A kind of warm knitted fabric based on bioprotein aerogel and preparation method thereof

Abstract

The present invention belongs to the technical field of textile materials, and discloses a warm knitted fabric based on bioprotein aerogel and a preparation method thereof. The preparation method of the present invention comprises the steps of: pretreatment of knitted fabric; degumming of silk fiber, washing, drying, crushing, dissolving, filtering, and dialyzing after degumming to obtain a silk protein solution; arranging the silk protein solution onto the pretreated knitted fabric, performing vacuum freeze drying and heat treatment to obtain a warm knitted fabric based on bioprotein aerogel. The present invention uses aqueous blocked diisocyanate to pretreat knitted fabric to improve the bonding strength and elasticity between fiber and protein aerogel; in the process of forming protein aerogel by vacuum freeze drying, the fiber material is further fibrillated, the pores inside the fiber increase, the static air content inside the fiber is increased, and the warmth retention of the fabric itself is improved; using low-value silk as raw material, the comfort and skin-friendliness of the fabric are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of textile materials, and in particular to a warm-keeping knitted fabric based on bioprotein aerogel and a preparation method thereof. Background Art

[0002] Aerogel is a porous network structure material. It uses a large amount of gas to replace the liquid in the gel and form a stable three-dimensional network structure of solid material. It is characterized by extremely low density. The density of aerogel is generally 0.001~0.5g / cm 3 , is currently the lightest solid material in the world. The pores inside aerogel are filled with still air, giving it low thermal conductivity, which makes aerogel material have broad application prospects in the field of thermal insulation.

[0003] Aerogel materials can be divided into three categories based on their source: inorganic aerogels, organic polymer aerogels, and biomass aerogels. The raw materials and preparation methods for inorganic and organic polymer aerogels have long attracted research attention, and the related technologies have been continuously optimized and improved, and have been widely used. However, inorganic and organic polymer aerogels have poor biocompatibility and are difficult to biodegrade, limiting their application in textile fabrics. Biomass aerogel raw materials are abundant and offer advantages such as good biocompatibility and biodegradability. Silk fibroin is a natural polymer protein extracted from silk. It contains 18 amino acids and has good compatibility with human tissue. Currently, research focuses on its medical applications. Protein aerogels can provide a favorable biological environment for cell growth, adhesion, and proliferation, and can be used in medical dressings, tissue repair, tissue culture scaffolds, and other medical fields. However, little research has been conducted on their thermal insulation properties.

[0004] The current method for preparing bioprotein aerogels primarily involves dissolving natural protein to create a protein solution. Then, using supercritical fluid drying or freeze-drying techniques, ice crystals sublime into water vapor and detach from the fabric. The protein molecules in the solution are supported by the ice crystals, leaving gaps between the protein molecules as the ice crystals sublime, thus dehydrating the protein solution to form a protein aerogel. However, the aerogels obtained using this method suffer from low strength and prone to collapse. Therefore, there is an urgent need for a textile material based on bioprotein aerogels that offers higher strength, structural stability, and thermal insulation. Summary of the Invention

[0005] Based on the current status of the utilization of the above-mentioned low-value natural fiber raw material aerogel and the development of thermal insulation functional textile fabrics, the purpose of the present invention is to provide a thermal insulation knitted fabric based on bioprotein aerogel and a preparation method thereof, so as to solve the technical problems of low strength and easy collapse of existing bioprotein aerogels.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing a warm knitted fabric based on bioprotein aerogel, comprising the following steps:

[0008] (1) pretreating the knitted fabric with a finishing agent to obtain a pretreated knitted fabric;

[0009] (2) degumming the silk fibers, washing, drying, and crushing the silk fibers after degumming, and dissolving, filtering, and dialyzing the crushed silk fibers to obtain a silk protein solution;

[0010] (3) Arranging the silk protein solution onto the pretreated knitted fabric, performing vacuum freeze drying, and then performing heat treatment to obtain a warm knitted fabric based on bioprotein aerogel;

[0011] There is no restriction on the order of step (1) and step (2).

[0012] Furthermore, in the preparation method of the warm knitted fabric based on bioprotein aerogel, the finishing agent in step (1) contains water-based blocked diisocyanate, and the concentration of the finishing agent is 10 to 20 g / L; the pretreatment method in step (1) is an immersion method, the pretreatment temperature is 20 to 30° C., and the pretreatment time is 20 to 60 min.

