Preparation method of functional waste edible mushroom residue-based vegan leather

Abstract

The application discloses a preparation method of functional waste edible mushroom residue-based vegan leather, and the vegan leather comprises, from outside to inside, a surface layer, a foaming layer, a bonding layer and a base layer; the mushroom residue is subjected to demethylation and boron crosslinking modification, phenolic hydroxyl groups converted from methoxyl groups are reacted with isocyanate in bio-based waterborne polyurethane to form phenolic carbamic acid ester bonds, and the interface interaction between the mushroom residue and resin is improved; crosslinking of boron compounds and phenolic hydroxyl groups inhibits the agglomeration of mushroom residue particles, and the flame retardant property of the vegan leather is improved; meanwhile, borate anions are complexed with phenolic hydroxyl groups converted from methoxyl groups, and the two have a synergistic effect, which jointly influences the compatibility between the mushroom residue and resin, the breaking strength of the vegan leather, the flame retardant property and the ultraviolet radiation resistance; the modified mushroom residue is prepared into vegan leather by using bio-based polymers, the preparation process is energy-saving and consumption-reducing, the finished product is green, environment-friendly and degradable, and the use of petroleum-based synthetic leather is replaced.

Description

Technical Field

[0001] This invention relates to a method for preparing functional vegan leather based on waste edible fungi residue, belonging to the fields of materials science and leather processing technology. Background Technology

[0002] Today, most raw hides used for leather are byproducts of the meat industry. The production and processing of animal leather require the use of large amounts of harmful chemicals, posing numerous environmental, social, and health problems.

[0003] However, current veneer production mainly uses solvent-based polyurethane and polyvinyl chloride materials. The production process is highly polluting and uses a large amount of toxic chemical solvents, making it difficult to achieve clean production. In addition, about 10% of the organic solvents cannot be recycled, and companies will discharge them into the environment as waste gas and wastewater, resulting in serious waste of resources and potential threats to the environment and consumer health.

[0004] Patent CN114908586A discloses a bio-based water-based bamboo residue leather and its manufacturing method. Specifically, bamboo residue is decolorized and deoiled, ground, and then mixed with water-based polyurethane, color paste, and other additives. The resulting synthetic leather is then prepared using a dry process. However, the amount of bamboo residue added is very small, and petroleum-based polyurethane is still the main raw material. In addition, the synthetic leather prepared using the dry process lacks a high-elasticity microporous structure, has poor breathability and moisture permeability, lacks a fleshy feel, and has a flat hand feel.

[0005] Patent CN216782913U discloses a fire-retardant leather with flame-retardant properties, specifically by coating the outer leather layer with multiple layers of oil-wax film, and then coating the outermost layer of oil-wax film with a flame retardant. However, since the flame retardant and oil-wax film are only sprayed onto the surface of the leather, the main flame-retardant component is the surface coating. When the surface coating is damaged by wear or other means, the leather loses its flame-retardant properties and does not have durable flame-retardant properties.

[0006] Meanwhile, with the continuous expansion of edible fungi cultivation in my country, the amount of mushroom residue has also increased explosively. However, due to the lack of effective means of resource utilization, mushroom residue is usually treated as waste and disposed of, which not only leads to the waste of resources, but also causes the breeding of harmful bacteria and pests, resulting in serious environmental pollution. Summary of the Invention

[0007] To address the problems of energy waste and environmental pollution in the production of vegan leather, poor resilience, fullness, and breathability of the prepared vegan leather, lack of flame retardancy and durability, and the ineffective utilization of large amounts of edible mushroom residue generated in agriculture, this invention provides a method for preparing functional vegan leather based on waste edible mushroom residue. The method modifies the waste edible mushroom residue, significantly increasing the proportion of the modified residue added to the resin. While ensuring the physical properties of the finished product, it endows the vegan leather with excellent flame retardant and UV-resistant properties.

[0008] The first objective of this invention is to provide a method for preparing functional vegan leather based on waste edible mushroom residue, comprising the following steps:

[0009] (1) Preparation of surface slurry: Bio-based waterborne polyurethane, bactericide and dispersant are mixed and dispersed for the first time. After uniform dispersion, waste edible fungus residue is added and thickener is added for the second dispersion. After centrifugation and degassing, surface slurry is obtained.

[0010] (2) Preparation of foamed layer slurry: mix bio-based waterborne polyurethane, foaming agent, bactericide and dispersant and disperse for the first time. After uniform dispersion, add waste edible fungus residue and thickener, and disperse for the second time to obtain foamed layer slurry;

[0011] (3) Preparation of adhesive layer slurry: mix bio-based waterborne polyurethane, bactericide and dispersant and disperse for the first time. After uniform dispersion, add waste edible fungus residue and thickener, and disperse for the second time to obtain adhesive layer slurry;

[0012] (4) Preparation of base layer: The base fabric is pretreated by impregnation, rolling, ironing and drying.

