A semi - interpenetrating network cellulose - based aqueous colloidal material for spinning, its preparation method and application

Abstract

The present invention relates to the technical field of cellulose spinning, and discloses a semi-interpenetrating network cellulose-based aqueous colloidal material for spinning, its preparation method and application. The method includes: subjecting cellulose pulp to mechanical shearing and then performing homogenization treatment in water to obtain a fibrillated cellulose dispersion liquid, and then adding a cross-linking agent to form a cellulose aqueous colloidal solution; adding an aqueous polymer to the cellulose aqueous colloidal solution and stirring to dissolve it, and adding an initiator and a cross-linking agent to prepare a semi-interpenetrating network cellulose-based aqueous colloid with spinnability. The preparation method of the present invention is different from the cellulose solvent system, adopts a pure water system instead of an organic solvent system, and does not have many problems such as complex processes, high energy consumption and pollutant emissions generated during the cellulose dissolution process. The invention of this technology is expected to realize the green processing and manufacturing of cellulose-based fibers in a true sense, and provides a new technical direction for the green processing and manufacturing and in-depth development of cellulose fibers.

Description

Technical Field

[0001] The present invention relates to the technical field of cellulose spinning, and particularly relates to a semi-interpenetrating network cellulose-based aqueous colloidal material for spinning, a preparation method thereof, and an application thereof. Background Art

[0002] In recent years, for the purpose of reducing and replacing petrochemical resources, the research on the fiber resource utilization of biomass such as cellulose has received more attention from the academic and industrial circles, especially the processing and manufacturing of regenerated cellulose fibers. However, the currently commercialized regenerated cellulose fibers are all limited by problems such as complex and expensive production processes and serious pollution of the solvent system, making it difficult to achieve the true green processing and development of cellulose fibers. This is mainly attributed to the fact that the crystalline structure of cellulose restricts the movement and arrangement between molecular chains, making it difficult to process. At present, the industrial production of cellulose fibers mainly relies on solvent systems, but there are many problems. For example, the viscose process has a long processing process and the generation of pollutant CS2, and the Lyocell process has difficulties in synthesizing raw material NMMO, mainly imported at a high price, is easily decomposed at high temperatures, and has important quality problems such as wet fibers being prone to fibrillation; while the relatively green low-temperature alkali-urea system and ionic liquid system still face various challenges in industrialization due to their own defects (such as solvent recovery costs and process equipment problems). Therefore, the preparation of high-quality cellulose spinning dope based on green processing is particularly important for the green and environmentally friendly industrial production and development of cellulose fibers.

[0003] In the existing technologies regarding cellulose colloidal solutions, Chinese Patent No. CN116396405A discloses a preparation method of microcrystalline cellulose colloid based on straw pith. In this invention, the pretreated straw pith raw material is added to an alkali solution and impregnated for a certain time, and then the alkali solution is filtered out, crushed, shear-dispersed, filtered, and washed to obtain a stably dispersed microcrystalline cellulose colloid; Chinese Patent No. CN103304824A discloses a preparation method of a high-concentration nano-microcrystalline cellulose colloid. This invention prepares a low-concentration nano-microcrystalline cellulose dispersion by sulfuric acid hydrolysis, and then removes water by rotary evaporation to obtain a nano-microcrystalline cellulose colloid with a mass fraction of 35 - 85 wt%; Chinese Patent No. CN104072787B also discloses a preparation method of a high-concentration nano-cellulose colloid. This invention prepares nano-cellulose by mechanical method, chemical method, biological method or mechanochemical method, and the obtained nano-cellulose is separated by centrifugation or microporous filter cloth filtration to obtain a nano-cellulose colloid. Then, the nano-cellulose colloid is cryogenically frozen to form aggregation and entanglement between nano-celluloses, and then the frozen nano-cellulose colloid is placed at 0 oThaw at a temperature above C, and finally disperse the precipitate in a solvent through filtration, pressure filtration, washing and mechanical shearing to obtain a high-concentration nanocellulose colloid; Chinese Patent Nos. CN107090607B and CN113150314B both disclose the invention technology of preparing composite fibers or gel materials by mixing a cellulose dissolution solution based on a cellulose solvent system with a polyvinyl alcohol component. There is no relevant report on the above-mentioned green processing technology for preparing a cellulose-based aqueous colloid with good spinnability in the published inventions. Summary of the Invention

