Sea-island nano composite fiber and production process thereof

Abstract

The invention discloses a sea-island nano composite fiber and a production process thereof, and belongs to the field of sea-island fibers. The sea-island type nano composite fiber comprises an island component and a sea component, wherein the island component comprises the following raw materials in parts by mass: 100 parts of polyester, 6-10 parts of modified vinyl mesoporous silica and 3-5 parts of cellulose nanocrystals; and sulfonated polystyrene is grafted on the surface of the modified vinyl mesoporous silica. The uniform pore channels of the vinyl mesoporous silica can increase the diffusion path of the dye, slow down the diffusion rate of the dye and play a certain slow release effect, and through the repulsive force effect of the grafted sulfonated polystyrene, the aggregation of the dye is hindered, so that the level-dyeing property of the fiber is improved; dye molecules can be anchored in the fibers, so that the color fastness and the light fastness of the fibers are improved. The cellulose nanocrystals can synergistically enhance the leveling property and the dyeing fastness, and by improving the crystallization behavior of island components, internal defects are reduced, and the mechanical strength of the fiber is improved.

Description

Technical Field

[0001] The present invention relates to the field of sea-island fibers, and in particular to a sea-island nanocomposite fiber and a production process thereof. Background Art

[0002] Sea-island fibers are formed by embedding a polymer in another polymer in an extremely fine form. After fibrillation and removal of the sea component, microfibers can be obtained. The fineness of the sea-island fibers is very fine, and the bending stiffness is relatively low, which can make the fabric feel soft and smooth, and the comfort is obvious. In addition, the sea-island microfibers have a large specific surface area and pores, which can give the fabric a strong cleaning effect. At the same time, because the fibers are fine and soft, they can protect the items being cleaned from damage.

[0003] However, the dyeing and finishing properties of island fibers have defects. On the one hand, because the fineness of island microfibers is fine, the finer the fiber, the faster the dyeing rate and the worse the levelness. Uneven fiber linear density, uneven and insufficient fiber opening will also lead to poor levelness of island fibers. It is difficult to overcome the problem of poor levelness by simply controlling the dyeing conditions. Moreover, due to its fast dyeing rate and poor levelness, the dyeing reproducibility of island fibers is also poor, and there are many factors that affect it.

[0004] On the other hand, due to the characteristics of sea island microfibers, the concentration of dyes adsorbed on the surface is high, which will accelerate the fading process of the fibers after absorbing light. Therefore, the wet fastness of sea island microfibers is lower than that of conventional fibers.

[0005] Therefore, there is an urgent need to obtain a sea island microfiber with good levelness, washability, sun resistance and excellent color fastness. Summary of the Invention

[0006] The present invention provides a sea-island nanocomposite fiber, which can solve the problem of poor level dyeing property of sea-island fibers in the prior art.

[0007] In a first aspect, the present invention provides a sea-island nanocomposite fiber, comprising an island component and a sea component; the island component comprises the following raw materials in parts by weight:

[0008] 100 parts of polyester;

[0009] 6-10 parts of modified vinyl mesoporous silica;

[0010] 3-5 parts of cellulose nanocrystals;

[0011] The surface of the modified vinyl mesoporous silica is grafted with sulfonated polystyrene.

[0012] Preferably, the diameter of the cellulose nanocrystals is 10 to 50 nm, and the length is 200 to 500 nm.

[0013] Preferably, the sea component includes any one of alkali-soluble polyester, polyvinyl alcohol, polyethylene, polypropylene and acrylate copolymer.

[0014] Preferably, the mass ratio of the island component to the sea component is 1:(0.6-0.8).

[0015] Because we want to obtain ultra-fine sea-island fibers, but as the specific surface area increases, the dye adsorption rate will be too fast, which will easily lead to problems of local uneven dyeing. Moreover, due to the large specific surface area, the dye is mostly concentrated on the fiber surface, resulting in reduced color fastness and light resistance.