[0013] (5) Preparation of vegan leather: Coat the surface layer slurry on the release paper and dry it to obtain the surface layer; then coat the surface layer with foaming layer slurry, dry it, then coat the adhesive layer slurry, and finally attach the base layer and dry it to obtain vegan leather.

[0014] The waste edible mushroom residue is modified edible mushroom residue. The specific modification method is as follows: the demethylated waste edible mushroom residue is soaked in boric acid solution, filtered and dried so that the moisture content of the residue is <3%.

[0015] The functionality mentioned in this invention refers to the flame-retardant and UV-resistant properties of vegan leather prepared based on modified fungal residue.

[0016] In one embodiment of the present invention, the method for preparing demethylated waste edible mushroom residue is as follows: waste edible mushroom residue and surfactant are mixed, a catalyst is added under ice-water bath conditions and continuously stirred, the mixture after reaction is subjected to oil bath, condensed and refluxed under nitrogen, then the pH is adjusted to neutral with HCl solution, and the waste edible mushroom residue is obtained after centrifugation and drying.

[0017] In one embodiment of the present invention, the surfactant includes at least one selected from dodecyl mercaptan, tetramethyl dithiothiuram, sodium hydrosulfide, sodium methylthiosulfate, and diethyl sulfite.

[0018] In one embodiment of the present invention, the mass-to-volume ratio of the surfactant to the waste edible mushroom residue is 1~5 g / mL, the temperature of the ice-water bath is 2~12℃, the mass ratio of the surfactant to the catalyst is 2~10, the temperature of the oil bath is 100~180℃, the reflux time is 1~3 h, and the concentration of HCl is 0.2~2 mol / L.

[0019] In one embodiment of the present invention, the boric acid solution has a mass fraction of 1-15%, the soaking time is 2-24 hours, the drying temperature is 60-150°C, and the drying time is 2-12 hours.

[0020] In one embodiment of the present invention, the waste edible fungi residue includes at least one of crushable solid agricultural wastes such as Ganoderma lucidum substrate, Auricularia auricula-judae substrate, Pleurotus ostreatus substrate, Enoki mushroom substrate, and Agrocybe aegerita substrate.

[0021] In one embodiment of the present invention, the waste edible mushroom residue needs to be cleaned, sterilized and crushed before modification. The sterilization method includes steaming and / or high-temperature heating. The particle size of the crushed mushroom residue is 0.1~10um.

[0022] In one embodiment of the present invention, in step (1), the amounts of each component of the surface slurry are 20-80 parts of bio-based waterborne polyurethane, 0.3-10 parts of bactericide, 0.5-15 parts of dispersant, 10-90 parts of bacterial residue, and 0.5-15 parts of thickener.

[0023] In one embodiment of the present invention, in step (1), the rotation speed during the first dispersion is 300~1000 rpm and the dispersion time is 10~40 min; the rotation speed during the second dispersion is 1000~5000 rpm and the dispersion time is 10~40 min.

[0024] In one embodiment of the present invention, after adding the thickener in step (1), the viscosity of the mixed slurry is 1500~6000 cps.

[0025] In one embodiment of the present invention, in step (2), the amounts of each component of the foaming layer slurry are 20-80 parts of bio-based waterborne polyurethane, 1-10 parts of foaming agent, 0.3-10 parts of bactericide, 0.5-15 parts of dispersant, 10-90 parts of bacterial residue, and 0.5-15 parts of thickener.

[0026] In one embodiment of the present invention, in step (2), the rotation speed during the first dispersion is 300~1000 rpm and the dispersion time is 10~40 min; the rotation speed during the second dispersion is 1000~5000 rpm and the dispersion time is 10~40 min.

[0027] In one embodiment of the present invention, after adding the thickener in step (2), the viscosity of the mixed slurry is 3000~25000 cps.

[0028] In one embodiment of the present invention, in step (3), the amounts of each component of the adhesive layer slurry are 10-80 parts of bio-based waterborne polyurethane, 0.3-10 parts of bactericide, 0.5-15 parts of dispersant, 10-90 parts of bacterial residue, and 0.5-15 parts of thickener.

[0029] In one embodiment of the present invention, in step (3), the rotation speed during the first dispersion is 300~1000 rpm and the dispersion time is 10~40 min; the rotation speed during the second dispersion is 1000~5000 rpm and the dispersion time is 10~40 min.

[0030] In one embodiment of the present invention, after adding the thickener in step (3), the viscosity of the mixed slurry is 10,000 to 45,000 cps.

[0031] In one embodiment of the present invention, in step (4), the base layer is obtained by impregnating, rolling, ironing and drying the base fabric, wherein the impregnation liquid contains a fluorine-free waterproofing agent, a salt solution and bacterial residue, wherein the mass ratio of the fluorine-free waterproofing agent, the salt solution and the bacterial residue is 2~15:2~13:3~20.