[0004] Based on the existing production processes of regenerated cellulose fibers, they are all limited by the cellulose dissolution process - solvent system, such as serious pollution emissions, expensive solvents, complex dissolution processes and equipment, and difficult solvent recovery. It is difficult to truly achieve the green production and processing of cellulose fibers. The purpose of the present invention is to solve the above-mentioned technical problems existing in the existing production, and provide a semi-interpenetrating network cellulose-based aqueous colloid material for cellulose spinning, its preparation method and application based on a pure water system.

[0005] To achieve the above object, on the one hand, the present invention provides a preparation method of a semi-interpenetrating network cellulose-based aqueous colloid material for spinning, which includes the following steps:

[0006] S1. Using cellulose pulp as raw material, obtain micro / nano fibrillated cellulose with uniform fineness through mechanical shearing, then prepare an aqueous suspension of fibrillated cellulose with water as the solvent, and then obtain a non-derivatized fibrillated cellulose dispersion with a solid content of 2-20 wt% through homogenization treatment;

[0007] S2. Add a cross-linking agent to the fibrillated cellulose dispersion prepared in step S1, and perform sufficient stirring at a constant temperature to obtain a uniform cellulose aqueous colloid solution with a solid content of 2.1-24 wt%. This cellulose aqueous colloid solution is a network cross-linking based on covalent bonds or hydrogen bonds between cellulose and the cross-linking agent, where the mass ratio of cellulose to the cross-linking agent is 1:0.05-1:0.2, and the cross-linking agent is at least one of epichlorohydrin, glutaraldehyde, tannic acid, citric acid, sodium alginate, calcium chloride, ferrous chloride.

[0008] S3. Using the cellulose aqueous colloidal solution prepared in step S2 as the first component - cellulose aqueous solution, add the monomer or prepolymer of the aqueous polymer to the first component - cellulose aqueous solution, stir and dissolve it, and add an initiator and a crosslinking agent, so that the monomer or prepolymer of the aqueous polymer is in - situ polymerized and crosslinked in the first component - cellulose aqueous solution under the action of the initiator and the crosslinking agent to form the second component - polymer network, and finally obtain a semi - interpenetrating network cellulose - based aqueous colloid with certain spinnability, where the mass ratio of cellulose to the aqueous polymer is 1:0.1 - 1:1, and the solid content of the obtained semi - interpenetrating network cellulose - based aqueous colloid is 2.3 - 46 wt%.

[0009] As a further preferred technical solution of the present invention, the cellulose pulp in step S1 is any one of wood pulp, cotton pulp, bamboo pulp, hemp pulp, straw pulp or bacterial cellulose.

[0010] As a further preferred technical solution of the present invention, the mechanical shearing treatment method in step S1 is one or more of high - pressure homogenization, disk milling, ball milling, crusher crushing, steam explosion, twin - screw kneading, and mechanical stirring and crushing.

[0011] As a further preferred technical solution of the present invention, in step S2, the temperature for sufficient stirring is 20 - 90 o °C, and the time is 4 - 24 h.

[0012] As a further preferred technical solution of the present invention, in step S3, the aqueous polymer is any one of polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, polyethylene glycol, sodium polyacrylate, and polyvinyl alcohol.

[0013] As a further preferred technical solution of the present invention, in step S3, the mass ratio of the amount of the aqueous polymer monomer to the initiator is 1:0.005 - 1:0.015, and the mass ratio of the aqueous polymer to the crosslinking agent is 1:0.01 - 1:0.2.

