High-foaming-multiple sole material and preparation method thereof

Abstract

The invention discloses a high-foaming-multiple sole material and a preparation method thereof, and belongs to the technical field of sole materials. According to the high-foaming-multiple sole material, firstly, bio-based polyurethane, modified crab shell powder, tetrabutylammonium iodide and L-ascorbic acid are evenly mixed and then subjected to foaming treatment through supercritical carbon dioxide, and then the mixture is heated and subjected to a heat preservation reaction in a carbon dioxide environment under the specific pressure; the synthetic process of the bio-based polyurethane comprises the following steps: pre-polymerizing castor oil and a diisocyanate monomer, then adding a chain extender 1, 4-butanediol and a catalyst, carrying out a mixed reaction, and finally carrying out epoxidation treatment, thereby obtaining the bio-based polyurethane. In the formula, 1, 4-butanediol is selected as a chain extender, namely 1, 4-butanediol, and lysine diisocyanate is selected as a diisocyanate monomer; the modified crab shell powder is obtained by carrying out surface modification treatment on crab shell powder by utilizing 3-aminopropyltriethoxysilane; the high-foaming-multiple sole material disclosed by the invention is good in wear resistance, good in shrinkage resistance, good in high temperature resistance and good in environmental protection performance.

Description

Technical Field

[0001] The invention relates to the technical field of sole materials, in particular to a high foaming multiple sole material and a preparation method thereof. Background Art

[0002] With the increasing global awareness of environmental protection and consumers' increasing requirements for product performance, the development of new materials that meet environmental standards and have excellent physical and chemical properties has become an important topic in the field of materials science. Among many application fields, shoe sole materials have received special attention because they are directly related to wearing comfort, durability and safety. Traditional shoe sole materials are mostly made of synthetic materials such as polyurethane (PU). Although these materials have good elasticity, softness and processing properties, they have obvious deficiencies in high temperature resistance, shrinkage resistance and wear resistance, especially when used in extreme environmental conditions, their performance deteriorates more significantly.

[0003] In recent years, with the development of bio-based and degradable materials, environmentally friendly sole materials have gradually become a research hotspot. However, existing environmentally friendly materials often fail to meet the requirements of high strength, high elasticity and good wear resistance at the same time, which limits their widespread application in high-performance footwear. In addition, traditional polyurethane foam materials are prone to shrinkage during the production process, which affects the dimensional stability and appearance quality of the product. In addition, their physical properties will further deteriorate in high temperature environments, resulting in a shortened service life.

[0004] In view of the above problems, the present invention provides a high foaming multiple sole material and a preparation method thereof. Summary of the invention

[0005] The purpose of the present invention is to provide a high foaming multiple sole material and a preparation method thereof, so as to solve the technical problems mentioned in the above background technology.

[0006] The technical solution for achieving the purpose of the present invention is: a high foaming multiple sole material, wherein the high foaming multiple sole material is obtained by mixing bio-based polyurethane, modified crab shell powder, tetrabutylammonium iodide, and L-ascorbic acid, firstly foaming with supercritical carbon dioxide, and then heating and keeping warm in a carbon dioxide environment with a certain pressure.

[0007] Furthermore, the bio-based polyurethane is obtained by prepolymerizing castor oil and diisocyanate monomers, then mixing with a chain extender 1,4-butanediol and a catalyst, and finally epoxidizing.

[0008] Furthermore, the diisocyanate monomer is lysine diisocyanate.

[0009] Furthermore, the modified crab shell powder is obtained by modifying crab shell powder with 3-aminopropyltriethoxysilane.