[0032] In one embodiment of the present invention, in step (4), the fluorine-free waterproofing agent is selected from at least one of polydimethylsiloxane, polymethylhydrosiloxane, long-chain alkane fluorine-free waterproofing agent, ammonium aminosulfonate, sodium octadecenoate, and calcium naphthenate; the salt solution is selected from at least one of sodium chloride, sodium sulfate, sodium bismuthate, sodium bicarbonate, sodium carbonate, and sodium trititanate; the concentration of the fluorine-free waterproofing agent is 2% to 15%, and the concentration of the salt solution is 2% to 13%.

[0033] In one embodiment of the present invention, in step (4), the impregnation is performed at 5~35°C for 5~25 min, and the liquid rolling rate is 50%~90%.

[0034] In one embodiment of the present invention, in step (5), the coating thickness of the surface slurry is 0.1~0.6mm, and the drying temperature is 40℃~100℃; the coating thickness of the foam layer is 0.1~0.6mm, and the drying temperature is 50~120℃; the coating thickness of the adhesive layer is 0.1~0.5mm, and the drying temperature after bonding with the base layer is 60~110℃.

[0035] The present invention also provides a functional vegan leather based on waste edible fungi residue prepared according to the above method.

[0036] This invention also provides an application of functional waste edible mushroom residue-based vegan leather in the textile field.

[0037] In one embodiment of the present invention, the applications include those for apparel textiles and industrial textiles.

[0038] Beneficial effects of the present invention

[0039] (1) The present invention provides a method for preparing functional waste edible mushroom residue-based vegan leather. The mushroom residue is modified by chemical modification under mild conditions. The phenolic hydroxyl groups converted from methoxy groups react with isocyanates in bio-based waterborne polyurethane to form dynamic covalent bonds at the interface, forming phenolic carbamate bonds, which greatly improves the interfacial interaction between the mushroom residue and the resin matrix. In addition, the polar groups in the modified mushroom residue also interact with the resin segments through interfacial hydrogen bonds to form a chemical-physical double cross-linked network structure. The dynamic covalent bonds and hydrogen bonds at the interface constrain the movement of the chain segments at the molecular level, which improves the toughness and elasticity of the vegan leather.

[0040] (2) Fungal residue is combustible, but compared with pure polymers, its carbonization tendency helps reduce the combustion tendency of vegan leather. However, due to poor structure, pore fusion, and high condensation of aromatic structures, the flame retardant performance of the finished product is poor. Based on this, the present invention crosslinks demethylated fungal residue with boron compounds. The addition of boron increases the glass transition temperature and thermal stability of fungal residue, reduces the gas-liquid ratio, and increases the CO and CO2 content. The crosslinking of boron compounds inhibits the agglomeration of fungal residue particles and reshapes the microstructure of pyrolytic char. While ensuring good compatibility with the matrix, it greatly improves the flame retardant performance of vegan leather.

[0041] (3) After modification, the proportion of fungal residue added to bio-based waterborne polyurethane is greatly increased. Moreover, the functional groups such as phenolic hydroxyl groups, ketone groups and carboxyl groups contained in the fungal residue, due to intramolecular hydrogen bonding and conjugation, endow vegan leather with excellent flame retardant and UV radiation resistance while ensuring the physical properties of the finished product.

[0042] (4) Compared with commercially available leather, the vegan leather prepared by this invention has the following advantages:

[0043] Environmentally friendly vegan leather is prepared using agricultural waste, edible mushroom residue, as a biomass filler, thus reusing waste edible mushroom residue resources and realizing the high value of low-value waste. While ensuring good compatibility with the matrix, the amount of modified mushroom residue added is significantly increased. Based on the structural characteristics of the modified mushroom residue, while ensuring a high bio-based content in the vegan leather, the finished product is endowed with flame-retardant and UV-resistant functional properties. Using bio-based polymers and waste edible mushroom residue as the main raw materials for vegan leather manufacturing reduces the consumption of petroleum energy and replaces the use of synthetic leather made primarily from petroleum. The entire preparation process does not use any heavy metals or toxic chemicals and does not involve any animal-related components. Attached Figure Description

[0044] Figure 1 Structural cross-sectional view of vegan leather based on waste edible mushroom residue;

[0045] Figure 2 Comparison of limiting oxygen index of vegan leather prepared in Examples 1-6 and Comparative Examples 1-3;

[0046] Figure 3 Comparison of moisture permeability of vegan leather prepared in Examples 9-12;

[0047] Figure 4 Comparison of the tensile strength of the vegan leathers prepared in Examples 9-12;

[0048] Figure 5 A schematic diagram illustrating the effect of the microbial residue powder fiber on the water vapor permeability of the foamed layer in this invention. Detailed Implementation

[0049] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0050] Test method:

[0051] 1. Limiting Oxygen Index (LOI) Test:

[0052] According to ASTM D2863-77 standard, a HC900-2 oxygen index meter was used to test vegan leather samples with a sample size of 14.0 cm × 5.2 cm. The limiting oxygen index is the percentage of the lowest oxygen volume concentration required for the sample to burn stably for 3 minutes.