[0013] Furthermore, in the preparation method of the warm knitted fabric based on bioprotein aerogel, the preparation method of the aqueous blocked diisocyanate is: preparing a sodium bisulfite aqueous solution with a mass concentration of 20-30%, adding ethanol in an amount of 30-50% of the volume of the sodium bisulfite aqueous solution to the sodium bisulfite aqueous solution to obtain an ethanol aqueous solution with a mass concentration of 12-20% sodium bisulfite, using an aqueous solution with a volume fraction of 10-20% ethyl acetate to dissolve the diisocyanate to obtain a diisocyanate mixed solution, and adding the diisocyanate mixed solution dropwise to the ethanol aqueous solution of sodium bisulfite for reaction, the reaction temperature is 20-30°C, wherein the molar ratio between the sodium bisulfite and the -NCO group contained in the diisocyanate is 1:1-1.5, and the diisocyanate comprises any one of hexamethylene diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate, and 4,4-dicyclohexylmethane diisocyanate.

[0014] Furthermore, in the method for preparing a warm knitted fabric based on bioprotein aerogel, the knitted fabric in step (1) includes any one of cellulose fiber knitted fabric, protein fiber knitted fabric, and cellulose fiber and protein fiber blended knitted fabric.

[0015] Furthermore, in the preparation method of the thermal insulation knitted fabric based on bioprotein aerogel, the specific method of the degumming treatment in step (2) is to use an alkali-urea system for degumming: the silk fiber is placed in a mixed system with a sodium carbonate mass concentration of 1 to 5% and a urea mass concentration of 0 to 50%, the bath ratio of the silk fiber to the mixed system is 1:40 to 50, the temperature of the degumming treatment is 90 to 100°C, and the time of the degumming treatment is 1 to 2 hours.

[0016] Furthermore, in the method for preparing the thermal insulation knitted fabric based on bioprotein aerogel, the dissolving solvent in step (2) is selected from one of lithium bromide solution or a ternary mixed solution of calcium chloride, anhydrous ethanol and water.

[0017] Furthermore, in the preparation method of the thermal knitted fabric based on bioprotein aerogel, the conditions for dissolving the crushed silk fibers in the lithium bromide (LiBr) solution are as follows: the concentration of LiBr is 9.0-9.5 mol / L, the bath ratio of the crushed silk fibers to the lithium bromide solution is 1:8-12, the dissolution temperature is 60-70°C, and the dissolution time is 1.0-2.0h to obtain a silk fiber dissolved solution.

[0018] Furthermore, in the preparation method of the thermal knitted fabric based on bioprotein aerogel, the conditions for dissolving the crushed silk fibers in the ternary mixed solution of calcium chloride, anhydrous ethanol and water are as follows: the molar ratio of calcium chloride: anhydrous ethanol: water is 1:1.8~2.2:7.7~8.3, the bath ratio of the crushed silk fibers and the ternary mixed solution of calcium chloride, anhydrous ethanol and water is 1:15~25, the dissolution temperature is 75~85℃, and the dissolution time is 1.5~2.5h to obtain a silk fiber dissolved solution.

[0019] Furthermore, in the preparation method of the thermal knitted fabric based on bioprotein aerogel, the dialysis method in step (2) is specifically: dialyzing in water using a dialysis bag with a molecular weight cutoff of 8 to 14 kD, changing the water every 3 to 5 hours, the dialysis time is 40 to 60 hours, and the concentration of the silk protein solution is 10 to 25 mg / mL.

[0020] Furthermore, in the preparation method of the thermal insulation knitted fabric based on bioprotein aerogel, the finishing method in step (3) is an immersion method, the bath ratio of the pretreated knitted fabric to the silk protein solution is 1:20-30, the finishing temperature is 40-50°C, and the finishing time is 30-60 minutes.

[0021] Furthermore, in the method for preparing a warm knitted fabric based on bioprotein aerogel, step (3) is also performed before vacuum freeze-drying, the pre-freezing treatment temperature is -15 to -25°C, and the pre-freezing treatment time is 15 to 30 hours.

