

8. An inflatable foot drop correction shoe according to claim 1, characterized in that, The modified nano zinc oxide preparation steps are as follows: Step D1: Add zinc oxide powder to anhydrous ethanol, ultrasonically disperse for 20-40 min, add 3-aminopropyltriethoxysilane, heat to 60-70℃, reflux for 3-5 h, centrifuge and wash, vacuum dry to obtain the carrier; Step D2: Add the carrier to deionized water, add silver nitrate, heat to 20-30℃, stir for 1-3 hours, add 0.1 mol / L sodium borohydride aqueous solution as reducing agent, stir for 50-70 minutes, add polyvinylpyrrolidone as dispersant, heat to 40-60℃, stir for 2-4 hours, add 1% glutaraldehyde aqueous solution, react for 50-70 minutes, after the reaction is complete, centrifuge, wash, and dry to obtain modified nano zinc oxide; The mass ratio of zinc oxide powder to 3-aminopropyltriethoxysilane is 1:0.48-0.52; The mass ratio of the carrier, silver nitrate, reducing agent, dispersant and glutaraldehyde aqueous solution is 1:0.04-0.06:0.0035-0.004:0.08-0.12:0.004-0.

006.

9. A method for preparing an inflatable foot drop correction shoe according to any one of claims 1-8, characterized in that, The preparation steps are as follows: Step S1: Under a nitrogen atmosphere, add the modified polyurethane rubber into a mixer, heat to 70-90℃, add the modified chain extender, modified chitosan microspheres, modified nano silica, modified nano zinc oxide, polyethylene glycol and antioxidant, mix for 10-20 minutes at a speed of 50-70 rpm to obtain the rubber compound. Step S2: Add the modified polyurethane rubber into a mixer, heat it to 70-90℃, rotate it at 50-70 rpm, add the modified chain extender, modified nano silica, modified chitosan microspheres and antioxidant, react for 10-20 minutes, add it to a twin-screw extruder, water-cool and pelletize it, vacuum dry it to obtain masterbatch. Step S3: Place the masterbatch into a double-layer co-extrusion blown film machine, add modified nano zinc oxide, heat to 150-160℃, and traction speed 7-9m / min to obtain the airbag inner liner. Step S4: Add the rubber compound to the open mill, heat it to 60-80℃, perform 4-6 thin passes, put it into the mold, add the air bladder inner layer, heat it to 150-170℃, pressurize it to 14-16MPa, vulcanize for 15-25 minutes, after the reaction is complete, cool it down and let it stand, assemble and inflate it to obtain an inflatable foot drop correction shoe.

10. A method for preparing an inflatable foot drop correction shoe according to claim 9, characterized in that, In step S1, the mass ratio of modified polyurethane rubber, modified chain extender, modified chitosan microspheres, modified nano silica, modified nano zinc oxide, polyethylene glycol, and antioxidant is 1:0.085-0.095:0.13-0.15:0.07-0.08:0.07-0.08:0.05-0.052:0.009-0.

01. In step S2, the mass ratio of the modified polyurethane rubber, modified chain extender, modified nano silica, modified chitosan microspheres, and antioxidant is 1:0.085-0.095:0.07-0.08:0.13-0.15:0.009-0.

01. In step S3, the mass ratio of the masterbatch to the modified nano zinc oxide is 1:0.04-0.06; The mass ratio of the adhesive material to the inner liner of the airbag in step S4 is 2.8-3.2:1.

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