[0053] 2. Vertical burning test:

[0054] The vertical burning parameters of leather samples were tested according to the ALCA Method E50 standard, including burning time, flameless burning time, carbonization length, and mass loss rate.

[0055] 2. UV radiation resistance test:

[0056] According to GB / T18830-2009 Evaluation of UV protection performance of textiles, the sample is irradiated with UV rays, the spectral transmission rays are collected, the spectral transmittance is measured, and the UV protection factor (UPF) and UV transmittance of the sample are calculated.

[0057] 3. Air permeability and moisture permeability test:

[0058] The moisture permeability of the foamed coating was tested according to GB / T 12704.2-2009 "Textiles - Test Methods for Moisture Permeability - Part 1: Moisture Absorption Method". The test environment temperature was (38±2)℃ and the humidity was (50±2)%.

[0059] 4. Mechanical property testing:

[0060] The fracture strength of the foamed coating was tested according to QB / T 2710-2005 "Physical and Mechanical Tests of Leather - Determination of Tensile Strength and Elongation". The sample width was 50 mm, the spacing was 200 mm, and the tensile speed was 100 mm / min.

[0061] Raw materials used in the examples:

[0062] Preparation of waste edible mushroom residue: The waste edible mushroom residue is washed to remove impurities and dirt; the washed residue is steamed at 100℃ for 20 min or heated at 121℃ for 30 min to kill bacteria and other microorganisms in the residue; the sterilized residue is dried and mechanically ground.

[0063] The thickener is carboxymethyl cellulose;

[0064] The bactericide is isothiazolinone;

[0065] The dispersant is a polycarboxylate;

[0066] The foaming agent is sodium α-alkenyl sulfonate;

[0067] The catalyst is sodium methoxide;

[0068] The nucleophile is 1-dodecylthiol;

[0069] The boron compound is ammonium borate;

[0070] Bio-based waterborne polyurethane is an anionic aliphatic polyether (viscosity 100-500 mpa∙s-25℃; pH 7-9);

[0071] In the examples, solutions without a specific solvent are all water-based; percentages and proportions without a specific content are all mass percentages or mass ratios; and parts are all parts by mass.

[0072] Example 1

[0073] A method for preparing vegan leather based on waste edible mushroom residue (particle size 1 μm) includes the following steps:

[0074] S1: Preparation of surface layer slurry:

[0075] 25 parts of bio-based waterborne polyurethane, 1.6 parts of isothiazolinone, and 2 parts of polycarboxylate were dispersed at 500 rpm for 20 min. Then, 85 parts of waste edible fungus residue and 4.5 parts of carboxymethyl cellulose were added to make the viscosity of the mixed slurry 2000 cps. The mixture was dispersed at 1200 rpm for 20 min, stirred thoroughly, centrifuged to remove bubbles for 20 min, and then sealed and allowed to stand at room temperature for later use.

[0076] S2: Preparation of foaming layer slurry:

[0077] 25 parts of bio-based waterborne polyurethane, 1.6 parts of isothiazolinone, 4 parts of sodium α-olefin sulfonate, and 3 parts of polycarboxylate were dispersed at 500 rpm for 20 min; then 65 parts of waste edible fungus residue and 4.8 parts of carboxymethyl cellulose were added to make the viscosity of the mixed slurry 10000 cps and dispersed at 3500 rpm for 20 min to obtain the foamed layer slurry.

[0078] S3: Preparation of adhesive layer slurry:

[0079] 36 parts of bio-based waterborne polyurethane, 1.6 parts of isothiazolinone, and 2.7 parts of polycarboxylate were dispersed at 500 rpm for 20 min; then 53 parts of waste edible fungus residue and 4.1 parts of carboxymethyl cellulose were added to make the viscosity of the mixed slurry 11000 cps and dispersed at 3500 rpm for 20 min to obtain the bio-based waterborne residue adhesive layer slurry.

[0080] S4: Preparing the base layer:

[0081] A 5% sodium chloride solution, a 10% sodium octadecenoate solution, and fungal residue were mixed evenly in a mass ratio of 6.5:7.5:12 to obtain the impregnation solution.

[0082] Woven cotton fiber fabric (weight 180 g / m²) 2 The fabric is immersed in the impregnation solution at 28℃ for 15 minutes, then rolled with a liquid-pinching rate of 90%, ironed, and dried at 75℃ to obtain a pretreated base fabric with a thickness of 0.4 mm.

[0083] S5: Preparation of environmentally friendly vegan leather:

[0084] A surface layer slurry with a thickness of 0.2 mm is coated onto the release paper and dried at 90 ℃. Then, a foaming layer slurry with a thickness of 0.2 mm is coated onto the surface layer and dried at 80 ℃. Next, an adhesive layer slurry with a thickness of 0.1 mm is coated. Finally, the base layer is bonded together and dried at 95 ℃ to obtain vegan leather.

