Keratin materials

Abstract

The present invention relates to thermoset biopolymers derived from isolated keratin fiber cell components, to composite keratin materials comprising thermoset biopolymers, to processes for their preparation and to their uses.

Description

Technical Field

[0001] The present invention relates to thermosetting biopolymers derived from isolated keratin fiber cell fractions, composite keratin materials comprising thermosetting biopolymers, methods for their preparation and uses. Background Art

[0002] Fibrous proteins (also called hard proteins) are generally inert and insoluble in water. Fibrous proteins form long protein filaments shaped like rods or threads. They are structural or storage proteins. Fibrous proteins include keratin, collagen, elastin, and fibroin.

[0003] Keratin fibers include wool, fur, hair, and feathers. Wool is a keratin fiber produced by a variety of animals, including sheep, goats, camels, and rabbits. The fiber structure consists of a cuticle, cortex, and medulla, although fine wool may lack the medulla.

[0004] Sheep wool typically has a diameter ranging from about 10 microns to about 45 microns. Fiber diameter is an important characteristic of wool, correlated with its quality and price. Finer wools are softer and suitable for clothing. There are still a limited number of consumer applications for stronger wool types, such as flooring, bedding, upholstery, and hand-knitting yarns.

[0005] Wool consists of three main histological components: two cellular components and a cell membrane complex, which exists between cells and holds the structure together. The cellular components are the cortical cells, which comprise the fiber's internal structure, and the cuticle cells, which overlap to form the outer layer. This complex biological assembly is produced by the body in the hair follicle during wool growth.

[0006] One limitation of wool is that it is not a thermoset material. While keratin is known to have a glass transition temperature, keratin fibers cannot be effectively melted or processed as thermoplastics. Therefore, wool processing has traditionally been limited by its shape and properties. Previous attempts to alter wool's shape and properties have used wool in fiber form and relatively simple methods such as heat, steam, or chemical setting of the fibers.

[0007] The lack of the ability to thermally process wool into various shapes and achieve complete thermal transformation has limited the use of wool beyond conventional fiber and textile products.

[0008] It is therefore an object of the present invention to go some way to avoiding the above disadvantages; and / or at least to provide the public with a useful choice.

[0009] Other objects of the present invention will become apparent from the following description which is given by way of example only.

[0010] Any discussion of documents, acts, materials, devices, articles of manufacture and the like that has been included in this specification is solely for the purpose of providing a context for the present invention and is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date. Summary of the Invention

[0011] In a first aspect, the present invention provides thermosetting biopolymers derived from isolated keratin fiber cell fractions.

[0012] In some embodiments, the thermosetting biopolymer is obtained by subjecting the isolated keratin fiber cell fraction to elevated temperature and elevated pressure.

[0013] In another aspect, the present invention provides a composite keratin material comprising a thermosetting biopolymer, wherein the thermosetting biopolymer is derived from an isolated keratin fiber cell fraction.

[0014] In some embodiments, the thermosetting biopolymer is obtained by subjecting the isolated keratin fiber cell fraction to elevated temperature and elevated pressure.

[0015] In some embodiments, the composite keratin material further comprises cellulosic fibers or polyethylene terephthalate (PET).

[0016] In another aspect, the present invention provides a method for preparing a composite keratin material, comprising the steps of:

[0017] a) providing a mixture comprising isolated keratinocyte fiber fractions, and

[0018] b) subjecting the mixture to elevated temperature and elevated pressure such that the separated keratinocyte fiber components form a thermosetting biopolymer to provide a composite keratin material.

[0019] In some embodiments, the elevated temperature is equal to or greater than the glass transition temperature of the isolated keratin fiber cell fraction. In some embodiments, the elevated temperature is at least about 140°C. In some embodiments, the elevated temperature is at least about 160°C. In some embodiments, the elevated temperature is from about 140°C to about 220°C. In some embodiments, the elevated temperature is from about 160°C to about 200°C. In some embodiments, the elevated temperature is about 160°C.

[0020] In some embodiments, the pressure of increase is at least about 40kN. In some embodiments, the pressure of increase is at least about 50kN. In some embodiments, the pressure of increase is at least about 90kN. In some embodiments, the pressure of increase is at least about 100kN, about 150kN, about 200kN, about 250kN, about 300kN, about 350kN, about 400kN, about 450kN, about 500kN, about 550kN, about 600kN, about 650kN, about 700kN, about 750kN, about 800kN, about 850kN or about 900kN. In some embodiments, the pressure of increase is at least about 450kN. In some embodiments, the pressure of increase is at least about 900kN.

[0021] In some embodiments, the mixture is subjected to elevated temperature and elevated pressure for a period of at least about 1 minute. In some embodiments, the keratin mixture is subjected to elevated temperature and elevated pressure for a period of at least about 1 minute, about 2 minutes, or about 3 minutes. In some embodiments, the keratin mixture is subjected to elevated temperature and elevated pressure for a period of about 3 minutes.

[0022] In some embodiments, the elevated temperature and elevated pressure are achieved by hot pressing the mixture. In some embodiments, the mixture is hot pressed between metal plates.

[0023] In some embodiments, the mixture in step (a) is provided in the form of a sheet. In some embodiments, the mixture in step (a) is provided in the form of a layer of two or more sheets, optionally a layer of 2 to 10 sheets or 2 to 5 sheets. In some embodiments, each sheet is formed by pressing a slurry comprising separated keratinocyte fiber components. In some embodiments, each sheet is pressed, pressed, and dried.

[0024] In some embodiments, the mixture is subjected to elevated temperature and elevated pressure for a time sufficient to provide a material having at least one of the following properties:

[0025] i) a tensile strength of at least about 30 Nm / g,

[0026] ii) an air resistance of at least about 10 s / 100 mL,

[0027] iii) less than about 100 g / m 2 Cobb 30 value.

[0028] In some embodiments, the mixture also includes a cellulosic material. In some embodiments, the cellulosic material is derived from a plant or multiple plant parts. In some embodiments, the cellulosic material is derived from one or more plant parts selected from the group consisting of: wood, cotton, corn, flax, jute, ramie, straw, hemp, bagasse, Miscanthus and any two or more combinations thereof. In some embodiments, wood is wood pulp or wood fiber.

[0029] In some embodiments, the mixture further comprises synthetic fibers. In some embodiments, the synthetic fibers comprise a polymer selected from the group consisting of polyesters (e.g., polyethylene terephthalate, PET), polyacrylics, polychloroprenes (e.g., neoprene), polyolefins, polyurethanes (e.g., spandex), polyamides (e.g., nylon), and combinations of any two or more thereof. In some embodiments, the synthetic fiber is polyethylene terephthalate.

[0030] In some embodiments, the mixture further includes water.

[0031] In some embodiments, the mixture further comprises an additive selected from the group consisting of a reducing agent, a plasticizer, an oil, and a combination of any two or more thereof.

[0032] In some embodiments, the mixture in step (a) is provided in the form of a sheet or layer of sheets, and the additive is applied to the sheet or layer of sheets prior to step (b), and optionally wherein the additive is applied by dipping the sheet or layer of sheets into the additive, brushing the additive onto the sheet or layer of sheets, or spraying the additive onto the sheet or layer of sheets. In some embodiments, the additive is applied to each sheet prior to forming the sheet layer.

[0033] In some embodiments, the reducing agent is selected from the group consisting of sulfites, metabisulfites, sulfides, thioglycolates, cysteine, and combinations of any two or more thereof. In some embodiments, the reducing agent is selected from the group consisting of sodium sulfite, sodium metabisulfite, sodium sulfide, sodium thioglycolate, cysteine, and combinations of any two or more thereof. In some embodiments, the reducing agent is sodium sulfite.

[0034] In some embodiments, the plasticizer is selected from glycerol or polypropylene glycol. In some embodiments, the glycerol is a glycerol aqueous solution, a 1-50 w / w% glycerol aqueous solution, a 10-50 w / w% glycerol aqueous solution or a 50 w / w% glycerol aqueous solution.

[0035] In some embodiments, the oil is an oil with a flash point greater than about 155°C. In some embodiments, the oil is an oil with a smoke point greater than about 140°C. In some embodiments, the oil is a natural oil or a synthetic oil. In some embodiments, the natural oil is a vegetable oil or an animal-derived oil. In some embodiments, the vegetable oil is almond oil, avocado oil, coconut oil, palm oil, peanut oil, canola oil, safflower oil, sesame oil, soybean oil, sunflower oil, or grapeseed oil. In some embodiments, the synthetic oil is a silicone oil.

[0036] In some embodiments, the composite keratin material has one or more of the following properties:

[0037] i) a tensile strength of at least about 30 Nm / g,

[0038] ii) an air resistance of at least about 10 s / 100 mL,

[0039] iii) less than about 100 g / m 2 Cobb 30 value.

