Xanthan gum reinforced alginate high-strength composite fiber and preparation method thereof
By crosslinking xanthan gum with sodium alginate to form a three-dimensional network, the mechanical properties of alginate composite fibers are improved, solving the problem of insufficient strength of seaweed fibers and achieving a combination of high strength and biodegradability.
Patent Information
- Application Number
- CN202511708972.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-01-20
AI Technical Summary
Existing seaweed fibers have low mechanical strength, and the introduction of nanoparticles or synthetic polymers can affect biocompatibility and biodegradability. Improving their mechanical properties without affecting their biological characteristics is a key challenge.
By utilizing the rigid double helix conformation of xanthan gum molecular chains to crosslink with sodium alginate metal ions to form a three-dimensional network, the molecular chain orientation and crosslinking degree of the fiber are improved through wet spinning process and secondary crosslinking technology.
Without compromising biocompatibility, the tensile strength of alginate composite fibers was significantly improved to 560 MPa, an increase of 60%, while maintaining good biodegradability.
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Figure CN121363067A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of preparation of alginate composite fibers, in particular to a xanthan gum reinforced alginate high-strength composite fiber and a preparation method thereof. BACKGROUND
[0002] Natural polysaccharide polymers are gradually replacing some synthetic fibers due to their unique structure and properties, especially excellent biodegradability and processability. Through technological innovation, the mechanical properties of natural polysaccharide polymers are improved to achieve high modulus and high strength, and they show significant advantages in the field of environmentally friendly materials.
[0003] Seaweed fiber, as an important branch of polysaccharide fiber, has developed rapidly in the field of environmental protection and functional materials in recent years, and has become an indispensable part of the textile, medical and high-performance material fields. However, seaweed fiber still faces one major problem: the low molecular weight and random molecular structure of sodium alginate (SA) result in lower mechanical strength of fibers prepared using SA compared to synthetic fibers. The reported conventional seaweed fiber strength is 150-220 MPa, and the high-strength seaweed fiber is 250-350 MPa. The strategy of introducing nanoparticles or synthetic polymers will affect the biocompatibility and biodegradability of the fiber. Therefore, under the premise of not affecting the biological properties of seaweed fiber, how to improve its mechanical properties is the main challenge in broadening the application field of seaweed fiber.
[0004] Therefore, the prior art still needs to be further improved. SUMMARY
[0005] To solve the technical problems existing in the prior art, the present application provides a preparation method of a xanthan gum reinforced alginate high-strength composite fiber, which creatively utilizes the synergistic effect of the unique rigid double helix conformation of the xanthan gum molecular chain and the three-dimensional network formed by the cross-linking metal ions of sodium alginate, thereby improving the mechanical properties of the seaweed fiber without affecting its biological properties.
[0006] To achieve the above purpose, the present application adopts the following technical solutions:
[0007] A preparation method of a xanthan gum reinforced alginate high-strength composite fiber, comprising the following steps in sequence:
[0008] a. Dissolve sodium alginate and xanthan gum in water and stir to obtain a uniform mixed solution; degas the mixed solution to obtain a uniform spinning solution; in the mixed solution, the mass fraction of sodium alginate is 3%, and the mass fraction of xanthan gum is 1.3-2%;
[0009] b. The spinning solution obtained in step a is slowly extracted into a syringe, and the spinning solution in the syringe is pushed through the needle at a constant injection rate and extruded into a 1.5% calcium chloride solution to obtain calcium alginate / xanthan gum gel filaments by cross-linking, and the excess calcium chloride solution is washed away;
[0010] c. The calcium alginate / xanthan gum gel filaments obtained in step b are stretched by a drawing process and then immersed in a 1.5% zinc chloride solution for secondary cross-linking, and after cleaning and drying, the calcium alginate / xanthan gum high-strength composite filaments are obtained.
[0011] In the above method for preparing the xanthan gum reinforced alginate high-strength composite filaments, in step a, the mixing solution is uniformly mixed and degassed by using a centrifugal stirrer.
