Graphene enhanced polyester yarn and preparation method thereof

Abstract

The invention relates to the field of textile materials, and particularly discloses a graphene enhanced polyester yarn and a preparation method thereof.The preparation method comprises the following steps that silicon dioxide aerogel serves as a porous carrier to be loaded with graphene, and a graphene-porous carrier composite material is prepared; the graphene-porous carrier composite material is subjected to modification treatment through vinyl trimethoxy silane and 3-amino propyl triethoxy silane, and then a modified graphene composite material is prepared; reacting the modified graphene composite material, a styrene monomer, an acrylate monomer and an initiator to prepare modified graphene; mixing the prepared modified graphene with polyester chips, and then carrying out melt spinning to prepare graphene enhanced polyester yarns; the invention further discloses the graphene enhanced polyester yarn prepared by adopting the preparation method. The preparation method has the characteristics that the dispersion of the graphene in the polyester is improved, and the direct interface compatibility of the graphene and the polyester fiber is improved, so that the mechanical property of the polyester yarn is improved.

Description

Technical Field

[0001] This application relates to the field of textile materials, and more specifically, it relates to a graphene-reinforced polyester filament and its preparation method. Background Art

[0002] As a type of textile fiber, polyester filament occupies an important position in the textile field due to its excellent wear resistance and strength characteristics. It is widely used in the production of various clothing, home textiles, and industrial textiles, showing good application prospects. However, with the rapid development of the textile industry and the diversification of consumer demands, the limitations of traditional polyester filaments have become increasingly prominent. Although the performance of polyester filaments has been improved through a series of modification technologies, there is still limited room for improvement in their mechanical properties, making it difficult to fully meet the market's demands for high-end and high-performance textiles.

[0003] To overcome the performance limitations of traditional polyester filaments, graphene, a nanomaterial with excellent mechanical, electrical, and thermal properties, is considered an ideal choice for enhancing fiber performance. The addition of graphene is expected to significantly improve the tensile strength of polyester filaments while endowing the fibers with additional properties such as weather resistance, conductivity, and thermal stability. Although graphene has great potential in enhancing fiber performance, there are still many challenges in its application to the modification of polyester fibers. Due to the chemical structure and physical properties of traditional polyester filaments, it is difficult to disperse and integrate graphene within them. The uneven distribution of graphene in polyester fibers not only reduces its reinforcement effect but also affects the processing performance and final product performance of the fibers. In addition, the interfacial compatibility between graphene and polyester fibers is also one of the key factors restricting its application. Poor interfacial compatibility will lead to a weakening of the binding force between graphene and polyester fibers, thus affecting the mechanical properties and stability of the fibers.

[0004] Therefore, further research on graphene-reinforced polyester filaments is needed to improve the dispersion of graphene in polyester and the interfacial compatibility between graphene and polyester fibers, thereby enhancing the mechanical properties of polyester filaments, which is of great significance for the current applications of high-end and high-performance textiles. Summary of the Invention

[0005] In order to improve the dispersion of graphene in polyester and the interfacial compatibility between graphene and polyester fibers, thereby enhancing the mechanical properties of polyester filaments, this application provides a graphene-reinforced polyester filament and its preparation method.

[0006] In the first aspect, this application provides a preparation method for a graphene-reinforced polyester filament, adopting the following technical solution: A preparation method for a graphene-reinforced polyester filament, comprising the following steps: S1. Using silica aerogel as a porous carrier to load graphene, a graphene-porous carrier composite material is prepared; S2. The graphene-porous carrier composite material is modified with vinyltrimethoxysilane and 3-aminopropyltriethoxysilane to obtain a modified graphene composite material; S3. The modified graphene composite material, styrene monomer, acrylate monomer and initiator are polymerized at 70-80 °C to obtain modified graphene; S4. The obtained modified graphene is mixed with polyester chips and then melt-spun to obtain graphene-reinforced polyester filaments.