[0040] In some embodiments, the isolated keratin fiber cell fraction is obtained from a source selected from the group consisting of wool, hair, fur, feathers, and combinations of any two or more thereof. In some embodiments, the isolated keratin fiber cell fraction is obtained from wool. In some embodiments, the isolated keratin fiber cell fraction is obtained from sheep wool.

[0041] In some embodiments, the composite keratin material further comprises a cellulosic material. In some embodiments, the cellulosic material is derived from a plant or multiple plant parts. In some embodiments, the cellulosic material is derived from one or more plant parts selected from the group consisting of wood, cotton, corn, flax, jute, ramie, straw, hemp, bagasse, Miscanthus, and combinations of any two or more thereof. In some embodiments, the wood is wood pulp or wood fiber.

[0042] In some embodiments, the composite keratin material further comprises synthetic fibers. In some embodiments, the synthetic fibers comprise polymers selected from the group consisting of polyesters (e.g., polyethylene terephthalate, PET), polyacrylics, polychloroprenes (e.g., neoprene), polyolefins, polyurethanes (e.g., spandex), polyamides (e.g., nylon), and combinations of any two or more thereof. In some embodiments, the synthetic fibers are polyethylene terephthalate.

[0043] In some embodiments, the composite keratin material comprises a keratin fiber cell component and a cellulosic material in a weight ratio of about 5:95 to about 95:5. In some embodiments, the composite keratin material comprises a keratin fiber cell component and a cellulosic material in a weight ratio of about 10:90 to about 90:10, about 20:80 to about 80:20, about 30:70 to about 70:30, about 40:60 to about 60:40, or about 45:55 to about 55:45. In some embodiments, the composite keratin material comprises a keratin fiber cell component and a cellulosic material in a weight ratio of about 30:70 to about 70:30, about 40:60 to about 60:40, or about 45:55 to about 55:45.

[0044] In some embodiments, the composite keratin material has at least two of properties i) through iii). In some embodiments, the composite keratin material has properties i) through iii).

[0045] In some embodiments, the composite keratin material has a tensile strength of at least about 35 Nm / g, about 36 Nm / g, about 37 Nm / g, about 38 Nm / g, about 39 Nm / g, about 40 Nm / g, about 41 Nm / g, about 42 Nm / g, about 43 Nm / g, about 44 Nm / g, about 45 Nm / g, about 46 Nm / g, about 47 Nm / g, about 48 Nm / g, about 49 Nm / g, about 50 Nm / g, about 51 Nm / g, about 52 Nm / g, about 53 Nm / g, about 54 Nm / g, or about 55 Nm / g. In some embodiments, the composite keratin material has a tensile strength of at least about 40 Nm / g. In some embodiments, the composite keratin material has a tensile strength of at least about 45 Nm / g. In some embodiments, the composite keratin material has a tensile strength of at least about 50 Nm / g. In some embodiments, the composite keratin material has a tensile strength of at least about 55 Nm / g.

[0046] In some embodiments, the composite keratin material has an air resistance of at least about 20 s / 100 mL, about 30 s / 100 mL, about 40 s / 100 mL, about 50 s / 100 mL, about 60 s / 100 mL, about 70 s / 100 mL, about 80 s / 100 mL, about 90 s / 100 mL, about 100 s / 100 mL, about 110 s / 100 mL, about 120 s / 100 mL, or about 130 s / 100 mL. In some embodiments, the composite keratin material has an air resistance of at least about 50 s / 100 mL.

[0047] In some embodiments, the composite keratin material has a g / m 2 , about 80g / m 2 , about 70g / m2 , about 60g / m 2 , about 50g / m 2 , about 45g / m 2 or about 40g / m 2 Cobb 30 value.

[0048] In some embodiments, the composite keratin material is in the form of a sheet.

[0049] In some embodiments, the sheet has a thickness greater than 100 μm, greater than 150 μm, greater than 200 μm, or greater than 250 μm.

[0050] In another aspect, the present invention provides a composite keratin material prepared by the method according to the invention.

[0051] In another aspect, the present invention provides paper comprising a composite keratin material according to the invention.

[0052] In another aspect, the present invention provides artificial leather comprising the composite keratin material according to the present invention.

[0053] In another aspect, the present invention provides a fabric comprising a composite keratin material according to the invention.

[0054] In some embodiments, the composite keratin material according to the invention is paper, fabric or artificial leather.

[0055] In some embodiments, the fabric is a nonwoven fabric.

[0056] In another aspect, the present invention relates to the use of a composite keratin material as a plastic substitute.

[0057] In another aspect, the present invention relates to the use of a composite keratin material as a replacement for chemical adhesives in the preparation of synthetic nonwoven fabrics.

[0058] The invention may also be broadly described as including the parts, elements and features referred to or indicated in the specification of this application, either individually or collectively, and any or all combinations of any two or more parts, elements or features, and where specific integers referred to herein have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0059] In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0060] As used herein, "(one or more)" following a noun is intended to refer to the plural and / or singular forms of the noun.

[0061] As used herein, the term "and / or" means "and" or "or" or both.

[0062] As used in this specification, the term "comprising" means "consisting at least in part of." When interpreting each statement in this specification that includes the term "comprising," features other than the feature or features beginning with the term may also be present. Related terms such as "comprise" and "comprises" should be interpreted in the same manner.

[0063] The term "keratin fiber cell component" used in this specification refers to keratin fiber epidermal cells, keratin fiber cortical cells, or a combination of keratin fiber epidermal cells and cortical cells. The isolated keratin fiber cell components are provided as physically different separate cells from each other. This is different from natural keratin fibers, in which the keratin cells and cortical cells are combined in a specific orderly arrangement, and the arrangement is determined by the growth of the fiber through the hair follicle. The keratin fiber cell component can be prepared by the method disclosed in WO 2020 / 080961 A1, which is incorporated herein by reference in its entirety. Wool cortical cells are typically ellipsoidal (preferably spindle-shaped) and are typically 50-150 μm long (preferably 70-120 μm) and 1-10 μm in diameter (preferably 4-8 μm). Wool epidermal cells are typically irregular shapes with a size of 1×10-15×15-40 μm. Preferably, the keratin fiber cell component is a combination of keratin fiber epidermal and cortical cells.

[0064] Reference to a numerical range disclosed herein (e.g., 1 to 10) also includes all rational numbers within the range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10) and any range of rational numbers within the range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7), and thus, all subranges of all ranges explicitly disclosed herein are hereby explicitly disclosed. These are merely examples of what is specifically intended, and all possible combinations of numerical values ​​between the lowest and highest values ​​recited are to be considered to be expressly stated in this application in a similar manner.

[0065] Although the present invention is broadly defined above, it will be understood by those skilled in the art that the invention is not limited thereto and that it also encompasses embodiments of which the following description gives examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The present invention will now be described with reference to the accompanying drawings, in which:

[0067] Figure 1 The effect of hot pressing treatment on tensile strength is shown.

[0068] Figure 2 Shown is the effect of heat pressure on air resistance for a 45% wool cell:55% wood fiber handsheet wet pressed at 160°C for 3 minutes.

[0069] Figure 3 Shown is the effect of pressing force on the Cobb water absorption results of 45% wool cell:55% wood fiber paper wet pressed at 160°C for 3 minutes.

[0070] Figure 4 The effect of pressing force on air resistance is shown for unpressed and pressed wood fiber and wool cell:wood fiber mixture sheets.

[0071] Figure 5 The effects of adding wool fibers to wood fibers and wet pressing on the Cobb water absorption of handsheets are shown.

[0072] Figure 6 Shown are the stain areas (mm) for the wool cell:wood fiber blend handsheet and the 100% wood fiber handsheet. 2 ).

[0073] Figure 7 A wet-laid nonwoven fabric comprising PET and softened wool cells in a weight ratio of 60:40 is shown.

[0074] Figure 8 A wet-laid nonwoven fabric comprising PET and softened wool cells in a weight ratio of 80:20 is shown.

[0075] Figure 9 A wet-laid nonwoven fabric comprising PET and softened wool cells in a weight ratio of 90:10 is shown.

[0076] Figure 10 The liquid absorption capacity of wet-laid nonwoven PET fabrics with and without softening wool cells (SC) is shown.

[0077] Figure 11 The liquid wicking rates of wet-laid nonwoven PET fabrics with and without softening wool cells (SC) are shown.