[0022] Furthermore, in the preparation method of the warm knitted fabric based on bioprotein aerogel, the internal air pressure of the vacuum freeze-drying treatment in step (3) is <10Pa, the temperature of the vacuum freeze-drying treatment is -40 to -55°C, the time of the vacuum freeze-drying treatment is 40 to 60h, the temperature of the heat treatment is 80 to 120°C, and the time of the heat treatment is 20 to 60min.

[0023] The present invention also provides a bioprotein aerogel-based warm-keeping knitted fabric prepared by a preparation method of the bioprotein aerogel-based warm-keeping knitted fabric.

[0024] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention aims to improve the bonding strength between knitted fabrics and aerogels and improve the feel of knitted fabrics. Before the knitted fabrics are treated with a silk protein solution, the knitted fabrics are pretreated with a diisocyanate having blocked active end groups. At this time, the diisocyanate has no reaction activity. The knitted fabrics are then treated with a silk protein solution, and aerogels are formed on the knitted fabrics using a vacuum freeze-drying technique. The knitted fabrics are then treated under high temperature conditions to unblock the diisocyanate active groups, thereby restoring their reaction activity and reacting with fiber macromolecules and protein aerogels. The fibers and the silk protein aerogels are covalently bonded together, thereby increasing the bonding strength and elasticity between the fibers and the aerogels, preventing the collapse of the aerogels, and obtaining aerogel-based textile fabrics with a warming function.

[0026] (2) The present invention utilizes the good biocompatibility and thermal insulation properties of protein aerogel to develop a bio-protein aerogel-based comfortable and warm functional textile fabric, which can not only effectively utilize low-value protein fibers such as wool and silk, but also open up new avenues for the development of new thermal insulation textile fabrics; in addition, the development of bio-protein aerogel-based composite textile fabrics also meets the "dual carbon" target requirements. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing a warm knitted fabric based on bioprotein aerogel, comprising the following steps:

[0028] (1) pretreating the knitted fabric with a finishing agent to obtain a pretreated knitted fabric;

[0029] (2) degumming the silk fibers, washing, drying, and crushing the silk fibers after degumming, and dissolving, filtering, and dialyzing the crushed silk fibers to obtain a silk protein solution;

[0030] (3) Arranging the silk protein solution onto the pretreated knitted fabric, performing vacuum freeze drying, and then performing heat treatment to obtain a warm knitted fabric based on bioprotein aerogel;

[0031] There is no restriction on the order of step (1) and step (2).

[0032] In the present invention, the finishing agent in step (1) contains an aqueous blocked diisocyanate. The present invention uses an aqueous blocked diisocyanate to pretreat knitted fabrics. The diisocyanate contains highly unsaturated bonds and is highly reactive. It can react with hydroxyl groups on cellulose molecules to produce carbamates. It can also react with active hydrogen-containing groups such as hydroxyl groups, amino groups, amide groups, and carboxyl groups on protein molecules to form covalent bonds.

[0033] In the present invention, the concentration of the finishing agent in step (1) is preferably 10 to 20 g / L, more preferably 13 to 17 g / L, and even more preferably 15 g / L.

[0034] In the present invention, the pretreatment method in step (1) is preferably an immersion method.

[0035] In the present invention, the temperature of the pretreatment in step (1) is preferably 20-30°C, more preferably 22-27°C, and even more preferably 25°C.

[0036] In the present invention, the pretreatment time in step (1) is preferably 20 to 60 minutes, more preferably 30 to 45 minutes, and even more preferably 35 minutes.

[0037] In the present invention, the preparation method of the aqueous blocked diisocyanate comprises: adding a certain volume of ethanol to an aqueous sodium bisulfite solution to obtain an ethanolic aqueous solution of sodium bisulfite; dissolving the diisocyanate in an aqueous ethyl acetate solution to obtain a diisocyanate mixed solution; and dropwise adding the diisocyanate mixed solution to the ethanolic aqueous solution of sodium bisulfite to carry out a reaction.

[0038] In the present invention, the mass concentration of the sodium bisulfite aqueous solution is preferably 20-30%, more preferably 22-27%, and even more preferably 24%.

[0039] In the present invention, the volume of the ethanol is preferably 30-50% of the volume of the sodium bisulfite aqueous solution, more preferably 34-46%, and even more preferably 42%.