[0007] By adopting the above technical solution, in this application, graphene is loaded on silica aerogel and then modified. On the one hand, by utilizing the three-dimensional network porous structure of silica aerogel with a higher porosity, the graphene sheets enter the pores of the aerogel and are supported and separated by the pore walls, thereby effectively preventing the mutual stacking and aggregation of graphene sheets, which helps to improve the uniform dispersion of graphene in polyester chips. On the other hand, the porous structure of silica aerogel and polyester can form an anchoring effect through physical adsorption. Compared with the direct addition and dispersion of graphene, the interfacial binding force and compatibility between silica aerogel and polyester are better. Moreover, the two-dimensional sheet structure of graphene is prone to agglomeration in the polyester matrix, resulting in interfacial defects. In this application, loading graphene on silica aerogel and then adding it not only helps to improve its dispersibility, but also helps to improve the interfacial compatibility between the two, and finally enhances the performance better.

[0008] In addition, in this application, after loading graphene on silica aerogel, it is first modified with vinyltrimethoxysilane and 3-aminopropyltriethoxysilane. The methoxy or ethoxy in the above silane coupling agent forms a bond with the porous carrier, thereby introducing amino and double bond functional groups into the composite material. Then, it is polymerized with styrene monomer and acrylate monomer to achieve in-situ polymerization on the composite material. The double bond functional groups copolymerize with styrene and acrylate monomers to form a styrene-acrylate copolymer, and a core-shell structure with the composite material as the core and the polymer as the shell is formed, further improving the dispersibility of graphene in the polymer matrix and enhancing the interaction between graphene and the polymer. The styrene-acrylate copolymer formed by in-situ polymerization on the surface of the composite material can provide certain rigidity and strength in the styrene part, which matches the mechanical properties of polyester filaments, while the acrylate part can entangle or chemically bond with the polyester molecular chains to form a good interfacial layer, effectively transmitting stress and improving the interfacial compatibility between graphene and polyester filaments. Finally, it significantly improves the dispersion of graphene in polyester and improves the direct interfacial compatibility between graphene and polyester fibers, thereby enhancing the mechanical properties of polyester filaments.

[0009] Optionally, the specific operation in step S1 is as follows: Graphene oxide is dissolved in water and then ultrasonically dispersed to obtain a graphene oxide dispersion; then the graphene oxide dispersion is mixed with silica aerogel, impregnated for 1-2 h and then dried to obtain silica aerogel loaded with graphene oxide; Then the silica aerogel loaded with graphene oxide is added to an ascorbic acid solution, reacted at 60-80 °C for 2-3 h, filtered, washed and dried to achieve the loading of graphene on the silica aerogel, and a graphene-porous carrier composite material is prepared.

[0010] By adopting the above technical solution, compared with the direct impregnation loading of graphene on a porous carrier, the loading method of graphene in this application is realized by loading graphene oxide on silica aerogel and then reducing it. By utilizing the water solubility of graphene oxide, a stable dispersion can be formed in an aqueous solution and uniformly penetrate into the pores of silica aerogel through the impregnation method, avoiding the agglomeration problem caused by the van der Waals force between the lamellae when directly using graphene, improving the uniform loading of graphene, and further better improving the dispersion of the composite material in polyester and the interfacial compatibility; moreover, after reduction, a small amount of carboxyl and hydroxyl functional groups are retained in graphene oxide, which can form chemical bonding with polyester molecules through the silane coupling agent in step S2, further enhancing the interaction between the composite material and polyester, and ultimately playing a better strengthening role.

[0011] Optionally, in step S1, the mass ratio of graphene oxide to water added is 1:(3-4), the mass ratio of graphene oxide to silica aerogel added is 1:(0.8-1.2), the mass concentration of ascorbic acid in the ascorbic acid solution is 10-20%, and the addition amount of the ascorbic acid solution is 2-3 times the mass of graphene oxide.

[0012] By adopting the above technical solution, ascorbic acid is used as a reducing agent to reduce graphene oxide in silica aerogel to generate graphene.

[0013] Optionally, when adding the silica aerogel loaded with graphene oxide to the ascorbic acid solution for reduction treatment in step S1, first pre-reduce at normal pressure and 60-65 °C for 40-60 min, and then raise the temperature to 70-80 °C and pressurize to 0.2-0.3 MPa for continuous reduction treatment.