[0078] Figure 12 Shown are the tensile strengths of wet-laid nonwoven PET fabrics with and without softened wool cells (SC). DETAILED DESCRIPTION

[0079] The present invention relates to the surprising discovery that isolated keratin fiber cell components form thermosetting biopolymers when subjected to elevated temperatures and elevated pressures. Thermosetting biopolymers can be used to prepare composite keratin materials, such as those comprising cellulosic materials or synthetic fibers. Advantageously, the composite keratin materials can have improved properties, such as tensile strength or barrier properties, relative to the same materials without the thermosetting biopolymer. Importantly, this effect is not observed in comparable materials prepared using keratin fibers rather than isolated keratin fiber cell components. Furthermore, unlike keratin fibers, the thermosetting nature of thermosetting biopolymers allows them to be formed into a variety of shapes, for example.

[0080] A thermosetting biopolymer is prepared by subjecting a mixture comprising an isolated keratin fiber cell component to elevated temperature and elevated pressure. In some embodiments, the elevated temperature may be selected based on the glass transition temperature of the keratin fiber cell component. For example, the keratin mixture may be subjected to a temperature at or above the glass transition temperature of the isolated keratin fiber cell component. In some embodiments, the keratin mixture may be subjected to a temperature of at least about 140°C. In some embodiments, the keratin mixture may be subjected to a temperature of about 160°C. Those skilled in the art will appreciate that the temperature required to form a thermosetting biopolymer may be affected by pressure. For example, at higher pressures, a lower temperature may be required to form a thermosetting biopolymer.

[0081] For example, the mixture can be subjected to a pressure of at least about 40 kN. In some embodiments, the keratin mixture can be subjected to a pressure of at least about 50 kN, about 90 kN, about 100 kN, about 150 kN, about 200 kN, about 250 kN, about 300 kN, about 350 kN, about 400 kN, about 450 kN, about 500 kN, about 550 kN, about 600 kN, about 650 kN, about 700 kN, about 750 kN, about 800 kN, about 850 kN, or about 900 kN. In some embodiments, the keratin mixture can be subjected to a pressure of at least about 450 kN. In some embodiments, the keratin mixture can be subjected to a pressure of at least about 900 kN.

[0082] In some embodiments, the mixture is subjected to elevated temperature and elevated pressure for a period of at least about 1 minute. In some embodiments, the mixture is subjected to elevated temperature and elevated pressure for a period of about 3 minutes.

[0083] In some embodiments, the mixture is subjected to a temperature of at least about 160°C and a pressure of at least about 40 kN for a period of about 3 minutes. In some embodiments, the mixture is subjected to a temperature of at least about 160°C and a pressure of at least about 90 kN for a period of about 3 minutes. In some embodiments, the mixture is subjected to a temperature of at least about 160°C and a pressure of at least about 450 kN for a period of about 3 minutes. In some embodiments, the mixture is subjected to a temperature of at least about 160°C and a pressure of at least about 900 kN for a period of about 3 minutes. One skilled in the art can select an appropriate combination of temperature, pressure, and time to obtain a thermosetting biopolymer or composite keratin material.

[0084] The mixture can be subjected to elevated temperature and elevated pressure by, for example, hot pressing the mixture. In some embodiments, the mixture is hot pressed between metal plates.

[0085] To obtain the desired pressure, the mixture can be pressed between two plates (eg two metal plates).For example, the hot pressing step can be carried out in a Siempelkamp press.

[0086] This specification generally relates to keratin fiber cell fractions obtained from wool. However, the present invention is not limited thereto, and cell fractions obtained from other keratin fibers, such as wool, hair, fur, and feathers, may also be used in the present invention. In a preferred embodiment, the keratin fiber is wool, hair, or fur, or a mixture of any two or more thereof. In a preferred embodiment, the wool is sheep wool.

[0087] The keratin fiber cell component of the present invention can be prepared by methods known to those skilled in the art. For example, the keratin fiber cell component can be prepared by the method disclosed in WO 2020 / 080961 A1.

[0088] The mixture may further include a cellulosic material. The cellulosic material may be derived from a plant or plant part, such as wood, cotton, corn, flax, jute, ramie, straw, hemp, bagasse, Miscanthus, or any two or more thereof. In some embodiments, the wood is wood pulp or wood fiber. It will be appreciated by those skilled in the art that other sources of cellulose, particularly cellulose fibers, may be used in the invention disclosed herein.

[0089] The mixture can include a keratin fiber cell component and a cellulosic material in a weight ratio of about 5:95 to about 95:5, for example, about 10:90 to about 90:10, about 20:80 to about 80:20, about 30:70 to about 70:30, about 40:60 to about 60:40, or about 45:55 to about 55:45. In some embodiments, the mixture includes a keratin fiber cell component and a cellulosic material in a weight ratio of about 30:70 to about 70:30, about 40:60 to about 60:40, or about 45:55 to about 55:45. The weight ratio of the keratin fiber cell component to the cellulosic material can be selected based on the desired application of the resulting material. For example, paper comprising a composite keratin material can be prepared by a keratin mixture comprising a keratin fiber cell component and a cellulosic material in a weight ratio of about 45:55 to about 55:45.

[0090] Thus, the composite keratin material may include a keratin fiber cell component and a cellulosic material in a weight ratio of about 5:95 to about 95:5, for example, about 10:90 to about 90:10, about 20:80 to about 80:20, about 30:70 to about 70:30, about 40:60 to about 60:40, or about 45:55 to about 55:45. In some embodiments, the composite keratin material includes a keratin fiber cell component and a cellulosic material in a weight ratio of about 30:70 to about 70:30, about 40:60 to about 60:40, or about 45:55 to about 55:45.

[0091] The composite keratin material may include synthetic fibers. Suitable synthetic fibers include, but are not limited to, polymers selected from the group consisting of polyesters (e.g., polyethylene terephthalate, PET), polyacrylics, polychloroprenes (e.g., neoprene), polyolefins, polyurethanes (e.g., spandex), polyamides (e.g., nylon), and combinations of any two or more thereof.

[0092] For example, the mixture can include a keratin fiber cell component and a synthetic fiber in a weight ratio of about 5:95 to about 75:25, about 10:90 to about 70:30, such as about 15:85 to about 65:35, about 20:80 to about 60:40, about 25:75 to about 65:45, about 30:70 to about 50:50, or about 35:65 to about 45:55. In some embodiments, the mixture includes a keratin fiber cell component and a synthetic fiber in a weight ratio of about 30:70 to about 70:30 or about 35:65 to about 45:55. The weight ratio of the keratin fiber cell component to the PET can be selected based on the desired application of the resulting material. For example, a fabric comprising a composite keratin material can be prepared from a keratin mixture comprising a keratin fiber cell component and synthetic fibers in a weight ratio of about 40:60.

[0093] Thus, the composite keratin material may comprise a keratin fiber cell component and synthetic fibers in a weight ratio of about 5:95 to about 75:25, about 10:90 to about 70:30, for example, about 15:85 to about 65:35, about 20:80 to about 60:40, about 25:75 to about 65:45, about 30:70 to about 50:50, or about 35:65 to about 45:55. In some embodiments, the composite keratin material comprises a keratin fiber cell component and synthetic fibers in a weight ratio of about 20:80 to about 60:40, about 25:75 to about 65:45, about 30:70 to about 50:50, or about 35:65 to about 45:55.

[0094] The mixture may further include additives such as a reducing agent, a plasticizer, an oil, or a combination of any two or more thereof.

[0095] Suitable reducing agents include, but are not limited to, sulfites, metabisulfites, sulfides, thioglycolates, cysteine, and any combination of two or more thereof. The reducing agent can be a salt, such as a sodium salt or a potassium salt. Thus, in some embodiments, the reducing agent is selected from the group consisting of sodium sulfite, sodium metabisulfite, sodium sulfide, sodium thioglycolate, cysteine, and any combination of two or more thereof. Without wishing to be bound by theory, it is believed that the reducing agent can reduce disulfide bonds in the isolated keratin fiber cell fraction, resulting in increased bonding when the fraction is subjected to elevated temperature and elevated pressure. Advantageously, the reducing agent can improve the material properties of the resulting thermosetting biopolymer or composite keratin material, such as oil and fat resistance.

[0096] Suitable plasticizers include, but are not limited to, glycerol and propylene glycol. For example, glycerol can be provided as a glycerol aqueous solution, such as a 1-50 w / w% glycerol aqueous solution or a 10-50 w / w% glycerol aqueous solution. Suitable oils include, but are not limited to, natural oils (such as vegetable oils or oils of animal origin) or synthetic oils. In some embodiments, vegetable oils are almond oil, avocado oil, coconut oil, palm oil, peanut oil, canola oil, safflower oil, sesame oil, soybean oil, sunflower oil, or grapeseed oil. In some embodiments, the synthetic oil is silicone oil. Generally, it is expected that suitable oils will have a flash point higher than about 155°C and / or a smoke point higher than about 140°C. Advantageously, plasticizers and / or oils can improve the flexibility of the resulting thermosetting biopolymer or composite keratin material.