[0010] The present invention also provides a method for preparing a high foaming multiple sole material, comprising the following steps:

[0011] (1) under nitrogen protection, heating the castor oil to 102-104° C. and stirring for 50-70 min to remove water molecules in the castor oil, then cooling to 64-66° C., adding diisocyanate monomer under stirring at 300 rpm, and then continuing to stir at 80° C. at 800 rpm for 50-70 min to obtain a bio-based polyurethane prepolymer;

[0012] (2) adding a chain extender 1,4-butanediol and a catalyst triethylamine to the bio-based polyurethane prepolymer prepared in step (1), continuing to stir at 80° C. for 50 to 70 minutes, then cooling to 54 to 56° C., adding formic acid and continuing to stir for 4 to 6 minutes, and then dripping a mixture of hydrogen peroxide and phosphoric acid within 14 to 16 minutes, continuing to keep warm and stir for 3.5 to 4.5 hours to obtain a bio-based polyurethane;

[0013] (3) 80 parts by weight of bio-based polyurethane, 78 to 82 parts by weight of modified crab shell powder, 4.8 to 4.9 parts by weight of tetrabutylammonium iodide, and 1.1 to 1.2 parts by weight of L-ascorbic acid were mixed in an internal mixer at 88 to 92° C. for 4 to 5 minutes to obtain a composite polyurethane;

[0014] (4) placing the composite polyurethane into a high-pressure reactor and flushing the reactor with low-pressure carbon dioxide to remove the air in the reactor; then, heating the high-pressure reactor to 38-42°C; next, injecting carbon dioxide into the reactor until the internal pressure reaches 14-15 MPa; maintaining this temperature and pressure condition, maintaining pressure and penetrating for 1.8-2.2 hours; then, rapidly releasing the pressure to ensure that the pressure release rate exceeds 20 MPa / min; then, transferring the material to a steam foaming device, heating and foaming at 100-110°C for 45-55 seconds; after completion, returning the material to the high-pressure reactor again, filling the reactor with carbon dioxide to increase the pressure to 0.34-0.36 MPa, rapidly raising the temperature to 78-82°C, and reacting under this condition for 47.5-48.5 hours. After the reaction is completed, the excess carbon dioxide in the reactor is discharged, and the reaction is continued at a temperature of 24 hours to obtain a high foaming multiple sole material.

[0015] Furthermore, the molar ratio of the hydroxyl group in the castor oil to the isocyanate group in the diisocyanate monomer is 1:1.8-2.2.

[0016] Furthermore, the molar ratio of the hydroxyl group in the chain extender 1,4-butanediol to the isocyanate group in the bio-based polyurethane prepolymer is 1:0.8-1.2; the mass of the catalyst triethylamine is 0.05%-0.5% of the mass of the bio-based polyurethane prepolymer.

[0017] Furthermore, the mass ratio of castor oil, formic acid, hydrogen peroxide and phosphoric acid is 1:2.5-3.5:5.5-6.5:0.009.

[0018] Furthermore, the bio-based polyurethane is 80 parts by weight, the modified crab shell powder is 8-12 parts by weight, the tetrabutylammonium iodide is 4.8-4.9 parts by weight, and the L-ascorbic acid is 1.1-1.2 parts by weight.

[0019] Furthermore, the mixed solution of hydrogen peroxide and phosphoric acid is obtained by mixing a hydrogen peroxide solution with a concentration of 30% and phosphoric acid.

[0020] Furthermore, the preparation steps of the modified crab shell powder are as follows: after cleaning the crab shell, dry it at 100-110° C. for 23-25 ​​hours to remove the moisture therein, naturally cool it and then crush it, and separate it through a 200-mesh sieve to obtain crab shell powder; mix the crab shell powder with 24 times its mass of anhydrous ethanol, stir it at room temperature until the crab shell powder is evenly dispersed in the anhydrous ethanol, then add the silane coupling agent aqueous solution and continue stirring for 20-40 minutes, condense and reflux at 69-71° C. for 2.8-3.2 hours, and after the reaction is completed, repeatedly wash and filter with anhydrous ethanol until the filtrate is clear and transparent, place the filter residue in a vacuum drying oven, and dry it at 60-80° C. for 23-25 ​​hours to obtain modified crab shell powder; wherein the silane coupling agent aqueous solution is obtained by mixing and stirring the silane coupling agent and water in a mass ratio of 1:2 until the silane coupling agent is fully hydrolyzed; the silane coupling agent is measured according to a liquid-to-solid ratio of 4-6:1 mL / g to the crab shell powder.