[0012] In the above method for preparing the xanthan gum reinforced alginate high-strength composite filaments, in step b, the inner diameter of the needle of the syringe is 0.41 mm, and the ambient temperature is room temperature.
[0013] In the above method for preparing the xanthan gum reinforced alginate high-strength composite filaments, in step b, the sodium alginate in the spinning solution is cross-linked with calcium chloride to form a three-dimensional network structure.
[0014] In the above method for preparing the xanthan gum reinforced alginate high-strength composite filaments, in step c, the drawing process uses a multi-roller stretching machine, and the stretching ratio is 75-225%.
[0015] In the above method for preparing the xanthan gum reinforced alginate high-strength composite filaments, in step c, after stretching, the calcium alginate / xanthan gum gel filaments are immersed in a zinc chloride solution for secondary cross-linking to fix the orientation structure and improve the orientation degree and cross-linking degree of the calcium alginate / xanthan gum molecular chains.
[0016] In the above method for preparing the xanthan gum reinforced alginate high-strength composite filaments, in step c, drying is performed by using an oven lamp to remove the water in the alginate high-strength composite filaments, and a calcium alginate / xanthan gum network with ultra-high orientation degree is obtained.
[0017] In the above method for preparing the xanthan gum reinforced alginate high-strength composite filaments, in step c, the rigid double helix conformation of the xanthan gum molecular chains and the three-dimensional network structure formed by cross-linking of the sodium alginate and calcium chloride produce physical entanglement; the orientation degree of the xanthan gum molecular chains is improved by the secondary cross-linking of zinc ions after the drawing process and the drying process under the action of stress.
[0018] Another object of the present application is to provide the calcium alginate / xanthan gum high-strength composite filaments prepared by the above method.
[0019] The breaking strength of the alginate composite fiber is 560 MPa when the draw ratio is 225%.
[0020] Compared with the prior art, the application has the following beneficial technical effects:
[0021] (1) The application applies xanthan gum to the field of high-performance fiber preparation, utilizes the synergistic effect of the unique rigid double helix conformation of the xanthan gum molecular chain and the three-dimensional network formed by the cross-linking metal ions of sodium alginate, and successfully develops a xanthan gum reinforced alginate high-strength composite fiber which is simple in process and degradable, and improves the mechanical properties of the alginate fiber without affecting the biological properties of the alginate fiber.
[0022] (2) The application prepares the alginate high-strength composite fiber by using a wet spinning process, and the strength of the composite fiber is 2.82 cN / dtex (about 350 MPa) under the condition of a draw ratio of 225%, which is about 60% higher than that of the alginate high-strength fiber reported at present, reaching 560 MPa, and showing excellent mechanical properties. During the secondary cross-linking and drying processes under the action of stress after the drawing process, the unique rigid double helix conformation of the xanthan gum molecular chain and the three-dimensional network formed by the cross-linking metal ions of sodium alginate are fully utilized to produce synergistic effect. Specifically, under the action of stretching, the three-dimensional cross-linking network induces the orientation of the xanthan gum molecular chain, and the orientation structure is fixed in the secondary cross-linking process; in the drying process under the action of stress, as the water content decreases, the high-rigidity xanthan gum molecular chain promotes the further improvement of the network orientation degree because the rigid chain is more prone to orientation, and the ultra-high molecular chain orientation degree effectively improves the Young's modulus and breaking strength of the alginate fiber. The raw materials of sodium alginate and xanthan gum used are low in price, the equipment required is simple to operate and easy to control, the prepared composite fiber has a smooth and flat surface and uniform morphology. In addition, the fiber shows good biodegradability in a natural environment and can be completely degraded in soil in 56 days. BRIEF DESCRIPTION OF DRAWINGS
[0023] The application will be further described below in combination with the drawings:
[0024] Figure 1 It is a schematic diagram of the physical entanglement state of the unique rigid double helix conformation of the xanthan gum molecular chain and the three-dimensional network formed by the cross-linking metal ions of sodium alginate in the application;
[0025] Figure 2 It is a mechanical property characterization diagram of the alginate high-strength composite fiber prepared in Example 1 of the application;
[0026] Figure 3 It is a real photo of the alginate high-strength composite fiber prepared in Example 1 of the application;
[0027] Figure 4 The birefringence image of the alginate high-strength composite fiber prepared in Example 1 of the present application under a polarizing microscope;
[0028] Figure 5 The SEM image of the fracture section of the alginate high-strength composite fiber prepared in Example 1 of the present application;
[0029] Figure 6 The mechanical property characterization graph of the alginate high-strength composite fiber prepared in Example 2 of the present application;
[0030] Figure 7 The mechanical property characterization graph of the alginate high-strength composite fiber prepared in Example 3 of the present application;
[0031] Figure 8 The mechanical property characterization graph of the alginate high-strength fiber prepared in Comparative Example 1 of the present application. DETAILED DESCRIPTION
[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.
