Hydrophobic treatment-based mycelium leather and method for preparing the same

Abstract

This invention belongs to the field of mycelial leather and provides mycelial leather based on hydrophobic treatment and its preparation method. The method of this invention includes four steps: mechanical squeezing, dehydration with solvent and absorbent medium, plasticizing and hydrophobic treatment, drying, and finishing. The plasticizing and hydrophobic treatment step involves dissolving or fully dispersing a silicon-containing polymer material, a silicon-based wetting agent, a silane coupling agent, and / or silicone oil in a solvent to obtain a plasticizing and hydrophobic treatment agent. The plasticizing and hydrophobic treatment agent and dehydrated mycelial sheets are then placed in a rotating drum, and the drum is rotated for 2-8 hours under a constant temperature of 35-60°C to produce the leather. The method of this invention avoids the use of chemical cross-linking agents and also avoids the problems of hardening and poor bending resistance in mycelial leather during processing. It yields mycelial leather products with softness, fullness, and good toughness, and the process is more in line with the requirements of green chemical engineering.

Description

Technical Field

[0001] This invention belongs to the field of mycelial leather, and relates to mycelial leather based on hydrophobic treatment and its preparation method. Background Technology

[0002] Mycelial leather-like products, as a future alternative to petroleum-based synthetic leather and animal leather, have the advantages of being environmentally friendly and sustainable. The advantages of mycelial leather are mainly reflected in the following aspects: (1) Mycelial leather is made from mycelium, which is obtained by fermentation and cultivation using agricultural and forestry by-products as a nutrient base. The production process of mycelium emits less greenhouse gas and consumes less water and natural resources. At the same time, its biocarbon content is as high as about 95%, which is more environmentally friendly and sustainable than traditional animal leather and synthetic leather; (2) Traditional leather uses harmful chemicals such as chromium in the production process. These harmful chemicals are easy to remain in the product and pose a potential threat to the health of consumers. At the same time, the production process of mycelial leather will generate a large amount of industrial wastewater. However, the production process of mycelial leather products does not require the addition of harmful chemicals such as chromium. Therefore, mycelial leather products are safer and their production process can avoid the discharge of a large amount of industrial wastewater; (3) Mycelial leather is a leather substitute made from bio-based materials. It has a low polymer content and is easy to biodegrade after the product's life cycle, which is less likely to cause environmental problems.

[0003] MycoWorks, a biotechnology company, developed Reishi™ material using Fine Mycelium™ technology. This material, made from mycelium with a polymer content of less than 1%, exhibits excellent tensile strength, tear resistance, and durability, comparable to animal leather, and holds promise as a potential alternative to natural leather. This has sparked a global research boom in mycelium-based leather.

[0004] Fungal mycelium is composed of a network of tubular microfilaments called hyphae. The main component of the hyphal cell wall is polysaccharide, followed by protein and lipids, accounting for 30% of the cell's dry matter. The polysaccharides that make up the hyphal cell wall are mainly polymers such as chitin, glucan, and mannan. Among them, chitin is a polysaccharide composed of N-acetylglucosamine molecules linked by β-(1,4) glucosidic bonds, and is a tough, elastic, inert, and water-insoluble polysaccharide. Based on the compositional characteristics of the hyphal cell wall, mycelial materials can be processed into leather-like products or combined with cotton textiles, macromolecular polymers, and other materials to form complexes, which can be used as textiles, packaging materials, and building materials.

[0005] Currently, some literature discloses methods for modifying mycelial materials to prepare composite materials through crosslinking. These methods are basically based on the processing ideas of animal leather. First, a crosslinking agent is used to form chemical crosslinks between deacetylated mycelial fibers to stabilize the fiber structure. Then, plasticizing or lubricating treatments are used to obtain a soft leather-like preform. Finally, finishing and surface modification are performed to obtain a product similar to animal leather. Chemical crosslinking modification can regulate the properties of mycelial materials. For example, chemical crosslinking can improve the tensile strength, tear strength, and abrasion resistance of mycelial leather to a certain extent. However, the prerequisite for chemical crosslinking modification is to treat the mycelial fibers with alkali to achieve the deacetylation of chitin in the mycelial fibers and obtain chitosan components containing amino groups. This alkali treatment process dissolves and removes some polysaccharides in the mycelial fibers, causing a loss of mycelial fiber components, resulting in a decrease in the mechanical properties and fullness of mycelial leather. Therefore, in reality, chemical crosslinking does not significantly improve the mechanical properties of mycelial leather. Meanwhile, the chemical cross-linking agents added during the chemical cross-linking process also bring some environmental problems, such as the emission of harmful chemicals during production, the residue of harmful chemical components in the product, and the difficulty in achieving complete biodegradation after the product's life cycle. Furthermore, while the mechanical properties of animal leather can be improved after filling, mycelial leather, due to the hollow tubular structure of mycelial fibers and the limited interweaving between fibers, often becomes stiff and less resistant to bending after filling. Especially during finishing processes, mycelial leather is prone to breakage or tearing due to repeated "water absorption and loss" during processing. Therefore, the processing methods for animal leather are not entirely suitable for mycelial leather.

[0006] Therefore, finding a suitable processing method for mycelial leather and solving the problem of mycelial leather easily hardening and becoming less resistant to bending after filling is a major challenge currently facing this field. Furthermore, developing a method for preparing mycelial leather that does not require chemical cross-linking would have positive implications for reducing the loss of mycelial fiber components during preparation, avoiding the residue of harmful chemicals in the product, reducing the emission of harmful chemicals during preparation, and increasing the biodegradability of the product at the end of its life cycle. Summary of the Invention

[0007] To address the problems of poor toughness and low bending resistance in existing mycelial leather preparation methods that borrow from animal skin processing techniques, as well as the issues of harmful chemical residues in the product due to the need for chemical cross-linking, the emission of harmful substances during the preparation process, and the difficulty in achieving complete biodegradability after the product's life cycle, this invention provides mycelial leather based on hydrophobic treatment and its preparation method. This avoids the problems of hardening and low bending resistance of mycelial leather caused by the use of chemical cross-linking agents and processing, resulting in mycelial leather products that are soft, full, and have good toughness, while also making the process more in line with the requirements of green chemical engineering.

