A light-absorbing and heat-generating regenerated polyester fiber material and preparation method thereof

Abstract

The present invention discloses a light-absorbing, heat-generating regenerated polyester fiber material and a preparation method thereof, comprising the following steps: S1. Recycled plastic bottles are crushed into small pieces, depolymerized using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, the dimethyl terephthalate is subjected to an ester exchange reaction with methanol, and then polymerized to produce fiber-grade regenerated PET chips; S2. A mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol is used as a precursor solution, and a hybrid hierarchical porous material is prepared by freeze-drying technology. The organic matter is then removed by high-temperature calcination to ultimately obtain hierarchical porous γ-alumina; S3. Graphene is uniformly dispersed into the pores of the porous γ-alumina by ultrasonic dispersion or high-shear stirring, and the graphene-doped porous γ-alumina composite material is then heat-treated. This solution utilizes recycled plastic bottles for reuse, and the addition of light-absorbing, heat-generating particles to improve the fiber enables the preparation of a material with thermal insulation properties.

Description

Technical Field

[0001] The present invention relates to the field of fiber technology, and in particular to a light-absorbing and heat-generating regenerated polyester fiber material and a preparation method thereof. Background Art

[0002] At present, a large amount of waste textiles cannot be recycled, which brings huge pressure to the environment. Since the waste textile utilization industry chain is still incomplete, the overall recycling efficiency is low. Therefore, it is an important development direction to build a waste textile recycling system and improve the resource utilization and high-value utilization of waste textiles. At present, chemical method is the main method for recycling waste cotton and polyester textiles, but there are still problems such as low recycling rate and poor product quality.

[0003] Progress has been made in the performance research and product development of light-absorbing, heat-generating, far-infrared polyester interwoven fabrics. For example, the 3.33dtex light-absorbing, heat-generating hollow fiber produced on Toyobo's indirect spinning line meets product requirements by adjusting melt delivery and heat medium temperatures, reducing initial component pressure, and rationally adjusting the post-draft ratio. This light-absorbing, heat-generating, far-infrared polyester interwoven fabric exhibits significantly enhanced warming and insulation properties under sunlight and far-infrared light, making it suitable for use in clothing and textiles requiring additional warmth and health benefits. With technological advancements and increasing market demand, further development of light-absorbing, heat-generating polyester fiber materials is needed.

[0004] Chinese patent application number 201910951301.5, the name of the invention patent is a modified polyester fiber and a preparation method. The application discloses a modified polyester fiber and a preparation method. The coating includes two components. The modified polyester fiber includes: the modified polyester fiber includes functional particles with a core-shell structure, wherein the core of the functional particles is a light-absorbing and heat-generating particle, and the shell of the functional particles is a light-transmitting layer. Since the functional particles include functional particles with a core-shell structure, and the core of the functional particles is a light-absorbing and heat-generating particle and the shell is a light-transmitting layer, when the fabric made of the modified polyester fiber is irradiated with light, the light can pass through the light-transmitting layer, and the light-absorbing and heat-generating particles absorb the light and convert it into heat, thereby providing a warming effect. However, the functional particles with a core-shell structure prepared by this invention do not have the function of conducting heat to the inside of the shell to store heat.

[0005] Therefore, in view of this, the inventors have conducted research and improvements on the existing technology and its shortcomings, and provide a light-absorbing and heat-generating regenerated polyester fiber material and a preparation method thereof, in order to achieve a more practical purpose. Summary of the Invention

[0006] In order to solve the problems mentioned in the above background technology, the present invention provides a light-absorbing and heat-generating regenerated polyester fiber material and a preparation method thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0009] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0010] S2. Using a mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol as a precursor solution, a hybrid hierarchical porous material is prepared by freeze-drying technology, and then calcined at high temperature to remove organic matter, ultimately obtaining a hierarchical porous γ-alumina;

[0011] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the hierarchical porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0012] S4. Add a modifier to a urea-formaldehyde resin precursor solution, heat and stir for 30-45 minutes, then add a certain mass fraction of a graphene-doped porous γ-alumina composite material, and use a mechanical stirrer to stir the solution at a speed of 300 to 2000 rpm for 30-60 minutes to obtain a uniformly dispersed precursor mixed solution;

[0013] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, adding an emulsifier and using a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 600-700 rpm for 110min-125min to obtain a micropolymer, wherein the weight ratio of paraffin, emulsifier, and citric acid is, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymer, and washing the micropolymer with deionized water several times, and then drying it at room temperature for use;

[0014] S6. The PET chips are heated to a molten state, and the micropolymers are surface-modified to make the micropolymers compatible with the PET chips to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0015] The graphene-doped porous gamma-alumina composite material of the present invention is used as a heat-conducting material for the fibers and can provide an efficient heat transfer channel, so that heat energy can be transferred to the interior of the micropolymer.