[0033] The raw materials mentioned in the present application can be obtained by commercial channels.
[0034] The technical concept of the present application is that xanthan gum (XG) is a polysaccharide polymer compound, and the molecular chain contains rich carboxyl and hydroxyl functional groups, which endows it with excellent solubility, biocompatibility and pseudoplasticity, and is applied in the fields of food additives, drug carriers and oil exploitation. However, there are few reports in the field of high-performance fiber preparation. The present application utilizes the synergistic effect of the unique rigid double helix conformation of xanthan gum molecular chain and the three-dimensional network formed by crosslinking metal ions of sodium alginate to develop an alginate high-strength composite fiber, and it is found through testing that the mechanical properties are significantly improved.
[0035] The reaction mechanism of the present application is as follows:
[0036] First, a certain proportion of sodium alginate and xanthan gum are mixed to prepare a spinning solution; then the spinning solution is extruded into a calcium chloride solution through a needle by a wet spinning method, and the sodium alginate is chelated with calcium ions to form a three-dimensional network structure, such as Figure 1As shown, the rigid double helix structure of xanthan gum is interwoven within the three-dimensional network structure, creating a synergistic effect. The unique double helix conformation of xanthan gum molecules gives them high molecular chain rigidity. During stretching, the three-dimensional cross-linking network induces the orientation of xanthan gum molecular chains. Subsequently, the orientation structure is fixed during the secondary cross-linking process, and the moisture gradually decreases during drying under applied stress, making it easier for the highly rigid xanthan gum molecular chains to orient, thereby improving the overall orientation degree of the alginate high-strength composite fiber. In this invention, a multi-roller stretching machine is used for stretching in the stretching process, with a stretching ratio of 75-225%.
[0037] Example 1:
[0038] This invention discloses a method for preparing xanthan gum-reinforced alginate high-strength composite fibers, specifically comprising the following steps:
[0039] Step 1: Dissolve sodium alginate and xanthan gum in deionized water and stir with a magnetic stirrer for 24 h to obtain a mixed solution with sodium alginate mass fraction of 3% and xanthan gum mass fraction of 2%; perform a homogenization and degassing treatment on the mixed solution to obtain a uniform spinning solution.
[0040] Step 2: Slowly extract the spinning solution obtained in Step 1 into a syringe. Using a syringe pump, push the spinning solution in the syringe through the needle at a constant injection rate, squeezing it into a 1.5 wt% calcium chloride solution. Crosslink in the calcium chloride solution for 15 min to obtain calcium alginate / xanthan gum gel fibers. The syringe needle inner diameter is 0.41 mm, and the ambient temperature is room temperature.
[0041] Step 3: Stretch the obtained calcium alginate / xanthan gum gel filaments to 225%, then immerse them in a 1.5 wt% zinc chloride solution for secondary cross-linking for 15 min to fix the orientation structure and improve the cross-linking degree of the calcium alginate / xanthan gum molecular chains. After cleaning, dry them with a drying lamp to obtain the final product.