[0008] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0009] The method for preparing hydrophobically treated mycelial leather includes the following steps:

[0010] (1) Mechanical dewatering

[0011] Freshly harvested and inactivated mycelial sheets or pretreated mycelial sheets were mechanically squeezed to a water content of 40 wt% to 70 wt% to obtain water-squeezed mycelial sheets;

[0012] (2) Dehydration of solvent and water-absorbing medium

[0013] 100 parts by weight of water-dehydrated mycelial sheets were placed in a dehydration container with 100-300 parts by weight of hydrophilic solvent and 100-200 parts by weight of water-absorbing medium. The container was allowed to stand at room temperature to 50 °C for 30-150 min for dehydration. Then, the container was centrifuged. The centrifuged mycelial sheets were heated to remove the hydrophilic solvent from the mycelial sheets, resulting in dehydrated mycelial sheets.

[0014] (3) Plasticizing and hydrophobic treatment

[0015] 6-40 parts by weight of silicon-containing polymer material, 1-10 parts by weight of silicon-based wetting agent, 8-30 parts by weight of silane coupling agent and / or silicone oil are dissolved or fully dispersed in 60-300 parts by weight of solvent to obtain a plasticizing and hydrophobic treatment agent; the obtained plasticizing and hydrophobic treatment agent and 100 parts by weight of dehydrated mycelial sheets are put into a drum, and the drum is rotated for 2-8 hours under constant temperature conditions of 35-60 ℃ to obtain a plasticized and hydrophobic mycelial skin blank;

[0016] (4) Drying and finishing

[0017] The mycelial leather blanks that have undergone plasticization and hydrophobic treatment are dried and finished to obtain mycelial leather.

[0018] In the above technical solution, the silicon-containing polymer material in step (3) includes at least one of OMBRELLON 072, PERFECTOL HQ, and PERFECTOL QX.

[0019] In the above technical solution, the silicon-based wetting agent in step (3) is Silok 8008 or Silok 8000.

[0020] In the above technical solution, the silane coupling agent in step (3) includes at least one of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, and N-β-aminoethyl-γ-aminopropyltrimethoxysilane, and the silicone oil includes at least one of hydrogen-containing silicone oil, hydroxyl silicone oil, and dimethyl silicone oil. In step (3), the silane coupling agent or silicone oil is mainly used to react with the hydroxyl groups of the mycelial fibers and coat the surface of the mycelial fibers to form a hydrophobic effect.

[0021] In the above technical solution, the solvent used in preparing the plasticizing and hydrophobic treatment agent is an organic solvent, water, or a mixture of organic solvent and water. When the solvent cannot dissolve the hydrophobic material, the hydrophobic material needs to be added to a solvent at a temperature of 50~90 ℃ and stirred to emulsify in order to form the plasticizing and hydrophobic treatment agent. The hydrophobic material is a combination of a silicone-containing polymer material, a silicone-based wetting agent, a silane coupling agent, and / or silicone oil.

[0022] In the above technical solution, in step (3), when preparing the plasticizing and hydrophobic treatment agent, it is best to fully disperse the silicon-containing polymer material, silicon-based wetting agent, and silane coupling agent in the solvent, or to dissolve or fully disperse the silicon-containing polymer material, silicon-based wetting agent, silane coupling agent, and silicone oil in the solvent to obtain the plasticizing and hydrophobic treatment agent.

[0023] In the above technical solution, the water-absorbing medium in step (2) includes zeolite, porous silica gel, or color-changing silica gel. To avoid damaging the mycelial sheets during the treatment process in step (2), the water-absorbing medium is preferably in the form of spherical granules. Furthermore, to improve the water absorption efficiency of the water-absorbing medium, the particle size of the spherical granular water-absorbing medium is preferably 2~10 mm.

[0024] In the above technical solution, the hydrophilic solvent in step (2) is an organic solvent that is miscible with water and has a boiling point of no more than 90 °C, so as to facilitate recovery and recycling. For example, feasible hydrophilic solvents include anhydrous ethanol, methanol, acetone or methyl ethyl ketone, etc.

[0025] In the above technical solution, the liquid phase obtained by centrifugation in step (2) is collected, the hydrophilic solvent in the liquid phase is recovered, and the recovered hydrophilic solvent is recycled. For example, the hydrophilic solvent can be recovered by distillation of the collected liquid phase and then recycled. The water-absorbing medium obtained by centrifugation in step (2) is collected, regenerated by heating, and then recycled. In order to reduce process costs and increase the environmental friendliness of the process, the hydrophilic solvent volatilized during the heating of the mycelial sheet obtained by centrifugation in step (2) can also be collected and recycled.

[0026] In the above technical solution, when heating the mycelial sheet obtained by centrifugation to remove the hydrophilic solvent from the mycelial sheet in step (2), the heating temperature is controlled above the boiling point of the hydrophilic solvent. Usually, the heating temperature can be controlled between T and (T+5 ℃), where T is the boiling point of the hydrophilic solvent.

[0027] In the above technical solution, the dehydration container in step (2) is a closed container to prevent the hydrophilic solvent from evaporating during the dehydration operation in step (2) and causing environmental pollution, and also to facilitate the recycling of the hydrophilic solvent.