[0016] By adopting the above technical solution, modified vinyl mesoporous silica is added to the island component. On the one hand, the uniform pores of the mesoporous silica can temporarily store dye molecules and adsorb part of the dye in the early stage of dyeing, thereby slowing down the diffusion rate of the dye and achieving a certain sustained-release effect, thereby avoiding uneven distribution of the dye due to excessively fast adsorption rate.

[0017] The negatively charged sulfonic acid groups in the modified, grafted sulfonated polystyrene also inhibit dye aggregation through electrostatic repulsion, improving dye dispersion within the fiber. Furthermore, the nanoparticle size of the modified vinyl mesoporous silica helps fill surface defects within the island component, resulting in a smoother surface for the resulting sea-island nanocomposite fiber. This reduces localized dye aggregation at these defects and improves the fiber's levelness.

[0018] On the other hand, the nanopores of modified vinyl mesoporous silica can also encapsulate dye molecules and anchor the dye inside the fiber, thereby reducing the migration of the dye to the fiber surface and effectively improving the color fastness of the fiber.

[0019] Furthermore, vinyl mesoporous silica can leverage the non-polar nature of the vinyl group to blend with the polyester in the island component, exhibiting good compatibility and forming physical entanglements. Furthermore, the modified vinyl mesoporous silica can utilize sulfonic acid groups to bind to dye molecules through hydrogen bonding, thereby strengthening the bond between the dye molecules and the fiber, improving the fiber's color fastness and dye adsorption capacity. The chemical stability of mesoporous silica can also form a physical barrier within the island component, thereby enhancing the fiber's light fastness.

[0020] In addition, cellulose nanocrystals are introduced into the island components of the sea-island nanocomposite fibers of the present invention. The large number of hydroxyl groups contained in the cellulose nanocrystals can strengthen the binding effect with the dye molecules, and have a significant bonding ability with dyes containing amino and hydroxyl groups, while also reducing the uneven dyeing caused by dye aggregation in the early stage of dyeing; the addition of cellulose nanocrystals can introduce physical cross-linking points into the island components, thereby limiting the movement of polymer chain segments, thereby reducing the migration of dyes to the fiber surface, and helping to improve the dyeing fastness of the fiber.

[0021] The physical crosslinking points of cellulose nanocrystals can bind to the sulfonic acid groups contained in modified vinyl mesoporous silica, enhancing interfacial crosslinking, synergistically reducing dye aggregation, and enhancing the anchoring effect of the dye within the fiber, inhibiting dye migration. The addition of cellulose nanocrystals can also improve the crystallization behavior of the island component, reduce the content of amorphous regions in the island component, and reduce internal defects and stress concentration points in the fiber, thereby improving dyeing differences while increasing the mechanical strength of the fiber.

[0022] Preferably, the raw materials of the modified vinyl mesoporous silica include vinyl mesoporous silica and sodium styrene sulfonate in a mass ratio of 1: (0.6-0.8).

[0023] Preferably, the particle size of the vinyl mesoporous silica is 5 to 15 nm.

[0024] Preferably, the raw materials of vinyl mesoporous silica include ethyl orthosilicate and vinyl silane in a mass ratio of 1: (0.1-0.2).

[0025] Preferably, the vinylsilane includes one or more of vinyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane and vinylmethyldiethoxysilane.

[0026] More preferably, vinyl mesoporous silica is prepared according to the following method:

[0027] Adding a template and sodium chloride to a hydrochloric acid solution, stirring and dissolving, and obtaining a mixed solution;

[0028] Add ethyl orthosilicate and vinyl silane to the mixed solution, raise the temperature to 30-40°C, stir and mix, then raise the temperature to 90-100°C, carry out hydrothermal reaction for 20-24 hours, and finally obtain vinyl mesoporous silica through filtration, washing, extraction and drying.

[0029] More preferably, the template comprises one or a combination of two of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and hexadecyltrimethylammonium bromide.

[0030] More preferably, the mass ratio of tetraethyl orthosilicate, template and sodium chloride is 1:(0.5-0.6):(1.4-1.5).