[0042] like Figure 2 As shown, the tensile strength of the alginate high-strength composite fiber reaches 560 MPa, which is nearly 60% higher than the strength of the currently reported alginate high-strength fiber, which is 2.82 cN / dtex (approximately 350 MPa). Figure 3 This is a photograph of alginate high-strength composite fiber. The fiber surface is smooth and flat with a uniform morphology. Figure 4 The image shows a birefringence of high-strength alginate composite fibers under a polarizing microscope. The bright birefringence confirms that the addition of xanthan gum can effectively improve the orientation of the fibers. Figure 5The SEM image of the fracture section of the alginate high-strength composite fiber is shown in the figure, and the addition of xanthan gum makes the fiber section more dense after high-magnification stretching. This dense structure is very important for improving the breaking strength of the fiber. In addition, the fiber exhibits good biodegradability in a natural environment and can be completely degraded in soil in 56 days.
[0043] Example 2:
[0044] The application discloses a preparation method of xanthan gum reinforced alginate high-strength composite fiber, which specifically comprises the following steps:
[0045] Step 1: sodium alginate and xanthan gum are dissolved in deionized water, and a mixed solution with a sodium alginate mass fraction of 3% and a xanthan gum mass fraction of 1.3% is obtained by magnetic stirring for 24 hours; the mixed solution is uniformly mixed and defoamed to obtain a uniform spinning solution.
[0046] Step 2: the spinning solution obtained in step 1 is slowly extracted into a syringe, and the spinning solution in the syringe is pushed through the needle at a constant injection rate by using a syringe pump, and is extruded into a 1.5 wt% calcium chloride solution, and is crosslinked in the calcium chloride solution for 15 minutes to obtain a calcium alginate / xanthan gum gel filament.
[0047] Step 3: the obtained calcium alginate / xanthan gum gel filament is stretched by 225%, and then is immersed in a 1.5 wt% zinc chloride solution for secondary crosslinking for 15 minutes, so that the oriented structure is fixed and the crosslinking degree of the calcium alginate / xanthan gum molecular chain is improved, and after cleaning and drying by an oven lamp, the xanthan gum reinforced alginate high-strength composite fiber is obtained.
[0048] The mechanical property characterization diagram of the alginate high-strength composite fiber prepared in the example is shown in the figure. Figure 6
[0049] Example 3:
[0050] The difference between the example and example 1 is that in step 3, the stretching is 75%.
[0051] The mechanical property characterization diagram of the alginate high-strength composite fiber prepared in the example is shown in the figure. Figure 7
[0052] Comparative Example 1:
[0053] The difference between the comparative example and example 1 is that no xanthan gum is added.
[0054] The specific steps are as follows:
[0055] Step one, dissolve sodium alginate in deionized water, stir for 24 h by magnetic stirrer to obtain sodium alginate solution with 3% sodium alginate mass fraction, and uniformly mix and defoam the sodium alginate solution to obtain a uniform spinning solution.
[0056] Step two, slowly extract the spinning solution obtained in step one into a syringe, use a syringe pump to push the spinning solution in the syringe at a constant injection rate through the needle, extrude into a 1.5 wt% calcium chloride solution, crosslink in the calcium chloride solution for 15 min to obtain a calcium alginate gel fiber.
[0057] Step three, stretch the obtained calcium alginate gel fiber by 225%, after stretching, immerse it in a 1.5 wt% zinc chloride solution for secondary crosslinking for 15 min, fix the orientation structure, increase the crosslinking degree of the calcium alginate molecular chain, and after washing, dry it by an oven lamp to obtain the product.
[0058] The mechanical property characterization graph of the alginate high-strength fiber prepared in the present comparative example is shown in Figure 8 .