[0028] In the above technical solution, the preparation method of the pretreated mycelial sheets in step (1) is as follows: 100 parts by weight of freshly harvested and inactivated mycelial sheets are added to a pretreatment container along with 100-500 parts by weight of water and 0.1-0.4 parts by weight of alkaline material. The mixture is then soaked at 35-80 °C for 10-200 min, followed by washing with water. During the pretreatment process with water and alkaline material, the main purpose is to remove soluble polysaccharides and attached culture medium impurities from the surface of the mycelial sheets and between mycelial fibers. Since the amount of alkaline material added is very small, this process will not cause excessive loss of polysaccharide components in the mycelium or damage to the chitin in the cell wall of the mycelium.

[0029] Furthermore, in the above technical solution, the alkaline material is at least one of sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, sodium formate, and sodium acetate.

[0030] In the above technical solution, step (1) can be performed by mechanically squeezing the water from freshly harvested and inactivated mycelial sheets or pretreated mycelial sheets using methods such as rolling or pressing, in order to remove a large amount of free water. In practical applications, mechanical squeezing can be performed using a through-feed water squeezer, a plate press, etc.

[0031] In the above technical solution, the method of controlling the rotation of the drum in step (3) is intermittent rotation. For example, the drum can be rotated intermittently for 5 to 15 minutes per hour.

[0032] In the above technical solution, step (4) uses conventional methods of existing technology to dry and process the plasticized and hydrophobic mycelial blanks, mainly including stretching drying, rehumidification, softening, peeling or shaving.

[0033] In the above technical solution, the mycelial sheet refers to a sheet-like mycelium, preferably a sheet-like fungal mycelium. The mycelial sheet can be prepared according to existing techniques, typically by transplanting mycelium obtained from liquid fermentation onto a solid culture medium. For example, mycelium obtained from liquid fermentation of Ganoderma lucidum strains can be transplanted onto a solid culture medium for cultivation.

[0034] The present invention also provides mycelial leather prepared by the above method.

[0035] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0036] 1. This invention provides a method for preparing mycelial leather based on hydrophobic treatment. The method first combines physical and chemical dehydration methods to completely dehydrate the mycelial sheets, so that the mycelial fibers are in a well-separated state. On this basis, a high-performance hydrophobic material is used to treat the well-separated mycelial fibers to form a hydrophobic film on the surface or between the mycelial fibers, so that the mycelial fibers can better maintain a dispersed state. This can effectively avoid the problem of mycelial fibers easily losing too much water and sticking together during drying, and effectively reduce the water adsorption capacity of mycelial fibers. In particular, it solves the problem of fiber hardening and even cracking of mycelial leather caused by repeated "water absorption-water loss" processes during the finishing process. The key point of the method described in this invention is to use silane coupling agents in combination with silicon-containing polymer materials and silicon-based wetting agents in an appropriate ratio. Through the interaction of the silane coupling agent with the hydroxyl groups on the mycelial fibers, the silane coupling agent is firmly coated on the surface of the mycelial fibers. Combined with the filling and hydrophobic effects of the silicon-containing polymer materials and silicon-based wetting agents, not only is the flexibility and water resistance of the product increased, but also mycelial leather-like leather is given good softness and fullness.

[0037] 2. The method of this invention, in the preparation of mycelial leather, does not use chemical cross-linking agents, thus eliminating pollutant emissions during processing and the ecological safety of the final product at the source, and improving the biodegradability of the final product. In the dehydration process of the solvent and absorbent medium described in this invention, the hydrophilic solvent and absorbent medium used can be recycled. In the plasticizing and hydrophobic treatment processes, the method of this invention applies hydrophobic materials in solution or emulsion form, which can improve the absorption rate of hydrophobic materials and reduce or even avoid waste liquid discharge during processing. Through the combination of the above process details, the method of this invention can better meet the requirements of sustainability, environmental protection, and greening.

[0038] 3. The present invention has demonstrated through soil landfill natural degradation tests that the mycelium-based leather prepared by the method described in this invention can achieve near-complete natural degradation within 40 days when landfilled in a natural environment, exhibiting excellent biodegradability.

[0039] 4. The mycelium-based leather prepared by the method of the present invention is pale yellow to light brown in color, odorless, soft, fluffy, full, and has a natural texture, which is comparable to the sensory properties of animal leather. Attached Figure Description

[0040] Figure 1 This is a process flow diagram of the preparation method of mycelial leather based on hydrophobic treatment according to the present invention.

[0041] Figure 2 This is a photograph of the grain surface of the mycelial leather prepared in Example 1.

[0042] Figure 3 This is a microscope photograph of the fibers of the mycelial sheet used in Example 1.

[0043] Figure 4 This is a microscopic photograph of the fibers of the mycelial leather prepared in Example 1.

[0044] Figure 5 This is a photograph of the mycelial leather prepared in Comparative Example 1 when it is bent.

[0045] Figure 6 This is a photograph of the grain surface of the mycelial leather prepared in Example 2.

[0046] Figure 7 This is a microscopic photograph of the fibers of the mycelial leather prepared in Example 2.

[0047] Figure 8 This is a photograph of the grain surface of the mycelial leather prepared in Example 3.

[0048] Figure 9 This is a microscopic photograph of the fibers of the mycelial leather prepared in Example 3. Detailed Implementation

[0049] The following examples further illustrate the hydrophobic mycelium-based leather and its preparation method provided by the present invention. It should be noted that the following examples are only for further illustration and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above description are still within the scope of protection of the present invention.

[0050] In the following examples and comparative examples, the silicone-containing polymer materials, silicone-based wetting agents, water-absorbing media, silane coupling agents, silicone oils, etc., used are all commercially available products that can be purchased directly. Specifically: the silicone-containing polymer material OMBRELLON072 is a commercial product of Zschimmer & Schwarz (Germany); the silicone-containing polymer materials PERFECTOLHQ and PERFECTOL QX are commercial products of Schill & Seiacher (Germany); the silicone-based wetting agents Silok 8008 and Silok 8000 are commercial products of Guangzhou Silok Polymer Co., Ltd.; and the fatliquoring agent XG-60 is a commercial product of Brothers Chemical Co., Ltd.