[0014] As a further preferred technical solution of the present invention, in step S3, the initiator is at least one of potassium persulfate, sodium persulfate, azobisisobutyronitrile, and methylmagnesium bromide, and the crosslinking agent is at least one of N,N'-methylenebisacrylamide and glutaraldehyde.

[0015] On the other hand of the present invention, the present invention also provides a semi - interpenetrating network cellulose - based aqueous colloid material prepared by the above - mentioned method.

[0016] On the other hand of the present invention, the present invention also provides an application of the semi - interpenetrating network cellulose - based aqueous colloid material in spinning, and wet spinning can be used for fiber formation.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The present invention uses natural cellulose pulp as raw material and water as solvent, and obtains a homogeneous cellulose aqueous colloidal dispersion through mechanical shearing and chemical crosslinking. Then, with the cellulose aqueous colloid as the first component and the aqueous polymer as the second component, an interpenetrating semi-interpenetrating network is formed, and the prepared semi-interpenetrating network cellulose-based aqueous colloid has certain spinnability.

[0019] The spinning dope of the semi-interpenetrating network cellulose-based aqueous colloid prepared by the present invention is a green processing based on a water system, different from the dissolution processing technology of the solvent system, that is, the preparation process is pollution-free, the process is green and environmentally friendly, and the green processing and manufacturing of cellulose-based fibers in the water system are realized in a true sense. This technology has great reference significance for the green processing and in-depth development of cellulose fibers. Brief Description of the Drawings

[0020] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0021] Figure 1 It is the physical diagram of the semi-interpenetrating network cellulose-based aqueous colloid with different cellulose contents in Examples 1-3, where a, b, and c are the spinnable semi-interpenetrating network cellulose-based aqueous colloids with cellulose contents of 6 wt%, 10 wt%, and 14 wt% respectively, and the corresponding solid contents are 10 wt%, 16.6 wt%, and 22.3 wt% respectively;

[0022] Figure 2 It is the cellulose-based fiber obtained by wet spinning the semi-interpenetrating network cellulose-based aqueous colloid with 6 wt% cellulose content (solid content 10 wt%) in Example 2, the single fiber strength-elongation relationship curve and the fiber surface and cross-section morphology diagrams measured by optical microscope. Among them, a is the cellulose-based fiber collected by wet spinning of the cellulose-based aqueous colloid, indicating the product property of this colloidal spinning; b is the stress-strain parameter of the fiber single filament, that is, the breaking strength and elongation at break, and the strength of 2.83 cN / dtex is close to the strength of the Lyocell cellulose fiber prepared based on the laboratory NMMO dissolution process; the fiber morphologies of c and d indicate that the fibers obtained by spinning have good orientation and integrity.

[0023] Figure 3 It is the comparison diagram of the single fiber mechanical properties of the cellulose-based fibers prepared by wet spinning of the semi-interpenetrating network cellulose-based aqueous colloid in Examples 1-5 and the wet spinning of the Lyocell process (dissolving cellulose in NMMO aqueous solution) in Comparative Example 1. Among them, a and b are the breaking strength and elongation at break respectively, where samples 1-5 are the fiber strength parameters obtained in Examples 1-5, and sample 6 is the corresponding parameter obtained in Comparative Example 1.

[0024] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed Embodiments

[0025] The following further elaborates on the detailed embodiments of the present invention with reference to the accompanying drawings. It should be understood that the detailed embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not intended to limit the present invention.

[0026] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art to which the present invention pertains. The test reagents used in the following embodiments are all conventional biochemical reagents unless otherwise specified; the experimental methods are all conventional methods unless otherwise specified.