[0059] In summary, under the premise of not affecting the biodegradability and biological properties of the alginate high-strength composite fiber, the present application introduces xanthan gum to significantly improve the breaking strength of the alginate high-strength composite fiber. During the secondary crosslinking after the drawing process and the drying process under the action of stress, xanthan gum plays a key role. First, when the initial network is formed, sodium alginate is crosslinked with calcium ions to form a three-dimensional crosslinked network structure, and the xanthan gum molecular chain is inserted therein to produce physical entanglement; then, under the action of stretching, the three-dimensional crosslinked network induces the orientation of the xanthan gum molecular chain, and the orientation structure is fixed in the secondary crosslinking process; finally, in the drying process under the action of stress, the high-rigidity xanthan gum molecular chain promotes the further improvement of the orientation degree, and the ultra-high molecular chain orientation degree effectively improves the Young's modulus and breaking strength of the alginate composite fiber.
[0060] The parts not mentioned in the present application can be realized by referring to the prior art.
[0061] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application, and are not used as a limitation on the present application, and as long as the above embodiments are appropriately changed and changed within the scope of the spirit of the present application, they fall within the scope of the present application.
Claims
1. A process for the preparation of a xanthan gum reinforced alginate high strength composite fiber, characterized by, Comprise the following steps in sequence: a. Dissolve sodium alginate and xanthan gum in water, and stir to obtain a uniform mixed solution; and defoam the mixed solution to obtain a uniform spinning solution; In the mixed solution, the mass fraction of sodium alginate is 3%, and the mass fraction of xanthan gum is 1.3-2%; b. Slowly extract the spinning solution obtained in step a into a syringe, push the spinning solution in the syringe through the needle at a constant injection rate, and extrude it into a calcium chloride solution with a mass fraction of 1.5% to obtain calcium alginate / xanthan gel filaments through cross-linking, and wash off the excess calcium chloride solution; c. After stretching through a drawing process, immerse the calcium alginate / xanthan gel filaments obtained in step b in a zinc chloride solution with a mass fraction of 1.5% for secondary cross-linking, and after cleaning and drying, obtain the product.
2. The method for preparing xanthan gum-reinforced alginate high-strength composite fiber according to claim 1, characterized in that, In step a, use a centrifugal stirrer to mix and defoam the mixed solution.
3. A process for the preparation of xanthan gum reinforced alginate high strength composite fibres as claimed in claim 1, characterized in that: In step b, the inner diameter of the needle of the syringe is 0.41 mm, and the ambient temperature is room temperature.
4. The method of claim 1, wherein the xanthan gum is added in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the alginic acid sodium salt. 5 In step b, the sodium alginate in the spinning solution is cross-linked with calcium chloride to form a three-dimensional network structure.
5. A process for the preparation of xanthan gum reinforced alginate high strength composite fibres according to claim 4 characterised in that: In step c, a multi-roller stretching machine is used for stretching in the drawing process, and the stretching ratio is 75-225%.
6. A process for the preparation of xanthan gum reinforced alginate high strength composite fibres according to claim 5 characterised in that: In step c, after stretching, the calcium alginate / xanthan gel filaments are immersed in a zinc chloride solution for secondary cross-linking to fix the orientation structure and improve the orientation and cross-linking degree of the calcium alginate / xanthan molecular chain.
7. A process for the preparation of xanthan gum reinforced alginate high strength composite fibres according to claim 6 characterised in that: In step c, an oven lamp is used for drying to remove the water in the alginate high-strength composite fiber.
8. A process for the preparation of xanthan gum reinforced alginate high strength composite fibres according to claim 7 characterised in that: In step c, the rigid double helix conformation of the xanthan molecular chain and the three-dimensional network structure formed by the cross-linking of sodium alginate and calcium chloride produce physical entanglement; the orientation degree of the xanthan molecular chain is improved through secondary cross-linking of zinc ions after stretching and the drying process under stress.
9. A xanthan gum-reinforced alginate high-strength composite fiber, characterized by, It is prepared by the preparation method of any one of claims 1-8.
10. The xanthan gum-reinforced alginate high-strength composite fiber according to claim 9, characterized by: When the stretching ratio is 225%, the breaking strength of the alginate composite fiber is 560 MPa.