[0051] In the following examples and comparative examples, the mycelial sheet refers to the sheet-like mycelium. The mycelial sheet is from Tianjin Meikexin Biotechnology Co., Ltd., and is obtained by transplanting the mycelium obtained by liquid fermentation of Ganoderma lucidum strain onto a solid culture medium.

[0052] In the following examples and comparative examples, the static water absorption rate was tested according to the method in GB / T 22899-2008 "Determination of Static Water Absorption Rate in Physical and Mechanical Tests of Leather".

[0053] Example 1

[0054] This embodiment provides a method for preparing mycelium-based leather based on hydrophobic treatment. The process flow of this method is as follows: Figure 1 As shown, the steps are as follows:

[0055] (1) Mechanical dewatering

[0056] 100 parts by weight of freshly harvested and inactivated mycelial sheets were placed in a container with 200 parts by weight of water and 0.3 parts by weight of sodium carbonate and soaked at 50 °C for 120 min to remove soluble polysaccharides and attached culture medium from the surface of the mycelial sheets and between the mycelial fibers. After washing with water, pretreated mycelial sheets were obtained.

[0057] The pretreated mycelial sheets were squeezed with a through-type dewatering machine at a roller pressure of 10 MPa until the water content was 40 wt%~50 wt%, thus obtaining dewatered mycelial sheets.

[0058] (2) Dehydration of solvent and water-absorbing medium

[0059] 100 parts by weight of dehydrated mycelial sheets, 300 parts by weight of acetone, and 100 parts by weight of spherical porous color-changing silica particles with a particle size of approximately 3-5 mm were placed in a sealed container and allowed to stand at room temperature for 50 min for dehydration. Then, the mycelial sheets were centrifuged to remove most of the acetone and the porous color-changing silica particles attached to the mycelial sheets. The centrifuged mycelial sheets were heated to 57 °C and maintained at this temperature until the acetone in the mycelial sheets was completely removed, resulting in dehydrated mycelial sheets.

[0060] The liquid phase obtained by centrifugation in this step is collected, and the collected liquid phase is distilled to recover acetone and the recovered acetone is recycled. The acetone volatilized during the heating of the mycelial sheets obtained by centrifugation at 57 °C is collected and recycled. The porous color-changing silica particles obtained by centrifugation are recovered, heated to remove moisture, and then regenerated and recycled.

[0061] (3) Plasticizing and hydrophobic treatment

[0062] 40 parts by weight of OMBRELLON 072, 5 parts by weight of Silok 8008, and 10 parts by weight of γ-aminopropyltriethoxysilane (KH550) were thoroughly mixed. The resulting mixture was then added to 200 parts by weight of hot water at 60°C and stirred to emulsify, yielding a plasticizing and hydrophobic treatment agent. The plasticizing and hydrophobic treatment agent and 100 parts by weight of dehydrated mycelial sheets were placed in a rotating drum. The drum was intermittently rotated at 3 rpm for 4 hours (5 minutes per hour) under a constant temperature of 40°C, and the mycelial skin was extruded to obtain a plasticized and hydrophobic treated mycelial skin preform.

[0063] (4) Drying and finishing

[0064] Following standard procedures, the plasticized and hydrophobic treated leather blanks are stretched, dried, rehydrated, softened, and shaved evenly to obtain mycelial leather.

[0065] A photograph of the grain surface of the mycelium-based leather prepared in this embodiment is shown below. Figure 2 As shown, the mycelium-based leather prepared in this embodiment exhibits a natural grain texture, a soft feel, and extremely fine inner fiber fibers, giving it a velvety texture. Furthermore, the mycelium-based leather prepared in this embodiment possesses good fullness and flexibility. Microscopic observation of the mycelium sheets used in step (1) of this embodiment reveals that although mycelial fiber components are visible at the edges of the mycelium sheets, there is obvious adhesion between the mycelial fibers (see...). Figure 3 Microscopic observation of the fibers on the grain surface of the mycelial leather prepared in this embodiment clearly shows that the mycelial fibers of the mycelial leather have a good dispersion state after plasticization and hydrophobic treatment, and the fibers in the core area are all in a separated state (see...). Figure 4Since no cross-linking agent was used for chemical cross-linking during the entire mycelial leather processing in this embodiment, the mycelial leather prepared in this embodiment does not contain chemical cross-linking agents that are harmful to the human body and the environment, and the preparation process does not discharge wastewater containing chemical cross-linking agents, thus having the characteristics of safety and environmental protection.

[0066] The static water absorption rate of the mycelium-based leather prepared in this embodiment was tested, and the results showed that its static water absorption rate was between 115% and 125%.

[0067] Three small samples of 5 cm × 5 cm were cut from the mycelial leather sample prepared in this embodiment. The small samples were buried in garden soil about 30 cm below the surface under natural conditions. The soil was dug up and observed on the 20th, 30th and 40th days respectively. It was found that the small samples had been basically naturally degraded into fine particles by the 40th day.

[0068] Comparative Example 1

[0069] This comparative example provides a method for preparing mycelial leather without plasticizing and hydrophobic treatment. The operation of this comparative example is basically the same as that of Example 1, except that step (3) of Example 1 is omitted.

[0070] The mycelium-based leather prepared in this comparative example appears very bubbly and is very lightweight, but it feels stiff, has almost no resilience, and breaks very easily when bent. Figure 5 As shown, the mycelial leather prepared in this comparative example can be easily broken by one hand, as observed under an optical microscope. Figure 5 At the fracture points of the fibers, although there were voids between the mycelial fibers, the dispersion of the mycelial fibers was poor, and there was obvious adhesion between the mycelial fibers. The mycelial leather prepared in this comparative example readily absorbed water and bubbled upon contact with it; after absorbing water, even mycelial fiber delamination occurred. Static water absorption rate tests on the mycelial leather prepared in this comparative example showed that its static water absorption rate was between 280% and 290%.