[0021] By adopting the above technical solution, the present invention has the following beneficial effects:

[0022] (1) The high foaming multiple sole material of the present invention comprises the following steps: firstly, a bio-based polyurethane, modified crab shell powder, tetrabutylammonium iodide and L-ascorbic acid are uniformly mixed, and then foamed by supercritical carbon dioxide, and then heated and insulated for reaction in a carbon dioxide environment under a specific pressure; the synthesis process of the bio-based polyurethane involves pre-polymerizing castor oil and diisocyanate monomers, then adding a chain extender 1,4-butanediol and a catalyst for mixed reaction, and finally performing an epoxidation treatment to obtain the obtained product; in this formula, 1,4-butanediol is selected as the chain extender 1,4-butanediol, and lysine diisocyanate is selected as the diisocyanate monomer; the modified crab shell powder is obtained by surface-modifying the crab shell powder with 3-aminopropyltriethoxysilane; the high foaming multiple sole material of the present invention has good wear resistance, good shrinkage resistance, good high temperature resistance and good environmental performance.

[0023] (2) The present invention uses castor oil and lysine diisocyanate to prepare a bio-based polyurethane prepolymer, wherein castor oil is a natural vegetable oil that is renewable and biodegradable, meets environmental protection requirements, and reduces dependence on fossil resources. Castor oil molecules contain multiple hydroxyl groups that can react with isocyanate groups to form multiple cross-linking points, thereby improving the mechanical properties and thermal stability of the material; lysine diisocyanate is derived from the natural amino acid lysine, has good biocompatibility and biodegradability, and further improves the environmental performance of the material; lysine diisocyanate has high reactivity and can react rapidly with the hydroxyl groups in castor oil to form a stable prepolymer.

[0024] (3) The high foaming multiple sole material of the present invention is added with crab shell powder modified with 3-aminopropyltriethoxysilane, wherein the crab shell powder is a natural material with a wide source, low cost and good biodegradability. The crab shell powder modified with 3-aminopropyltriethoxysilane can improve the dispersibility and compatibility of the crab shell powder in bio-based polyurethane, so that the modified crab shell powder is evenly dispersed in the bio-based polyurethane, which helps to form a uniform and fine pore structure, improve the lightness and high elasticity of the material, and reduce the merging and growth of bubbles, thereby improving the overall performance of the foaming material; the high hardness and good dispersibility of the modified crab shell powder enable it to form uniform hard points in the material, significantly improve the wear resistance of the material, enhance the mechanical strength of the pore wall, improve the wear resistance of the material, and extend the service life of the sole.

[0025] (4) When preparing the high foaming multiple sole material of the present invention, the bio-based polyurethane prepolymer is first mixed with the chain extender 1,4-butanediol and the catalyst for reaction and then epoxidized, and the unsaturated bonds in the bio-based polyurethane prepolymer are epoxidized to convert the unsaturated bonds in the castor oil into epoxy groups; the bio-based polyurethane, modified crab shell powder, tetrabutylammonium iodide and L-ascorbic acid are then uniformly mixed and foamed with supercritical carbon dioxide, and then heated and kept warm in a carbon dioxide environment under a specific pressure. During this process, the epoxy group reacts with the carbon dioxide to form a cyclic carbonate, and the cyclic carbonate further reacts with the amino group on the surface of the modified crab shell powder to form a cross-linked structure, which significantly increases the cross-linking density of the pore wall, effectively prevents the shrinkage and deformation of the material during the foaming process, and ensures the dimensional stability and thermal stability of the product. DETAILED DESCRIPTION

[0026] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0027] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0028] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention.