[0040] In the present invention, the mass concentration of the ethanol aqueous solution of sodium bisulfite is preferably 12 to 20%, more preferably 13 to 16%, and even more preferably 14%.

[0041] In the present invention, the volume fraction of ethyl acetate is preferably 10 to 20%, more preferably 13 to 18%, and even more preferably 16%.

[0042] In the present invention, the reaction temperature when the diisocyanate mixed solution is added dropwise to the ethanol aqueous solution of sodium bisulfite is preferably 20-30°C, more preferably 22-28°C, and even more preferably 25°C.

[0043] In the present invention, the molar ratio between the sodium bisulfite and the -NCO group contained in the diisocyanate is preferably 1:1 to 1.5, more preferably 1:1.1 to 1.4, and even more preferably 1:1.2.

[0044] In the present invention, the diisocyanate is preferably any one of hexamethylene diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate, and 4,4-dicyclohexylmethane diisocyanate, more preferably any one of hexamethylene diisocyanate and 4,4-dicyclohexylmethane diisocyanate, and more preferably hexamethylene diisocyanate.

[0045] In the present invention, the knitted fabric in step (1) is preferably any one of cellulose fiber knitted fabric, protein fiber knitted fabric, and cellulose fiber and protein fiber blended knitted fabric, further preferably any one of cellulose fiber knitted fabric, cellulose fiber and protein fiber blended knitted fabric, and more preferably cellulose fiber and protein fiber blended knitted fabric.

[0046] In the present invention, the specific method of the degumming treatment in step (2) is to use an alkali-urea mixed system for degumming.

[0047] In the present invention, the mass concentration of sodium carbonate in the mixed system is preferably 1 to 5%, more preferably 1 to 4%, and even more preferably 4%.

[0048] In the present invention, the mass concentration of urea in the mixed system is preferably 0 to 50%, more preferably 3 to 20%, and even more preferably 6%.

[0049] In the present invention, the bath ratio of the silk fiber to the mixed system is preferably 1:40-50, more preferably 1:47-50, and even more preferably 1:50.

[0050] In the present invention, the temperature of the degumming treatment in step (2) is preferably 90-100°C, more preferably 93-99°C, and even more preferably 95°C.

[0051] In the present invention, the degumming treatment time in step (2) is preferably 1 to 2 hours, more preferably 1.2 to 1.8 hours, and more preferably 1.5 hours.

[0052] In the present invention, the dissolving solvent in step (2) is preferably selected from lithium bromide solution or a ternary mixed solution of calcium chloride, anhydrous ethanol and water, and is further preferably a ternary mixed solution of calcium chloride, anhydrous ethanol and water.

[0053] In the present invention, LiBr solution is used to dissolve the crushed silk fibers to obtain a silk fiber dissolving solution.

[0054] In the present invention, the concentration of the LiBr solution is preferably 9.0 to 9.5 mol / L, more preferably 9.1 to 9.4 mol / L, and even more preferably 9.3 mol / L.

[0055] In the present invention, the temperature for dissolving the LiBr solution is preferably 60-70°C, more preferably 62-67°C, and even more preferably 65°C.

[0056] In the present invention, the dissolution time using the LiBr solution is preferably 1.0 to 2.0 h, more preferably 1.3 to 1.8 h, and even more preferably 1.5 h.

[0057] In the present invention, the bath ratio of the pulverized silk fibers dissolved in the LiBr solution is preferably 1:8-12, more preferably 1:9-11, and even more preferably 1:10.

[0058] In the present invention, a ternary mixed solution of calcium chloride, anhydrous ethanol and water is used to dissolve the crushed silk fibers to obtain a silk fiber dissolving solution.

[0059] In the present invention, the molar ratio of calcium chloride:anhydrous ethanol:water is preferably 1:1.8-2.2:7.7-8.3, more preferably 1:1.9-2.1:7.9-8.2, and even more preferably 1:2:8.

[0060] In the present invention, the dissolution temperature of the ternary mixed solution of calcium chloride, anhydrous ethanol and water is preferably 75-85°C, more preferably 78-84°C, and even more preferably 80°C.

[0061] In the present invention, the dissolution time of the ternary mixed solution of calcium chloride, anhydrous ethanol and water is preferably 1.5 to 2.5 hours, more preferably 1.7 to 2.2 hours, and even more preferably 2.0 hours.