[0085] In this embodiment, the waste edible mushroom residue is modified Ganoderma lucidum waste residue, and the specific modification method includes the following steps:

[0086] (1) Under a nitrogen atmosphere, 5 mL of 1-dodecyl mercaptan and 5 g of bacterial residue were added to a three-necked round-bottom flask equipped with a magnetic stirrer and placed in an ice-water bath. When the internal temperature of the flask was below 10°C, 2 g of catalyst was added and stirred continuously. Then the flask was transferred to an oil bath and heated to 110°C. The mixture was refluxed under nitrogen for 2.5 h. After quenching, the flask was cooled in ice water. The pH of the reactants was adjusted to neutral with 1 mol / L HCl solution and centrifuged. After drying at 70°C, demethylated bacterial residue was obtained.

[0087] (2) Soak the demethylated fungal residue in 1% ammonium borate solution for 12 h, filter it and dry it in an oven at 85℃ for 3 h so that the final moisture content of the fungal residue is <3%.

[0088] Example 2

[0089] The difference between Example 2 and Example 1 is that the concentration of the ammonium borate solution is 2%.

[0090] Example 3

[0091] The difference between Example 3 and Example 1 is that the concentration of the ammonium borate solution is 3%.

[0092] Example 4

[0093] The difference between Example 4 and Example 1 is that the concentration of the ammonium borate solution is 4%.

[0094] Example 5

[0095] The difference between Example 5 and Example 1 is that the concentration of the ammonium borate solution is 5%.

[0096] Example 6

[0097] The difference between Example 6 and Example 1 is that the concentration of the ammonium borate solution is 6%.

[0098] Comparative Example 1

[0099] The difference between Comparative Example 1 and Example 5 is that the waste Ganoderma lucidum residue in Example 5 was made into vegan leather without demethylation and flame retardant modification.

[0100] Comparative Example 2

[0101] The difference between Comparative Example 2 and Example 5 is that the waste Ganoderma lucidum residue in Example 5 was not demethylated, but only modified for flame retardancy.

[0102] Comparative Example 3

[0103] The difference between Comparative Example 3 and Example 5 is that the waste Ganoderma lucidum residue in Example 5 was only demethylated without flame retardant modification.

[0104] The performance of the vegan leathers prepared in Examples 1-6 and Comparative Examples 1-3 was tested respectively. Figure 2 The limiting oxygen index of the vegan leathers prepared in Examples 1-6 and Comparative Examples 1-3 is shown. Tables 1-3 give the physical properties, vertical burning properties and UV radiation resistance of the relevant examples and comparative examples, respectively.

[0105] Comparative Example 1 showed that: (1) compared with vegan leather made from boron-crosslinked modified fungal residue, vegan leather prepared from unmodified fungal residue had a lower limiting oxygen index (LOI) of 25.6%; (2) its optimal addition amount in 20 mL of bio-based waterborne polyurethane was 7.8 g; (3) when a 0.2 mm surface layer was prepared according to the patented process, the mechanical strength of the prepared surface layer was 1.4 MPa when the amount of fungal residue added was the same; and the moisture permeability was 5874.65 g∙(m 2 ∙24h) -1 (4) The UPF value in the UV resistance test was 32.46.

[0106] The results of Comparative Example 2 showed that (1) the optimal addition amount in 20 mL of bio-based aqueous polyurethane was 8.6 g; (2) when a 0.2 mm surface layer was prepared according to the patented process, the mechanical strength of the surface layer prepared from the modified microbial residue was 1.7 MPa when the amount of microbial residue added was the same; and the moisture permeability was 6174.58 g∙(m 2 ∙24h) -1(3) The limiting oxygen index of the raw leather is 27.6%; (4) The UPF value in the UV resistance test is 35.78.

[0107] The results of Comparative Example 3 showed that (1) the optimal addition amount in 20 mL of bio-based waterborne polyurethane was 14.5 g; (2) the UPF value in the UV resistance test was 34.62; (3) the limiting oxygen index was 26.2%; (4) when a 0.2 mm surface layer was prepared according to the patented process, the mechanical strength of the prepared surface layer was 1.5 MPa when the amount of bacterial residue added was the same; and the moisture permeability was 6483.69 g∙(m 2 ∙24h) -1 .

[0108] The matrix compatibility in Table 1 refers to the optimal addition amount of modified bacterial residue in 20 mL of bio-based waterborne polyurethane; the 0.2 mm surface layer prepared according to the patented process was subjected to a fracture strength test.

[0109]

[0110] Analysis of the data in Tables 1-3 and Comparative Examples 1-3 shows that:

[0111] (1) The amount of fungal residue modified by demethylation and boron crosslinking in waterborne polyurethane is greater than that of fungal residue modified by demethylation only. This indicates that boron crosslinking modification not only imparts flame retardancy to the raw leather but also improves the compatibility between fungal residue and the waterborne polyurethane matrix.