[0014] By adopting the above technical solution, when adding the silica aerogel loaded with graphene oxide into the ascorbic acid solution for reduction treatment, first, pre-reduction treatment is carried out under normal pressure and low temperature, which can gradually reduce the oxygen-containing functional groups on the surface of graphene oxide. The mild conditions can prevent the rapid reduction and aggregation of graphene oxide sheets and maintain their dispersion in the pores of the aerogel. Then, temperature-raising and pressure-increasing reduction treatment is carried out to accelerate the reduction progress and complete the deep reduction of graphene oxide in the pore structure. Moreover, the high-pressure conditions promote the repair of the graphene sp 2 network, reduce defects, and improve its performance. Moreover, graphene is more likely to be embedded in the pores of the aerogel under pressure conditions, forming mechanical interlocks, with a more firm load and preventing detachment during subsequent operations.

[0015] Optionally, the specific operation of step S2 is as follows: Mix vinyltrimethoxysilane and 3-aminopropyltriethoxysilane in a mass ratio of 1:(0.6 - 0.8) to obtain a silane modifier. Then dissolve the silane modifier in an ethanol solution with a mass concentration of 50 - 60%, and adjust the pH value to 4 - 5.5. Obtain a modified solution. Then add the graphene-porous carrier composite material prepared in step S1 into the modified solution, stir and react at 60 - 80°C for 40 - 60 min, filter, wash, and dry to obtain a modified graphene composite material, and the addition amount of vinyltrimethoxysilane is 5 - 10 wt% of the graphene-porous carrier composite material.

[0016] By adopting the above technical solution, in this application, after the prepared graphene-porous carrier composite material is modified with vinyltrimethoxysilane and 3-aminopropyltriethoxysilane, vinyl and amino groups are introduced. The introduction of vinyl groups participates in the copolymerization with styrene and acrylate monomers in step S3 as active groups, realizing in-situ copolymerization, thereby improving the interfacial bonding strength between the composite material and polyester filaments, and further improving the mechanical properties of the final polyester filaments.

[0017] Optionally, the specific operation in step S3 is as follows: Mix the modified graphene composite material, styrene monomer, and acrylate monomer in a mass ratio of 1:(3 - 4):(1 - 2), then heat up to 70 - 80°C, add benzoyl peroxide, stir and react for 2 - 3 h, and then cool, wash, and dry to obtain modified graphene, where the addition amount of benzoyl peroxide is 0.5 - 2 wt% of the modified graphene composite material.

[0018] Optionally, the acrylate monomer is selected from one or more of methyl acrylate and ethyl acrylate.

[0019] Optionally, the added mass ratio of the modified graphene to the polyester chips in step S4 is (5-10):(90-95).

[0020] Optionally, when mixing the modified graphene and the polyester chips in step S4, cellulose acetate is further added, and the added mass ratio of the cellulose acetate to the modified graphene is 1:(2-3).

[0021] By adopting the above technical solution, cellulose acetate is further added to the raw materials in the present application. The cellulose acetate molecules are adsorbed on the surface of the modified graphene, and the agglomeration of graphene is prevented through steric hindrance to form a stable dispersion system. Moreover, the acetyl groups and hydroxyl groups of cellulose acetate can form hydrogen bonds with the oxygen-containing functional groups on the surface of the carrier in the modified graphene, further enhancing the dispersion stability. Moreover, it can reduce the surface tension of the molten system and promote the uniform dispersion of the modified graphene in the polyester matrix. Moreover, the hydroxyl groups of cellulose acetate can also undergo transesterification reactions with the terminal carboxyl groups and terminal hydroxyl groups of the polyester to form covalent bonds, while the acetyl groups form hydrogen bonds with the oxygen-containing functional groups on the surface of the modified graphene, thereby forming a bridge between the modified graphene and the polyester, improving the interfacial bonding strength between the two, and ultimately playing a better reinforcing role.

[0022] In a second aspect, the present application provides a method for preparing a graphene-reinforced polyester filament, adopting the following technical solution: A graphene-reinforced polyester filament is prepared by the preparation method.