[0031] By adopting the above technical solution, the present invention uses mesoporous silica, whose pore structure can selectively adsorb dye molecules, slowing the adsorption rate of dye in the early stages of dyeing, thereby avoiding uneven dyeing caused by localized dye aggregation. Furthermore, its mesoporous structure provides more adsorption sites, which adsorb the dye within the pores through capillary forces and release it in stages, achieving a certain slow-release effect. It also anchors the dye within the fiber, improving the dye's color fastness. This has a greater adsorption capacity than ordinary silica particles, providing a unique slow-release effect.

[0032] Furthermore, the mesoporous silica of the present invention is subjected to ethylene functionalization treatment. On the one hand, the vinyl groups can serve as grafting sites to provide reactive active sites for sulfonated polystyrene.

[0033] On the other hand, vinyl mesoporous silica can weaken the interaction between mesoporous silica and water while enhancing the interaction between mesoporous silica and dye molecules, improving the adsorption performance of dye molecules and also improving the compatibility with polyester, thereby improving the levelness and color fastness of the resulting sea-island nanocomposite fiber.

[0034] Preferably, the modified vinyl mesoporous silica is prepared according to the following method:

[0035] Dissolve 50-60 wt% of sodium styrene sulfonate in a solvent, add an initiator, stir evenly, and react at 80-85°C for 2-4 hours to obtain a prepolymer solution;

[0036] Vinyl mesoporous silica and the balance sodium styrene sulfonate are added to the solvent, and after stirring and dispersing, a prepolymer solution and an initiator are added. The mixture is reacted at 80-90° C. for 2-3 hours, and finally filtered, washed and dried to obtain the modified vinyl mesoporous silica.

[0037] Preferably, the initiator comprises a combination of one or more of dibenzoyl peroxide, ammonium persulfate, potassium persulfate and azobisisobutyronitrile; and the added amount of the initiator is 4-6% of the mass of sodium styrene sulfonate.

[0038] More preferably, the solvent includes any one of dimethyl sulfoxide, dimethylformamide and N-methylpyrrolidone.

[0039] By adopting the above technical solution, the vinyl groups on the surface of the vinyl mesoporous silica can undergo side chain grafting and cross-linking with sodium styrene sulfonate and sulfonated polystyrene prepolymer, thereby further grafting the sulfonated polystyrene onto the vinyl mesoporous silica.

[0040] Because mesoporous silica has a small particle size and a large specific surface area, it is easy to agglomerate in the island component. In addition, in the non-polar polyester matrix, the dispersibility and binding force of vinyl mesoporous silica are very limited, which is not conducive to maintaining long-term stability. Poor dispersion leads to the agglomeration of vinyl mesoporous silica, which not only acts as a stress concentration point and causes a decrease in mechanical properties, but also causes a decrease in the uniformity and color fastness of the fiber due to agglomeration, and fails to play a corresponding reinforcing role.

[0041] After graft polymerization modification, the sulfonated polystyrene chain segments are grafted onto the surface of vinyl mesoporous silica. On the one hand, the dispersibility of vinyl mesoporous silica can be improved through steric hindrance and electrostatic effects, and the aggregation of vinyl mesoporous silica can be prevented.

[0042] Furthermore, the good compatibility between the polystyrene and polyester segments enhances the interfacial bonding strength of the vinyl mesoporous silica within the island component. Adjusting the dispersion of the vinyl mesoporous silica further amplifies its sustained release, improving both the fiber's leveling and color fastness, resulting in sea-island fibers with exceptional mechanical strength and dyeing and finishing properties.

[0043] In a second aspect, the present invention provides a process for producing sea-island nanocomposite fibers, comprising the following steps:

[0044] S1. The polyester, modified vinyl mesoporous silica and cellulose nanocrystals are mixed and melt-blended and extruded to obtain an island component;

[0045] S2. The island component and the sea component are melt-processed and composite-spun to obtain sea-island nanocomposite fiber precursors;

[0046] S3. The island-in-sea nanocomposite fiber precursors are bundled, oiled, stretched, bent, and dried to obtain island-in-sea nanocomposite fibers.