[0062] In the present invention, the bath ratio of the pulverized silk fibers dissolved in a ternary mixed solution of calcium chloride, anhydrous ethanol and water is preferably 1:15-25, more preferably 1:18-22, and even more preferably 1:20.

[0063] In the present invention, the dialysis method in step (2) is specifically: dialyzing the filtered silk fiber solution in deionized water using a dialysis bag.

[0064] In the present invention, the molecular weight cut-off of the dialysis bag is preferably 8 to 14 KD.

[0065] In the present invention, the dialysis time in step (2) is preferably 40 to 60 hours, more preferably 45 to 50 hours, and even more preferably 48 hours.

[0066] In the present invention, the deionized water for dialysis needs to be replaced during the dialysis process in step (2), and the interval time for replacing the deionized water for dialysis is preferably 3 to 5 hours, more preferably 3.7 to 4.2 hours, and more preferably 4 hours.

[0067] In the present invention, the concentration of the silk protein solution in step (2) is preferably 10 to 25 mg / mL, more preferably 13 to 18 mg / mL, and even more preferably 15 mg / mL.

[0068] In the present invention, the finishing method in step (3) is preferably an immersion method.

[0069] In the present invention, the bath ratio of the pretreated knitted fabric in step (3) to the silk protein solution is preferably 1:20-30, more preferably 1:24-28, and even more preferably 1:25.

[0070] In the present invention, the finishing temperature in step (3) is preferably 40-50°C, more preferably 43-48°C, and even more preferably 45°C.

[0071] In the present invention, the time for the preparation in step (3) is preferably 30 to 60 minutes, more preferably 35 to 50 minutes, and even more preferably 45 minutes.

[0072] In the present invention, the step (3) is further subjected to a pre-freezing treatment before the vacuum freeze-drying treatment.

[0073] In the present invention, the temperature of the pre-freezing treatment is preferably -15 to -25°C, more preferably -18 to -24°C, and even more preferably -20°C.

[0074] In the present invention, the pre-freezing treatment time is preferably 15 to 30 hours, more preferably 20 to 27 hours, and even more preferably 25 hours.

[0075] In the present invention, the internal air pressure of the vacuum freeze-drying treatment in step (3) is less than 10Pa.

[0076] In the present invention, the temperature of the vacuum freeze-drying treatment in step (3) is preferably -40 to -55°C, more preferably -43 to -52°C, and even more preferably -50°C.

[0077] In the present invention, the time of the vacuum freeze-drying treatment in step (3) is preferably 40 to 60 hours, more preferably 45 to 50 hours, and even more preferably 48 hours.

[0078] In the present invention, the temperature of the heat treatment in step (3) is preferably 80-120° C., more preferably 85-110° C., and even more preferably 95° C. Under the conditions of the heat treatment, the temperature increase can deblock the active groups of the water-based blocked diisocyanate, causing them to chemically react with the fibers and aerogel, thereby improving the bonding strength and elasticity of the bioprotein aerogel and the fibers.

[0079] In the present invention, the heat treatment time in step (3) is preferably 20 to 60 minutes, more preferably 30 to 50 minutes, and even more preferably 48 minutes.

[0080] The present invention also provides a thermal insulation knitted fabric based on bioprotein aerogel.

[0081] The present invention does not limit the processes of the cleaning, drying, crushing and filtering in step (2), and methods well known to those skilled in the art may be used.

[0082] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0083] Example 1

[0084] This embodiment provides a method for preparing a warm knitted fabric based on bioprotein aerogel, comprising the following steps:

[0085] (1) placing silk fibers in a mixture of 5% sodium carbonate and 5% urea at a bath ratio of 1:50, heating to 95°C, and subjecting the fibers to a constant temperature degumming treatment for 1 hour. The degummed silk fibers were then washed, dried, and shredded into fiber segments of approximately 2 mm in length;

[0086] The chopped silk fibers were immersed in a 9.3 mol / L LiBr solution with a bath ratio of 1:10 between the chopped silk fibers and the LiBr solution. The mixture was stirred at 65°C in a magnetic stirrer for 2 h and filtered to obtain a silk fiber solution.