[0097] The mixture may include additional additives. It will be appreciated by those skilled in the art that conventional additives known in the art may be useful based on the intended product and application. For example, the mixture may include a dispersant (e.g., Pluronic F-108, poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) polymer) and / or a defoamer (e.g., Tetronic 90R4, ethylenediaminetetra(ethoxylate-block-propoxylate) tetraol). Advantageously, such agents may improve the uniformity and dispersibility of the mixture.

[0098] The keratin mixture may be formed into a sheet prior to being subjected to elevated temperature and elevated pressure.Handsheets may be formed by conventional techniques known in the art, such as based on the Australian Pulp and Paper Technology Association (Appita) standard method AS / NZS 1301.203s:2017 or TAPPI standard T205.

[0099] For example, sheet material can be formed by preparing a slurry comprising a keratin fiber cell component in a liquid (e.g., water). Slurry can be prepared by dispersing a dry keratin fiber cell component material in a liquid. When the keratin mixture also includes a cellulose material and / or synthetic fiber, the keratin mixture can be prepared by dispersing a dry keratin fiber cell component material and a dry cellulose material and / or synthetic fiber together in a liquid or dispersed in a separate slurry mixed subsequently. The preparation of slurry can include a disintegration step in which the material is dispersed. Optionally, dry keratin fiber cell component material and / or dry cellulose material and / or synthetic fiber can be refined before forming the slurry.

[0100] The slurry is then formed into a sheet, for example, by transferring it to a sheet press and at least partially removing the liquid (e.g., water). The sheet can then be subjected to elevated temperature and pressure without any further processing to obtain the composite keratin material. Alternatively, prior to being subjected to elevated temperature and pressure, the sheet can be subjected to one or more processing steps, including but not limited to crouching, pressing, drying, and / or conditioning. These further processing steps can be conventional techniques known in the art, such as those described in TAPPI Standard T205.

[0101] When the mixture includes an additive, the additive can be added to the slurry or applied to the sheet. For example, the additive can be applied to the sheet by dipping the sheet into the additive, brushing the additive onto the sheet, or spraying the additive onto the sheet. In embodiments where the sheet layers are heat pressed, the additive can be applied to the sheet layers or to each sheet prior to forming the sheet layers.

[0102] Optionally, before the hot pressing step, the sheet may be washed, for example with water or a dilute acid (eg 2 w / w % sulfuric acid).The washed sheet is then optionally dried and pressed again before the hot pressing step.

[0103] In some embodiments, the keratin mixture consists of a keratinocyte fiber component and a cellulosic material. In some embodiments, the keratin mixture consists essentially of a keratinocyte fiber component and a cellulosic material. In some embodiments, the keratin mixture consists of a keratinocyte fiber component, a cellulosic material, and water. In some embodiments, the keratin mixture consists essentially of a keratinocyte fiber component, a cellulosic material, and water. In some embodiments, the keratin mixture consists of a keratinocyte fiber component, a cellulosic material, water, and sodium sulfite. In some embodiments, the keratin mixture consists essentially of a keratinocyte fiber component, a cellulosic material, water, and sodium sulfite.

[0104] In some embodiments, the keratin mixture consists of a keratinocyte fiber component and a synthetic fiber. In some embodiments, the keratin mixture consists essentially of a keratinocyte fiber component and a synthetic fiber. In some embodiments, the keratin mixture consists of a keratinocyte fiber component, a synthetic fiber, and water. In some embodiments, the keratin mixture consists essentially of a keratinocyte fiber component, a synthetic fiber, and water. In some embodiments, the keratin mixture consists of a keratinocyte fiber component, a synthetic fiber, water, and sodium sulfite. In some embodiments, the keratin mixture consists essentially of a keratinocyte fiber component, a synthetic fiber, water, and sodium sulfite.

[0105] The composite keratin material may be in the form of a sheet. The sheet may be prepared in various thicknesses. The desired thickness may be selected, for example, based on the intended use of the sheet. For example, a sheet comprising a composite keratin material intended for use as paper may have a thickness of about 50 μm to about 200 μm. In some embodiments, the sheet comprising the composite keratin material has a thickness of about 75 μm to about 175 μm, about 90 μm to about 150 μm, or about 100 μm to about 130 μm. In some embodiments, the sheet comprising the composite keratin material has a thickness of about 90 μm to about 110 μm. In some embodiments, the sheet comprising the composite keratin material has a thickness of about 100 μm to about 130 μm. For example, a sheet comprising a composite keratin material may have a thickness of about 80 μm, about 85 μm, about 90 μm, about 95 μm, about 100 μm, about 105 μm, about 100 μm, about 105 μm, about 110 μm, about 115 μm, about 120 μm, about 125 μm, about 130 μm, about 135 μm, or about 140 μm. A sheet comprising a composite keratin material intended for use as paper may have a thickness of greater than about 100 μm, greater than about 150 μm, greater than about 200 μm, or greater than 250 μm.

[0106] The sheets can also be provided in various weights. For example, a sheet comprising a composite keratin material may have a weight of about 50 g / m 2 About 150g / m 2 In some embodiments, the sheet has a weight of about 60 g / m 2 About 140g / m 2 , about 70g / m 2 About 130g / m 2 , about 80g / m 2 About 120g / m 2 or about 90g / m 2 to about 110g / m 2 In some embodiments, the sheet has a weight of about 80 g / m 2 , about 90g / m 2 , about 100g / m 2 or about 110g / m 2 In some embodiments, the sheet has a weight of about 100 g / m 2 weight.

[0107] Advantageously, the composite keratin material may have one or more improved properties, such as improved tensile strength or improved barrier properties, relative to the same material without the thermosetting biopolymer. Barrier properties may include resistance to air, water, and / or grease.

[0108] The composite keratin material can have improved tensile strength compared to a similar material that does not contain a thermosetting biopolymer derived from isolated keratin fiber cell components. For example, the composite keratin material can have a tensile strength of at least about 30 Nm / g, such as at least about 35 Nm / g, about 40 Nm / g, about 45 Nm / g, about 50 Nm / g, about 51 Nm / g, about 55 Nm / g, about 60 Nm / g, about 65 Nm / g, about 70 Nm / g, about 75 Nm / g, about 80 Nm / g, about 85 Nm / g, about 90 Nm / g In some embodiments, the composite keratin material has a tensile strength of at least about 40 Nm / g, about 45 Nm / g, about 50 Nm / g, or about 55 Nm / g. In some embodiments, the composite keratin material includes a thermosetting biopolymer and a cellulosic material and has a tensile strength of at least about 30 Nm / g, for example, at least about 35 Nm / g, about 36 Nm / g, about 37 Nm / g, about 38 Nm / g, about 39 Nm / g, about 40 Nm / g, about 41 Nm / g, about 42 Nm / g, about 43 Nm / g, about 44 Nm / g, about 45 Nm / g, about 46 Nm / g, about 47 Nm / g, about 48 Nm / g, about 49 Nm / g, about 50 Nm / g, about 51 Nm / g, about 52 Nm / g, about 53 Nm / g, about 54 Nm / g or about 55 Nm / g. In some embodiments, the composite keratin material comprises a thermosetting biopolymer and a synthetic fiber (e.g., PET fiber) and has a tensile strength of at least about 100 Nm / g, about 105 Nm / g, about 110 Nm / g, about 115 Nm / g, about 120 Nm / g, about 125 Nm / g, about 130 Nm / g, about 135 Nm / g, about 140 Nm / g, about 145 Nm / g, about 150 Nm / g, about 155 Nm / g, or about 160 Nm / g. In some embodiments, the composite keratin material comprises a thermosetting biopolymer and a synthetic fiber (e.g., PET fiber) and has a tensile strength of at least about 140 Nm / g, about 145 Nm / g, about 150 Nm / g, or about 155 Nm / g. Tensile strength can be measured by conventional techniques known in the art, such as "Tensile Properties of Paper and Paperboard," Test Method T 494 2013.

[0109] The composite keratin material may have improved Cobb's ratio compared to a similar material that does not contain a thermosetting biopolymer derived from isolated keratin fiber cell components. 30For example, the Cobb value of composite keratin materials 30 The value can be lower than about 90g / m 2 , about 80g / m 2 , about 70g / m 2 , about 60g / m 2 , about 50g / m 2 , about 45g / m 2 or about 40g / m 2 In some embodiments, the composite keratin material comprises a thermosetting biopolymer and a cellulosic material, and the Cobb 30 Values ​​below approximately 90 g / m 2 , about 80g / m 2 , about 70g / m 2 , about 60g / m 2 , about 50g / m 2 , about 45g / m 2 or about 40g / m 2 The Cobb test can be performed based on the procedure described in TAPPI T441 om-20 "Water Absorption of Sized (Non-Absorbent) Paper and Paperboard (Cobb Test)". 30 Values ​​are based on a sample test time of 30 seconds.