[0047] Beneficial effects of the present invention:

[0048] 1. The island component of the sea-island nanocomposite fiber of the present invention contains modified vinyl mesoporous silica. The uniform pores of the vinyl mesoporous silica can increase the diffusion path of the dye, slow down the diffusion rate of the dye, and have a certain sustained-release effect. By combining with the repulsive effect of the grafted sulfonated polystyrene, it hinders the aggregation of the dye, thereby improving the uniformity of the fiber; and the modified vinyl mesoporous silica can attract and adsorb dye molecules, anchoring the dye molecules inside the fiber, thereby reducing the tendency of the dye to diffuse to the surface and improving the color fastness and light fastness of the fiber.

[0049] 2. Cellulose nanocrystals are also added to the island component of the present invention. On the one hand, they can cooperate with modified vinyl mesoporous silica to improve the uniformity and color fastness of the fiber. On the other hand, they can improve the crystallization behavior of the fiber island component, reduce the content of amorphous regions in the island component, reduce internal defects and stress concentration points in the fiber, and improve the mechanical strength of the fiber while improving the coloring difference. DETAILED DESCRIPTION

[0050] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0051] Preparation Example

[0052] Preparation Example 1: A modified vinyl mesoporous silica was prepared according to the following method:

[0053] Preparation of vinyl mesoporous silica:

[0054] 5.5 g of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and 14 g of sodium chloride were added to 200 mL of 1 mol / L hydrochloric acid solution, and the mixture was stirred and dissolved to obtain a mixed solution;

[0055] 10 g of ethyl orthosilicate and 1 g of vinyl triethoxysilane were added to the mixed solution, the temperature was raised to 35°C, and after stirring and mixing, the temperature was raised to 100°C, and the hydrothermal reaction was carried out for 24 hours. Finally, vinyl mesoporous silica was obtained by filtration, washing, extraction and drying.

[0056] Preparation of modified vinyl mesoporous silica:

[0057] Weigh 7 g of sodium styrene sulfonate, dissolve 50 wt% of sodium styrene sulfonate, i.e., 3.5 g of sodium styrene sulfonate, in 70 mL of N-methylpyrrolidone, add 0.35 g of dibenzoyl peroxide, stir well, and react at 80°C for 3 h to obtain a prepolymer solution;

[0058] 10 g of the vinyl mesoporous silica obtained above and the balance, i.e., 3.5 g of sodium styrene sulfonate, were added to 200 mL of N-methylpyrrolidone. After stirring and dispersing, the prepolymer solution and 0.35 g of dibenzoyl peroxide were added. The mixture was reacted at 85° C. for 2 h. Finally, the modified vinyl mesoporous silica was obtained by filtration, washing, and drying.

[0059] Preparation Example 2: A modified vinyl mesoporous silica was prepared according to the following method:

[0060] Preparation of vinyl mesoporous silica:

[0061] 5.5 g of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and 14 g of sodium chloride were added to 200 mL of 1 mol / L hydrochloric acid solution, and the mixture was stirred and dissolved to obtain a mixed solution;

[0062] 10 g of ethyl orthosilicate and 2 g of vinyl triethoxysilane were added to the mixed solution, the temperature was raised to 35°C, and after stirring and mixing, the temperature was raised to 100°C, and the hydrothermal reaction was carried out for 24 hours. Finally, vinyl mesoporous silica was obtained by filtration, washing, extraction and drying.

[0063] Preparation of modified vinyl mesoporous silica:

[0064] Weigh 8 g of sodium styrene sulfonate, dissolve 50 wt% of sodium styrene sulfonate, i.e., 4 g of sodium styrene sulfonate, in 70 mL of N-methylpyrrolidone, add 0.4 g of dibenzoyl peroxide, stir well, and react at 80°C for 3 h to obtain a prepolymer solution;

[0065] 10 g of the vinyl mesoporous silica obtained above and the balance, i.e., 4 g of sodium styrene sulfonate, were added to 200 mL of N-methylpyrrolidone. After stirring and dispersing, the prepolymer solution and 0.4 g of dibenzoyl peroxide were added. The mixture was reacted at 85° C. for 2 h. Finally, the modified vinyl mesoporous silica was obtained by filtration, washing, and drying.