[0087] At room temperature, the silk fiber solution was dialyzed in deionized water using a dialysis bag with a molecular weight cutoff of 8-14KD for 48 hours, and the deionized water was replaced every 4 hours to remove Li + and Br - , to obtain a 20 mg / mL silk protein solution;

[0088] (2) preparing a sodium bisulfite aqueous solution with a mass concentration of 20%, adding ethanol in an amount of 40% by volume of the sodium bisulfite aqueous solution to obtain an ethanol aqueous solution with a mass concentration of 14% of sodium bisulfite, dissolving hexamethylene diisocyanate in an ethyl acetate aqueous solution with a volume fraction of 16%, obtaining a hexamethylene diisocyanate mixed solution, and adding the hexamethylene diisocyanate mixed solution dropwise to the sodium bisulfite ethanol aqueous solution for reaction, wherein the molar ratio of the sodium bisulfite to the -NCO group contained in the hexamethylene diisocyanate is 1:1.2, and the reaction temperature is 20° C. to obtain an aqueous blocked hexamethylene diisocyanate;

[0089] The cotton / wool blended knitted fabric was pretreated with a finishing agent containing 10 g / L water-based blocked hexamethylene diisocyanate at 20° C. for 30 minutes to obtain a pretreated cotton / wool blended knitted fabric;

[0090] (3) The silk protein solution was impregnated onto the pretreated cotton / wool blended knitted fabric by the impregnation method. The bath ratio of the pretreated cotton / wool blended knitted fabric to the silk protein solution was 1:30, the finishing temperature was 45°C, and the finishing time was 45 min. The fabric was first pre-frozen at -15°C for 24 h, and then the internal air pressure of the vacuum freeze dryer was controlled to be <10 Pa. The fabric was vacuum freeze-dried at -40°C for 48 h, and finally treated in an oven at 90°C for 60 min to deblock the active groups of hexamethylene diisocyanate to obtain a bioprotein aerogel-based warm knitted fabric.

[0091] After testing, the thermal resistance of the bioprotein aerogel-based warm knitted fabric prepared in this embodiment is 0.0627m 2 k / w, the warmth retention rate is 36%, and after ten washes, the warmth retention rate remains above 30%.

[0092] Example 2

[0093] This embodiment provides a method for preparing a warm knitted fabric based on bioprotein aerogel, comprising the following steps:

[0094] (1) The silk fibers were placed in a mixture with a sodium carbonate concentration of 5% at a bath ratio of 1:50. The mixture was heated to 100°C and subjected to a constant temperature degumming treatment for 1 hour. The degummed silk fibers were then washed, dried, and cut into fiber segments of approximately 2 mm in length.

[0095] The chopped silk fibers were immersed in a ternary mixed solution of calcium chloride: anhydrous ethanol: water with a molar ratio of 1:2:8, and the bath ratio of the chopped silk fibers to the ternary mixed solution was 1:20. The mixture was shaken at a constant temperature of 80°C for 2 hours and filtered to obtain a silk fiber solution.

[0096] At room temperature, the silk fiber solution was dialyzed in deionized water using a dialysis bag with a molecular weight cutoff of 8-14 kD for 48 h, and the deionized water was replaced every 4 h to remove the Ca in the solution. 2+ and Cl - , to obtain a 20 mg / mL silk protein solution;

[0097] (2) preparing a sodium bisulfite aqueous solution with a mass concentration of 20%, adding ethanol in an amount of 50% by volume of the sodium bisulfite aqueous solution to obtain an ethanol aqueous solution with a mass concentration of 13% sodium bisulfite, dissolving hexamethylene diisocyanate in an ethyl acetate aqueous solution with a volume fraction of 16%, obtaining a hexamethylene diisocyanate mixed solution, and adding the hexamethylene diisocyanate mixed solution dropwise to the sodium bisulfite aqueous solution with ethanol to react, wherein the molar ratio of the sodium bisulfite to the -NCO group contained in the hexamethylene diisocyanate is 1:1.2, and the reaction temperature is 20° C. to obtain an aqueous blocked hexamethylene diisocyanate;

[0098] The cotton / wool blended knitted fabric was pretreated with a finishing agent containing 10 g / L of water-based blocked hexamethylene diisocyanate at 25° C. for 30 minutes to obtain a pretreated cotton / wool blended knitted fabric.