[0029] Example 1

[0030] A method for preparing a high foaming multiple sole material comprises the following steps:

[0031] (1) under nitrogen protection, the castor oil was heated to 102° C. and stirred for 50 min to remove water molecules in the castor oil, then cooled to 64° C., lysine diisocyanate was added under stirring at 300 rpm, and then stirred at 80° C. at 800 rpm for 50 min to obtain a bio-based polyurethane prepolymer;

[0032] (2) adding a chain extender 1,4-butanediol and a catalyst triethylamine to the bio-based polyurethane prepolymer prepared in step (1), continuing to stir at 80° C. for 50 min, then cooling to 54° C., adding formic acid and continuing to stir for 4 min, and then dripping a mixture of hydrogen peroxide and phosphoric acid, the dripping is completed within 14 min, and continuing to keep warm and stir for 3.5 h to obtain a bio-based polyurethane;

[0033] (3) 80 parts by weight of bio-based polyurethane, 8 parts by weight of modified crab shell powder, 4.8 parts by weight of tetrabutylammonium iodide, and 1.1 parts by weight of L-ascorbic acid were placed in an internal mixer at 88° C. and kneaded for 4 minutes to obtain a composite polyurethane;

[0034] (4) The composite polyurethane is placed in a high-pressure reactor and flushed with low-pressure carbon dioxide to remove the air in the reactor; then, the high-pressure reactor is heated to 38°C; next, carbon dioxide is injected into the reactor until the internal pressure reaches 14 MPa; while maintaining this temperature and pressure condition, the pressure is maintained for 1.8 hours; then, the pressure is rapidly released to ensure that the pressure release rate exceeds 20 MPa / min; then, the material is transferred to a water vapor foaming device and heated and foamed at 100°C for 45 seconds; after completion, the material is returned to the high-pressure reactor, carbon dioxide is filled into the reactor to increase the pressure to 0.34 MPa, the temperature is rapidly raised to 78°C, and the reaction is carried out under this condition for 47.5 hours. After the reaction is completed, the excess carbon dioxide in the reactor is discharged, and the reaction is continued at a temperature of 24 hours to obtain a high foaming multiple sole material.

[0035] The molar ratio of the hydroxyl group in castor oil to the isocyanate group in lysine diisocyanate is 1:1.8; the molar ratio of the hydroxyl group in the chain extender 1,4-butanediol to the isocyanate group in the bio-based polyurethane prepolymer is 1:0.8; the mass of the catalyst triethylamine is 0.05% of the mass of the bio-based polyurethane prepolymer; the mass ratio of the castor oil, formic acid, hydrogen peroxide, and phosphoric acid is 1:2.5:5.5:0.009;

[0036] The mixed solution of hydrogen peroxide and phosphoric acid is obtained by mixing a hydrogen peroxide solution with a concentration of 30% and phosphoric acid.

[0037] The preparation steps of modified crab shell powder are as follows: clean the crab shells and dry them at 100°C for 23 hours to remove the moisture therein, naturally cool and crush them, and separate them through a 200-mesh sieve to obtain crab shell powder; mix the crab shell powder with 24 times its mass of anhydrous ethanol, stir at room temperature until the crab shell powder is evenly dispersed in the anhydrous ethanol, then add the silane coupling agent aqueous solution and continue stirring for 20 minutes, condense and reflux at 69°C for 2.8 hours, and after the reaction is completed, repeatedly wash and filter with anhydrous ethanol until the filtrate is clear and transparent, place the filter residue in a vacuum drying oven, and dry it at 60°C for 23 hours to obtain modified crab shell powder; wherein, the silane coupling agent aqueous solution is obtained by mixing and stirring the silane coupling agent and water in a mass ratio of 1:2 until the silane coupling agent is fully hydrolyzed; the silane coupling agent is measured according to a liquid-to-solid ratio of 4:1 mL / g to the crab shell powder.