[0112] (2) The flame retardancy of the fungal residue leather modified by demethylation and boron crosslinking is greater than that of the fungal residue leather modified by boron crosslinking alone, indicating that the demethylation modification improves the compatibility with the matrix while also improving the flame retardancy of the fungal residue leather.

[0113] (3) The synergistic effect between the demethylation of fungal residue and the boron crosslinking modification jointly affects the compatibility with the matrix, UV resistance, tensile strength and flame retardancy. The reason for this effect may be that the borate anion complexes with the phenolic hydroxyl group converted from methoxy group, which greatly improves the tensile strength and flame retardancy of the raw leather.

[0114] (4) Fungal enzymatic hydrolysis will etch the crude fiber, crude protein and polysaccharide in the fungal residue, forming many fine pits, increasing the roughness of its surface, resulting in the exposure of a large number of polar functional groups. After demethylation, the number of phenolic hydroxyl groups increases, and the borate anion complexes with the phenolic hydroxyl group converted from methoxy group, which greatly improves the moisture permeability of the veneer.

[0115] Example 7

[0116] The difference between Example 7 and Example 1 is that the waste Ganoderma lucidum fungus residue (particle size of 1μm) in Example 1 is replaced with waste Pleurotus ostreatus fungus residue (particle size of 1μm).

[0117] The results showed that the mechanical strength, moisture permeability, flame retardancy, and UV resistance of vegan leather prepared from oyster mushroom waste residue were not significantly different from those of vegan leather prepared from Ganoderma lucidum waste residue.

[0118] Example 8

[0119] The difference between Example 8 and Example 1 is that the waste Ganoderma lucidum mycelium residue (particle size of 1μm) in Example 1 is replaced with waste Enoki mushroom mycelium residue (particle size of 1μm).

[0120] The results showed that the mechanical strength, moisture permeability, flame retardancy, and UV resistance of vegan leather prepared from enoki mushroom waste residue were not significantly different from those of vegan leather prepared from Ganoderma lucidum waste residue.

[0121]

[0122] Example 9

[0123] The difference between Example 9 and Example 1 is that the foaming layer slurry is coated on a tetrafluoroethylene plate, and the drying temperature of the foaming layer in step S5 is changed from 80°C to 90°C to obtain the foaming layer.

[0124] Example 10

[0125] The difference between Example 10 and Example 1 is that the foaming layer slurry is coated on a tetrafluoroethylene plate, and the drying temperature of the foaming layer in step S5 is changed from 80°C to 100°C to obtain the foaming layer.

[0126] Example 11

[0127] The difference between Example 11 and Example 1 is that the foaming layer slurry is coated on a tetrafluoroethylene plate, and the drying temperature of the foaming layer in step S5 is changed from 80°C to 110°C to obtain the foaming layer.

[0128] Example 12

[0129] The difference between Example 12 and Example 1 is that the foaming layer slurry is coated on a tetrafluoroethylene plate, and the drying temperature of the foaming layer in step S5 is changed from 80°C to a three-stage heating and drying process of 90°C-100°C-110°C to obtain the foaming layer.

[0130] Experiments have shown that different drying temperatures have a certain impact on the performance of the foamed layer, such as Figure 3 and 4As shown, the higher the drying temperature, the better the mechanical properties. This may be because the increase in temperature causes various particles and fibers in the foamed slurry to vibrate more violently during the drying process, which allows the fibers of the fungal residue powder to be better entangled with the molecular chains of the matrix, thereby enhancing the mechanical properties of the foamed layer. However, as the temperature rises, the water in the slurry evaporates violently, and the small bubbles formed on the surface of the foamed layer break down rapidly, resulting in an increasingly rough surface and a granular feel.

[0131] The results of Examples 9-12 show that the foamed layer obtained by the three-stage heating and drying process of 90℃-100℃-110℃ has the best mechanical properties and moisture permeability. Analysis revealed that when the temperature is low, some free water molecules evaporate from the foamed layer, which initially stabilizes the structure of the foamed layer and results in a relatively smooth surface. Then, the temperature is increased, which accelerates the evaporation of water and accelerates the vibration and entanglement of the bacterial residue powder fibers in the foaming slurry, thereby improving the mechanical properties and moisture permeability of the foamed layer.

[0132] Comparative Example 4

[0133] The difference between Comparative Example 4 and Example 5 is that ammonium borate was replaced with halogenated flame retardants, phosphorus-based flame retardants, inorganic flame retardants, and nitrogen-based flame retardants, respectively. The halogenated, phosphorus-based, inorganic, and nitrogen-based flame retardants were halophosphate esters, phosphate esters, aluminum hydroxide, and guanidine condensed phosphate, respectively, all at a concentration of 5%. The effects of different flame retardants on the performance of the veneer leather are shown in Table 5. Matrix compatibility refers to the optimal addition amount of modified bacterial residue in 20 mL of bio-based waterborne polyurethane. The 0.2 mm surface layer prepared according to the patented process was subjected to a tensile strength test.