[0023] By adopting the above technical solution, the polyester filament prepared by the method provided by the present application has better mechanical properties.

[0024] In summary, the present application has the following beneficial effects: 1. In this application, graphene is loaded onto silica aerogel and then modified. On the one hand, by utilizing the three-dimensional network porous structure of silica aerogel with a higher porosity, the graphene sheets enter the pores of the aerogel and are supported and separated by the pore walls, effectively preventing the mutual stacking and aggregation of graphene sheets, which helps to improve the uniform dispersion of graphene in polyester chips. On the other hand, the porous structure of silica aerogel and polyester can form an anchoring effect through physical adsorption. Compared with directly adding and dispersing graphene, the interfacial binding force and compatibility between silica aerogel and polyester are better. Moreover, the two-dimensional sheet structure of graphene is prone to agglomeration in the polyester matrix, resulting in interfacial defects. In this application, loading graphene onto silica aerogel and then adding it not only helps to improve its dispersibility but also helps to improve the interfacial compatibility between the two, ultimately enhancing the performance better. 2. In this application, after loading graphene onto silica aerogel, it is first modified with vinyltrimethoxysilane and 3-aminopropyltriethoxysilane. The methoxy or ethoxy groups in the above silane coupling agents form bonds with the porous carrier, thereby introducing amino and double bond functional groups into the composite material. Then, it is polymerized with styrene monomer and acrylate monomer to achieve in-situ polymerization on the composite material. The double bond functional groups copolymerize with styrene and acrylate monomers to form a styrene-acrylate copolymer, and a core-shell structure with the composite material as the core and the polymer as the shell is formed, further improving the dispersibility of graphene in the polymer matrix and enhancing the interaction between graphene and the polymer. The styrene-acrylate copolymer formed by in-situ polymerization on the surface of the composite material can provide certain rigidity and strength in the styrene part, which matches the mechanical properties of polyester filaments, while the acrylate part can entangle or chemically bond with the polyester molecular chains to form a good interfacial layer, effectively transmitting stress and improving the interfacial compatibility between graphene and polyester filaments. Ultimately, it significantly improves the dispersion of graphene in polyester and the interfacial compatibility between graphene and polyester fibers, thereby enhancing the mechanical properties of polyester filaments. 3. In this application, the loading method of graphene is achieved by loading graphene oxide onto silica aerogel and then reducing it. By utilizing the water solubility of graphene oxide, a stable dispersion can be formed in an aqueous solution, and it can uniformly penetrate into the pores of silica aerogel through the impregnation method, avoiding the agglomeration problem caused by the van der Waals force between the sheets when directly using graphene, improving the uniform loading of graphene, and further better improving the dispersion of the composite material in polyester and the interfacial compatibility. Moreover, after graphene oxide is reduced, a small amount of carboxyl and hydroxyl functional groups are retained, which can form chemical bonds with polyester molecules through the silane coupling agent in step S2, further enhancing the interaction between the composite material and polyester, and ultimately playing a better reinforcing role. Specific embodiments

[0025] The present application will be further described in detail below in conjunction with embodiments. It should be specifically noted that: for those conditions not specified in the following embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments can be obtained from ordinary commercial sources.

[0026] In the following embodiments, the silica aerogel is the silica aerogel powder of Langmiao Environmental Protection Technology (Tianjin) Co., Ltd.

