Composite mycelium leather-like material and preparation method thereof

Abstract

The application discloses a kind of composite mycelium imitation leather materials and preparation method thereof, and relates to the technical field of composite materials.The preparation method comprises the following steps: homogenizing mycelium to form mycelium paste, then mixing the mycelium paste with modified polyvinyl alcohol solution to obtain a mixture, adding glycerol, stirring uniformly, pouring into a mold after the elimination of bubbles, and after low-temperature treatment and drying treatment, the mycelium material is stripped from the mold to obtain the mycelium imitation leather material;The mycelium is the mycelium of polypore family fungi.The preparation method has the advantages of high production efficiency, easy to scale, simple operation, short production cycle, etc.The composite mycelium imitation leather material prepared by the preparation method of the application has good mechanical properties, including high tensile strength, tear strength and flexibility, etc., which can fully meet the requirements of imitation leather products.

Description

Technical Field

[0001] This invention relates to the field of composite materials technology, and in particular to a composite mycelium imitation leather material and its preparation method. Background Technology

[0002] Mycelium is the vegetative body of fungi, composed of numerous filamentous hyphae. It possesses unique biological characteristics, such as the ability to grow on various organic substrates, rapid reproduction, and the capacity to form complex three-dimensional structures through biosynthesis. These characteristics make mycelium a promising candidate for leather manufacturing. During its growth, mycelium naturally interweaves to form sheet-like structures with a certain strength and flexibility, similar to the natural texture and physical properties of leather. Furthermore, mycelial growth can utilize various renewable organic wastes as substrates, such as agricultural straw and sawdust, transforming these substances, originally considered waste, into valuable materials.

[0003] Currently, there are various methods for preparing mycelial imitation leather materials, generally based on solid-state culture and liquid surface culture. Both of these methods suffer from drawbacks such as cumbersome processes, high labor intensity, and long production cycles, resulting in high production costs. This invention aims to develop a new preparation method using a wet-laying method to prepare composite mycelial imitation leather materials, thereby overcoming the technical shortcomings of the aforementioned preparation methods. Summary of the Invention

[0004] The purpose of this invention is to provide a composite mycelium-based imitation leather material and its preparation method, thereby solving the problems existing in the prior art. This preparation method has advantages such as high production efficiency, ease of scaling up, simple operation, and short production cycle. The composite mycelium-based imitation leather material prepared using this invention has excellent mechanical properties, including high tensile strength, tear strength, and flexibility, which can fully meet the requirements of imitation leather products.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a method for preparing a composite mycelium imitation leather material, comprising the following steps:

[0007] The mycelium is homogenized to form a mycelium slurry, and then the mycelium slurry is mixed with a modified polyvinyl alcohol solution to obtain a mixture. Glycerin is then added and stirred evenly. After the bubbles are eliminated, the mixture is poured into a mold. After low-temperature treatment and drying, the mycelium material is peeled off from the mold to obtain the mycelium imitation leather material.

[0008] The mycelium is the mycelium of a fungus belonging to the Polyporaceae family.

[0009] Furthermore, the preparation method of the modified polyvinyl alcohol solution includes the following steps:

[0010] Polyvinyl alcohol is dissolved in water, and boric acid solution or citric acid solution is added while stirring. Then, maleic anhydride solution is added while stirring, and the mixture is stirred until homogeneous to obtain the modified polyvinyl alcohol solution.

[0011] Furthermore, the mycelium dry weight in the mycelium slurry is 2 wt%.

[0012] Furthermore, the mass ratio of the mycelial slurry to the modified polyvinyl alcohol solution is 5:2.

[0013] Furthermore, the mass ratio of the glycerol to the mixture is 1:50.

[0014] Furthermore, the low-temperature treatment involves refrigerating at 2-4°C for 72 hours.

[0015] Furthermore, the mycelium was obtained by fermentation culture using MEB medium;

[0016] The MEB culture medium consists of 20 g / L malt extract powder and 2 g / L soybean peptone.

[0017] Furthermore, the fermentation culture is carried out at a temperature of 25-32℃, with an initial pH of 4.5-6.5, a rotation speed of 110-170 rpm, an inoculation rate of 3%-25%, and a culture time of 2-6 days.

[0018] The present invention also provides a composite mycelium imitation leather material prepared according to the above preparation method.

[0019] The present invention also provides the application of the above-mentioned composite mycelium imitation leather material in the preparation of imitation leather products.

