A kind of multifunctional polyester fiber based on modified graphene and preparation method thereof

Abstract

The present invention relates to a multifunctional polyester fiber based on modified graphene and a preparation method thereof, and belongs to the technical field of functional fibers. The preparation method comprises the following steps: dissolving dopamine hydrochloride, benzaldehyde compounds and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in an alcohol solution to obtain a modified solution; under alkaline conditions and the action of a catalyst, graphene is polymerized in the modified solution to obtain modified graphene; granulating the modified graphene and polyester powder to obtain a multifunctional polyester masterbatch; spinning the multifunctional polyester masterbatch and polyester slices to obtain a multifunctional polyester fiber based on modified graphene, wherein the far-infrared normal emissivity is 0.90-0.93, the far-infrared radiation temperature rise is 2.6°C-3.3°C, the breaking strength is 3.1cN / detx-3.3cN / detx, the limiting oxygen index is 28.5%-29.1%, and the antibacterial property is higher than 99.9%.

Description

Technical Field

[0001] The invention belongs to the technical field of functional fibers, and in particular relates to a multifunctional polyester fiber based on modified graphene and a preparation method thereof. Background Art

[0002] Polyester fiber is the most widely used chemical synthetic fiber. Polyester fiber has excellent characteristics such as softness, economical and good resilience. It is widely used in furniture, car seats, mats, bedding, toys and other fields. With the rapid improvement of living standards, people have higher and higher requirements for safety, environmental protection and health care. Multifunctional polyester fiber with far infrared, flame retardant and antibacterial properties is in line with the development direction of differentiated polyester fiber. At present, nano-ceramic powder, graphene and other materials are often used as functional additives to prepare multifunctional polyester fiber. However, nano-powder has high surface energy and poor compatibility with polyester. It is easy to agglomerate in polyester fiber, resulting in spinning difficulties and even damage to spinning equipment. In addition, polyester fiber is extremely flammable, and the melting drop phenomenon is serious during the combustion process, which is extremely dangerous. Graphene is the king of emerging materials. It is peeled off from carbon materials and is composed of carbon atoms. It is a two-dimensional crystal with only one or more layers of atomic thickness. It has very superior optical, electromagnetic, mechanical and other physical properties and properties, which has attracted the attention of R&D personnel.

[0003] Chinese invention patent CN106222789A discloses a method for manufacturing biomass graphene flame-retardant polyester fiber, firstly, a dispersant is mixed with biomass graphene to obtain a biomass graphene dispersion, and then the biomass graphene dispersion, diethyl aluminum hypophosphite, diethyl magnesium hypophosphite, aluminum hydrogen phosphite and other flame retardants are added to polyester through polymerization reaction to prepare biomass graphene flame-retardant polyester slices and polyester fibers. However, the polymerization process is complicated and difficult to control, and has high requirements for equipment, etc. The preparation of multifunctional polyester fibers by melt blending and addition technology has wide applicability and is more friendly to polyester production enterprises; and the amount of flame retardant added by the polymerization process is small, and the flame retardant performance is difficult to meet high requirements.

[0004] Chinese invention patent CN104630928A discloses a method for preparing graphene-reinforced flame-retardant recycled polyester staple fibers, wherein graphene is first sulfonated to prepare graphene masterbatch, and then a reactive phosphorus-based flame retardant is mixed with polyester to prepare a phosphorus-based halogen-free flame-retardant masterbatch, and then the graphene masterbatch and the phosphorus-based halogen-free flame-retardant masterbatch are used to prepare the reinforced flame-retardant recycled polyester fiber by melt blending technology. However, the introduction of anionic sulfonic acid groups cannot improve the dispersion and compatibility of graphene in polyester fibers, and the flame retardants used are N-hydroxymethylpropionamide methyl phosphonate, dimethyl methyl phosphate and other flame retardants, which have poor thermal stability and are easily decomposed during the melt blending process, thereby affecting the dispersion and compatibility of the flame retardant in the polyester fiber.