[0134]

[0135] As shown in Table 5, boron compounds have a significant impact on the flame retardant properties of veneer leather. Other types of flame retardants, such as phosphorus-based and nitrogen-based flame retardants, can also improve the flame retardancy of veneer leather to some extent. However, they have poor compatibility and dispersibility with the matrix and cannot produce a significant synergistic effect with the demethylation modification of fungal residue.

[0136] Comparative Example 5

[0137] The difference between Comparative Example 5 and Example 1 is that the impregnation solution does not contain sodium octadecenoate solution.

[0138] The results showed that: (1) the UPF value in the UV resistance test was 32.45, which was less than the UPF value of 32.72 in Example 1; (2) the limiting oxygen index was 25.6%, which was less than the limiting oxygen index of 26.5% in Example 1; (3) the moisture permeability of the base fabric was 9564.75 g∙(m 2 ∙24h) -1 .

[0139] Comparative Example 6

[0140] The difference between Comparative Example 6 and Example 1 is that the impregnation solution contained 6% sodium octadecenoate solution. The results showed that: (1) the UPF value in the UV resistance test was 34.28; (2) the limiting oxygen index was 26.4%; and (3) the moisture permeability of the base fabric was 9003.78 g∙(m 2 ∙24h) -1 .

[0141] Comparative Example 7

[0142] The difference between Comparative Example 7 and Example 1 is that the impregnation solution contained 8% sodium octadecenoate solution. The results showed that: (1) the UPF value in the UV resistance test was 35.78; (2) the limiting oxygen index was 27.9%; and (3) the moisture permeability of the base fabric was 9137.65 g∙(m 2 ∙24h) -1 .

[0143] Comparative Example 8

[0144] The difference between Comparative Example 8 and Example 1 is that the impregnation solution contained 10% sodium octadecenoate solution. The results showed that: (1) the UPF value in the UV resistance test was 35.21; (2) the limiting oxygen index was 27.4%; and (3) the moisture permeability of the base fabric was 8549.31 g∙(m 2 ∙24h) -1 .

[0145] Comparative Example 9

[0146] The difference between Comparative Example 9 and Example 1 is that the impregnation solution contained only 8% sodium octadecenoate solution. The results showed that: (1) the UPF value in the UV resistance test was 27.79; (2) the limiting oxygen index was 18.7%; and (3) the moisture permeability of the base fabric was 8762.93 g∙(m 2 ∙24h) -1 .

[0147] According to comparative examples 6-9:

[0148] (1) When the impregnation solution contains 8% sodium octadecenoate solution, the veneer prepared in Example 1 has the best flame retardancy and UV radiation resistance. This may be because the anions in the sodium octadecenoate solution and the phenolic hydroxyl groups in the modified fungal residue crosslink, and under the action of van der Waals forces, hydrogen bonds and ionic bonds, more modified fungal residue is adsorbed into the base fabric fibers, thereby increasing the flame retardancy and UV radiation resistance.

[0149] (2) Comparative Examples 7 and 9 show that when the impregnation solution contains the same amount of sodium octadecenoate solution, the presence of fungal residue greatly affects the moisture permeability of the base fabric. The reason may be that the anions in the sodium octadecenoate solution and the phenolic hydroxyl groups in the modified fungal residue cross-link, and under the action of van der Waals forces, hydrogen bonds and ionic bonds, more modified fungal residue is adsorbed into the base fabric fibers. Based on the presence of a large number of loose fibers and the fine pits after being hydrolyzed by fungi in the fungal residue, the moisture permeability of the base fabric with adsorbed fungal residue is greatly improved.

[0150] (3) As the sodium octadecenoate content in the impregnation solution increases, the increase in these two properties is not significant, and the increase in sodium octadecenoate content will lead to a decrease in the moisture permeability of the veneer leather. Therefore, it is advisable to use an 8% sodium octadecenoate solution.

[0151] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined in the claims of this invention.