[0020] The present invention discloses the following technical effects:

[0021] This invention develops a novel method for preparing composite mycelium imitation leather materials. The method utilizes a wet-laying method to prepare composite mycelium imitation leather materials, which has advantages such as high production efficiency, ease of scaling up, simple operation, and short production cycle.

[0022] The composite mycelium imitation leather material prepared by the preparation method of the present invention has good mechanical properties, including high tensile strength, tear strength and flexibility, which can fully meet the requirements of imitation leather products. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A statistical graph showing the mycelial yield at different culture temperatures;

[0025] Figure 2 A statistical graph showing the mycelial yield and final pH at different initial pH values ​​in different culture media;

[0026] Figure 3 A statistical graph showing the mycelial yield at different shaking speeds;

[0027] Figure 4 A statistical graph showing mycelial yield at different inoculation rates;

[0028] Figure 5 Statistical graphs showing mycelial yield and final pH at different culture times;

[0029] Figure 6 Comparison of mycelial imitation leather materials with different mycelial pulp dry basis contents;

[0030] Figure 7 Comparison of mycelial imitation leather material samples prepared by different methods. Detailed Implementation

[0031] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0032] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0033] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0034] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0035] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0036] The experimental materials and equipment used in the following examples are as follows:

[0037] 1. Fungal strain: Korean Ganoderma lucidum was used as the experimental strain (Fungi such as Ganoderma lucidum and Ganoderma yunnanensis are also applicable to the method of this invention).

[0038] 2. Reagents and Materials: Glucose, malt extract, soybean peptone, corn steep liquor, agar, yeast extract, CaCO3, glutaraldehyde (25%), tannins, glycerol, boric acid, maleic anhydride, polyvinyl alcohol (degree of polymerization 1799), chitosan (degree of deacetylation > 90%), genipin (purity 95%), citric acid, etc., were all biochemical reagents or analytical grade. Potatoes were commercially available.

[0039] 3. Equipment and utensils: homogenizer, drying oven, shaking incubator, biochemical incubator, autoclave and clean bench, etc.; flat-bottomed shallow trays (paper and plastic), stainless steel filter screen, 500mL Erlenmeyer flasks, 250mL Erlenmeyer flasks, 2L Erlenmeyer flasks, beakers, etc.

[0040] 4. Culture medium:

[0041] PDA medium: 200 g / L potato, 20 g / L glucose, 14 g / L agar, natural pH.

[0042] PDB enriched medium: 300 g / L potato, 20 g / L glucose, 2 g / L corn steep liquor, natural pH.

[0043] MEA medium: 20 g / L malt extract, 2 g / L soybean peptone, 14 g / L agar, natural pH.

[0044] MEB medium: 20 g / L malt extract, 2 g / L soybean peptone, natural pH.

[0045] II5 culture medium: CaCO3 1.8 g / L, brown sugar 70 g / L, sugarcane molasses 50 g / L, yeast extract 4.8 g / L, corn steep liquor 10.4 g / L, safflower seed oil 3.8 g / L, initial pH 6.5.

[0046] Fermentation medium: 20 g / L malt extract powder, 3 g / L soybean peptone, pH 6.0.

[0047] All culture media were sterilized at 121℃ for 20 min.

[0048] Example 1

[0049] 1. Experimental Methods

[0050] 1.1 Fungal strain activation: Remove the Ganoderma lucidum strain from the refrigerator and allow it to recover at room temperature for more than 6 hours. Under sterile conditions, cut a small piece of the strain and inoculate it into PDA medium, then seal it with sealing film. Then, place it in a 25℃ biochemical incubator for dark incubation for 7 days.

[0051] 1.2 Preparation of Ganoderma lucidum spore suspension: A small piece of the mycelial tip of the activated Ganoderma lucidum strain was cut off and transferred to MEA medium. The culture was then incubated in the dark at 25°C for 7 days. Under aseptic conditions, 10 mL of sterile water was pipetted onto the MEA plate covered with mycelia. The mycelial layer was gently scraped with a glass spreader, and the suspension was collected using a pipette.

[0052] 1.3 Preparation of Ganoderma lucidum seed liquid: The Ganoderma lucidum spore suspension was inoculated into MEB medium at an inoculation rate of 2.5%-5% and cultured with shaking at 25℃ and 130 rpm for 3 days. Under aseptic conditions, mycelial balls were collected, homogenized at 5000 rpm for 20 seconds, and then sterile water or MEB medium was added to form a mycelial suspension. The mycelial content in the mycelial suspension was adjusted to above 20% (m / v), and then refrigerated for later use.