[0027] Example 1:

[0028] A preparation method of a semi-interpenetrating network cellulose-based aqueous colloid is as follows:

[0029] Using dry cotton pulp as raw material, micro / nano fibrillated cellulose is obtained through mechanical crushing treatment and then dried. Then, a certain amount of fibrillated cellulose is added to a beaker filled with pure water and continuously stirred to prepare a fibrillated cellulose (FC) aqueous suspension with good fluidity. Then, it is subjected to shear fragmentation homogenization (100 MPa) treatment for 30 cycles using a high-pressure homogenizer to obtain a 6 wt% fibrillated cellulose dispersion. Subsequently, the fibrillated cellulose dispersion is heated to 60 o °C, and citric acid with a mass ratio of 0.08 to cellulose is added and stirred to react to obtain a 6 wt% cellulose aqueous colloid solution.

[0030] A certain amount of aqueous polymer monomer - acrylamide is dissolved in the cellulose aqueous colloid solution and mechanically stirred at 50 o °C. Then, initiator potassium persulfate (with a mass ratio of 0.01:1 to acrylamide) and crosslinking agent N,N'-methylenebisacrylamide (with a mass ratio of 0.05:1 to polyacrylamide) are respectively added. Under stirring, acrylamide undergoes in-situ polymerization in the cellulose aqueous colloid solution to form a polymer network structure. After reacting for 6 h, a cellulose-polyacrylamide semi-interpenetrating network aqueous colloid solution with a solid content of 10 wt% is obtained, where the mass ratio of cellulose to polyacrylamide is 3:2.

[0031] The rheological properties of the semi - interpenetrating network cellulose - based aqueous colloid synthesized in Example 1 were tested. The apparent viscosity of the spinning dope was 18317 mPa·s. The cellulose colloid solution was spun using the wet spinning method for confirmation. After the spinning dope was extruded by an injection pump (3.0 m / min), it entered a multi - coagulation bath for washing. After coming out of the coagulation bath by a guiding roller, it was dried by heat and finally the fiber bundle was collected by traction of a winding roller (0.5 m / min). Among them, the multi - coagulation bath consisted of three groups, which were calcium chloride solutions with mass fractions of 1 wt% and 5 wt% and pure water in sequence.

[0032] Example 2:

[0033] A preparation method of a semi - interpenetrating network cellulose - based aqueous colloid is as follows:

[0034] Using dry cotton pulp as raw material, micro / nano fibrillated cellulose was obtained by mechanical crushing and then dried. Then, a quantitative amount of fibrillated cellulose was added to a beaker containing pure water and continuously stirred to prepare a fibrillated cellulose aqueous suspension with good fluidity. Then, it was sheared and homogenized (100 MPa) 30 times by a high - pressure homogenizer to obtain a 10 wt% fibrillated cellulose dispersion. Subsequently, the fibrillated cellulose dispersion was heated to 60 o °C, and citric acid with a mass ratio of 0.08 to cellulose was added and stirred to react to obtain a 10 wt% cellulose aqueous colloid solution.

[0035] A quantitative amount of aqueous polymer monomer - acrylamide was dissolved in the cellulose aqueous colloid solution and mechanically stirred at 60 o °C. Then, initiator potassium persulfate (mass ratio to acrylamide is 0.01:1) and cross - linker N,N'-methylenebisacrylamide (mass ratio to polyacrylamide is 0.05:1) were added respectively. Under stirring, in - situ polymerization of acrylate occurred in the cellulose aqueous colloid network. After reacting for 6 h, a cellulose - polyacrylate semi - interpenetrating network aqueous colloid solution with a solid content of 16.6 wt% was obtained, where the mass ratio of cellulose to polyacrylate was 3:2.

[0036] The rheological properties of the semi - interpenetrating network cellulose - based aqueous colloid synthesized in Example 2 were tested. The apparent viscosity of the spinning dope was 80410 mPa·s. The cellulose colloid solution was spun using the dry - wet spinning process for confirmation. After the spinning dope was extruded by an injection pump (3.0 m / min), it entered multiple coagulation baths for washing. After coming out of the coagulation bath by a guiding roller, it was dried by heat and finally the fiber bundle was collected by traction of a winding roller (0.5 m / min). Among them, the multiple coagulation baths consisted of three groups, which were calcium chloride solutions with mass fractions of 1 wt% and 5 wt% and pure water in sequence.