[0099] (3) The silk protein solution was impregnated onto the pretreated cotton / wool blended knitted fabric by the impregnation method. The bath ratio of the pretreated cotton / wool blended knitted fabric to the silk protein solution was 1:20, the finishing temperature was 40°C, the finishing time was 50 min, and the fabric was first pre-frozen at -20°C for 24 h. Then, the internal air pressure of the vacuum freeze dryer was controlled to be <10 Pa, and the fabric was vacuum freeze-dried at -50°C for 48 h. Finally, the fabric was treated in an oven at 90°C for 60 min to deblock the active groups of hexamethylene diisocyanate to obtain a bioprotein aerogel-based warm knitted fabric.

[0100] After testing, the thermal resistance of the bioprotein aerogel-based warm knitted fabric prepared in this embodiment is 0.0893m 2 k / w, the warmth retention rate is 40%, and after ten washes, the warmth retention rate remains above 30%.

[0101] Example 3

[0102] This embodiment provides a method for preparing a warm knitted fabric based on bioprotein aerogel, comprising the following steps:

[0103] (1) diluting the silk protein solution of Example 1 with deionized water to obtain a silk protein solution with a concentration of 10 mg / mL;

[0104] (2) preparing a sodium bisulfite aqueous solution with a mass concentration of 20%, adding ethanol in an amount of 40% by volume of the sodium bisulfite aqueous solution to obtain an ethanol aqueous solution with a mass concentration of 14% of sodium bisulfite, dissolving hexamethylene diisocyanate in an ethyl acetate aqueous solution with a volume fraction of 16%, obtaining a hexamethylene diisocyanate mixed solution, and adding the hexamethylene diisocyanate mixed solution dropwise to the sodium bisulfite ethanol aqueous solution for reaction, wherein the molar ratio of the sodium bisulfite to the -NCO group contained in the hexamethylene diisocyanate is 1:1.2, and the reaction temperature is 20° C. to obtain an aqueous blocked hexamethylene diisocyanate;

[0105] The pure cotton knitted fabric was pretreated with a finishing agent containing 10 g / L of water-based blocked hexamethylene diisocyanate at 30° C. for 30 minutes to obtain a pretreated pure cotton knitted fabric;

[0106] (3) The silk protein solution was impregnated onto the pretreated pure cotton knitted fabric. The bath ratio of the pretreated pure cotton knitted fabric to the silk protein solution was 1:25. The finishing temperature was 45°C and the finishing time was 45 min. The fabric was first pre-frozen at -15°C for 24 h, and then the internal air pressure of the vacuum freeze dryer was controlled to be <10 Pa. The fabric was vacuum freeze-dried at -40°C for 48 h, and finally treated in an oven at 90°C for 60 min to deblock the active groups of hexamethylene diisocyanate to obtain a bioprotein aerogel-based warm knitted fabric.

[0107] After testing, the thermal resistance of the bioprotein aerogel-based warm knitted fabric prepared in this embodiment is 0.0523m 2 k / w, the warmth retention rate is 34%, and after ten washes, the warmth retention rate remains above 30%.

[0108] The thermal insulation rates of the bio-protein aerogel-based thermal knitted fabrics prepared in Examples 1 to 3 all meet the requirement of the textile industry standard FZ / T 73022-2019 "Knitted Thermal Underwear" that the thermal insulation rate should be greater than 30%, indicating that the present invention uses aqueous blocked diisocyanate to pretreat the knitted fabric, thereby improving the bonding strength and elasticity between the fiber and the protein aerogel, using salt solution dissolution technology to prepare the bio-protein solution, and using vacuum freeze-drying technology to prepare the bio-protein aerogel-based thermal textile fabric; during the freeze-drying protein aerogel formation process, the fiber material is further fibrillated, the pores inside the fiber increase, and the static air content inside the fiber is increased, which can also improve the thermal insulation of the fabric itself.