[0071] As can be seen from Comparative Example 1, if plasticizing and hydrophobic treatment are not carried out during the preparation of mycelial leather, the prepared mycelial leather will not have flexibility, will not be resistant to bending, will be very easy to break, and will have extremely poor water resistance.

[0072] Comparative Example 2

[0073] This comparative example provides a method for preparing mycelial leather after plasticizing treatment. The operation of this comparative example is basically the same as that of Example 1, except that step (3) of Example 1 is replaced with the following plasticizing operation:

[0074] 100 parts by weight of water, 20 parts by weight of glycerol, 6 parts by weight of fatliquoring agent XG-60 and 100 parts by weight of dehydrated mycelial sheets were put into a rotating drum. The drum was rotated intermittently at 3 rpm for 4 h (5 min per hour) under constant temperature of 40 ℃. The skin was then extracted to obtain plasticized mycelial skin blanks.

[0075] In the drying and finishing process of step (4), the leather blanks that have been plasticized in step (3) are dried, rehydrated, softened, and shaved evenly according to conventional operations to obtain mycelial leather.

[0076] The mycelium-based leather prepared in this comparative example has a moist feel and improved softness compared to Comparative Example 1, but its softness and fullness are still lacking. It is slightly stiff and has poor toughness, mainly because the plasticizer is easily washed away during the finishing process. When exposed to water, the mycelium-based leather prepared in this comparative example readily absorbs moisture, resulting in bubbling. Static water absorption rate tests on the mycelium-based leather prepared in this comparative example showed that its static water absorption rate was between 185% and 195%.

[0077] Based on Comparative Examples 1 and 2, it can be seen that during the preparation of mycelial leather, although plasticizing can improve the softness, fullness and water resistance of mycelial leather to a certain extent, the softness and fullness are still not good, the water resistance is still at a poor level, and it is also difficult to effectively solve the problem of poor toughness of mycelial leather.

[0078] Comparative Example 3

[0079] This comparative example provides a method for preparing mycelial leather that has undergone glutaraldehyde crosslinking and plasticizing treatment, the steps of which are as follows:

[0080] (1) Deacetylation treatment

[0081] 100 parts by weight of freshly harvested and inactivated mycelial sheets were placed in a container with 200 parts by weight of water and 3 parts by weight of sodium carbonate. The mixture was soaked at 50 °C for 180 min to perform deacetylation treatment. After that, the mycelial sheets were washed with water and centrifuged to obtain deacetylated mycelial sheets.

[0082] (2) Crosslinking

[0083] 100 parts by weight of deacetylated mycelial sheets, 100 parts by weight of water, and 5 parts by weight of glutaraldehyde were added to a rotating drum. The temperature of the bath was controlled at 32 ℃, and the drum was rotated for 3 h. Then, sodium bicarbonate solution was added to the drum every 0.5 h for a total of 3 times to adjust the pH of the bath to 7.0~7.2. The temperature of the bath was raised to 40 ℃ and the drum was rotated for 1 h. After standing for 12 h, the skin was extracted to obtain cross-linked mycelial sheets.

[0084] (3) Plasticization

[0085] 100 parts by weight of cross-linked mycelial sheets, 100 parts by weight of water, 20 parts by weight of glycerol and 6 parts by weight of fatliquoring agent XG-60 were put into a drum. The drum was rotated intermittently at 3 rpm for 4 hours under constant temperature of 40 ℃ (rotating the drum for 5 minutes per hour) to extract the skin.

[0086] (4) Drying and finishing

[0087] Following standard procedures, the plasticized leather blanks are stretched, dried, rehydrated, softened, and shaved evenly to obtain mycelial leather.

[0088] The mycelium-based leather prepared in this comparative example showed significantly improved softness compared to Comparative Example 1, significantly improved fullness compared to Comparative Example 2, and improved toughness and water resistance compared to Comparative Example 2, but its water resistance was still not good. Static water absorption rate tests were conducted on the mycelium-based leather prepared in this comparative example, and the results showed that the static water absorption rate was between 160% and 170%.

[0089] Four small samples (5 cm × 5 cm) were cut from the mycelial leather samples prepared in this comparative example. The small samples were buried in garden soil about 30 cm below the surface under natural conditions. The soil was dug up and observed on the 60th, 90th, 120th and 150th days. It was found that the small samples took 150 days to be naturally degraded into fine particles.

[0090] As shown in Examples 1-3, introducing a chemical cross-linking agent before the plasticizing process in the preparation of mycelial leather can improve its fullness and water resistance to some extent, but the water resistance of the prepared mycelial leather is still not good. Since the mycelial fibers in mycelial leather are more porous than the collagen fibers in animal hides, this results in stronger water absorption. As shown in Example 1, even after plasticizing and hydrophobic treatment during the preparation process, the water absorption of the prepared mycelial leather is still stronger than that of natural animal leather. Therefore, for the preparation of mycelial leather, improving the problem of strong water absorption and poor water resistance caused by the relatively porous mycelial fibers is also very important for improving the application performance of mycelial leather. Cross-linking with chemical cross-linking agents can form covalent bonds between mycelial fibers, increasing the connection and tightness between them to some extent. Theoretically, cross-linking with chemical cross-linking agents can improve the water resistance of mycelial leather. However, as shown in Comparative Example 3, the improvement effect of chemical cross-linking with glutaraldehyde on the water resistance of mycelial leather is not good. This indicates that chemical cross-linking is actually difficult to effectively improve the water resistance of mycelial leather. In contrast, Example 1, through plasticization and hydrophobic treatment, can produce a better effect on improving the water resistance of mycelial leather than Comparative Examples 1-3.