[0053] 1.4 Selection of Culture Media: Ganoderma lucidum seed culture was inoculated at a rate of 2.5% into 500mL Erlenmeyer flasks containing 200mL of different liquid culture media: PDB, PDB enriched, MEB, and II5. The flasks were incubated at 25℃ and 130rpm for 8 days using a shaker. The mycelial pellets were filtered, washed three times, dried in a 70℃ oven to constant weight, weighed again, and the dry basis content was calculated.

[0054] 1.5 Optimization of cultivation conditions

[0055] Fermentation temperature, initial pH of the culture medium, shaking speed, inoculation rate, and culture time all affect the fermentation yield of Ganoderma lucidum mycelium. In this experiment, MEB was used as the fermentation medium, and Ganoderma lucidum seed liquid was inoculated. Fermentation temperature gradients were set at 24℃, 28℃, 32℃, and 36℃, with an inoculum rate of 2.5% and a natural pH in the culture medium, and cultured at 130 rpm for 8 days. Initial pH gradients were set at 4.5, 5, 5.5, 6, and 6.5, with an inoculum rate of 2.5%, and cultured at 25℃ and 130 rpm for 8 days. Shaking speed gradients were set at 110 rpm, 130 rpm, 150 rpm, and 170 rpm, with an inoculum rate of 2.5%, and cultured at 25℃ for 8 days. Inoculum rate gradients were set at 3%, 6%, 9%, 12%, 20%, and 25%, with a natural pH in the culture medium, and cultured at 25℃ and 130 rpm for 8 days. Culture time gradients were set at 2, 4, 6, 8, 10, 12, and 14 days, with an inoculum rate of 2.5% and a natural pH in the culture medium, and cultured at 25℃ and 130 rpm. Yield was calculated by measuring the dry basis mycelial biomass content of the fermentation broth, and the optimal conditions were selected.

[0056] 1.6 Analytical Methods

[0057] Determination of mycelial dry weight content: Take 100 mL of fermentation broth, filter the mycelium, wash it three times with distilled water, dry it at 80℃ to constant weight, and weigh it on an electronic balance. This is the mycelial dry weight content per 100 mL.

[0058] 2. Results

[0059] 2.1 Selection of Fermentation Culture Medium

[0060] As is well known, the composition of the culture medium affects the mycelial morphology and mycelial biomass yield in liquid submerged fermentation. The culture media selected for this experiment were PDB, PDB enriched, MEB, and II5. The experimental results are shown in Table 1.

[0061] Table 1 Selection of Fermentation Culture Medium

[0062]

[0063] The results showed that medium II5 had the highest mycelial yield, followed by MEB and PDB-enriched medium, while PDB had the lowest yield. The mycelial pellets in PDB and PDB-enriched media were more dense and smaller in size; the mycelial pellets in MEB and II5 media were more loose, with the II5 medium pellets being larger and of varying sizes. The fermentation broth in II5 was viscous, difficult to filter, and the presence of impurities in the medium gave the mycelium a dark red color. These results indicate that the nutrient composition of the culture medium affects the formation and development of mycelial pellets. MEB medium, as the fermentation medium, yields relatively pure mycelial pellets, making it the optimal medium for mycelial production via liquid submerged fermentation.

[0064] 2.2 Optimization of fermentation conditions

[0065] Besides the significant impact of nutrient components on mycelial yield, fermentation conditions such as temperature, initial pH, shaking speed, inoculum rate, and culture time also affect mycelial biomass yield and mycelial pellet formation. In this experiment, single-factor experiments were conducted on fermentation temperature, initial pH of the culture medium, shaking speed, inoculum rate, and culture time.

[0066] 2.2.1 Selection of incubation temperature

[0067] The results showed that mycelial biomass increased with increasing culture temperature, reaching 0.58 g / 100 mL at 32℃, and then decreased. This indicates that increasing temperature promotes mycelial growth, and the optimal culture temperature is 32℃. Figure 1 ).