[0027] Example 1 A preparation method of graphene-reinforced polyester filaments includes the following steps: S1. Using silica aerogel as a porous carrier to load graphene. The specific operation is as follows: Dissolve graphene oxide in water and disperse it by ultrasonic to obtain a graphene oxide dispersion. The added mass ratio of graphene oxide to water is 1:3.5; Then mix the graphene oxide dispersion with silica aerogel, carry out impregnation treatment for 1.5 h and then drying treatment to obtain silica aerogel loaded with graphene oxide. The added mass ratio of graphene oxide to silica aerogel is 1:1; Then add the silica aerogel loaded with graphene oxide to an ascorbic acid solution with a mass concentration of 15%, and the added amount of the ascorbic acid solution is 2 mass times that of graphene oxide. Then carry out pre-reduction at normal pressure and 65 °C for 50 min, then raise the temperature to 75 °C and increase the pressure to 0.2 MPa for continued reduction treatment for 90 min. Then filter, wash and dry to achieve the loading of graphene by silica aerogel, and obtain a graphene-porous carrier composite material; S2. Mix vinyltrimethoxysilane and 3-aminopropyltriethoxysilane according to a mass ratio of 1:0.7 to obtain a silane modifier. Then dissolve the silane modifier in an ethanol solution with a mass concentration of 55% and adjust the pH value to 5 to obtain a modified solution. Then add the graphene-porous carrier composite material prepared in step S1 to the modified solution, stir and react at 70 °C for 50 min, filter, wash and dry to obtain a modified graphene composite material, and the added amount of vinyltrimethoxysilane is 8 wt% of the graphene-porous carrier composite material; S3. Mix the modified graphene composite material, styrene monomer, and acrylate monomer according to a mass ratio of 1:3.5:1.5, then raise the temperature to 75 °C, add benzoyl peroxide, stir and react for 2.5 h, then cool, wash and dry to obtain modified graphene, where the added amount of benzoyl peroxide is 1 wt% of the modified graphene composite material, and the acrylate monomer is methyl acrylate; S4. Based on 1 kg of polyester chips, mix the prepared modified graphene with the polyester chips according to a mass ratio of 5:95 and then carry out melt spinning to obtain graphene-reinforced polyester filaments.

[0028] Example 2 A preparation method of graphene-reinforced polyester filaments, comprising the following steps: S1. Using silica aerogel as a porous carrier loaded with graphene, the specific operation is as follows: Dissolve graphene oxide in water and then ultrasonically disperse it to obtain a graphene oxide dispersion liquid, and the added mass ratio of graphene oxide to water is 1:3; Then mix the graphene oxide dispersion liquid with silica aerogel, impregnate for 1 h and then dry to obtain silica aerogel loaded with graphene oxide, and the added mass ratio of graphene oxide to silica aerogel is 1:0.8; Then add the silica aerogel loaded with graphene oxide to an ascorbic acid solution with a mass concentration of 10%, and the added amount of the ascorbic acid solution is 2 mass times that of graphene oxide. Then pre-reduce at normal pressure and 60 °C for 60 min, then raise the temperature to 70 °C and pressurize to 0.3 MPa for continued reduction treatment for 80 min, and then filter, wash and dry to achieve the loading of graphene by silica aerogel, and obtain a graphene-porous carrier composite material; S2. Mix vinyltrimethoxysilane and 3-aminopropyltriethoxysilane according to a mass ratio of 1:0.6 to obtain a silane modifier, then dissolve the silane modifier in an ethanol solution with a mass concentration of 50%, adjust the pH value to 4 to obtain a modified liquid, and then add the graphene-porous carrier composite material prepared in step S1 to the modified liquid, stir and react at 60 °C for 60 min, filter, wash and dry to obtain a modified graphene composite material, and the added amount of vinyltrimethoxysilane is 5 wt% of the graphene-porous carrier composite material; S3. Mix the modified graphene composite material, styrene monomer, and acrylate monomer according to a mass ratio of 1:3:1, then raise the temperature to 70 °C, add benzoyl peroxide, stir and react for 3 h, and then cool, wash and dry to obtain modified graphene, wherein the added amount of benzoyl peroxide is 0.5 wt% of the modified graphene composite material, and the acrylate monomer is methyl acrylate; S4. Based on 1 kg of polyester chips, mix the prepared modified graphene with the polyester chips according to a mass ratio of 5:95 and then melt-spin to obtain graphene-reinforced polyester filaments.