[0110] The composite material can have an improved liquid absorption capacity compared to a similar material that does not contain a thermosetting biopolymer derived from isolated keratin fiber cell components. For example, the composite keratin material can have a liquid absorption capacity of about 25 to 60 w / w%, about 30 to about 55 w / w%, about 35 to 50 w / w%, or about 40 to 45 w / w%. In some embodiments, the composite keratin material includes a thermosetting biopolymer and a synthetic fiber (e.g., PET fiber) and has a liquid absorption capacity of about 25 to 60 w / w%, about 30 to about 55 w / w%, about 35 to 50 w / w%, or about 40 to 45 w / w%.

[0111] The composite material can have an improved liquid wicking rate compared to a similar material that does not contain the thermosetting biopolymer derived from isolated keratin fiber cell components.

[0112] The above values ​​for improved properties are provided for illustration of the present invention. Those skilled in the art will appreciate that different values ​​may be achieved depending on the other components of the composite keratin material. For example, a composite keratin material prepared with synthetic fibers having high tensile strength will inherently have a higher tensile strength than a composite keratin material prepared with materials having lower tensile strength. Advantageously, keratin materials prepared with thermosetting biopolymers and synthetic fibers having high tensile strength can have improved tensile strength and / or other improved properties relative to the same material prepared without the thermosetting biopolymer.

[0113] Without wishing to be bound by theory, it is believed that the keratin fiber cell component of separation is subjected to the temperature and pressure of raising to cause the keratin fiber component of cell separation to form a film, i.e., a continuous layer at least in part. The degree that the cell component forms a film can be measured by measuring the amount of the air that can pass through the material. For example, the composite keratin material can have at least about 10s / 1000mL, for example, at least about 20s / 100mL, about 30s / 100mL, about 40s / 100mL, about 50s / 100mL, about 60s / 100mL, about 70s / 100mL, about 80s / 100mL, about 90s / 100mL, about 100s / 100mL, about 110s / 100mL, about 120s / 100mL or about 130s / 100mL air resistance. In some embodiments, the composite keratin material has an air resistance of at least about 50s / 100mL. Air resistance can be measured by conventional techniques known in the art, for example ("Air Resistance of Paper (Gurley Method)", Test Method T 460 om-21.

[0114] The composite keratin material according to the present invention can be used in various applications, including but not limited to as a paper material, fabric, artificial leather or plastic substitute. Those skilled in the art will understand that the composition and manufacturing method of the composite material of the present invention can be modified according to the requirements of such applications.

[0115] For example, a composite keratin material comprising a thermosetting biopolymer and synthetic fibers can be used as a fabric. In some embodiments, the fabric is a nonwoven fabric. In one application, the thermosetting biopolymer can be used as a binder in a nonwoven fabric comprising synthetic fibers. Advantageously, in one application, the composite keratin material can be used as a partial or complete replacement for chemical binders conventionally used to prepare nonwoven fabrics comprising synthetic fibers.

[0116] As a plastic replacement, composite keratin materials can be used in any application where oil-based plastics are used, such as packaging materials. To this end, the formulation of the composite keratin material can be varied to provide a material with properties suitable for the intended application, for example, as a soft, flexible material or a rigid material. For example, a rigid composite keratin material can be used as a solid packaging component, such as a tray for food. Advantageously, the composite keratin material can be formed into a variety of shapes. In some embodiments, the composite keratin material used for plastic replacement includes a thermosetting biopolymer and a cellulosic material.

[0117] The following non-limiting examples are provided to illustrate the invention and not to limit its scope in any way.

[0118] Example

[0119] Example 1 Paper composite materials with different compositions

[0120] Wool cells were added to the wood fiber raw material at 10%, 45% and 70% by weight.

[0121] Methods and Materials

[0122] Separated wool cell sheets (prepared according to Example 1a of WO 2020 / 080961 A1, provided below) were supplied by Lincoln Agritech. Two grades of softwood, unbleached Kraft drywall pulp, were sourced from OjiFibre Solutions; fiber cement grade (FCP) and a standard commercial kraft paper.

[0123] Isolated wool cells were prepared using the following procedure as described in WO 2020 / 080961 A1:

[0124] In a 12 L container, premix 10 L of a solution of 1.5 g / L sodium metabisulfite and 0.5 g / L citric acid and heat to 65°C.

[0125] Adjust the pH of the premix to 8.5 with dilute sodium hydroxide;

[0126] Addition of 5% by mass of Protex 6L (a bacterial alkaline protease derived from a selected strain of Bacillus licheniformis);

[0127] 450 g of clean chopped wool was added to the solution and soaked at pH 8.5 and 65°C for 8 hours; 1% by mass of Protex 6L was added to the container and kept fully immersed at pH 8.5 and 65°C for a further 16 hours;

[0128] The slurry was mixed using high shear in a vessel with a diameter of 55 mm for 30 min;

[0129] A mixing head using a toothed rotor suitable for fibrous materials at approximately 13,000 rpm;

[0130] Transfer the mixture to a mesh filter and sieve through a 63 micron mesh.

[0131] Rinse with water;

[0132] Freeze-dry the retentate;

[0133] • Fluff up the resulting dry wool cell fraction sheet in a food processor.

[0134] Wool refining

[0135] A 40-gram sample of wool sheet material was refined in a Wiley mill equipped with a 2.0 mm φ mesh screen for about 2.0 minutes. After refining, the resulting wool cell material was light and fluffy in nature, and a sweet taste was apparent. The moisture content of the refined wool cells was approximately 12%.

[0136] Sample preparation

[0137] Refined wool cell and softwood pulp samples were diluted to a consistency of 1.2% in demineralized water and soaked overnight. The slurry was then milled using a standard British mill specified in TAPPI standard T205 at 3000 rpm for 20 minutes. The slurry was then further diluted to a consistency of 0.3% in demineralized water in a plastic bucket. The consistency was confirmed by filtering the slurry through a Whatman 113 filter based on oven drying (OD) at 105°C.

[0138] Pulp blending

[0139] Slurries were blended on a Messmer sheet former at a target basis weight of 100 gsm, according to T205 sp-02, to produce handsheets with a diameter of 159 mm, based on a predetermined consistency. The weight ratios of wool cell to wood pulp in the slurry mixtures were 10:90, 45:55, and 70:30, respectively. A control sheet with zero wool cell content (0:100) was used as a basis for comparison.

[0140] The appropriate amount of slurry to produce a single handsheet was pre-weighed into a plastic jug and transferred to a handsheet maker to form sheets (five sheets per set). The handsheets were laminated (transferred to blotting paper), pressed, dried, and conditioned according to T205 sp-02 and T402 sp-08.

[0141] Hot pressing of handsheets

[0142] Hot pressing can be used to modify the properties of fiber-based sheets, including strength. When dry or when wet, the handsheets are hot pressed at 160°C for 3 minutes at 900 kN (optimum load for Siempelkamp hot press) immediately after forming and pressing, i.e., for a 200 cm 2 The sheets were compressed to 45 MPa. To examine the effect of sulfite, sodium sulfite was added to the pulp suspension during the sheeting process or after sheeting by spraying it directly onto the sheet surface for comparison. The results were compared with sheets that were conventionally pressed and dried after sheeting (i.e., not hot pressed).

[0143] Paper test

[0144] Test the conditioned handsheet for grammage, thickness (caliper), density / bulk, tensile strength and air resistance. The relevant standards are listed below:

[0145] "Physical testing of pulp handsheets," test method T 220sp-21

[0146] "Tensile properties of paper and paperboard," test method T 494om-06

[0147] "Air resistance of paper (Gurley method)", test method T 460om-21

[0148] “Determination of equilibrium moisture in pulp, paper and paperboard for chemical analysis,” test method T 550om-03.

[0149] result

[0150] Production Observation

[0151] Handsheets with wool cell contents above 45% were difficult to remove from the sheet wire and required considerable rewetting; retention during the sheeting process averaged 94%.

[0152] Handwritten nature.

[0153] The physical properties of the handsheets are shown in Table 1. The sheets containing wool cells were bulkier and less dense than the control. The gradual addition of wool cells to wood fibers was detrimental to sheet strength (tensile index), presumably due to a lack of interfiber bonding between the two different fiber types.

[0154] Table 1: Physical properties of handsheets (23°C, 50% RH).