[0068] 2.2.2 Selection of initial pH of culture medium

[0069] The results showed that with the increase of the initial pH of the culture medium, both the mycelial biomass and the final pH of the fermentation broth exhibited a trend of first increasing and then decreasing. When the initial pH of the culture medium was 5, the dry basis content of the Ganoderma lucidum mycelial biomass reached its maximum value of 0.64 g / 100 mL. At this point, the final pH of the fermentation broth was 5.11. However, when the initial pH of the culture medium was 5.5, the final pH of the fermentation broth decreased to 5.18. Figure 2 This indicates that the optimal initial pH of the culture medium is 5.

[0070] 2.2.3 Selection of Shaking Machine Speed

[0071] The results showed that mycelial biomass increased with increasing shaking speed. When the shaking speed reached 130 rpm, the dry basis mycelial biomass content reached 0.6 g / 100 mL. Then, with further increases in shaking speed, the mycelial biomass decreased. This indicates that increasing the shaking speed can increase the dissolved oxygen rate and promote mycelial growth. However, further increases in shaking speed tend to make the mycelial balls more compact, affecting the diffusion of oxygen from the liquid environment into the mycelial balls, thus reducing the mycelial yield. Figure 3 This indicates that the optimal shaking speed is 130 rpm.

[0072] 2.2.4 Selection of vaccination rate

[0073] The results showed that the mycelial biomass increased with the increase of the inoculation rate. The mycelial biomass reached its maximum value of 2.54 g / 100 mL on a dry basis when the inoculation rate was 15%. However, the mycelial biomass decreased when the inoculation rate exceeded 15%, indicating that the optimal inoculation rate was 15%. Figure 4 ).

[0074] 2.2.5 Selection of Culture Time

[0075] The results showed that the mycelial biomass yield increased with the extension of culture time, reaching 0.65 g / 100 mL on day 6. Subsequently, the mycelial yield decreased with the extension of culture time. Figure 5 ).

[0076] Example 2

[0077] 1. Experimental Methods

[0078] 1.1 Preparation of Ganoderma lucidum mycelium

[0079] Take 5 mL of Ganoderma lucidum spore suspension and inoculate it into a 250 mL Erlenmeyer flask containing 100 mL of MEB medium. Place the flask in a shaking incubator and culture for 3 days at 25°C and 130 rpm. Then inoculate it into a 2 L Erlenmeyer flask containing 800 mL of MEB medium and culture at 25°C and 130 rpm for 8 days. Filter to obtain mycelium, wash three times with water, and use for later use.

[0080] 1.2 Analytical Methods

[0081] Tensile strength determination: At least five dog-bone shaped samples were cut from each piece of mycelial imitation leather material. The thickness of each sample was measured at three random locations using electronic calipers. Tensile measurements were performed on a Shimadzu EZ-LX single-column electronic universal testing machine under RT conditions with a displacement of 50 mm / min. The ultimate tensile strength (σ) was calculated by dividing the maximum force (N) of each sample by the cross-sectional area (mm²). 2The elongation at break (ε) is calculated as a percentage of the gauge length before and after the test.

[0082] TGA determination: Thermogravimetric analysis (TGA) was performed using a thermal analysis system. 7–15 mg of mycelial powder was subjected to a temperature scan ranging from 25–700 °C at a rate of 10 °C / min under a constant nitrogen flow.

[0083] 1.3 Using Korean Ganoderma lucidum mycelium slurry as the main raw material, mycelium-based imitation leather materials were prepared by the wet-laying method. The effects of mycelium dry basis content, the amount of PVA modification solution added, the amount of glycerol added, and low-temperature treatment on the surface properties and mechanical properties of the mycelium-based imitation leather materials were mainly investigated in order to obtain the optimal process conditions.

[0084] Preparation of mycelium-based imitation leather materials:

[0085] Preparation of modified PVA solution: Dissolve 10g of polyvinyl alcohol (PVA) in 100mL of ultrapure water. After complete dissolution by heating, slowly add boric acid (or citric acid for modification) while stirring for 1 minute. Then slowly add maleic anhydride while stirring until homogeneous to obtain the modified PVA solution. The amounts of boric acid and maleic anhydride added are 1% (m / v) and 1.5% (m / v) of the polyvinyl alcohol solution, respectively.

[0086] Mycelial imitation leather material is prepared by wet-laying method: The washed mycelium is filtered and homogenized to form mycelial slurry. The dry weight of mycelium in the mycelial slurry is adjusted to 1-4 wt%. Then, 100g of mycelial slurry is mixed with 10-50g of modified PVA solution. During the stirring process, 1.5-3.5 wt% glycerol is added and stirred evenly. After the bubbles are eliminated, it is poured into a shallow dish with a flat bottom. After low-temperature treatment, it is placed in a drying oven at 60℃ for more than 8 hours. Then, it is taken out and the mycelial material is peeled off from the shallow dish to obtain the mycelial imitation leather material.