[0091] Furthermore, based on the natural degradation performance test results of Example 1 and Comparative Example 3, it can be seen that introducing a chemical crosslinking agent for crosslinking will lead to a decrease in the natural degradation performance of mycelial leather.

[0092] Example 2

[0093] This embodiment provides a method for preparing mycelium-based leather based on hydrophobic treatment. The process flow of this method is as follows: Figure 1 As shown, the steps are as follows:

[0094] (1) Mechanical dewatering

[0095] 100 parts by weight of freshly harvested and inactivated mycelial sheets were placed in a container with 300 parts by weight of water and 0.4 parts by weight of sodium carbonate and soaked at 40 °C for 100 min to remove soluble polysaccharides and attached culture medium from the surface of the mycelial sheets and between the mycelial fibers. After that, the sheets were washed with deionized water to obtain pretreated mycelial sheets.

[0096] The pretreated mycelial sheets were squeezed with a through-type dewatering machine at a roller pressure of 6 MPa until the water content was 45 wt% to 55 wt%, thus obtaining dewatered mycelial sheets.

[0097] (2) Dehydration of solvent and water-absorbing medium

[0098] 100 parts by weight of dehydrated mycelial sheets, 250 parts by weight of anhydrous ethanol, and 200 parts by weight of spherical porous color-changing silica particles with a particle size of approximately 6-8 mm were placed in a sealed container and allowed to stand at 40 °C for 40 min to dehydrate. Then, the mycelial sheets were centrifuged to remove most of the anhydrous ethanol and the porous color-changing silica particles attached to the mycelial sheets. The centrifuged mycelial sheets were heated to 79 °C and maintained at this temperature until the anhydrous ethanol was completely removed from the mycelial sheets, resulting in dehydrated mycelial sheets.

[0099] The liquid phase obtained by centrifugation in this step is collected, and the collected liquid phase is distilled to recover anhydrous ethanol and the recovered anhydrous ethanol is recycled. The anhydrous ethanol volatilized during the heating of the mycelial sheets obtained by centrifugation at 79 °C is collected and recycled. The porous color-changing silica particles obtained by centrifugation are recovered, heated to remove moisture, and then regenerated and recycled.

[0100] (3) Plasticizing and hydrophobic treatment

[0101] Six parts by weight of PERFECTOL QX, one part by weight of Silok 8000, and 16 parts by weight of N-β-aminoethyl-γ-aminopropyltrimethoxysilane (KH792) were thoroughly mixed. The resulting mixture was then added to 40 parts by weight of anhydrous ethanol and 50 parts by weight of hot water at 50 °C and stirred to emulsify, yielding a plasticizing and hydrophobic treatment agent. The plasticizing and hydrophobic treatment agent and 100 parts by weight of dehydrated mycelial sheets were placed in a rotating drum. The drum was intermittently rotated at 5 rpm for 5 hours (10 min per hour) under constant temperature conditions of 50 °C, and the mycelial skin was extruded to obtain a plasticized and hydrophobic treated mycelial skin preform.

[0102] (4) Drying and finishing

[0103] Following standard procedures, the plasticized and hydrophobic treated leather blanks are stretched, dried, rehydrated, softened, and shaved evenly to obtain mycelial leather.

[0104] A photograph of the grain surface of the mycelium-based leather prepared in this embodiment is shown below. Figure 6 As shown, the mycelium-based leather prepared in this embodiment exhibits a natural texture and a finer grain surface (compared to Example 1), with a soft feel and extremely fine inner fiber fibers, giving it a velvety texture. Simultaneously, the mycelium-based leather prepared in this embodiment possesses good fullness and flexibility. Microscopic observation of the mycelium sheets used in step (1) of this embodiment revealed obvious adhesion between the mycelium fibers. Microscopic observation of the grain surface fibers of the mycelium-based leather prepared in this embodiment clearly shows that the mycelium fibers of the mycelium-based leather have a good dispersion state (see...). Figure 7The static water absorption rate of the mycelium-based leather prepared in this embodiment was tested, and the results showed that its static water absorption rate was between 120% and 130%.

[0105] Example 3

[0106] This embodiment provides a method for preparing mycelium-based leather based on hydrophobic treatment. The process flow of this method is as follows: Figure 1 As shown, the steps are as follows:

[0107] (1) Mechanical dewatering

[0108] Freshly harvested and inactivated mycelial sheets were squeezed with a through-feed dewatering machine at a roller pressure of 20 MPa until the water content was 55 wt% to 65 wt%, thus obtaining dewatered mycelial sheets.

[0109] (2) Dehydration of solvent and water-absorbing medium

[0110] 100 parts by weight of dehydrated mycelial sheets, 250 parts by weight of acetone, and 150 parts by weight of spherical porous color-changing silica particles with a particle size of approximately 4-6 mm were placed in a sealed container and allowed to stand at 40 °C for 40 min to dehydrate. Then, the mycelial sheets were centrifuged to remove most of the acetone and the porous color-changing silica particles attached to the mycelial sheets. The centrifuged mycelial sheets were heated to 60 °C and maintained at this temperature until the acetone in the mycelial sheets was completely removed, resulting in dehydrated mycelial sheets.

[0111] The liquid phase obtained by centrifugation in this step is collected, and the collected liquid phase is distilled to recover acetone and the recovered acetone is recycled. The acetone volatilized during the heating of the mycelial sheets obtained by centrifugation at 60 °C is collected and recycled. The porous color-changing silica particles obtained by centrifugation are recovered, heated to remove moisture, and then regenerated and recycled.