[0005] Based on the above background, it is still necessary to develop multifunctional polyester fibers based on modified graphene. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a multifunctional polyester fiber based on modified graphene and a preparation method thereof. Firstly, dopamine hydrochloride, benzaldehyde compounds and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) are used to modify graphene by in-situ polymerization deposition to obtain modified polydopamine-coated graphene, i.e., modified graphene; then, the modified graphene is used to prepare a multifunctional polyester fiber based on the modified graphene by melt blending.

[0007] The first object of the present invention is to provide a method for preparing a multifunctional polyester fiber based on modified graphene, comprising the following steps:

[0008] S1. dissolving dopamine hydrochloride, a benzaldehyde compound and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in an alcohol solution to obtain a modified solution; the benzaldehyde compound is selected from terephthalaldehyde and / or isophthalaldehyde;

[0009] S2. Under alkaline conditions and the action of a catalyst, the graphene is polymerized in the modified solution described in S1 to obtain modified graphene;

[0010] S3, granulating the modified graphene and polyester powder described in S2 to obtain a multifunctional polyester masterbatch;

[0011] S4. Spinning the multifunctional polyester masterbatch and polyester chips described in S3 to obtain the multifunctional polyester fiber based on modified graphene.

[0012] In one embodiment of the present invention, in S1, the mass ratio of dopamine hydrochloride to benzaldehyde compounds is 3:(1-2); the molar ratio of benzaldehyde compounds to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:(2-2.2); modified polydopamine is used to coat graphene, so that the surface of graphene is rich in organic aromatic compounds, thereby improving its compatibility with polyester fibers and its dispersibility in polyester fibers. The aldehyde group of the benzaldehyde compound, the PH bond of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and the amino group of dopamine hydrochloride or polydopamine can undergo a Kabachnik–Fields reaction, thereby grafting the benzaldehyde compound and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide onto polydopamine through covalent bonds.

[0013] In one embodiment of the present invention, in S2, the mass ratio of graphene to dopamine hydrochloride is (3-4):1; the molar ratio of the catalyst to dopamine hydrochloride is 1:(1-2).

[0014] In one embodiment of the present invention, in S2, the catalyst is hydrogen peroxide; the pH of the alkaline condition is 8.5-9.5; the alkaline condition and the catalyst help promote the polymerization of dopamine, thereby improving the coating effect on the graphene surface.

[0015] In one embodiment of the present invention, in S2, the polymerization reaction temperature is 60°C-70°C, and the time is 3h-5h; dopamine hydrochloride is polymerized in the presence of a catalyst to generate polydopamine, benzaldehyde compounds and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide can be co-polymerized with polydopamine, and a Kabachnik–Fields reaction can occur between the three, and benzaldehyde compounds and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are interspersed in the polydopamine to generate modified polydopamine. On the one hand, the catechol structure in dopamine hydrochloride is easily oxidized and polymerized under the action of a catalyst to generate polydopamine, which has high adhesion and can produce good grafting on graphene; on the other hand, the aldehyde group of the benzaldehyde compound can react with the amino group of polydopamine to produce a Schiff base reaction, and the aldehyde group of the benzaldehyde compound and the PH bond of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide can react with the amino group of polydopamine to produce a Kabachnik–Fields reaction, and the phosphorus-containing structure of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, the aromatic structure and the Schiff base structure of the benzaldehyde compound are introduced into the polydopamine molecular chain to improve the antibacterial properties, thermal stability and flame retardant properties of the modified polydopamine-coated graphene and its compatibility with polyester fibers.

[0016] In one embodiment of the present invention, in S2, after the reaction is completed, the steps of centrifugation, washing and drying are further included; the washing is performed by washing with ethanol and distilled water for 1-3 times respectively.

[0017] In one embodiment of the present invention, before S3, the process further includes a step of drying the modified graphene and the polyester powder, wherein the drying temperature of the modified graphene is 70°C-80°C, and the time is 7h-9h; the drying temperature of the polyester powder is 120°C-130°C, and the time is 10h-12h.

[0018] In one embodiment of the present invention, in S3, the granulation is performed by melt blending, extrusion molding, cooling and pelletizing through a twin-screw extruder; the granulation temperature is 255°C-270°C; if the processing temperature is too low, the modified graphene and polyester powder cannot be mixed evenly, which is not conducive to granulation; if the temperature is too high, it will cause energy waste.