[0087] 2. Results

[0088] 2.1 Effect of mycelial pulp dry weight content on mycelial imitation leather materials

[0089] The mycelium content in the mycelium slurry may have a certain influence on the surface roughness and flexibility of the mycelium material. In the experiment, the dry basis content of the mycelium slurry was set to four gradients: 1wt%, 2wt%, 3wt%, and 4wt%, with an addition amount of 100g. The amount of modified PVA solution added was 40g, and glycerol was added at 2wt% of the mixture weight. The slurry was laid to a thickness of 1cm and refrigerated at 2-4℃ for 72h. After thawing at room temperature, it was dried at 60℃ for 12h. Each gradient was performed in triplicate, and the average value was calculated. The results are shown below. Figure 6 As shown in Table 2.

[0090] Table 2. Effect of dry basis content of mycelial pulp on mycelial imitation leather materials

[0091]

[0092] The results showed that as the dry basis content of the mycelial pulp increased, the thickness of the material sample increased, while the softness decreased. When the dry basis content of the mycelial pulp was 2 wt%, the tensile strength of the obtained mycelial material was 18.84 MPa, with moderate softness and a smooth, flat surface. When the dry basis content was ≥3 wt%, the softness and strength of the obtained material also decreased, and the surface of the formed material became rough and hard. The results indicate that the mycelial imitation leather material with the best performance was obtained when the dry basis content of the mycelial pulp was 2 wt%.

[0093] 2.2 Effect of modified PVA solution addition on the mechanical properties of mycelial imitation leather materials

[0094] In the experiment, the amount of modified PVA solution added was set to 10g, 20g, 30g, 40g and 50g, mycelial pulp (2wt%) 100g, and glycerol added at 2wt% of the total weight. The above mixture was placed on an electric stirrer and stirred at 450rpm for 30min. After the bubbles in the mixture were eliminated, it was poured into a 10cm×10cm plate with a thickness of 1cm and placed in a refrigerator at 2-4℃ for 72h. After being thawed at room temperature, it was dried at 60℃ for 12h. The cured mycelial sheet was taken out and subjected to tensile test and appearance evaluation. The results are shown in Table 3.

[0095] Table 3. Effect of modified PVA solution addition on the mechanical properties of mycelial imitation leather materials.

[0096]

[0097]

[0098] The results showed that with the increase of PVA modification solution addition, the tensile strength of the mycelial material increased, the fracture strain decreased, and the softness of the mycelial material decreased. When the PVA modification solution addition was 40g, the mycelial material exhibited good flexibility and softness. The results indicate that the tensile strength of the mycelial imitation leather material increases with the increase of PVA modification solution addition, and the optimal addition amount of PVA modification solution is 40g.

[0099] 2.3 Effect of Glycerin Addition on Mechanical Properties of Mycelial Imitation Leather Materials

[0100] The amount of glycerol added affects the appearance and mechanical properties of mycelial imitation leather materials. In the experiment, the amount of modified PVA solution added was 40g, mycelial pulp (2wt%) was 100g, and the amount of glycerol added was set to 1.5wt%, 2wt%, 2.5wt%, 3wt%, and 3.5wt% of the mixture mass. The mixture was placed on an electric stirrer and stirred at 450rpm for 30min. After the air bubbles in the mixture were eliminated, it was poured into a 10cm×10cm plate with a thickness of 1cm and placed in a refrigerator at 2-4℃ for 72h. After thawing at room temperature, it was dried at 60℃ for 12h, and tensile tests and appearance evaluations were performed. The results are shown in Table 4 below.

[0101] Table 4. Effect of glycerol addition on mycelial imitation leather materials

[0102]

[0103] The results showed that the tensile strength of the mycelial material increased with increasing glycerol content, but the increase was small. The fracture strain also increased. When the glycerol content was ≥3.5 wt%, the increase in fracture strain was small. When the glycerol content was ≤2.5 wt%, the surface of the mycelial material was dry. When the glycerol content was ≥2.5 wt%, the surface of the mycelial material was moist or had a large amount of liquid accumulation, and the surface was sticky. This indicates that the optimal glycerol content is 2 wt% of the mixture weight.