[0037] Example 3:

[0038] A preparation method of a semi - interpenetrating network cellulose - based aqueous colloid is as follows:

[0039] Using dry cotton pulp as raw material, micro / nano fibrillated cellulose is obtained by mechanical crushing and then dried. Then, a certain amount of fibrillated cellulose is added to a beaker filled with pure water and continuously stirred to prepare a fibrillated cellulose aqueous suspension with good fluidity. Then, it is treated by high - pressure shearing and crushing homogenization (100 MPa) 25 times in a high - pressure homogenizer to obtain a cellulose dispersion with a mass fraction of 14 wt%. Subsequently, the cellulose dispersion is heated to 60 o °C, and citric acid with a mass ratio of 0.08 to cellulose is added and stirred to react to obtain a cellulose aqueous colloid solution with a mass fraction of 14 wt%.

[0040] A certain amount of aqueous polymer monomer - acrylamide is dissolved in the cellulose aqueous colloid solution, mechanically stirred at 60 o °C, and then initiator potassium persulfate (mass ratio to acrylamide is 0.01:1) and cross - linker N,N'-methylenebisacrylamide (mass ratio to polyacrylamide is 0.05:1) are added respectively. Under stirring, in - situ polymerization of acrylate occurs in the cellulose aqueous colloid network. After reacting for 6 h, a cellulose - polyacrylate semi - interpenetrating network aqueous colloid solution with a solid content of 22.3 wt% is prepared, and the mass ratio of cellulose to polyacrylate is 3:2.

[0041] The rheological properties of the above - synthesized semi - interpenetrating network cellulose - based aqueous colloid are tested. The apparent viscosity of the spinning dope is 251237 mPa·s. The spinning of the cellulose colloid solution is confirmed by the dry - wet process. After the spinning dope is extruded by an injection pump (3.0 m / min), it enters multiple coagulation baths for washing treatment, exits the coagulation bath through a guide roller, is dried by heat, and finally the fiber bundle is collected by traction of a winding roller (0.5 m / min). Among them, the multiple coagulation baths are three groups, which are calcium chloride solutions with mass fractions of 1 wt% and 5 wt% and pure water in sequence.

[0042] Example 4:

[0043] A preparation method of a semi - interpenetrating network cellulose - based aqueous colloid is as follows:

[0044] Using dry bleached hardwood pulp as raw material, micro / nano fibrillated cellulose is obtained by mechanical crushing treatment. Then, a certain amount of fibrillated cellulose is added to a beaker filled with pure water and continuously stirred to prepare a fibrillated cellulose aqueous suspension with good fluidity. Then, it is treated by ball - milling and crushing (zirconia balls with a diameter of 6 mm, rotation speed of 120 rpm) 20 times in a high - speed ball mill to obtain a cellulose dispersion with a mass fraction of 6 wt%. Subsequently, the cellulose dispersion is heated to 60 oC, add glutaraldehyde with a mass ratio of 0.05 to cellulose and stir to react to obtain a 6 wt% cellulose aqueous colloidal solution.

[0045] Dissolve a quantitative aqueous polymer monomer - vinylpyrrolidone in the cellulose aqueous colloidal solution, and mechanically stir at 50 o °C. Then, respectively add an initiator azobisisobutyronitrile (with a mass ratio of 0.02:1 to vinylpyrrolidone) and a crosslinking agent N,N'-methylenebisacrylamide (with a mass ratio of 0.02:1 to polyvinylpyrrolidone). Under stirring, vinylpyrrolidone undergoes in-situ polymerization in the cellulose aqueous colloidal solution to form a polymer network structure. After reacting for 8 h, a cellulose-polyvinylpyrrolidone semi-interpenetrating network aqueous colloidal solution with a solid content of 10 wt% is prepared, and the mass ratio of cellulose to polyvinylpyrrolidone is 3:2.