[0112] (3) Plasticizing and hydrophobic treatment

[0113] 10 parts by weight of PERFECTOL HQ, 2 parts by weight of Silok 8008, and 30 parts by weight of N-β-aminoethyl-γ-aminopropyltrimethoxysilane (KH792) were thoroughly mixed. The resulting mixture was then added to 30 parts by weight of anhydrous ethanol and 30 parts by weight of n-hexane and stirred thoroughly until dissolved to obtain a plasticizing and hydrophobic treatment agent. The plasticizing and hydrophobic treatment agent and 100 parts by weight of dehydrated mycelial sheets were placed in a rotating drum. The drum was intermittently rotated at 6 rpm for 3 hours (15 min per hour) under a constant temperature of 40 °C. The mycelial skin was then extracted to obtain a plasticized and hydrophobic treated mycelial skin preform.

[0114] (4) Drying and finishing

[0115] Following standard procedures, the plasticized and hydrophobic treated leather blanks are stretched, dried, rehydrated, softened, and shaved evenly to obtain mycelial leather.

[0116] A photograph of the grain surface of the mycelium-based leather prepared in this embodiment is shown below. Figure 8 As shown, the mycelial leather prepared in this embodiment has a natural and fine grain texture, a soft feel, and a velvety inner layer. Simultaneously, the mycelial leather prepared in this embodiment exhibits good fullness and flexibility. Microscopic observation of the mycelial fibers used in step (1) of this embodiment revealed obvious adhesion between the mycelial fibers. Microscopic observation of the grain fibers of the mycelial leather prepared in this embodiment showed that the mycelial fibers of the mycelial leather have a good dispersion state (see...). Figure 9 The static water absorption rate of the mycelium-based leather prepared in this embodiment was tested, and the results showed that its static water absorption rate was between 120% and 130%.

[0117] Example 4

[0118] This embodiment provides a method for preparing mycelium-based leather based on hydrophobic treatment. The process flow of this method is as follows: Figure 1 As shown, the steps are as follows:

[0119] (1) Mechanical dewatering

[0120] 100 parts by weight of freshly harvested and inactivated mycelial sheets were placed in a container with 100 parts by weight of water and 0.1 parts by weight of sodium carbonate and soaked at 35 °C for 200 min to remove soluble polysaccharides and attached culture medium from the surface of the mycelial sheets and between the mycelial fibers. After that, the sheets were washed with deionized water to obtain pretreated mycelial sheets.

[0121] Freshly harvested and inactivated mycelial sheets were squeezed with a through-feed dewatering machine at a roller pressure of 15 MPa until the water content was 60 wt% to 70 wt%, thus obtaining dewatered mycelial sheets.

[0122] (2) Dehydration of solvent and water-absorbing medium

[0123] 100 parts by weight of dehydrated mycelial sheets, 300 parts by weight of anhydrous ethanol, and 200 parts by weight of spherical zeolite particles with a particle size of approximately 8-10 mm were placed in a sealed container and allowed to stand at 50 °C for 100 min to dehydrate. Then, the mycelial sheets were centrifuged to remove most of the anhydrous ethanol and the zeolite particles attached to the mycelial sheets. The centrifuged mycelial sheets were heated to 80 °C and maintained at this temperature until the anhydrous ethanol was completely removed from the mycelial sheets, resulting in dehydrated mycelial sheets.

[0124] The liquid phase obtained by centrifugation in this step is collected, and the collected liquid phase is distilled to recover anhydrous ethanol and the recovered anhydrous ethanol is recycled. The anhydrous ethanol volatilized during the heating of the mycelial sheets obtained by centrifugation at 80 °C is collected and recycled. The zeolite particles obtained by centrifugation are recovered, heated to remove moisture, and then regenerated and recycled.

[0125] (3) Plasticizing and hydrophobic treatment

[0126] 15 parts by weight of OMBRELLON 072, 4 parts by weight of Silok 8008, and 8 parts by weight of dimethyl silicone oil were thoroughly mixed. The resulting mixture was then added to 250 parts by weight of hot water at 70°C and stirred to emulsify, yielding a plasticizing and hydrophobic treatment agent. The plasticizing and hydrophobic treatment agent and 100 parts by weight of dehydrated mycelial sheets were placed in a rotating drum. The drum was intermittently rotated at 6 rpm for 8 hours (10 min per hour) under a constant temperature of 35°C, and the mycelial skin was extruded to obtain a plasticized and hydrophobic treated mycelial skin preform.

[0127] (5) Drying and finishing

[0128] Following standard procedures, the plasticized and hydrophobic treated leather blanks are stretched, dried, rehydrated, softened, and shaved evenly to obtain mycelial leather.

[0129] The mycelium-based leather prepared in this embodiment exhibits a natural grain texture, a soft feel, a slightly firm grain surface, and a velvety inner layer. Compared to Example 1, the fullness of the mycelium-based leather prepared in this embodiment is slightly insufficient. Static water absorption rate tests were conducted on the mycelium-based leather prepared in this embodiment, and the results showed that its static water absorption rate was between 125% and 135%.

[0130] Example 5

[0131] This embodiment provides a method for preparing mycelium-based leather based on hydrophobic treatment. The process flow of this method is as follows: Figure 1 As shown, the steps are as follows:

[0132] (1) Mechanical dewatering

[0133] 100 parts by weight of freshly harvested and inactivated mycelial sheets were placed in a container with 500 parts by weight of water and 0.4 parts by weight of sodium carbonate and soaked at 80 °C for 10 min to remove soluble polysaccharides and attached culture medium from the surface of the mycelial sheets and between the mycelial fibers. After that, the sheets were washed with deionized water to obtain pretreated mycelial sheets.

[0134] The pretreated mycelial sheets were squeezed to a water content of 40 wt% to 50 wt% using a through-type dewatering machine with a roller pressure of 12 MPa, thus obtaining dewatered mycelial sheets.