[0104] 2.4 Effects of Low-Temperature Treatment on the Mechanical Properties of Mycelial Leather-like Materials

[0105] Under varying temperature and pH conditions, the interactions between components of mycelial slurry change, leading to the formation of a network structure. For example, as the temperature decreases, the hydrogen bonding between polysaccharide molecules in the mycelial slurry strengthens, fixing small molecules such as water within it, thus forming a gel. Alternatively, a cross-linking agent can be added to form covalent or ionic bonds with the components of the mycelial slurry, thereby constructing a gel network structure. In the experiment, the amount of modified PVA solution added was 40g, mycelial slurry (2wt%) was 100g, and glycerol was added at 2wt% of the mixture mass. The well-stirred mycelial slurry-modified PVA mixture was poured into a plate to a thickness of 1cm, and a plastic film was placed on the surface. The plates were then refrigerated at 2-4℃ for 72h and frozen at -20℃ for 6h, respectively. After thawing at room temperature, they were dried at 60℃ for 12h and then air-dried at room temperature. Tensile tests were then performed, and the results are shown in Table 5.

[0106] Table 5. Effects of low-temperature treatment on the mechanical properties of mycelial imitation leather materials

[0107]

[0108] The results showed that the mycelial slurry and modified PVA mixture exhibited a typical gel-like state after being refrigerated at 2-4℃ for 72 hours, while it showed a honeycomb-like structure after being frozen at -20℃ for 12 hours. After drying, the surface of the refrigerated imitation leather material was relatively smooth, while the surface of the frozen imitation leather material was rougher and had larger pores.

[0109] Example 3

[0110] Preparation of mycelium-based imitation leather materials:

[0111] (1) Preparation of modified PVA solution: Dissolve 10g of polyvinyl alcohol (PVA) in 100mL of ultrapure water. After heating and dissolving completely, slowly add 1.5% boric acid solution (or citric acid solution for modification) while stirring for 1min. Then slowly add 1% maleic anhydride solution while stirring until homogeneous to obtain modified PVA solution for later use.

[0112] (2) Preparation of mycelial imitation leather material using the wet-laying method: Washed Ganoderma lucidum mycelium (prepared according to the method in Example 2) was filtered and homogenized to form a mycelial slurry. The dry weight of the mycelium in the slurry was adjusted to 2 wt%. Then, 100 g of mycelial slurry was mixed with 40 g of modified PVA solution. During stirring, 2.8 g of glycerin was added and stirred until homogeneous. After the bubbles were eliminated, the mixture was poured into a shallow, flat-bottomed dish and refrigerated at 2-4°C for 72 hours. Then, it was dried in a drying oven at 60°C for at least 8 hours. After drying, the mycelial material was removed from the dish, yielding the mycelial imitation leather material. The mycelial leather material can be further processed through coating, dyeing, and embossing to obtain mycelial imitation leather.

[0113] Comparative Example 1

[0114] (1) Preparation of PVA solution: Dissolve 10g of polyvinyl alcohol (PVA) in 100mL of ultrapure water, heat until completely dissolved to obtain PVA solution for later use.

[0115] (2) Preparation of mycelial imitation leather material by wet spreading method: The washed Ganoderma lucidum mycelium (prepared according to the method of Example 2) was filtered and homogenized to form mycelial slurry. The dry weight of mycelium in the mycelial slurry was adjusted to 2wt%. Then, 100g of mycelial slurry was mixed with 40g of PVA solution. During the stirring process, 2.8g of glycerol was added and stirred evenly. After the bubbles were eliminated, it was poured into a shallow dish and refrigerated in a refrigerator at 2-4℃ for 72h. Then, it was placed in a drying oven at 60℃ for more than 8h. Then, it was taken out and the mycelial material was peeled off from the shallow dish to obtain the mycelial imitation leather material.

[0116] Comparative Example 2

[0117] The washed Ganoderma lucidum mycelium (same as in Example 3) was filtered and homogenized to form mycelium slurry. The dry weight of the mycelium in the mycelium slurry was adjusted to 2 wt%. Then, 100 g of mycelium slurry was mixed with 100 g of 2 wt% chitosan solution (dissolved in 1% acetic acid solution) and 4 g of glycerol. Then, the cross-linking agent genipin was added according to the ratio of 1 wt% of the dry weight of mycelium and the total amount of chitosan. The mixture was stirred at 400 rpm for 30 min on a stirrer. When there were no bubbles, it was poured into a shallow dish and dried in a drying oven at 40 ℃ for 24 h. Then, it was taken out and air-dried naturally. The mycelium material was then peeled off from the shallow dish.