[0155]

[0156] New Zealand hybrid wool fibers were also incorporated into unbleached kraft pulp of lower coarseness (and therefore higher fiber count per gram) at a weight ratio of 45% wool fiber:55% wood to see if tensile strength could be improved. Limited testing showed that these alternative sheets had a tensile strength of 6.23 Nm / g, compared to 4.88 Nm / g for a furnish based on equivalent FCP-wool units.

[0157] Comparison of the physical appearance of the sheets showed lighter coloration as the amount of wool fiber relative to the FCP wood fiber mix was gradually increased. Upon processing, the sheets became texturally weaker due to the inclusion of more wool fibers in the overall fiber mix (consistent with the bulk test results).

[0158] tensile strength

[0159] Although the sheet is deformed by wet hot pressing, the tensile strength of the sheet can be significantly improved compared with conventional sheet manufacturing methods ( Figure 1 The increase in tensile strength of the blended sheets after wet hot pressing was similar regardless of wool cell content; however, this was not the case for the hot pressed air dried sheets.

[0160] Example 2 - Effects of Hot Pressing Optimization and Sodium Sulfite Addition on Wool Cell Paper Composites

[0161] The effects of varying the pressing force on paper properties using sodium sulfite as an additive were investigated; of particular interest was the degree of achievable air, water, and grease barrier properties. Immediately after forming and pressing, the handsheets were hot-pressed at 160°C for 3 minutes under varying press loads (90 kN-900 kN). Sulfite additions included either addition to the pulp suspension during sheeting or spraying directly onto the sheet surface after sheeting for comparison. All handsheets were made from a blend of 45% wool fiber and 55% wood fiber. The results were compared with previous sheets containing wool cells that had been subjected to conventional pressing and drying (i.e., not hot-pressed) and sheets made from 100% wood fiber.

[0162] Refining of wool cells

[0163] The wool cell material was prepared as described in Example 1.

[0164] Handwritten film production

[0165] The handsheets were formed based on Appita standard method AS / NZS 1301.203s:2017 - "Forming handsheets for physical testing of pulp", but instead of the conventional pressing and drying procedure, the sheets were immediately hot pressed.

[0166] Hot pressing method

[0167] The handsheets were hot pressed between two metal plates using a Siempelkemp press at 160°C for 3 min using three wet pressures: 90 kN, 450 kN and 900 kN (equivalent to sheet pressures of 4.5 MPa, 22.5 MPa and 45 MPa, respectively).

[0168] Paper test

[0169] The conditioned handsheets were tested for grammage, thickness (caliper), density / bulk, tensile strength, bursting strength, and short span compressive strength (SCT) according to the methods listed in Example 1. In addition, air, water, and grease resistance were tested according to the following procedures.

[0170] air resistance

[0171] Initial testing indicated that it was not possible to test air resistance using the previously used manual Gurley porosimeter, as some sheet permeability values ​​were beyond the machine's measurement range, and testing proved slow and laborious. Instead, an automated L&W air permeability tester was used, which is suitable for a variety of paper products and can easily test highly impermeable materials. The tester was configured according to the most common measurement method ("Air Resistance of Paper (Gurley Method)", Test Method T 460 om-21). Relative air resistance values ​​are reported as sec / 100 mL.

[0172] Waterproof

[0173] The Cobb test was conducted based on the procedure described in TAPPI T441 om-20 "Water Absorption of Sized (Non-Absorbent) Paper and Paperboard (Cobb Test)". Due to the nature of the sample material, the time period for the test was reduced to 30 seconds and the water charge was halved to ensure accurate testing. 30 Water absorption in g / m 2 count.

[0174] Grease resistance

[0175] According to ISO 16532-1:2008 (en) "Paper and board—Determination of grease resistance—Part 1: Permeability test".

[0176] Report the print-through and strike-through times (in seconds) (mean and range) and the stain area (mm2) after 24 hours for the handsheet according to ISO 5634-1986E “Paper and board – Determination of grease resistance”. 2 ) to measure long-term grease resistance.

[0177] Results - Effect of Wet Pressure on Sheet Properties

[0178] Visual observation

[0179] As observed in the previous examples, there was deformation of the sheet surface after wet hot pressing; gradually increasing the pressure resulted in more blistering of the sheet surface.

[0180] Table 2 summarizes the properties of sheets hot wet pressed at forces ranging from 90 kN to 900 kN.

[0181] Table 2. Physical properties of wet, hot pressed (0 kN-900 kN) 45% wool cell handsheets (23°C, 50% RH): 55% wood pulp sheets.

[0182]

[0183] Wet hot pressing generally doubled the sheet density of 45% wool unit:55% wood fiber sheets compared to unpressed sheets, which remained relatively constant despite the use of different pressing forces. Sheet density for the 900 kN sheets was lower than expected, but this may be due to the difficulty of accurately measuring the caliper across the uneven sheet surface. Sheet tensile strength improved significantly when wet hot pressing at 90 kN, and further strength gains were achieved if the force was increased to 450 kN or above. Bursting strength and short span compression (SCT) are also considered important properties for some paper products and were therefore tested at sample locations where sufficient test material was available. Hot pressing and increased pressing force resulted in a higher burst index compared to the control sheet. Like other properties, the short span compression index improved significantly with hot pressing.

[0184] Impermeability

[0185] Because paper is composed of random mats of fibers, the structure has varying degrees of porosity. Therefore, the ability of fluids (liquids and gases) to penetrate the structure is crucial for paper's usefulness and can vary widely depending on manufacturing conditions. The following sections compare the air, water, and oil repellency of 45% wool cell and 55% wood fiber handsheets.

[0186] air resistance

[0187] Figure 2 The effect of increasing pressure on air resistance is shown. It is believed that air resistance is affected by the internal structure of the sheet, which in turn is controlled by compaction, fines, etc. Increasing wet pressing pressure gradually increases air resistance until 450 kN, at which point the air resistance begins to level off.

[0188] Waterproof

[0189] The Cobb test is commonly used to measure a paper material's ability to resist water penetration and the amount of water absorbed through its surface. The Cobb test procedure determines the amount of water absorbed by a sheet of material over a specified period of time under standardized conditions. If a fibrous material absorbs too much water, paper formed from it may struggle to maintain its strength and integrity.

[0190] A high Cobb value means the substrate has a greater ability to absorb and retain water.

[0191] A low Cobb value means the substrate is more resistant to water penetration and retention.

[0192] The effect of pressure on the Cobb value of 45% wool cell: 55% wood fiber handsheets is shown in Figure 3 It is worth noting that wet hot pressing significantly reduced the water absorption rate, among which Cobb 30 313g / m2 of unpressed sheet 2 Reduced to less than 40g / m after pressing 2 .

[0193] Grease resistance

[0194] Grease resistance is tested by applying a standard oil sample to the sheet surface and is described by two characteristics: "Show-through" time (visual breakthrough) and "Strike-through" time (actual breakthrough). Show-through refers to the visual appearance of an oil stain on the underside of the sample, while strike-through is the visual staining of the copy paper (as specified) beneath the sample.

[0195] The print-through and strike-through times (mean and range) for handsheets made from a 45% wool fiber:55% wood fiber blend and 100% wood fiber are summarized in Table 3. The results show that wet pressing reduced the show-through time (i.e., reduced grease resistance). The strike-through time was also reduced, which is a common observation in many papers using the test.

[0196] Table 3. Mean and range of "print-through" and "break-through" times for wool cells: wood fiber blend handsheets and 100% wood fiber handsheets.

[0197]

[0198] To measure long-term grease penetration, the stain area (mm) under the sample can be measured after 24 hours. 2 At 900 kN, the stain areas of the unpressed and pressed sheets were 1541 mm 2 and 1335mm 2 , and showed that pressing had a limited negative impact on long-term grease resistance.

[0199] Results - Effect of Sodium Sulfite on Sheet Properties

[0200] The effects of sodium sulfite addition on the properties of 45% wool cell:55% wood sheets are shown in Table 4. The additive was either applied directly to the surface of the handsheet after coating or added to the papermaking solution before papermaking. All sheets were wet hot pressed at 900 kN and 160°C for 3 minutes.

[0201] Table 4: Physical properties of wet, hot pressed (900 kN, 160°C, 3 min) 45% wool cell handsheets (23°C, 50% RH): 55% wood pulp sheet with additives.

[0202]

[0203] The addition of sulfite to wet-pressed 45% wool fiber:55% wood fiber handsheets had a positive effect on grease resistance, increasing printthrough and strikethrough times from 100 to 513 seconds and from 618 to 1108 seconds, respectively (Table 5). The wool cell stain area was also reduced: the wood fiber sheet containing the additive (938 mm 2 ) and wood fiber chips without additives (1335mm 2 )compared to.