[0109] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a warm knitted fabric based on bioprotein aerogel, characterized in that: The following steps are involved: (1) pretreating the knitted fabric with a finishing agent to obtain a pretreated knitted fabric; (2) degumming the silk fibers, washing, drying, and crushing the silk fibers after degumming, and dissolving, filtering, and dialyzing the crushed silk fibers to obtain a silk protein solution; (3) arranging the silk protein solution onto the pretreated knitted fabric, performing vacuum freeze drying, and then performing heat treatment to obtain a warm knitted fabric based on bioprotein aerogel; There is no order restriction for step (1) and step (2); The finishing agent in step (1) comprises an aqueous blocked diisocyanate; The knitted fabric in step (1) is any one of cellulose fiber knitted fabric, protein fiber knitted fabric, and cellulose fiber and protein fiber blended knitted fabric; The dialysis method in step (2) is specifically as follows: dialyzing in water using a dialysis bag with a molecular weight cutoff of 8 to 14 KD, replacing the water every 3 to 5 hours, and the dialysis time is 40 to 60 hours.

2. The method for preparing a warm knitted fabric based on bioprotein aerogel according to claim 1, characterized in that: The concentration of the finishing agent in step (1) is 10-20 g / L; the pretreatment method in step (1) is an immersion method, the pretreatment temperature is 20-30° C., and the pretreatment time is 20-60 min.

3. The method for preparing a warm knitted fabric based on bioprotein aerogel according to claim 2, characterized in that: The preparation method of the aqueous blocked diisocyanate comprises the following steps: preparing a sodium bisulfite aqueous solution with a mass concentration of 20-30%, adding ethanol in an amount of 30-50% by volume of the sodium bisulfite aqueous solution to the sodium bisulfite aqueous solution to obtain an ethanol aqueous solution with a mass concentration of 12-20%, dissolving the diisocyanate in an aqueous solution of ethyl acetate with a volume fraction of 10-20% to obtain a diisocyanate mixed solution, and dripping the diisocyanate mixed solution into the sodium bisulfite ethanol aqueous solution for reaction at a temperature of 20-30° C., wherein the molar ratio between the sodium bisulfite and the -NCO group contained in the diisocyanate is 1:1-1.5, and the diisocyanate comprises any one of hexamethylene diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate, and 4,4-dicyclohexylmethane diisocyanate.

4. A method for preparing a warm knitted fabric based on bioprotein aerogel according to any one of claims 1 to 3, characterized in that: The specific method of the degumming treatment in step (2) is to use an alkali-urea system for degumming: the silk fiber is placed in a mixed system with a sodium carbonate mass concentration of 1 to 5% and a urea mass concentration of 0 to 50%, the bath ratio of the silk fiber to the mixed system is 1:40 to 50, the temperature of the degumming treatment is 90 to 100°C, and the time of the degumming treatment is 1 to 2 hours.

5. The method for preparing a warm knitted fabric based on bioprotein aerogel according to claim 4, characterized in that: The dissolving solvent in step (2) is selected from a lithium bromide solution or a ternary mixed solution of calcium chloride, anhydrous ethanol and water.

6. A method for preparing a warm knitted fabric based on bioprotein aerogel according to claim 2 or 3, characterized in that: The concentration of the silk fibroin solution in step (2) is 10-25 mg / mL.

7. A method for preparing a warm knitted fabric based on bioprotein aerogel according to claim 2, 3 or 5, characterized in that: The finishing method in step (3) is an immersion method, the bath ratio of the pretreated knitted fabric to the silk protein solution is 1:20-30, the finishing temperature is 40-50°C, and the finishing time is 30-60 minutes.

8. The method for preparing a warm knitted fabric based on bioprotein aerogel according to claim 7, characterized in that: Before the vacuum freeze-drying treatment, step (3) also performs a pre-freezing treatment, the pre-freezing treatment temperature is -15 to -25°C, and the pre-freezing treatment time is 15 to 30 hours.

9. The method for preparing a warm knitted fabric based on bioprotein aerogel according to claim 1, characterized in that: The internal air pressure of the vacuum freeze-drying treatment in step (3) is <10Pa, the temperature of the vacuum freeze-drying treatment is -40 to -55°C, the time of the vacuum freeze-drying treatment is 40 to 60h, the temperature of the heat treatment is 80 to 120°C, and the time of the heat treatment is 20 to 60min.

10. A thermal knitted fabric based on bioprotein aerogel, prepared by the method for preparing a thermal knitted fabric based on bioprotein aerogel according to any one of claims 1 to 9.