[0066] Preparation Example 3, a modified vinyl mesoporous silica, is different from Preparation Example 1 only in that the total amount of sodium styrene sulfonate added is 6 g.

[0067] Preparation Example 4, a modified vinyl mesoporous silica, is different from Preparation Example 1 only in that the total amount of sodium styrene sulfonate added is 4 g.

[0068] Preparation Example 5, a modified vinyl mesoporous silica, is different from Preparation Example 1 only in that the total amount of sodium styrene sulfonate added is 10 g.

[0069] Preparation Example 6: A vinyl mesoporous silica was prepared according to the following method:

[0070] 5.5 g of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and 14 g of sodium chloride were added to 200 mL of 1 mol / L hydrochloric acid solution, and the mixture was stirred and dissolved to obtain a mixed solution;

[0071] 10 g of ethyl orthosilicate and 1 g of vinyl triethoxysilane were added to the mixed solution, the temperature was raised to 35°C, and after stirring and mixing, the temperature was raised to 100°C, and the hydrothermal reaction was carried out for 24 hours. Finally, vinyl mesoporous silica was obtained by filtration, washing, extraction and drying.

[0072] Preparation Example 7: A mesoporous silica was prepared according to the following method:

[0073] 5.5 g of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and 14 g of sodium chloride were added to 200 mL of 1 mol / L hydrochloric acid solution, and the mixture was stirred and dissolved to obtain a mixed solution;

[0074] 10 g of ethyl orthosilicate was added to the mixed solution, the temperature was raised to 35° C., and after stirring and mixing, the temperature was raised to 100° C. and hydrothermally reacted for 24 hours. Finally, mesoporous silica was obtained by filtration, washing, extraction and drying.

[0075] Example

[0076] Example 1: An island-in-sea nanocomposite fiber was prepared according to the following method:

[0077] S1. 100 parts of polyester (intrinsic viscosity 0.68 dl / g), 8 parts of modified vinyl mesoporous silica prepared in Preparation Example 1, and 4 parts of cellulose nanocrystals (diameter 10 to 50 nm, length 200 to 500 nm) were mixed and melt-blended and extruded to obtain an island component. The melt-blending temperature was 270 to 290 ° C.

[0078] S2. The island component and the sea component are melt-processed separately, wherein the mass ratio of the island component to the sea component is 1:0.7; the island component melt processing temperature is 265 to 280 ° C, the sea component is an alkali-soluble polyester, and the sea component melt processing temperature is 270 to 280 ° C, and the composite spinning is performed to obtain a sea-island nanocomposite fiber precursor;

[0079] S3. The island-in-sea nanocomposite fiber precursors are bundled, oiled, stretched, bent, and dried to obtain island-in-sea nanocomposite fibers.

[0080] Example 2, a sea-island nanocomposite fiber, differs from Example 1 only in that the amount of modified vinyl mesoporous silica prepared in Preparation Example 1 added is 6 parts; the amount of cellulose nanocrystals added is 5 parts.

[0081] Example 3, a sea-island nanocomposite fiber, is different from Example 1 only in that the amount of modified vinyl mesoporous silica prepared in Preparation Example 1 added is 10 parts; the amount of cellulose nanocrystals added is 3 parts.

[0082] Example 4 is a sea-island nanocomposite fiber, which differs from Example 1 only in that the modified vinyl mesoporous silica prepared in Preparation Example 1 is replaced by an equal amount of the modified vinyl mesoporous silica prepared in Preparation Example 2.

[0083] Example 5 is a sea-island nanocomposite fiber, which differs from Example 1 only in that the modified vinyl mesoporous silica prepared in Preparation Example 1 is replaced by an equal amount of the modified vinyl mesoporous silica prepared in Preparation Example 3.

[0084] Example 6 is a sea-island nanocomposite fiber, which differs from Example 1 only in that the modified vinyl mesoporous silica prepared in Preparation Example 1 is replaced by an equal amount of the modified vinyl mesoporous silica prepared in Preparation Example 4.

[0085] Example 7, a sea-island nanocomposite fiber, differs from Example 1 only in that the modified vinyl mesoporous silica prepared in Preparation Example 1 is replaced by an equal amount of the modified vinyl mesoporous silica prepared in Preparation Example 5.