[0204] Table 5. Mean and range of "print-through" and "break-through" times for wool cell / wood fiber blend handsheets.

[0205]

[0206] Primary outcome

[0207] The wet hot pressing method used in the examples provided the following results:

[0208] Raised sheet tensile strength: Under a pressure of 90kN, the sheet tensile strength increases from 7Nm / g to 37Nm / g, and can be further increased to a strength of 50Nm / g if the force is increased to 450kN and above.

[0209] • The air resistance gradually increased from 2 sec / 100 mL for the unpressed sheet to 138 sec / 100 mL for the sheet pressed at 900 kN.

[0210] Significantly reduced Cobb 30 Values; After compression at all levels of compression force, Cobb 30 Unpressed sheets from 313g / m 2 Reduced to less than 40g / m 2 .

[0211] Negatively affects both short-term and long-term grease resistance.

[0212] Furthermore, the addition of sodium sulfite provided the following results:

[0213] The method and amount of sulfite application does not change density, tensile strength or air resistance.

[0214] ·No improvement in the waterproofness of wet pressed sheets.

[0215] Positive impact on grease resistance, improving print-through time and punch-through time from 100 to 513 seconds and 618 to 1108 seconds, respectively.

[0216] Results - Effect of adding wool cells to wood fibers on sheet properties

[0217] The effect of adding wool cells to wood fibers on the sheet properties of unpressed and hot wet pressed (900 kN, 160°C, 3 min) sheets is shown in the table and figure below.

[0218] Table 6: Physical properties of handsheets of 100% wood pulp sheet and 45% wool fiber for unpressed and hot wet pressed (900 kN) (23°C, 50% RH): 55% wood fiber sheet.

[0219]

[0220] Adding wool cells to unpressed wood fiber sheets tended to reduce strength; however, if both sheets were wet-hot pressed, the wool cells substantially improved strength-related properties (Table 6).

[0221] Unpressed 100% wood fiber sheets and 45% wool fiber:55% wood fiber blend sheets had similar air resistance; however, when wet pressed under the same conditions, the air resistance of the sheets including wool cells increased significantly compared to the 100% wood fiber sheets ( Figure 4 ).

[0222] In the unpressed state, wool cells are added to the wood fibers to form Cobb 30 From 227g / m 2 Increased to 313g / m 2 However, upon wet pressing, both types of sheets became more water resistant ( Figure 5 ), in particular sheets comprising wool cells.

[0223] Primary outcome

[0224] Compared to 100% wood fiber handsheets:

[0225] Adding wool cells to wood fibers without wet hot pressing resulted in a decrease in the tensile strength of the sheet. However, upon wet hot pressing, the tensile strength more or less doubled for the handsheets including wool cells.

[0226] Wool Cell: When not pressed, the water resistance of the wood fiber blend sheet is low, but the opposite is true after wet pressing. Wool Cell: The wood fiber blend sheet shows excellent short-term and long-term grease resistance.

[0227] Example 3 - Preparation of wool cell / PET composite material

[0228] Four wet-laid nonwoven fabrics (Table 7) were prepared from PET fibers (6 mm, 1.7 dtex) and isolated wool cells (prepared according to WO 2020 / 080961 A1) using a wet-laid process. The PET fibers and isolated wool cells were blended with processing aids (Pluronic F-108-dispersant, 1 w / w% and Tetronic 90R4-defoaming agent, 1 w / w%) to provide a uniform slurry. The slurry was deposited on a surface and the water was removed to provide a dry web. A 1 w / w% Na2SO3 solution was added dropwise to the dry paper web until the web reached uniform saturation. The saturated web was hot pressed at 160°C for 3 min and hydraulically applied under a pressure as high as physically possible.

[0229] Table 7: Composite PET / wool cell weight ratio

[0230] sample <![CDATA[Total density (g / m 2 )]]> PET / wool cell ratio 3A 180 60:40 3B 180 80:20 3C 180 90:10 3D 180 100:0

[0231] result

[0232] The samples showed increasing hardness and browning with increasing wool cell content.

[0233] The SEM images of samples 3A-3C are shown in Figure 7-10 SEM analysis of these samples showed increased melting with increasing wool cell content. The fibers in sample 3D did not bond during hot pressing, resulting in a weak fabric. SEM analysis of sample 3D was not performed to avoid sensor damage due to loose fiber content.

[0234] Samples hot-pressed without wool cell content were weak, suggesting that the bond was related to the presence of softened wool cells. The wool cells effectively acted as a binder and replaced the chemical binders that would be used to produce synthetic nonwoven fabrics.

[0235] Example 4 - Comparison of PET materials with and without wool cells

[0236] Two examples of wet-laid nonwoven fabrics (Table 8) were prepared from PET fibers (6 mm, 1.7 dtex), 10 w / w% polypropylene / polyethylene biocomponent fibers (Bico) and isolated wool cells (prepared according to WO 2020 / 080961 A1) using a wet-laid process. 10% bicomponent fibers were included to enable processing of the PET samples without the need to separate the wool cells after the hot pressing process. Processing aids (Pluronic F-108-dispersant, 1 w / w% and Tetronic 90R4-defoamer, 1 w / w%) were added to the slurry to aid dispersion and uniformity of the slurry / fabric.

[0237] Table 8

[0238] sample <![CDATA[Total areal density (g / m 2 )]]> <![CDATA[SC areal density (g / m 2 )]]> Composition 4A 180 0 90% PET / 10% Bico 4B 180 72 50% PET / 40% SC / 10% Bico

[0239] result

[0240] The addition of wool units resulted in a decrease in the liquid absorption capacity of the softened wet-laid fabric (although the difference was not significant (P>0.05))( Figure 10 Without wishing to be bound by theory, it is believed that this reduction may be due to the closing of the pore structure and the formation of a film-like structure during melting of the SC.

[0241] The addition of wool cells results in a substantial increase in the fabric's wicking rate ( Figure 11 ). This demonstrates the wicking ability of the fused separated keratin fiber cell components of the fabric.

[0242] The addition of wool cells and subsequent melting results in a 62% increase in fabric tensile strength ( Figure 12 ). This increase is attributed to the melting process, which creates additional physical bonds between the fibers within the fabric.

[0243] These results demonstrate that melt-separated wool cells can bind fibers together and have a significant impact on fabric properties.

[0244] Example 5 - Keratin Film

[0245] A mixture of wool cells in a 2:1 w / w liquid ratio (1 w / w% sodium sulfite aqueous solution) was pressed into a solid film at 160°C and 780 bar (11318 psi) for 3 min. The material was placed in a contact area of ​​1096 mm 2 Pressed in a steel mold.

[0246] The resulting film was rigid and transparent, demonstrating that the individual wool cells had fused to create a single, continuous phase of the material. The material did not change size or appearance when immersed in water and remained physically strong.

[0247] Example 6 - Plastic Alternatives

[0248] The materials prepared using the methods of Examples 1, 2, and 5 are useful as physical barriers and packaging materials to contain a range of items. These materials serve as effective replacements for conventional synthetic plastics such as PET or PE films.

[0249] Example 7 - Artificial Leather

[0250] The materials prepared using the methods of Examples 1 and 2 were used as surface coverings and inner and outer layers for bags and clothing materials. The protein-rich composition of the materials (due to the high keratin content) gave a leather-like sensory feel. The robustness of the materials allowed them to be used as substitutes for natural leather, and thus the materials behaved as synthetic leather.

[0251] Example 8 - Glycerol Plasticizer

[0252] Cellulose / wool composite paper sheets prepared using the method of Example 1 were treated by immersion in an aqueous glycerol solution (1-50%), blotted dry, and then pressed according to the method described in Example 2. In some cases, after pressing, the sheets were washed in water or dilute sulfuric acid (2 w / w%), dried in a desiccator, and pressed again with water. Washing and drying these sheets made them less sticky than unwashed sheets. It was observed that the materials welded with glycerol (whether washed or not) were more flexible than the composites welded with water.

[0253] Example 9 - Preparation of multilayer composite materials

[0254] The sheets prepared using the method of Example 1 were stacked into 2 to 5 sheets and hot pressed as described in Example 2 to form a material having a caliper thickness greater than 200 μm.

[0255] Optionally, the sheets were treated with glycerol, as described in Example 2, and then layered on top of each other and pressed. The best results in terms of melt and leather-like feel were obtained under the following conditions: 3 x 70% SC handsheets were pretreated with 50 w / w% v / v glycerol and blotted dry, then hot pressed at 180°C and 50 kN pressure for 30 seconds. The hot pressing process was repeated up to 3 times.

[0256] It was observed that the products obtained by these methods were more flexible than the water welded composite materials and had a good hand (leather-like). These structures could be used to form artificial leather materials as described in Example 7.