Claims

1. A method for preparing functional vegan leather based on waste edible mushroom residue, characterized in that, Includes the following steps: (1) Preparation of surface slurry: Bio-based waterborne polyurethane, bactericide and dispersant are mixed and dispersed for the first time. After uniform dispersion, waste edible fungus residue is added and thickener is added for the second dispersion. After centrifugation and degassing, surface slurry is obtained. (2) Preparation of foamed layer slurry: mix bio-based waterborne polyurethane, foaming agent, bactericide and dispersant and disperse for the first time. After uniform dispersion, add waste edible fungus residue and thickener, and disperse for the second time to obtain foamed layer slurry; (3) Preparation of adhesive layer slurry: mix bio-based waterborne polyurethane, bactericide and dispersant and disperse for the first time. After uniform dispersion, add waste edible fungus residue and thickener, and disperse for the second time to obtain adhesive layer slurry; (4) Preparation of base layer: The base fabric is pretreated by impregnation, rolling, ironing and drying. (5) Preparation of vegan leather: Coat the surface layer slurry on the release paper and dry it to obtain the surface layer; then coat the surface layer with foaming layer slurry, dry it, then coat the adhesive layer slurry, and finally attach the base layer and dry it to obtain vegan leather. The waste edible mushroom residue is modified edible mushroom residue. The specific modification method is as follows: the demethylated waste edible mushroom residue is soaked in boric acid solution, filtered, and then dried to achieve a moisture content of <3%. The preparation method of the demethylated waste edible mushroom residue is as follows: the waste edible mushroom residue and surfactant are mixed, a catalyst is added under ice-water bath conditions with continuous stirring, the mixture is subjected to an oil bath, refluxed under nitrogen, and then the pH is adjusted to neutral with HCl solution. After centrifugation and drying, the demethylated waste edible mushroom residue is obtained. The surfactant includes at least one of dodecyl mercaptan, tetramethyl dithiothiuram, sodium hydrosulfide, sodium methylthiosulfate, and diethyl sulfite. The mass-to-volume ratio of the surfactant to the waste edible mushroom residue is 1-5 g / mL. The temperature of the ice-water bath is 2-12°C. The mass ratio of the surfactant to the catalyst is 2-10. The temperature of the oil bath is 100-180°C. The reflux time is 1-3 h. The mass fraction of the boric acid solution is 1-15%. The soaking time is 2-24 h. The drying temperature is 60-150°C. The drying time is 2-12 h.

2. The preparation method according to claim 1, characterized in that, The waste edible fungi residue includes at least one of the following: Ganoderma lucidum substrate, Auricularia auricula-judae substrate, Pleurotus ostreatus substrate, Enoki mushroom substrate, and Agrocybe aegerita substrate.

3. The preparation method according to claim 1, characterized in that, In step (1), the amounts of each component of the surface slurry are 20-80 parts of bio-based waterborne polyurethane, 0.3-10 parts of bactericide, 0.5-15 parts of dispersant, 10-90 parts of bacterial residue, and 0.5-15 parts of thickener. The rotation speed during the first dispersion is 300-1000 rpm, and the dispersion time is 10-40 min. The rotation speed during the second dispersion is 1000-5000 rpm, and the dispersion time is 10-40 min. After adding the thickener, the viscosity of the mixed slurry is 1500-6000 cps.

4. The preparation method according to claim 1, characterized in that, In step (2), the amounts of each component of the foaming layer slurry are 20-80 parts of bio-based waterborne polyurethane, 1-10 parts of foaming agent, 0.3-10 parts of bactericide, 0.5-15 parts of dispersant, 10-90 parts of bacterial residue, and 0.5-15 parts of thickener. The rotation speed during the first dispersion is 300-1000 rpm, and the dispersion time is 10-40 min. The rotation speed during the second dispersion is 1000-5000 rpm, and the dispersion time is 10-40 min. After adding the thickener, the viscosity of the mixed slurry is 3000-25000 cps.

5. The preparation method according to claim 1, characterized in that, In step (3), the amounts of each component of the adhesive layer slurry are 10-80 parts of bio-based waterborne polyurethane, 0.3-10 parts of bactericide, 0.5-15 parts of dispersant, 10-90 parts of bacterial residue, and 0.5-15 parts of thickener. The rotation speed during the first dispersion is 300-1000 rpm, and the dispersion time is 10-40 min. The rotation speed during the second dispersion is 1000-5000 rpm, and the dispersion time is 10-40 min. After adding the thickener, the viscosity of the mixed slurry is 10000-45000 cps.

6. The preparation method according to claim 1, characterized in that, In step (4), the base layer is obtained by impregnating, rolling, ironing, and drying the base fabric. The impregnation solution contains a fluorine-free waterproofing agent, a salt solution, and bacterial residue. The mass ratio of the fluorine-free waterproofing agent, salt solution, and bacterial residue is 2~15:2~13:3~20. The fluorine-free waterproofing agent is selected from at least one of polydimethylsiloxane, polymethylhydrosiloxane, long-chain alkane fluorine-free waterproofing agent, ammonium aminosulfonate, sodium octadecenoate, and calcium naphthenate. The salt in the salt solution is selected from at least one of sodium chloride, sodium sulfate, sodium bicarbonate, and sodium carbonate. The impregnation is carried out at 5~35℃ for 5~25 minutes, and the liquid rolling rate is 50%~90%.

7. The preparation method according to claim 1, characterized in that, In step (5), the coating thickness of the surface slurry is 0.1~0.6mm and the drying temperature is 40℃~100℃; the coating thickness of the foam layer is 0.1~0.6mm and the drying temperature is 50~120℃; the coating thickness of the adhesive layer is 0.1~0.5mm and the drying temperature after bonding with the base layer is 60~110℃.

8. The flame-retardant vegan leather based on waste edible fungi residue prepared by the method according to any one of claims 1 to 7.

9. The application of the waste edible mushroom residue-based flame-retardant vegan leather as described in claim 8 in the textile field, wherein the application includes use in apparel textiles and industrial textiles.

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