[0038] Example 2

[0039] A method for preparing a high foaming multiple sole material comprises the following steps:

[0040] (1) under nitrogen protection, the castor oil was heated to 103° C. and stirred for 60 min to remove water molecules in the castor oil, then cooled to 65° C., lysine diisocyanate was added under stirring at 300 rpm, and then stirred at 80° C. at 800 rpm for 60 min to obtain a bio-based polyurethane prepolymer;

[0041] (2) adding a chain extender 1,4-butanediol and a catalyst triethylamine to the bio-based polyurethane prepolymer prepared in step (1), continuing to stir at 80° C. for 60 min, then cooling to 55° C., adding formic acid and continuing to stir for 5 min, and then dripping a mixture of hydrogen peroxide and phosphoric acid, the dripping is completed within 15 min, and continuing to keep warm and stir for 4 h to obtain a bio-based polyurethane;

[0042] (3) 80 parts by weight of bio-based polyurethane, 10 parts by weight of modified crab shell powder, 4.85 parts by weight of tetrabutylammonium iodide, and 1.15 parts by weight of L-ascorbic acid were placed in an internal mixer at 90° C. and kneaded for 4.5 minutes to obtain a composite polyurethane;

[0043] (4) The composite polyurethane is placed in a high-pressure reactor and flushed with low-pressure carbon dioxide to remove the air in the reactor; then, the high-pressure reactor is heated to 40°C; next, carbon dioxide is injected into the reactor until the internal pressure reaches 14.5 MPa; under this temperature and pressure condition, the pressure is maintained for 2 hours; then, the pressure is rapidly released to ensure that the pressure release rate exceeds 20 MPa / min; then, the material is transferred to a water vapor foaming device and heated at 105°C for foaming for 50 seconds; after completion, the material is returned to the high-pressure reactor, carbon dioxide is filled into the reactor to increase the pressure to 0.35 MPa, the temperature is rapidly raised to 80°C, and the reaction is carried out under this condition for 48 hours. After the reaction is completed, the excess carbon dioxide in the reactor is discharged, and the reaction is continued for 24 hours to obtain a high foaming multiple sole material.

[0044] The molar ratio of the hydroxyl group in castor oil to the isocyanate group in lysine diisocyanate is 1:2; the molar ratio of the hydroxyl group in the chain extender 1,4-butanediol to the isocyanate group in the bio-based polyurethane prepolymer is 1:1; the mass of the catalyst triethylamine is 0.3% of the mass of the bio-based polyurethane prepolymer; the mass ratio of the castor oil, formic acid, hydrogen peroxide, and phosphoric acid is 1:3:6:0.009;

[0045] The mixed solution of hydrogen peroxide and phosphoric acid is obtained by mixing a hydrogen peroxide solution with a concentration of 30% and phosphoric acid.

[0046] The preparation steps of modified crab shell powder are as follows: clean the crab shells and dry them at 105°C for 24 hours to remove the moisture therein, naturally cool and then crush them, and separate them through a 200-mesh sieve to obtain crab shell powder; mix the crab shell powder with 24 times its mass of anhydrous ethanol, stir at room temperature until the crab shell powder is evenly dispersed in the anhydrous ethanol, then add the silane coupling agent aqueous solution and continue stirring for 30 minutes, condense and reflux at 70°C for 3 hours, and after the reaction is completed, repeatedly wash and filter with anhydrous ethanol until the filtrate is clear and transparent, place the filter residue in a vacuum drying oven, and dry it at 70°C for 24 hours to obtain modified crab shell powder; wherein, the silane coupling agent aqueous solution is obtained by mixing and stirring the silane coupling agent and water in a mass ratio of 1:2 until the silane coupling agent is fully hydrolyzed; the silane coupling agent is measured according to a liquid-to-solid ratio of 5:1 mL / g with the crab shell powder.