[0019] In one embodiment of the present invention, in S3, the mass fraction of modified graphene in the multifunctional polyester masterbatch is 25%-30%.

[0020] In one embodiment of the present invention, before S4, it also includes a step of drying the multifunctional polyester masterbatch and polyester chips, wherein the drying is performed by pre-crystallization at 90°C-100°C for 3h-4h, and then drying at 120°C-135°C for 10h-15h to ensure that the final moisture content of the multifunctional polyester masterbatch and polyester chips is less than 100ppm.

[0021] In one embodiment of the present invention, in S4, the spinning is performed by a melt spinning machine, followed by oiling, pre-stretching, winding, and stretching; the spinning process parameters are: speed of 2600m / min-2800m / min, temperature of 275℃-285℃, and traction ratio of 1.5-2.

[0022] In one embodiment of the present invention, in S4, the mass fraction of the multifunctional polyester masterbatch in the multifunctional polyester fiber based on modified graphene is 15%-20%.

[0023] The second object of the present invention is to provide a multifunctional polyester fiber based on modified graphene prepared by the method described.

[0024] In one embodiment of the present invention, the far-infrared normal emissivity of the modified graphene-based multifunctional polyester fiber is 0.90-0.93, the far-infrared radiation temperature rise is 2.6°C-3.3°C, the breaking strength is 3.1cN / detx-3.3cN / detx, the limiting oxygen index is 28.5%-29.1%, and the antibacterial property is higher than 99.9%.

[0025] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0026] (1) The preparation method of the present invention uses dopamine hydrochloride, benzaldehyde compounds and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to modify graphene by in-situ polymerization deposition. Under alkaline conditions and the action of a catalyst, the catechol structure of dopamine hydrochloride is easily oxidized to undergo a polymerization reaction to generate polydopamine, which has high adhesion and can produce good grafting on graphene. Benzaldehyde compounds and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide can be co-polymerized with polydopamine, and a Kabachnik–Fields reaction can occur between the three. Benzaldehyde compounds and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are interspersed in the polydopamine to generate modified polydopamine. On the one hand, the aldehyde group of benzaldehyde compounds can undergo Schiff base reaction with the amino group of polydopamine; on the other hand, the aldehyde group of benzaldehyde compounds and the PH bond of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide can produce Kabachnik–Fields reaction with the amino group of polydopamine, and the phosphorus-containing structure of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, the aromatic structure and Schiff base structure of benzaldehyde compounds are introduced into the polydopamine molecular chain to improve the antibacterial properties, thermal stability and flame retardant properties of the modified polydopamine-coated graphene and its compatibility with polyester fibers.

[0027] (2) The modified graphene of the present invention is evenly dispersed in the polyester fiber, not only has high functionality, but also has little damage to the strength performance of the polyester fiber. The phosphorus-containing structure of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, the nitrogen-containing structure of polydopamine, and the aromatic structure of polydopamine and benzaldehyde compounds in the modified graphene have a synergistic flame retardant effect and high flame retardant efficiency, so the modified polyester fiber has good flame retardant properties. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.

[0029] In the present invention, unless otherwise defined, technical and scientific terms used in the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention belongs.

[0030] In the present invention, unless otherwise stated, the term "and / or" used in the present invention includes any and all combinations of one or more of the associated listed items.

[0031] In the present invention, unless otherwise stated, the experimental methods used in the embodiments of the present invention are conventional methods unless otherwise stated, and the materials, reagents, etc. used are all commercially available unless otherwise stated.

[0032] In the present invention, unless otherwise specified, the graphene used in the embodiments of the present invention is purchased from Wuxi Graphene Source Technology Co., Ltd.

[0033] In the present invention, unless otherwise specified, the nano bamboo charcoal used in the embodiments of the present invention is purchased from Hunan Chuangchun New Materials Co., Ltd., and the particle size is 100nm-300nm.