[0029] Example 3 A preparation method of graphene-reinforced polyester filaments, comprising the following steps: S1. Using silica aerogel as a porous carrier loaded with graphene, the specific operation is as follows: Dissolve graphene oxide in water and then ultrasonically disperse it to obtain a graphene oxide dispersion liquid, and the added mass ratio of graphene oxide to water is 1:4; Then, the graphene oxide dispersion was mixed with silica aerogel. After impregnation treatment for 2 h, it was dried to obtain silica aerogel loaded with graphene oxide, and the added mass ratio of graphene oxide to silica aerogel was 1:1.2; Then, the silica aerogel loaded with graphene oxide was added to an ascorbic acid solution with a mass concentration of 20%, and the added amount of the ascorbic acid solution was 3 mass times that of graphene oxide. Then, it was pre-reduced at normal pressure and 65 °C for 40 min, and then the temperature was raised to 80 °C and the pressure was increased to 0.3 MPa for continued reduction treatment for 80 min. Then, it was filtered, washed, and dried to achieve the loading of graphene by silica aerogel, and a graphene-porous support composite material was prepared; S2: A silane modifier was prepared by mixing vinyltrimethoxysilane and 3-aminopropyltriethoxysilane at a mass ratio of 1:0.8. Then, the silane modifier was dissolved in an ethanol solution with a mass concentration of 60%, and the pH value was adjusted to 5.5 to obtain a modified solution. Then, the graphene-porous support composite material prepared in step S1 was added to the modified solution, and stirred and reacted at 80 °C for 40 min. After filtration, washing, and drying, a modified graphene composite material was prepared, and the added amount of vinyltrimethoxysilane was 10 wt% of the graphene-porous support composite material; S3: The modified graphene composite material, styrene monomer, and acrylate monomer were mixed at a mass ratio of 1:4:2. Then, the temperature was raised to 80 °C, benzoyl peroxide was added, and stirred and reacted for 2 h. Then, it was cooled, washed, and dried to obtain modified graphene, where the added amount of benzoyl peroxide was 2 wt% of the modified graphene composite material, and the acrylate monomer was methyl acrylate; S4: Based on 1 kg of polyester chips, the prepared modified graphene and polyester chips were mixed at a mass ratio of 10:90 and then melt-spun to obtain graphene-reinforced polyester filaments.

[0030] Example 4 A method for preparing graphene-reinforced polyester filaments was carried out according to the method in Example 1, except that when the modified graphene was mixed with polyester chips in step S4, cellulose acetate was also added, and the added mass ratio of cellulose acetate to modified graphene was 1:2.

[0031] Example 5 A method for preparing graphene-reinforced polyester filaments was carried out according to the method in Example 1, except that when the modified graphene was mixed with polyester chips in step S4, cellulose acetate was also added, and the added mass ratio of cellulose acetate to modified graphene was 1:3.

[0032] Example 6 A preparation method of graphene-reinforced polyester filaments is carried out according to the method in Example 1. The difference is that after adding silica aerogel loaded with graphene oxide to the ascorbic acid solution in step S1, it is directly heated and reduced at 70 °C for 140 min, and then filtered, washed and dried to achieve the loading of graphene, and a graphene-porous carrier composite material is prepared.

[0033] Example 7 A preparation method of graphene-reinforced polyester filaments is carried out according to the method in Example 1. The difference is that the specific operation of preparing the graphene-porous carrier composite material in step S1 is as follows: Graphene is directly dispersed in water, and after ultrasonic treatment for 15 min, a graphene suspension is prepared, wherein the added mass ratio of graphene to water is 1:3; Then silica aerogel is added to the graphene suspension, and the added mass ratio of graphene to silica aerogel is 1:1. After ultrasonic dispersion for 40 min, it is filtered and dried to obtain a graphene-porous carrier composite material.

[0034] Comparative Example 1 A preparation method of graphene-reinforced polyester filaments is carried out according to the method in Example 1. The difference is that the operations in steps S1-S3 are not carried out, and the modified graphene in step S4 is replaced with graphene in equal amount.

[0035] Comparative Example 2 A preparation method of graphene-reinforced polyester filaments is carried out according to the method in Example 1. The difference is that the operation in step S1 is not carried out, and the graphene-porous carrier composite material in step S2 is replaced with graphene in equal amount.