[0047] Example 3

[0048] A method for preparing a high foaming multiple sole material comprises the following steps:

[0049] (1) under nitrogen protection, the castor oil was heated to 104° C. and stirred for 70 min to remove water molecules in the castor oil, then cooled to 66° C., lysine diisocyanate was added under stirring at 300 rpm, and then stirred at 80° C. at 800 rpm for 70 min to obtain a bio-based polyurethane prepolymer;

[0050] (2) adding a chain extender 1,4-butanediol and a catalyst triethylamine to the bio-based polyurethane prepolymer prepared in step (1), continuing to stir at 80° C. for 70 min, then cooling to 56° C., adding formic acid and continuing to stir for 6 min, and then dripping a mixture of hydrogen peroxide and phosphoric acid, the dripping is completed within 16 min, and continuing to keep warm and stir for 4.5 h to obtain a bio-based polyurethane;

[0051] (3) 80 parts by weight of bio-based polyurethane, 12 parts by weight of modified crab shell powder, 4.9 parts by weight of tetrabutylammonium iodide, and 1.2 parts by weight of L-ascorbic acid were placed in an internal mixer at 92° C. and kneaded for 5 minutes to obtain a composite polyurethane;

[0052] (4) The composite polyurethane is placed in a high-pressure reactor and flushed with low-pressure carbon dioxide to remove the air in the reactor; then, the high-pressure reactor is heated to 42°C; next, carbon dioxide is injected into the reactor until the internal pressure reaches 15 MPa; while maintaining this temperature and pressure condition, the pressure is maintained for 2.2 hours; then, the pressure is rapidly released to ensure that the pressure release rate exceeds 20 MPa / min; then, the material is transferred to a water vapor foaming device and heated and foamed at 110°C for 55 seconds; after completion, the material is returned to the high-pressure reactor, carbon dioxide is filled into the reactor to increase the pressure to 0.36 MPa, the temperature is rapidly raised to 82°C, and the reaction is carried out under this condition for 48.5 hours. After the reaction is completed, the excess carbon dioxide in the reactor is discharged, and the reaction is continued at a temperature of 24 hours to obtain a high foaming multiple sole material.

[0053] The molar ratio of the hydroxyl group in castor oil to the isocyanate group in lysine diisocyanate is 1:2.2; the molar ratio of the hydroxyl group in the chain extender 1,4-butanediol to the isocyanate group in the bio-based polyurethane prepolymer is 1:1.2; the mass of the catalyst triethylamine is 0.5% of the mass of the bio-based polyurethane prepolymer; the mass ratio of the castor oil, formic acid, hydrogen peroxide, and phosphoric acid is 1:3.5:6.5:0.009;

[0054] The mixed solution of hydrogen peroxide and phosphoric acid is obtained by mixing a hydrogen peroxide solution with a concentration of 30% and phosphoric acid.

[0055] The preparation steps of modified crab shell powder are as follows: clean the crab shells and dry them at 110°C for 25 hours to remove the moisture therein, naturally cool and then crush them, and separate them through a 200-mesh sieve to obtain crab shell powder; mix the crab shell powder with 24 times its mass of anhydrous ethanol, stir at room temperature until the crab shell powder is evenly dispersed in the anhydrous ethanol, then add the silane coupling agent aqueous solution and continue stirring for 40 minutes, condense and reflux at 71°C for 3.2 hours, and after the reaction is completed, repeatedly wash and filter with anhydrous ethanol until the filtrate is clear and transparent, place the filter residue in a vacuum drying oven, and dry it at 80°C for 25 hours to obtain modified crab shell powder; wherein, the silane coupling agent aqueous solution is obtained by mixing and stirring the silane coupling agent and water in a mass ratio of 1:2 until the silane coupling agent is fully hydrolyzed; the silane coupling agent is measured according to a liquid-to-solid ratio of 6:1 mL / g with the crab shell powder.

[0056] Comparative Example 1

[0057] The difference between Comparative Example 1 and Example 2 is that only bio-based polyurethane, crab shell powder, tetrabutylammonium iodide and L-ascorbic acid are mixed to prepare composite polyurethane; the remaining steps and components are the same as those in Example 2.

[0058] Comparative Example 2

[0059] The difference between Comparative Example 2 and Example 2 is that only bio-based polyurethane, tetrabutylammonium iodide and L-ascorbic acid are mixed to prepare composite polyurethane; the remaining steps and components are the same as those in Example 2.