[0046] Perform rheological tests on the above-synthesized semi-interpenetrating network cellulose-based aqueous colloid. The apparent viscosity of the spinning dope is 19583 mPa·s. And confirm the spinning of the cellulose colloidal solution by wet spinning. After the spinning dope is extruded by an injection pump (3.5 m / min), it enters a multi-coagulation bath for washing. After coming out of the coagulation bath by a guide roller, it is heat-dried and finally collected by a winding roller (0.6 m / min) to pull the fiber bundle. Among them, the multi-coagulation bath has three groups, which are 1 wt%, 5 wt% calcium chloride solutions and pure water in sequence.

[0047] Example 5:

[0048] A preparation method of a semi-interpenetrating network cellulose-based aqueous colloid is as follows:

[0049] Using dry bamboo pulp as raw material, micro / nano fibrillated cellulose is obtained by mechanical crushing and dried. Then, take a quantitative amount of fibrillated cellulose and add it to a beaker containing pure water and stir continuously to obtain a fibrillated cellulose aqueous suspension with good fluidity. Then, use a high-pressure homogenizer to perform high-pressure shear crushing and homogenization (100 MPa) for 40 cycles to obtain a 6 wt% cellulose dispersion. Subsequently, heat the cellulose dispersion to 60 o °C, add sodium alginate with a molar ratio of 0.1 to cellulose and stir to react to obtain a 6 wt% cellulose aqueous colloidal solution.

[0050] Dissolve a quantitative aqueous polymer monomer - ethylene oxide in the cellulose aqueous colloidal solution, 80 oMechanical stirring treatment was carried out under C, and then methylmagnesium bromide (mass ratio to ethylene oxide is 0.06:1) and crosslinking agent glutaraldehyde (mass ratio to polyethylene oxide is 0.02:1) were added respectively. In-situ polymerization of ethylene oxide occurred in the cellulose aqueous colloid network under stirring. After reacting for 10 h, a cellulose-polyethylene oxide semi-interpenetrating network aqueous colloid solution with a solid content of 10 wt% was prepared, and the mass ratio of cellulose to polyethylene oxide is 3:2.

[0051] Rheological properties of the above-synthesized semi-interpenetrating network cellulose-based aqueous colloid were tested. The apparent viscosity of the spinning dope was 18795 mPa·s. And the spinning of the cellulose colloid solution was confirmed by the dry-wet process. The spinning dope was extruded through an injection pump (5.5 m / min) and then entered multiple coagulation baths for washing treatment. After coming out of the coagulation bath by the guide roller, it was dried by heat and finally the fiber bundle was collected by traction of the winding roller (0.8 m / min). Among them, the multiple coagulation baths are three groups, which are calcium chloride solutions with mass fractions of 1 wt% and 5 wt% and pure water in sequence.

[0052] Comparative Example 1:

[0053] In order to compare the mechanical properties of cellulose-based fibers prepared from cellulose-based aqueous colloids based on water systems with those prepared from cellulose dissolution systems, and to illustrate that the cellulose-based fibers developed using the green and environmentally friendly water system meet the industry standards. The spinning dope of the comparative example was compared with the semi-interpenetrating network cellulose-based aqueous colloid spinning solution with a solid content of 10% in Example 1 using the current industrial Lyocell process. The method of preparing the spinning dope and spinning in Comparative Example 1 using the traditional Lyocell process is as follows:

[0054] Taking dry cotton fibers (cotton pulp) as raw materials, they were dissolved in an aqueous solution of N-methylmorpholine-N-oxide (NMMO) with a mass fraction of 86 wt% to prepare a cellulose spinning solution with a mass fraction of 10 wt%; then the dissolved cellulose spinning solution was extruded through a spinneret (3.5 m / min) into a coagulation bath, where the first and second coagulation baths were aqueous solutions of NMMO with mass fractions of 30 wt% and 10 wt% respectively. Finally, the fibers prepared by wet spinning were placed in a water bath for washing to remove the residual solvent. After washing, the fibers were further stretched and dried by heat to obtain typical Lyocell fibers.