[0034] In the present invention, unless otherwise specified, the volume ratio of water to ethanol in the water / ethanol mixed solution used in the embodiments of the present invention is 1.5:1. Example 1

[0035] The multifunctional polyester fiber based on modified graphene and the preparation method thereof of this embodiment specifically include the following steps:

[0036] S1, dissolving dopamine hydrochloride, terephthalaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in a mixed solution of water / ethanol to obtain a modified solution; wherein the mass ratio of dopamine hydrochloride to terephthalaldehyde is 3:1.5, and the molar ratio of terephthalaldehyde to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:2.1;

[0037] S2, adding graphene to the modified liquid, ultrasonically dispersing for 1.5 hours, adjusting the pH to 9 with sodium hydroxide solution, then adding hydrogen peroxide to polymerize at 65° C. for 4 hours, centrifuging, washing with ethanol and distilled water twice in sequence, and drying to obtain modified graphene powder; wherein the mass ratio of graphene to dopamine hydrochloride is 3.5:1, and the molar ratio of hydrogen peroxide to dopamine hydrochloride is 1:1.5;

[0038] S3, the modified graphene powder was vacuum dried at 75°C for 8h; the polyester powder was vacuum dried at 125°C for 11h, and after mixing, melt blending, extrusion molding, cooling and pelletizing were carried out through a twin-screw extruder. The temperature of the twin-screw extruder was 262°C, and a multifunctional polyester masterbatch with a mass fraction of modified graphene powder of 28% was obtained;

[0039] S4, the multifunctional polyester masterbatch and the polyester chips were pre-crystallized in a 95°C blast oven for 3.5 hours, and then continued to be dried at 128°C for 13 hours, so that the final moisture content of the multifunctional polyester masterbatch and the polyester chips was less than 100 ppm. After mixing, they were spun through a melt spinning machine, cooled and oiled, pre-stretched, wound, and stretched. The speed of the melt spinning machine was 2700 m / min, the temperature was 280°C, and the traction ratio was 1.8, to obtain a multifunctional polyester fiber based on modified graphene with a mass fraction of 18% of the multifunctional polyester masterbatch. Example 2

[0040] The multifunctional polyester fiber based on modified graphene and the preparation method thereof of this embodiment specifically include the following steps:

[0041] S1, dissolving dopamine hydrochloride, terephthalaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in a mixed solution of water / ethanol to obtain a modified solution; wherein the mass ratio of dopamine hydrochloride to terephthalaldehyde is 3:1, and the molar ratio of terephthalaldehyde to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:2;

[0042] S2, adding graphene to the modified liquid, ultrasonically dispersing for 1 hour, adjusting the pH to 8.5 with sodium hydroxide solution, then adding hydrogen peroxide to polymerize at 60° C. for 5 hours, centrifuging, washing with ethanol and distilled water twice in sequence, and drying to obtain modified graphene powder; wherein the mass ratio of graphene to dopamine hydrochloride is 3:1, and the molar ratio of hydrogen peroxide to dopamine hydrochloride is 1:1;

[0043] S3, the modified graphene powder was vacuum dried at 70°C for 9h; the polyester powder was vacuum dried at 120°C for 12h, and after mixing, melt blending, extrusion molding, cooling and pelletizing were carried out through a twin-screw extruder, and the temperature of the twin-screw extruder was 255°C to obtain a multifunctional polyester masterbatch with a mass fraction of modified graphene powder of 25%;

[0044] S4, the multifunctional polyester masterbatch and the polyester chips were pre-crystallized in a 90°C blast oven for 4 hours, and then continued to be dried at 120°C for 15 hours, so that the final moisture content of the multifunctional polyester masterbatch and the polyester chips was less than 100 ppm. After mixing, they were spun through a melt spinning machine, cooled and oiled, pre-stretched, wound, and stretched. The speed of the melt spinning machine was 2600 m / min, the temperature was 285°C, and the traction ratio was 1.5, to obtain a multifunctional polyester fiber based on modified graphene with a mass fraction of 15% of the multifunctional polyester masterbatch. Example 3

[0045] The multifunctional polyester fiber based on modified graphene and the preparation method thereof of this embodiment specifically include the following steps:

[0046] S1, dissolving dopamine hydrochloride, terephthalaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in a mixed solution of water / ethanol to obtain a modified solution; wherein the mass ratio of dopamine hydrochloride to terephthalaldehyde is 3:2, and the molar ratio of terephthalaldehyde to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:2.2;