[0135] (2) Dehydration of solvent and water-absorbing medium

[0136] 100 parts by weight of dehydrated mycelial sheets, 100 parts by weight of methanol, and 150 parts by weight of spherical porous silica particles with a particle size of approximately 2-4 mm were placed in a sealed container and allowed to stand at room temperature for 150 min for dehydration. Then, the mycelial sheets were centrifuged to remove most of the methanol and the porous silica particles attached to the mycelial sheets. The centrifuged mycelial sheets were heated to 66 °C and maintained at this temperature until the methanol in the mycelial sheets was completely removed, resulting in dehydrated mycelial sheets.

[0137] The liquid phase obtained by centrifugation in this step is collected, and the collected liquid phase is distilled to recover methanol and the recovered methanol is recycled. The methanol volatilized during the heating of the mycelial sheets obtained by centrifugation at 66 °C is collected and recycled. The porous silica particles obtained by centrifugation are recovered, heated to remove moisture, and then regenerated and recycled.

[0138] (3) Plasticizing and hydrophobic treatment

[0139] 12 parts by weight of PERFECTOL HQ, 10 parts by weight of Silok 8000, 9 parts by weight of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane (KH602), and 6 parts by weight of hydroxyl silicone oil were thoroughly mixed. The resulting mixture was then added to 300 parts by weight of hot water at 80°C and stirred to emulsify, yielding a plasticizing and hydrophobic treatment agent. The plasticizing and hydrophobic treatment agent and 100 parts by weight of dehydrated mycelial sheets were placed in a rotating drum. The drum was intermittently rotated at 4 rpm for 2 hours (10 min per hour) under a constant temperature of 60°C, and the mycelial skin was extruded to obtain a plasticized and hydrophobic mycelial skin preform.

[0140] (5) Drying and finishing

[0141] Following standard procedures, the plasticized and hydrophobic treated leather blanks are stretched, dried, rehydrated, softened, and shaved evenly to obtain mycelial leather.

[0142] The mycelium-based leather prepared in this embodiment exhibits a natural grain texture, a soft feel, and a velvety inner layer. Static water absorption tests on the mycelium-based leather prepared in this embodiment showed that its static water absorption rate was between 115% and 125%.

Claims

1. A method for preparing mycelial leather based on hydrophobic treatment, characterized in that, Includes the following steps: (1) Mechanical dewatering Freshly harvested and inactivated mycelial sheets or pretreated mycelial sheets are mechanically squeezed to a water content of 40wt%~70wt% to obtain water-squeezed mycelial sheets; (2) Dehydration of solvent and water-absorbing medium 100 parts by weight of water-dehydrated mycelial sheets were placed in a dehydration container with 100-300 parts by weight of hydrophilic solvent and 100-200 parts by weight of water-absorbing medium. The container was allowed to stand at room temperature to 50 °C for 30-150 min for dehydration. Then, the container was centrifuged. The centrifuged mycelial sheets were heated to remove the hydrophilic solvent from the mycelial sheets, resulting in dehydrated mycelial sheets. (3) Plasticizing and hydrophobic treatment 6-40 parts by weight of silicon-containing polymer material, 1-10 parts by weight of silicon-based wetting agent, 8-30 parts by weight of silane coupling agent and / or silicone oil are dissolved or fully dispersed in 60-300 parts by weight of solvent to obtain a plasticizing and hydrophobic treatment agent; the obtained plasticizing and hydrophobic treatment agent and 100 parts by weight of dehydrated mycelial sheets are put into a drum, and the drum is rotated for 2-8 hours under constant temperature conditions of 35-60 ℃ to obtain a plasticized and hydrophobic mycelial skin blank; (4) Drying and finishing The hydrophobic mycelium rough is dried and processed to obtain mycelium-based leather.

2. The method for preparing hydrophobically treated mycelial leather according to claim 1, characterized in that, The silicon-containing polymer material in step (3) includes at least one of OMBRELLON 072, PERFECTOL HQ, and PERFECTOL QX.

3. The method for preparing hydrophobically treated mycelial leather according to claim 1, characterized in that, The silicon-based wetting agent in step (3) is Silok 8008 or Silok 8000.

4. The method for preparing hydrophobically treated mycelial leather according to claim 1, characterized in that, The silane coupling agent in step (3) includes at least one of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, and N-β-aminoethyl-γ-aminopropyltrimethoxysilane, and the silicone oil includes at least one of hydrogen-containing silicone oil, hydroxyl silicone oil, and dimethyl silicone oil.

5. The method for preparing hydrophobically treated mycelial leather according to any one of claims 1 to 4, characterized in that, The water-absorbing medium in step (2) includes zeolite, porous silica gel or color-changing silica gel, and the water-absorbing medium is in the form of spherical particles.

6. The method for preparing hydrophobically treated mycelial leather according to claim 5, characterized in that, The particle size of the water-absorbing medium is 2~10 mm.

7. The method for preparing hydrophobically treated mycelial leather according to any one of claims 1 to 4, characterized in that, The hydrophilic solvent in step (2) is an organic solvent that is miscible with water and has a boiling point not exceeding 90 °C.

8. The method for preparing hydrophobically treated mycelial leather according to any one of claims 1 to 4, characterized in that, Collect the liquid phase obtained by centrifugation in step (2), recover the hydrophilic solvent in the liquid phase and recycle the recovered hydrophilic solvent, and collect the water-absorbing medium obtained by centrifugation in step (2), regenerate it by heating and recycle it.

9. The method for preparing hydrophobically treated mycelial leather according to any one of claims 1 to 4, characterized in that, The method for preparing the pretreated mycelial sheets in step (1) is as follows: 100 parts by weight of freshly harvested and inactivated mycelial sheets, 100-500 parts by weight of water and 0.1-0.4 parts by weight of alkaline material are put into a pretreatment container and soaked at 35-80 ℃ for 10-200 min, and then washed with water.

10. Mycelial leather prepared by the method according to any one of claims 1 to 9.

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