[0055] It should be noted here that the thickness dimensions of the fibers obtained by the spinning processes in the above Examples 1-5 and Comparative Example 1 are the same. The semi-interpenetrating network cellulose-based aqueous colloid material samples and spinning fiber samples obtained in the above Examples and Comparative Examples were tested:

[0056] (1) Characterization of colloid rheology: A digital viscometer (SNB-2, China) was used to test the cellulose-based composite aqueous polymer colloid. 50 mL of the aqueous colloid was taken in a beaker and left standing for 24 h at room temperature of 25o Measurements were carried out using the L4 rotor at C, and the unit of measurement was mPa·s.

[0057] (2) Characterization of the mechanical properties of single fibers: The mechanical properties of the fibers prepared by wet spinning of cellulose-based aqueous colloids were tested using an electronic single yarn strength tester (YM061, China). The gauge length was set to 30 mm, the drawing speed was fixed at 10 mm / min, and each sample was measured 5 times and the average value was taken. The dry strength (cN / dtex) and elongation at break (%) were calculated and recorded.

[0058] (3) Characterization of the apparent morphology of fibers: The surface and cross-sectional micro-morphologies of the fibers prepared by wet spinning of cellulose-based aqueous colloids were tested using a scanning electron microscope (FEI Quanta 200, USA). For the complete sample preparation of the fiber cross-section, liquid nitrogen brittle fracture treatment was used.

[0059] The test data of Examples 1-3 are shown in Table 1.

[0060] Table 1

[0061]

[0062] Result analysis:

[0063] The semi-interpenetrating network cellulose-based aqueous colloids based on the water system prepared in Examples 1-3, and the cellulose-based aqueous colloids with different solid contents prepared using the same cellulose and aqueous polymer all have good spinnability. It can be seen that the preparation of aqueous colloids with different cellulose contents (solid contents) has good uniformity and processability. Further, a large number of spinning experiments were carried out using cellulose-based aqueous colloids with different solid contents as the spinning dope. By comparison, it was found that the solid content and apparent viscosity of the spinning dope are important indicators for determining the good spinnability of the aqueous colloids. According to the experimental results, when the solid content of the cellulose-based aqueous colloid is not less than 2 wt%, and the viscosity is greater than 12000 mPa·s, the colloid has good spinnability. However, when the solid content of the cellulose-based aqueous colloid exceeds 50 wt%, continuous spinning cannot be carried out due to excessive viscosity. Therefore, the preferred solid content of the cellulose-based aqueous colloid in this application is 2.3-46 wt%. In addition, by observing the apparent morphology of the cellulose-based fibers prepared by wet spinning in Example 2 through a scanning electron microscope ( Figure 1 c-d in), it can be clearly seen that the cellulose-based fibers obtained through multiple stretching treatments such as spinning, drying, and stretching have good orientation, which is beneficial to the improvement of the mechanical properties of the fibers. Figure 2 By comparing the cellulose-based fibers prepared from the cellulose-based aqueous colloids based on the water system of the present invention with the cellulose fibers produced by the current industrialized Lyocell process, the results are as

[0064] shown in Figure 3As shown. The tensile breaking strength of the cellulose-based fibers prepared in Examples 1-5 of the present invention is 2.98-3.74 cN / dtex, and the breaking strength of the cellulose fibers prepared by the laboratory Lyocell process is 2.83 cN / dtex; the corresponding breaking elongation rates are 6.14%-9.16% and 7.3% for the latter. From Figure 3 It can be seen that the average strength and breaking elongation rate of the fibers obtained by wet spinning of cellulose-based aqueous colloids are higher than those of the cellulose fibers prepared by the laboratory NMMO process, further illustrating the feasibility and practicality of the green process for preparing cellulose-based fibers by cellulose-based aqueous colloid spinning in an aqueous system.