[0118] Comparative Example 3

[0119] The washed Ganoderma lucidum mycelium (same as in Example 3) was filtered and homogenized to form a mycelium slurry. The dry weight of the mycelium in the slurry was adjusted to 2 wt%. Then, 100 g of mycelium slurry was mixed with 2 g of glycerol and poured into a shallow dish. The mixture was refrigerated at 2-4°C for one week. After that, the gelled mycelium pad was removed, the water was drained, and a 5% tannin solution was added for cross-linking and curing for 24 hours, during which time the sample needed to be turned over. Then, the cross-linking agent solution was removed, and the sample was dried at 60°C for 5 hours. After that, the sample was removed and allowed to air dry naturally at room temperature.

[0120] Comparative Example 4

[0121] The washed Ganoderma lucidum mycelium (same as in Example 3) was filtered and homogenized to form mycelium slurry. The dry weight of mycelium in the mycelium slurry was adjusted to 2 wt%. 100 g of mycelium slurry was taken, and then 1 g of citric acid and 2 g of glycerol were added. The mixture was stirred evenly and then poured into a shallow dish. After drying in an oven at 80°C for 6 hours, the mixture was taken out and air-dried at room temperature. The mixture was then peeled off from the shallow dish and soaked in a 2% citric acid solution for 24 hours. After that, it was taken out and air-dried.

[0122] Comparative Example 5

[0123] The washed mycelium (same as in Example 3) was filtered and homogenized to form a mycelial slurry. The dry weight of the mycelium in the slurry was adjusted to 2 wt%, and the slurry was filtered again to form a mycelial cake. After drying, the mycelial cake was peeled off from the filter screen and then soaked in a 1.5% glutaraldehyde solution (pH = 4-4.5) for at least 12 hours. The sample was then removed, rinsed, and soaked in a 10% glycerol solution for 12 hours before being air-dried.

[0124] Mycelial pulp was prepared into mycelial imitation leather material using the methods of Example 3 and Comparative Examples 1-5. The elastic modulus, flexibility, and material appearance were tested, and the results are shown in [Figure Number]. Figure 7 See Table 6.

[0125] Table 6. Comparison of several methods for preparing mycelial imitation leather materials

[0126]

[0127] The results showed that the mycelium-based imitation leather material obtained in Example 3 had the highest tensile strength (18.64 MPa) and the best flexibility, with a leather texture on the front (upper) side. These results indicate that the mycelium composite material prepared by the method of this invention has good application potential.

[0128] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a composite mycelium imitation leather material, characterized in that, Includes the following steps: The mycelium is homogenized to form a mycelium slurry, and then the mycelium slurry is mixed with a modified polyvinyl alcohol solution to obtain a mixture. Glycerin is then added and stirred evenly. After the bubbles are eliminated, the mixture is poured into a mold. After low-temperature treatment and drying, the mycelium material is peeled off from the mold to obtain the mycelium imitation leather material. The mycelium is the mycelium of a fungus belonging to the Polyporaceae family; The preparation method of the modified polyvinyl alcohol solution includes the following steps: Polyvinyl alcohol is dissolved in water, and boric acid solution or citric acid solution is added while stirring. Then, maleic anhydride solution is added while stirring, and the mixture is stirred until homogeneous to obtain the modified polyvinyl alcohol solution. The dry weight of mycelium in the mycelium slurry is 2 wt%; The mass ratio of the mycelial slurry to the modified polyvinyl alcohol solution is 5:2; The mass ratio of the glycerol to the mixture is 1:50; The low-temperature treatment involves refrigerating the food at 2-4°C for 72 hours.

2. The preparation method according to claim 1, characterized in that, The mycelium was obtained by fermentation culture in MEB medium; The MEB culture medium consists of 20 g / L malt extract powder and 2 g / L soybean peptone.

3. The preparation method according to claim 2, characterized in that, The fermentation culture was conducted at a temperature of 25-32℃, with an initial pH of 4.5-6.5, a rotation speed of 110-170 rpm, an inoculation rate of 3%-25%, and a culture time of 2-6 days.

4. A composite mycelium imitation leather material prepared by the preparation method according to any one of claims 1-3.

5. The application of the composite mycelium imitation leather material as described in claim 4 in the preparation of imitation leather products.

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