[0060] Comparative Example 3

[0061] The difference between Comparative Example 3 and Example 2 is only step (2). The specific steps of step (2) of this comparative example are as follows: add chain extender 1,4-butanediol and catalyst triethylamine to the bio-based polyurethane prepolymer prepared in step (1), continue stirring at 80° C. for 60 minutes, and naturally cool to room temperature to obtain bio-based polyurethane; the remaining steps and components are the same as those in Example 2.

[0062] Comparative Example 4

[0063] The difference between Comparative Example 4 and Example 2 is only step (4). The specific steps of step (4) of this comparative example are as follows: placing the composite polyurethane into a high-pressure reactor, and flushing the reactor with low-pressure carbon dioxide to remove the air in the reactor; then, heating the high-pressure reactor to 42°C; next, injecting carbon dioxide into the reactor until the internal pressure reaches 15MPa; maintaining this temperature and pressure condition, maintaining pressure and permeating for 2.2h; then, quickly releasing the pressure to ensure that the pressure release rate exceeds 20MPa / min; then, transferring the material to a water vapor foaming device, heating and foaming at 110°C for 55s to obtain a high foaming multiple sole material; the remaining steps and components are the same as those in Example 2.

[0064] Comparative Example 5

[0065] The only difference between Comparative Example 5 and Example 2 is that the bio-based polyurethane prepolymer is prepared by using polyether polyol and lysine diisocyanate, and the remaining steps and components are the same as those of Example 2.

[0066] The polyether polyol used is polyether polyol DL2000.

[0067] Effect example:

[0068] Foaming density: The apparent density of the high foaming multiple sole material prepared in the test examples and comparative examples according to GB / 6343-2009 in the foamed and foamed states is measured, and the ratio of the two is used to characterize the foaming ratio of the high foaming multiple sole material.

[0069] Wear resistance: GB / T 3903.2-2017 was used to test the wear resistance of the high foaming multiple sole materials prepared in the examples and comparative examples.

[0070] Thermogravimetric analysis: The high foaming multiple sole materials prepared in the embodiments and comparative examples were analyzed using a TGA / SDTA 851° thermogravimetric analyzer produced by Mettler-Toledo of Switzerland, wherein the mass of the high foaming multiple sole materials prepared in the embodiments and comparative examples was 10 mg, the test temperature range was from room temperature to 500°C, the heating rate was 10°C / min, the carrier gas was nitrogen, and the gas flow rate was 50 mL / min.

[0071]

[0072] It can be seen from the above table that the high foaming multiple shoe sole materials prepared in Examples 1 to 3 have high foaming multiples, good high temperature resistance and good wear resistance.

[0073] Compared with the high foaming multiple sole materials prepared in Comparative Examples 1 to 2, Example 2 uses modified crab shell powder to prepare high foaming multiple sole materials with better wear resistance and high temperature resistance, and the amino groups on the surface of the modified crab shell powder react with the cyclic carbonate in the subsequent preparation steps to cross-link and effectively prevent the shrinkage and deformation of the material during the foaming process.

[0074] Compared with the high foaming multiple sole materials prepared in Comparative Examples 3 to 4, in Example 2, the bio-based polyurethane prepolymer is first mixed with the chain extender 1,4-butanediol and the catalyst for reaction and then epoxidized, and the unsaturated bonds in the bio-based polyurethane prepolymer are epoxidized to convert the unsaturated bonds in the castor oil into epoxy groups; the bio-based polyurethane, modified crab shell powder, tetrabutylammonium iodide and L-ascorbic acid are then evenly mixed and foamed with supercritical carbon dioxide, and then heated and kept warm for reaction in a carbon dioxide environment under a specific pressure. During this process, the epoxy group reacts with the carbon dioxide to form a cyclic carbonate, and the cyclic carbonate further reacts with the amino group on the surface of the modified crab shell powder to form a cross-linked structure, which significantly increases the cross-linking density of the pore wall, effectively prevents the shrinkage and deformation of the material during the foaming process, and has good thermal stability.