[0036] Comparative Example 3 A preparation method of graphene-reinforced polyester filaments is carried out according to the method in Example 1. The difference is that the operations in steps S1-S3 are not carried out, and the modified graphene in step S4 is replaced with silica aerogel, graphene and styrene-acrylate copolymer, and the added mass ratio of graphene to silica aerogel is 1:1, while the added mass ratio of graphene to styrene-acrylate copolymer is 1:0.5.

[0037] Comparative Example 4 A preparation method of graphene-reinforced polyester filaments is carried out according to the method in Example 1. The difference is that the operation in step S3 is not carried out, and step S4 is directly carried out.

[0038] Comparative Example 5 A preparation method of graphene-reinforced polyester filaments is carried out according to the method in Example 1, except that the operation of step S1 is not carried out, and the graphene-porous support composite material in step S2 is replaced with an equal amount of a mixture of graphene and silicon dioxide, and the added mass ratio of graphene to silicon dioxide is 1:1.

[0039] Comparative Example 6 A preparation method of graphene-reinforced polyester filaments is carried out according to the method in Example 1, except that the operation of step S2 is not carried out, and step S3 is directly carried out.

[0040] Performance detection The tensile strength and elongation at break of the polyester filaments prepared in the examples and comparative examples of this application are detected, and the detection results are shown in Table 1 below.

[0041] Table 1: Referring to the detection results in Table 1 above, it can be seen that the polyester filaments prepared in the examples of this application have excellent mechanical properties. The method provided in this application realizes the uniform dispersion of graphene in the polyester filament matrix, forms a strong interfacial bond, and the prepared polyester filaments have higher tensile strength mechanical properties. The enhanced polyester filaments are more resistant to pulling and are not easily broken, and can be used to manufacture high-strength industrial fabrics, high-performance sportswear, etc., expanding the application range of polyester filaments. Combining the detection results of Example 1 with those of Example 4 and Example 5, the addition of cellulose acetate helps to improve the interfacial bond between the composite material and the polyester chips, further enhancing the mechanical properties of the polyester filaments. Combining the detection results of Example 6, when the graphene oxide loaded in the silica aerogel is directly reduced in one stage during reduction, compared with the staged reduction system in Example 1, the performance of the polyester filaments prepared in Example 1 is better. The reduction system in Example 1 is more thorough for the reduction of graphene oxide and helps to reduce defects, further improving the mechanical properties of the polyester filaments. Combining the detection results of Example 7, when graphene is directly loaded on the silica aerogel in step S1 of Example 7, the mechanical properties are significantly reduced compared with Example 1. In Example 1, the water solubility of graphene oxide and the remaining reducing functional groups after reduction are more helpful for the uniform dispersion of graphene and the improvement of interfacial bond, thus having better mechanical properties.

[0042] Referring to the test results of Example 1 and Comparative Example 1 again, when graphene and polyester chips were directly mixed and melt-spun in Comparative Example 1, the uneven dispersion of graphene and the weak interfacial bonding with the polyester matrix led to a decrease in its mechanical properties. Combining with the test results of Comparative Example 2, when the modified graphene was added, its mechanical properties were also reduced compared with those in Example 1. When the graphene was loaded on silica aerogel and then modified and added, its mechanical properties were significantly improved. Combining with the test results of Comparative Example 3, when graphene, silica aerogel and styrene-acrylate copolymer were directly mixed and added, its mechanical properties were also significantly reduced compared with those in Example 1. Combining with the test results of Comparative Example 4, when the graphene was loaded on silica aerogel and modified with a silane coupling agent but no styrene-maleic anhydride copolymer was formed, its mechanical properties were also reduced. The mechanical properties can be further improved when the styrene-maleic anhydride copolymer is in-situ polymerized on the surface of the composite material. Combining with the test results of Comparative Example 5, when the graphene was directly mixed with silica and then modified and added without undergoing the treatment in step S1, its mechanical properties were weaker than those in Example 1. Combining with the test results of Comparative Example 6, in Comparative Example 6, the operation of step S3 was directly carried out without modification with a silane coupling agent, lacking the unsaturated double bonds in the composite material as in-situ active sites, resulting in a reduction in the modification effect and mechanical properties.