[0086] Comparative Example

[0087] Comparative Example 1 is a sea-island nanocomposite fiber, which is different from Example 1 only in that the amount of modified vinyl mesoporous silica prepared in Preparation Example 1 added is 4 parts.

[0088] Comparative Example 2 is a sea-island nanocomposite fiber, which is different from Example 1 only in that the amount of modified vinyl mesoporous silica prepared in Preparation Example 1 added is 12 parts.

[0089] Comparative Example 3 is a sea-island nanocomposite fiber, which is different from Example 1 only in that the modified vinyl mesoporous silica prepared in Preparation Example 1 is replaced by an equal amount of vinyl mesoporous silica prepared in Preparation Example 6.

[0090] Comparative Example 4 is a sea-island nanocomposite fiber, which differs from Example 1 only in that the modified vinyl mesoporous silica prepared in Preparation Example 1 is replaced by an equal amount of mesoporous silica prepared in Preparation Example 7.

[0091] Comparative Example 5 is a sea-island nanocomposite fiber, which differs from Example 1 only in that no cellulose nanocrystals are added.

[0092] Comparative Example 6 is a sea-island nanocomposite fiber, which is different from Example 1 only in that the modified vinyl mesoporous silica and cellulose nanocrystals prepared in Preparation Example 1 are not added.

[0093] Performance testing:

[0094] Sample preparation: The sea-island nanocomposite fibers obtained in the examples and comparative examples were woven, and the resulting fabrics were immersed in a bath with a bath ratio of 1:50, a pH value of 6, and a dye of 2% (owf). The dye was neutral yellow 220, and dyed starting from 40°C at a heating rate of 1°C / min. After heating to 100°C, the heating was stopped and dyed for 60 minutes to obtain the dyed sample.

[0095] Performance testing:

[0096] 1. Levelness test: According to the relevant records in GB / T 2396-2013 "Disperse dyes - Determination of fixation rate - Hot melt dyeing method", the dyeing K / S value is tested;

[0097] The K / S values ​​of ten random points on the dyed sample were tested and the standard deviation was calculated to characterize the levelness of the fabric.

[0098] The test results are shown in Table 1.

[0099] 2. Color fastness test: According to the relevant records in GB / T 3921-2008 "Textiles - Tests for color fastness - Color fastness to washing with soap and soap" and GB / T 8427-2019 "Textiles - Tests for color fastness - Color fastness to artificial light: Xenon arc fading test", the color fastness to washing with soap and sunlight of the dyed samples are tested.

[0100] The test results are shown in Table 2.

[0101] Table 1 Levelness test results

[0102]

[0103] Table 2 Color fastness test results

[0104]

[0105] According to Tables 1 and 2, combined with Example 1, Comparative Examples 1, and 2, the leveling properties and color fastness of Comparative Examples 1 and 2 were both reduced compared to Example 1. This may be due to the reduced amount of modified vinyl mesoporous silica added in Comparative Example 1, which correspondingly reduced the sustained release and adsorption of the modified vinyl mesoporous silica on the fiber dye, resulting in improved leveling properties and color fastness. In contrast, in Comparative Example 2, the amount of modified vinyl mesoporous silica added was increased. Excessive amounts of inorganic particles, on the one hand, affect the softness of the sea-island fibers; on the other hand, excessive additions can lead to particle aggregation, hindering the dispersion of dye molecules and, in turn, affecting the improvement of leveling properties.

[0106] In combination with Example 1, Comparative Example 3 and Comparative Example 4, it can be seen that the levelness and color fastness of Comparative Example 3 and Comparative Example 4 are significantly reduced compared with Example 1. The reason may be that the vinyl mesoporous silica added in Comparative Example 3 has not been modified and lacks the introduction of sulfonated polystyrene chain segments. The dispersibility and interfacial bonding strength of the vinyl mesoporous silica in polyester are greatly reduced, resulting in a more serious agglomeration phenomenon, thereby affecting the levelness and color fastness of the fiber; the mesoporous silica in Comparative Example 4 has not only not undergone sulfonated polystyrene grafting treatment, but also has not undergone vinyl functionalization treatment, and the dispersibility and compatibility between it and polyester are significantly reduced, which leads to the agglomeration of mesoporous silica, causing the mechanical strength and dyeing and finishing properties of the fiber to be reduced.