[0075] Compared with the high foaming multiple sole material prepared in Comparative Example 5, Example 2 uses castor oil as a polyol for reaction, introduces unsaturated bonds in the bio-based polyurethane prepolymer, and subsequently reacts with carbon dioxide after epoxidation to form cyclic carbonates. The cyclic carbonates further react with the amino groups on the surface of the modified crab shell powder to form a cross-linked structure, which effectively prevents the shrinkage and deformation of the material during the foaming process and has good thermal stability.

[0076] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high foaming multiple sole material, characterized in that: The high foaming multiple sole material is obtained by mixing bio-based polyurethane, modified crab shell powder, tetrabutylammonium iodide and L-ascorbic acid, foaming with supercritical carbon dioxide, and then heating and keeping warm in a carbon dioxide environment with a certain pressure.

2. The high foaming multiple sole material according to claim 1, characterized in that: The bio-based polyurethane is obtained by prepolymerizing castor oil and diisocyanate monomers, then mixing with a chain extender 1,4-butanediol and a catalyst for reaction, and finally performing epoxidation.

3. The high foaming multiple sole material according to claim 1, characterized in that: The diisocyanate monomer is lysine diisocyanate.

4. The high foaming multiple sole material according to claim 1, characterized in that: The modified crab shell powder is obtained by modifying crab shell powder with 3-aminopropyltriethoxysilane.

5. A method for preparing a high foaming multiple sole material as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: (1) adding a diisocyanate monomer to the dehydrated castor oil under nitrogen protection and continuous stirring, and then stirring and reacting at a certain temperature to obtain a bio-based polyurethane prepolymer; (2) adding a chain extender 1,4-butanediol and a catalyst triethylamine to the bio-based polyurethane prepolymer prepared in step (1) to continue the heat preservation reaction for a period of time, then cooling to 54-56° C., adding a mixed solution of formic acid, hydrogen peroxide and phosphoric acid in sequence, and heat preservation reaction to obtain a bio-based polyurethane; (3) weighing and mixing the bio-based polyurethane, modified crab shell powder, tetrabutylammonium iodide, and L-ascorbic acid to obtain a composite polyurethane; (4) The composite polyurethane is placed in a high-pressure reactor for supercritical carbon dioxide foaming, and then the temperature is increased and kept warm under a certain pressure of carbon dioxide to obtain a high foaming multiple sole material.

6. The method for preparing a high foaming multiple sole material according to claim 5, characterized in that: The molar ratio of the hydroxyl group in the castor oil to the isocyanate group in the diisocyanate monomer is 1:1.8-2.

2.

7. The method for preparing a high foaming multiple sole material according to claim 5, characterized in that: The molar ratio of the hydroxyl group in the chain extender 1,4-butanediol to the isocyanate group in the bio-based polyurethane prepolymer is 1:0.8-1.2; the mass of the catalyst triethylamine is 0.05%-0.5% of the mass of the bio-based polyurethane prepolymer.

8. The method for preparing a high foaming multiple sole material according to claim 5, characterized in that: The mass ratio of the castor oil, formic acid, hydrogen peroxide and phosphoric acid is 1:2.5-3.5:5.5-6.5:0.

009.

9. The method for preparing a high foaming multiple sole material according to claim 5, characterized in that: In parts by weight, the bio-based polyurethane comprises 80 parts by weight, the modified crab shell powder comprises 8 to 12 parts by weight, the tetrabutylammonium iodide comprises 4.8 to 4.9 parts by weight, and the L-ascorbic acid comprises 1.1 to 1.2 parts by weight.

10. The method for preparing a high foaming multiple sole material according to claim 5, characterized in that: The mixed solution of hydrogen peroxide and phosphoric acid is obtained by mixing a hydrogen peroxide solution with a concentration of 30% and phosphoric acid.

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