[0047] S2, adding graphene to the modified liquid, ultrasonically dispersing for 2 hours, adjusting the pH to 9.5 with sodium hydroxide solution, then adding hydrogen peroxide to polymerize at 70° C. for 3 hours, centrifuging, washing with ethanol and distilled water twice in sequence, and drying to obtain modified graphene powder; wherein the mass ratio of graphene to dopamine hydrochloride is 4:1, and the molar ratio of hydrogen peroxide to dopamine hydrochloride is 1:2;

[0048] S3, the modified graphene powder is vacuum dried at 80°C for 7h; the polyester powder is vacuum dried at 130°C for 10h, and after mixing, it is melt blended, extruded, cooled and pelletized by a twin-screw extruder, and the temperature of the twin-screw extruder is 270°C to obtain a multifunctional polyester masterbatch with a mass fraction of modified graphene powder of 30%;

[0049] S4, the multifunctional polyester masterbatch and the polyester chips were pre-crystallized in a 100°C blast oven for 3 hours, and then continued to be dried at 135°C for 10 hours, so that the final moisture content of the multifunctional polyester masterbatch and the polyester chips was less than 100 ppm. After mixing, they were spun through a melt spinning machine, cooled and oiled, pre-stretched, wound, and stretched. The speed of the melt spinning machine was 2800 m / min, the temperature was 275°C, and the pulling ratio was 2, so as to obtain a multifunctional polyester fiber based on modified graphene with a mass fraction of 20% of the multifunctional polyester masterbatch. Comparative Example 1

[0050] The method is basically the same as Example 1, except that dopamine hydrochloride is not used to modify the graphene (only terephthalaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are used for modification). Comparative Example 2

[0051] The method is basically the same as Example 1, except that: terephthalaldehyde is not used to modify the graphene (only dopamine hydrochloride and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are used for modification). Comparative Example 3

[0052] The method is basically the same as Example 1, except that: 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is not used to modify the graphene (only dopamine hydrochloride and terephthalaldehyde are used for modification). Comparative Example 4

[0053] The method is basically the same as Example 1, except that graphene is replaced by nano bamboo charcoal. Comparative Example 5

[0054] The method is basically the same as Example 1, except that graphene and polyester powder are directly used for granulation and spinning. Comparative Example 6

[0055] The process is basically the same as Example 1, except that polyester powder is directly used for granulation and spinning (unmodified polyester fiber).

[0056] Test Case

[0057] The far infrared properties of the multifunctional polyester fibers (modified polyester fibers) based on modified graphene and the unmodified polyester fibers prepared in Examples 1-3 and Comparative Examples 1-6 were tested:

[0058] Far infrared performance: Refer to GB / T 30127-2013 "Testing and evaluation of far infrared performance of textiles" to test the far infrared emissivity and heating performance of unmodified polyester fiber and modified polyester fiber;

[0059] Physical properties: Refer to GB / T 14344-2022 "Test method for tensile properties of chemical fiber filaments" to test the breaking strength of unmodified polyester fiber and modified polyester fiber;

[0060] Flame retardant properties: Refer to FZ / T 50017-2011 "Test method for flame retardant properties of polyester fibers - oxygen index method" to test the limiting oxygen index of the fiber;

[0061] Antibacterial performance: Refer to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles Part 3: Oscillation method" to test the antibacterial rate of unmodified polyester fiber and modified polyester fiber;

[0062] Table 1 shows the relevant properties of the unmodified polyester fiber and the modified polyester fiber finally measured:

[0063] Table 1

[0064]

[0065] As can be seen from Table 1, the modified polyester fiber has good far-infrared performance, flame retardant performance, antibacterial performance and strength performance.

[0066] By comparing Example 1 and Comparative Example 1, it can be seen that when dopamine hydrochloride is not used to modify graphene, the far-infrared efficiency, flame retardant properties, antibacterial properties and breaking strength of the modified polyester fiber are reduced. This is because the content of active groups on the surface of graphene is relatively small, and terephthalaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are difficult to form a strong bond with graphene, resulting in poor modification effect and poor dispersion performance of modified graphene in polyester fibers.