[0065] In summary, the cellulose-based fibers prepared using cellulose-based aqueous colloids have good fiber-forming properties, and the mechanical properties of the fibers meet the current industrialization indicators.

[0066] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes or modifications can be made to these embodiments without departing from the principles and essence of the present invention. The protection scope of the present invention is only defined by the appended claims.

Claims

1. A preparation method of a semi - interpenetrating network cellulose - based aqueous colloidal material for spinning, characterized in that, It includes the following steps: S1. Using cellulose pulp as raw material, micro / nano fibrillated cellulose with uniform fineness is obtained through mechanical shearing. Then, a fibrillated cellulose aqueous suspension is prepared with water as the solvent, and after homogenization treatment, a non-derivatized fibrillated cellulose dispersion with a solid content of 2 - 20 wt% is obtained; S2. Adding a cross-linking agent to the fibrillated cellulose dispersion prepared in step S1, and stirring thoroughly at a constant temperature to obtain a uniform cellulose aqueous colloidal solution with a solid content of 2.1 - 24 wt%. This cellulose aqueous colloidal solution is a network cross-linking based on covalent bonds or hydrogen bonds between cellulose and the cross-linking agent, where the mass ratio of cellulose to the cross-linking agent is 1:0.05 - 1:0.2, and the cross-linking agent is at least one of epichlorohydrin, glutaraldehyde, tannic acid, citric acid, sodium alginate, calcium chloride, ferrous chloride; S3. Using the cellulose aqueous colloidal solution prepared in step S2 as the first component - cellulose aqueous solution, adding the monomer or prepolymer of the aqueous polymer to the first component - cellulose aqueous solution and stirring to dissolve, and adding an initiator and a cross-linking agent to cause the monomer or prepolymer of the aqueous polymer to in-situ polymerize and cross-link in the first component - cellulose aqueous solution to form the second component - polymer network, finally obtaining a semi-interpenetrating network cellulose-based aqueous colloid with certain spinnability, where the mass ratio of cellulose to the aqueous polymer is 1:0.1 - 1:1, and the solid content of the prepared semi-interpenetrating network cellulose-based aqueous colloid is 2.3 - 46 wt%; In step S3, the aqueous polymer is any one of polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, polyethylene glycol, sodium polyacrylate, polyvinyl alcohol, the initiator is at least one of potassium persulfate, sodium persulfate, azobisisobutyronitrile, methylmagnesium bromide, and the cross-linking agent is at least one of N,N'-methylenebisacrylamide, glutaraldehyde.

2. The preparation method of the semi - interpenetrating network cellulose - based aqueous colloidal material for spinning according to claim 1, wherein, The cellulose pulp in step S1 is any one of wood pulp, cotton pulp, bamboo pulp, hemp pulp, and straw pulp, or bacterial cellulose.

3. The preparation method of the semi-interpenetrating network cellulose-based aqueous colloid material for spinning according to claim 1, characterized in that, The mechanical shearing treatment method in step S1 is one or more of high-pressure homogenization, disk milling, ball milling, crusher crushing, steam explosion, twin-screw kneading, and mechanical stirring crushing.

4. The preparation method of the semi-interpenetrating network cellulose-based aqueous colloidal material for spinning according to claim 1, characterized in that, In step S2, the temperature for thorough stirring at a constant temperature is 20 - 90 °C, and the time is 4 - 24 h.

5. The preparation method of the semi-interpenetrating network cellulose-based aqueous colloid material for spinning according to claim 1, characterized in that, In step S3, the mass ratio of the amount of the aqueous polymer monomer to the initiator is 1:0.005 - 1: 0.015, and the mass ratio of the aqueous polymer to the cross-linking agent is 1:0.01 - 1:0.

2.

6. A semi-interpenetrating network cellulose-based aqueous colloidal material, characterized in that, It is prepared by the method described in any one of claims 1 - 5.

7. Application of the semi-interpenetrating network cellulose-based aqueous colloid material described in claim 6 in spinning.

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