[0043] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing graphene-enhanced polyester yarn, characterized in that: The following steps are involved: S1, using silica aerogel as a porous carrier to load graphene to prepare a graphene-porous carrier composite material; S2, modifying the graphene-porous carrier composite material with vinyltrimethoxysilane and 3-aminopropyltriethoxysilane to obtain a modified graphene composite material; S3, polymerizing the modified graphene composite material, styrene monomer, acrylate monomer and initiator at 70-80° C. to obtain modified graphene; S4. The prepared modified graphene is mixed with polyester chips and melt-spinned to prepare graphene-reinforced polyester yarns.

2. The method for preparing a graphene-enhanced polyester yarn according to claim 1, characterized in that: The specific operations in step S1 are: The graphene oxide is dissolved in water and then ultrasonically dispersed to obtain a graphene oxide dispersion; the graphene oxide dispersion is then mixed with the silica aerogel, and the mixture is immersed for 1-2 hours and then dried to obtain the silica aerogel loaded with graphene oxide; Then, the silica aerogel loaded with graphene oxide is added to the ascorbic acid solution, reacted at 60-80° C. for 2-3 hours, filtered, washed, and dried to load the silica aerogel with graphene, thereby obtaining a graphene-porous carrier composite material.

3. The method for preparing a graphene-enhanced polyester yarn according to claim 2, characterized in that: In step S1, the mass ratio of graphene oxide to water is 1:(3-4), the mass ratio of graphene oxide to silica aerogel is 1:(0.8-1.2), the mass concentration of ascorbic acid in the ascorbic acid solution is 10-20%, and the amount of ascorbic acid solution added is 2-3 times the mass of graphene oxide.

4. The method for preparing a graphene-enhanced polyester yarn according to claim 2, characterized in that: When the silica aerogel loaded with graphene oxide is added to the ascorbic acid solution for reduction treatment in step S1, it is first pre-reduced at normal pressure and 60-65° C. for 40-60 minutes, and then the temperature is raised to 70-80° C. and the pressure is increased to 0.2-0.3 MPa to continue the reduction treatment.

5. The method for preparing a graphene-enhanced polyester yarn according to claim 1, characterized in that: The specific operations of step S2 are: Vinyltrimethoxysilane and 3-aminopropyltriethoxysilane are mixed in a mass ratio of 1: (0.6-0.8) to obtain a silane modifier, and then the silane modifier is dissolved in an ethanol solution with a mass concentration of 50-60%, and the pH value is adjusted to 4-5.5 to obtain a modified liquid, and then the graphene-porous carrier composite material prepared in step S1 is added to the modified liquid, and the reaction is stirred at 60-80° C. for 40-60 minutes. After filtering, washing and drying, a modified graphene composite material is obtained, and the amount of vinyltrimethoxysilane added is 5-10wt% of the graphene-porous carrier composite material.

6. The method for preparing a graphene-enhanced polyester yarn according to claim 1, characterized in that: The specific operations in step S3 are: The modified graphene composite material, styrene monomer and acrylate monomer are mixed in a mass ratio of 1: (3-4): (1-2), then the temperature is raised to 70-80°C, benzoyl peroxide is added, the mixture is stirred for reaction for 2-3 hours, and then the mixture is cooled, washed and dried to obtain the modified graphene, wherein the amount of benzoyl peroxide added is 0.5-2wt% of the modified graphene composite material.

7. The method for preparing graphene-enhanced polyester yarn according to claim 1, characterized in that: The acrylic acid ester monomer is selected from one or more of methyl acrylate and ethyl acrylate.

8. The method for preparing graphene-enhanced polyester yarn according to claim 1, characterized in that: In step S4, the added mass ratio of modified graphene to polyester chips is (5-10): (90-95).

9. The method for preparing graphene-enhanced polyester yarn according to claim 1, characterized in that: When the modified graphene is mixed with the polyester chips in step S4, cellulose acetate is also added, and the mass ratio of cellulose acetate to modified graphene is 1:(2-3).

10. A graphene-enhanced polyester yarn prepared by the preparation method according to any one of claims 1 to 9.

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