[0067] By comparing Example 1 and Comparative Example 2, it can be seen that when terephthalaldehyde is not used to modify graphene, the far-infrared efficiency, flame retardancy, antibacterial properties and breaking strength of the modified polyester fiber are reduced. This is because the modification of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide alone is difficult to combine with polydopamine, resulting in poor dispersion of the modified graphene in the polyester fiber.

[0068] By comparing Example 1 and Comparative Example 3, it can be seen that when 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is not used for modification, the flame retardant properties of the modified polyester fiber are significantly reduced, and its far-infrared properties and mechanical properties are also reduced. This is because 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide modification can improve the thermal stability of the modified graphene and its compatibility with polyester fibers.

[0069] By comparing Example 1 and Comparative Example 4, it can be seen that when the modified nano-bamboo charcoal is used to modify the polyester fiber, the far-infrared performance, antistatic performance and mechanical properties of the modified polyester fiber deteriorate. This is because the far-infrared efficiency, antistatic performance and flame retardant performance of the nano-bamboo charcoal are lower than those of graphene, and its dispersion performance is weaker than that of graphene, resulting in greater damage to the mechanical properties.

[0070] By comparing Example 1 and Comparative Example 5, it can be seen that when graphene is directly mixed with polyester for spinning, the far-infrared emissivity and far-infrared radiation heating performance, flame retardant properties and antibacterial rate of the modified polyester fiber are significantly reduced. This is because graphene has a high surface energy, is easy to agglomerate in polyester fibers, and has poor compatibility, resulting in poor dispersion performance in polyester fibers.

[0071] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for preparing a multifunctional polyester fiber based on modified graphene, characterized in that: The following steps are involved: S1. Dissolving dopamine hydrochloride, benzaldehyde compounds and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in an alcohol solution to obtain a modified solution; the benzaldehyde compounds are selected from terephthalaldehyde and / or isophthalaldehyde; the mass ratio of dopamine hydrochloride to the benzaldehyde compounds is 3:(1-2); the molar ratio of the benzaldehyde compounds to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:(2-2.2); S2. Under alkaline conditions and the action of a catalyst, graphene is polymerized in the modified solution described in S1 to obtain modified graphene; the catalyst is hydrogen peroxide; S3, granulating the modified graphene and polyester powder described in S2 to obtain a multifunctional polyester masterbatch; S4. Spinning the multifunctional polyester masterbatch and polyester chips described in S3 to obtain the multifunctional polyester fiber based on modified graphene.

2. The method for preparing multifunctional polyester fiber based on modified graphene according to claim 1, characterized in that: In S2, the mass ratio of graphene to dopamine hydrochloride is (3-4):1; the molar ratio of the catalyst to dopamine hydrochloride is 1:(1-2).

3. The method for preparing the multifunctional polyester fiber based on modified graphene according to claim 1, characterized in that: In S2, the pH of the alkaline condition is 8.5-9.

5.

4. The method for preparing multifunctional polyester fiber based on modified graphene according to claim 1, characterized in that: In S2, the polymerization reaction temperature is 60°C-70°C, and the time is 3h-5h.

5. The method for preparing multifunctional polyester fiber based on modified graphene according to claim 1, characterized in that: In S3, the granulation is performed by melt blending, extrusion molding, cooling and pelletizing through a twin-screw extruder; the granulation temperature is 255°C-270°C.

6. The method for preparing multifunctional polyester fiber based on modified graphene according to claim 1, characterized in that: In S3, the mass fraction of modified graphene in the multifunctional polyester masterbatch is 25%-30%.

7. The method for preparing multifunctional polyester fiber based on modified graphene according to claim 1, characterized in that: In S4, the spinning is carried out by a melt spinning machine, followed by oiling after cooling, pre-stretching, winding, and stretching; the spinning process parameters are: speed of 2600m / min-2800m / min, temperature of 275℃-285℃, and traction ratio of 1.5-2.

8. The method for preparing multifunctional polyester fiber based on modified graphene according to claim 1, characterized in that: In S4, the mass fraction of the multifunctional polyester masterbatch in the multifunctional polyester fiber based on modified graphene is 15%-20%.

9. A multifunctional polyester fiber based on modified graphene prepared by the method according to any one of claims 1 to 8.

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