[0257] Example 10 - Natural or synthetic oils

[0258] Handsheets prepared according to the method of Example 1 were immersed in oil and blotted or lightly brushed with oil before melting. Silicone oil and coconut oil were tested. The samples were welded under the same conditions as described in Example 2, including 180°C and 50 kN pressure for 30 seconds.

[0259] Oil-welded materials appear more opaque than glycerin- or water-welded composites and are more flexible than water-welded materials.

[0260] It is not intended to limit the scope of the present invention to the examples described above. As those skilled in the art will appreciate, many variations are possible without departing from the scope of the invention as set forth in the appended claims.

[0261] Where reference is made in this specification to patent specifications, other external documents or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, the reference to such external documents is not to be construed as an admission that such documents or such sources of information are prior art or form part of the common general knowledge in the art in any jurisdiction.

Claims

1. A thermosetting biopolymer derived from isolated keratin fiber cell fractions.

2. The thermosetting biopolymer according to claim 1, wherein The thermosetting biopolymer is obtained by subjecting the isolated keratin fiber cell fraction to elevated temperature and elevated pressure.

3. A composite keratin material comprising a thermosetting biopolymer, wherein: The thermosetting biopolymer is derived from isolated keratin fiber cell fractions.

4. The composite keratin material according to claim 3, wherein The thermosetting biopolymer is obtained by subjecting the isolated keratin fiber cell fraction to elevated temperature and elevated pressure.

5. The composite keratin material according to claim 3 or 4, wherein The composite keratin material further comprises cellulose fibers or polyethylene terephthalate (PET).

6. A method for preparing a composite keratin material, comprising the following steps: a) providing a mixture comprising isolated keratinocyte fiber fractions, and b) subjecting the mixture to elevated temperature and elevated pressure such that the separated keratinocyte fiber components form a thermosetting biopolymer to provide the composite keratin material.

7. The method according to claim 6, wherein: The elevated temperature is equal to or greater than the glass transition temperature of the isolated keratin fiber cell fraction.

8. The method according to claim 6 or 7, wherein: The elevated temperature is at least about 140°C.

9. The method according to any one of claims 6 to 8, wherein The elevated pressure is at least about 40 kN, optionally at least about 90 kN.

10. The method according to any one of claims 6 to 9, wherein Hot pressing subjects the mixture to elevated temperatures and elevated pressures.

11. The method according to any one of claims 6 to 10, wherein The mixture in step (a) is provided as a sheet.

12. The method according to any one of claims 6 to 11, wherein The mixture in step (a) is provided as layers of two or more sheets, optionally layers of 2 to 10 sheets or 2 to 5 sheets.

13. The method according to claim 11 or 12, wherein: Each sheet is formed by pressing a slurry comprising separated keratinocyte fiber components, optionally wherein each sheet is laminated, pressed, and dried.

14. The method according to any one of claims 6 to 13, wherein The mixture also includes water.

15. The method according to any one of claims 6 to 14, wherein The mixture further includes an additive selected from the group consisting of a reducing agent, a plasticizer, an oil, and combinations of any two or more thereof.

16. The method according to claim 15, wherein The reducing agent is selected from the group consisting of sulfite, metabisulfite, sulfide, thioglycolate, cysteine ​​and a combination of any two or more thereof.

17. The method according to claim 15 or 16, wherein The plasticizer is selected from glycerol or polypropylene glycol, optionally wherein the glycerol is a glycerol aqueous solution, a 1-50 w / w% glycerol aqueous solution, a 10-50 w / w% glycerol aqueous solution or a 50 w / w% glycerol aqueous solution.

18. The method according to any one of claims 15 to 17, wherein The oil is a natural oil (e.g. a vegetable oil such as almond oil, avocado oil, coconut oil, palm oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, sunflower oil, grapeseed oil or an oil of animal origin) or a synthetic oil (e.g. silicone oil).

19. The method according to any one of claims 15 to 18, wherein The mixture in step (a) is provided as a sheet or layer of sheet and the additive is applied to the sheet prior to step (b), and optionally wherein the additive is applied by dipping the sheet or layer of sheet into the additive, brushing the additive onto the sheet or layer of sheet or spraying the additive onto the sheet or layer of sheet, optionally wherein the additive is applied to each sheet before forming the layer of sheet.

20. The composite keratin material according to any one of claims 3 to 5 or the method according to any one of claims 6 to 19, wherein The composite keratin material has one or more of the following characteristics: i) a tensile strength of at least about 30 Nm / g, ii) an air resistance of at least about 10 s / 100 mL, iii) less than about 100 g / m 2 Cobb 30 value.

21. The composite keratin material or method according to claim 20, wherein: The composite keratin material has at least two of properties i) to iii).

22. The composite keratin material according to any one of claims 3 to 5, 20 and 21 or the method according to any one of claims 6 to 21, wherein The keratin fiber cell fraction is obtained from a source selected from the group consisting of wool, hair, fur, feathers, and combinations of any two or more thereof.

23. The composite keratin material according to any one of claims 3 to 5 and 20 to 22 or the method according to any one of claims 6 to 22, wherein The keratin fiber cell fraction is obtained from wool.

24. The composite keratin material according to any one of claims 3 to 5 and 20 to 23 or the method according to any one of claims 6 to 23, wherein The composite keratin material also includes a cellulosic material.

25. The composite keratin material or method according to claim 24, wherein: The cellulosic material is derived from plants or plant parts.

26. The composite keratin material or method according to claim 24 or 25, wherein: The composite keratin material includes a keratin fiber cell component and the cellulosic material in a weight ratio of about 5:95 to about 95:

5.

27. The composite keratin material according to any one of claims 3 to 5 and 20 to 24 or the method according to any one of claims 6 to 24, wherein The composite keratin material also includes synthetic fibers.

28. The composite keratin material or method according to claim 27, wherein: The synthetic fibers include polymers selected from the group consisting of polyesters (such as polyethylene terephthalate, PET), polyacrylics, polychloroprenes (such as neoprene), polyolefins, polyurethanes (such as spandex), polyamides (such as nylon), and combinations of any two or more thereof.

29. The composite keratin material according to any one of claims 3 to 5 and 20 to 28 or the method according to any one of claims 6 to 28, wherein The composite keratin material has a tensile strength of at least about 35 Nm / g, about 36 Nm / g, about 37 Nm / g, about 38 Nm / g, about 39 Nm / g, about 40 Nm / g, about 41 Nm / g, about 42 Nm / g, about 43 Nm / g, about 44 Nm / g, about 45 Nm / g, about 46 Nm / g, about 47 Nm / g, about 48 Nm / g, about 49 Nm / g, about 50 Nm / g, about 51 Nm / g, about 52 Nm / g, about 53 Nm / g, about 54 Nm / g or about 55 Nm / g.

30. The composite keratin material according to any one of claims 3 to 5 and 20 to 29 or the method according to any one of claims 6 to 29, wherein The composite keratin material has an air resistance of at least about 20 s / 100 mL, about 30 s / 100 mL, about 40 s / 100 mL, about 50 s / 100 mL, about 60 s / 100 mL, about 70 s / 100 mL, about 80 s / 100 mL, about 90 s / 100 mL, about 100 s / 100 mL, about 110 s / 100 mL, about 120 s / 100 mL or about 130 s / 100 mL.

31. The composite keratin material according to any one of claims 3 to 5 and 20 to 30 or the method according to any one of claims 6 to 31, wherein The composite keratin material has a thickness of less than about 90 g / m 2 , about 80g / m 2 , about 70g / m 2 , about 60g / m 2 , about 50g / m 2 , about 45g / m 2 or about 40g / m 2 Cobb 30 value.

32. The composite keratin material according to any one of claims 3 to 5 and 20 to 31 or the method according to any one of claims 6 to 31, wherein The composite keratin material is in the form of a sheet.

33. The composite keratin material or method according to claim 32, wherein: The sheet has a thickness greater than 100 μm, greater than 150 μm, greater than 200 μm or greater than 250 μm.

34. A composite keratin material prepared by the method according to any one of claims 6 to 33.

35. Paper comprising the composite keratin material according to any one of claims 3 to 5 and 20 to 34.

36. Artificial leather comprising the composite keratin material according to any one of claims 3 to 5 and 20 to 34.

37. A fabric comprising the composite keratin material according to any one of claims 3 to 5 and 20 to 34.

38. The fabric of claim 37, wherein The fabric is a nonwoven fabric.

39. Use of a composite keratin material according to any one of claims 3 to 5 and 20 to 34 as a plastic substitute.

40. Use of a composite keratin material according to any one of claims 3 to 5 and 20 to 34 as a replacement for chemical adhesives in the production of synthetic nonwoven fabrics.

Images