[0107] Combining Example 1, Comparative Examples 5, and 6, it can be seen that the levelness and color fastness of Comparative Examples 5 and 6 are significantly reduced compared to Example 1. This may be because the absence of cellulose nanocrystals in Comparative Example 5 lacks a synergistic effect with the modified vinyl mesoporous silica, resulting in a decrease in the binding force of the dye molecules within the fiber and a decrease in color fastness. Furthermore, the lack of cellulose nanocrystals to improve the crystallization behavior of the polyester increases defects within the fiber, which not only affects surface smoothness but also leads to a decrease in dye dispersibility and mechanical strength. Comparative Example 6, which lacks either cellulose nanocrystals or modified vinyl mesoporous silica, shows an even more significant performance decline.

[0108] The above disclosures are only a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A sea-island nanocomposite fiber comprising an island component and a sea component, characterized in that: The island component includes the following raw materials in parts by weight: 100 parts of polyester; 6-10 parts of modified vinyl mesoporous silica; 3-5 parts of cellulose nanocrystals; The surface of the modified vinyl mesoporous silica is grafted with sulfonated polystyrene.

2. The island-in-the-sea nanocomposite fiber according to claim 1, characterized in that The raw materials of the modified vinyl mesoporous silica include vinyl mesoporous silica and sodium styrene sulfonate in a mass ratio of 1: (0.6-0.8).

3. The island-in-the-sea nanocomposite fiber according to claim 2, wherein The particle size of the vinyl mesoporous silica is 5 to 15 nm.

4. The island-in-the-sea nanocomposite fiber according to claim 2, wherein The raw materials of the vinyl mesoporous silica include ethyl orthosilicate and vinyl silane in a mass ratio of 1: (0.1-0.2).

5. The island-in-the-sea nanocomposite fiber according to claim 4, characterized in that The vinyl silane includes one or more of vinyl triethoxy silane, vinyl trimethoxy silane, vinyl methyl dimethoxy silane and vinyl methyl diethoxy silane.

6. The island-in-the-sea nanocomposite fiber according to claim 2, wherein The modified vinyl mesoporous silica is prepared according to the following method: Dissolve 50-60 wt% of sodium styrene sulfonate in a solvent, add an initiator, stir evenly, and react at 80-85°C for 2-4 hours to obtain a prepolymer solution; Vinyl mesoporous silica and the balance sodium styrene sulfonate are added to the solvent, and after stirring and dispersing, a prepolymer solution and an initiator are added. The mixture is reacted at 80-90° C. for 2-3 hours, and finally filtered, washed and dried to obtain the modified vinyl mesoporous silica.

7. The island-in-the-sea nanocomposite fiber according to claim 6, characterized in that The initiator comprises a combination of one or more of dibenzoyl peroxide, ammonium persulfate, potassium persulfate and azobisisobutyronitrile; and the added amount of the initiator is 4-6% of the mass of sodium styrene sulfonate.

8. The island-in-the-sea nanocomposite fiber according to claim 1, wherein The sea component includes any one of alkali-soluble polyester, polyvinyl alcohol, polyethylene, polypropylene and acrylate copolymer.

9. The island-in-the-sea nanocomposite fiber according to claim 1, wherein The mass ratio of the island component to the sea component is 1:(0.6-0.8).

10. A process for producing sea-island nanocomposite fibers according to any one of claims 1 to 9, characterized in that: The process steps include: S1. The polyester, modified vinyl mesoporous silica and cellulose nanocrystals are mixed and melt-blended and extruded to obtain an island component; S2. The island component and the sea component are melt-processed and composite-spun to obtain sea-island nanocomposite fiber precursors; S3. The island-in-sea nanocomposite fiber precursors are bundled, oiled, stretched, bent, and dried to obtain island-in-sea nanocomposite fibers.

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