[0016] Preferably, the urea-formaldehyde resin precursor solution is prepared by dissolving urea and a 37% formaldehyde solution in a reactor, and the modifier is melamine.

[0017] Furthermore, the urea-formaldehyde resin precursor solution is prepared by adding triethanolamine to adjust the pH value of the solution.

[0018] As a preferred solution of the present invention, the weight ratio of graphene and hierarchical porous γ-alumina in step S3 is (1-3): (110-180).

[0019] Preferably, the graphene solution in S3 is prepared by the following steps:

[0020] (1) Graphene oxide is obtained by oxidizing graphite by the Hummers method;

[0021] (2) removing the oxygen-containing groups of graphene oxide by chemical reduction to obtain reduced graphene oxide;

[0022] (3) The reduced graphene oxide powder is added to a solvent and subjected to long-term ultrasonic treatment using an ultrasonic processor.

[0023] Preferably, the mass fraction of the graphene-doped porous γ-alumina composite material relative to the micropolymer is 1%-8%.

[0024] Preferably, in step S5, the weight ratio of paraffin wax, emulsifier and citric acid is (20-40): (3-10): (0.3-1.8).

[0025] Preferably, the paraffin is replaced by one or more of nano zirconium carbide, polyethylene glycol, hydrocarbon wax, and carbon nanotubes.

[0026] Preferably, the molten mixture filtered in step S6 is melted by a screw extruder and quantitatively fed into a spinning assembly through a spinning pump, and then extruded from the capillaries of the spinneret to form liquid filaments, which are then cooled and formed, stretched into filaments at high speed by a winding device, and then heat-set to obtain fibers.

[0027] Preferably, the fiber-grade recycled PET chips in step S6 are melt-blended with titanium dioxide and then combined with the micropolymer.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention adopts the porous structure of hierarchical porous γ-alumina to provide mechanical support for graphene bonding. Graphene fills the pores of the hierarchical porous γ-alumina and is then mixed with a urea-formaldehyde resin precursor solution to which a modifier is added, so that it serves as the shell of the micropolymer. The porous γ-alumina composite material doped with graphene enhances the heat conduction and absorption rate.

[0030] 2. The present invention uses melt blending of titanium dioxide and fiber-grade recycled PET chips to form a bonding force between the titanium dioxide particles and the fiber-grade recycled PET chips. The titanium dioxide particles evenly distributed on the fiber-grade recycled PET chips can not only exert the light absorption and heat generation function of the photothermal powder but also improve the tensile strength and modulus of the fiber-grade recycled PET chips. At the same time, the high catalytic activity of the titanium dioxide particles gives it photocatalytic properties in the PET composite material, which can catalyze chemical reactions under light, thereby contributing to the self-cleaning and antibacterial properties of the fiber material surface. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] Unless otherwise specified, the raw materials used in the present invention are all conventional products purchased from the market, and some of the raw materials can be obtained homemade.

[0033] Preparation Example 1

[0034] The preparation of fiber-grade recycled PET chips specifically includes the following steps:

[0035] (1) crushing the recycled plastic bottles into small pieces, and using ethylene glycol as an alcoholysis agent to alcoholyze them into terephthalic acid and ethylene glycol;

[0036] (2) mixing dimethyl terephthalate with methanol, and adding a catalyst, such as tetrabutyl titanate (Ti(OBu)4) or an antimony compound, to the reaction mixture to promote the transesterification reaction;

[0037] (3) Dimethyl phthalate reacts with methanol at high temperature. The methyl formate generated during the reaction can be removed from the reaction system by distillation or other methods to promote the reaction to produce PET monomer.

[0038] (4) When the desired conversion rate is reached, the reaction is stopped and ethylene terephthalate is separated from the mixture by distillation or other separation techniques. The ethylene terephthalate is then purified and subjected to the next polymerization reaction to produce fiber-grade recycled PET chips.

[0039] Example 1

[0040] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0041] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0042] S2. A mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol is used as a precursor solution to prepare a hybrid hierarchical porous material by freeze-drying technology, and then calcined at 1100°C to remove organic matter, ultimately obtaining a hierarchical porous γ-alumina.

[0043] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0044] S4. Dissolve urea and a 37% formaldehyde solution in a reactor and add melamine. Heat and stir for 30 minutes. Then, add 1% by mass of a graphene-doped porous γ-alumina composite material. Use a mechanical stirrer to stir the solution at 800 rpm for 45 minutes to obtain a uniformly dispersed precursor mixed solution.

[0045] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 600 rpm for 110 minutes to obtain micropolymers, wherein the weight ratio of paraffin, emulsifier, and citric acid is 20:3:0.3, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymers, washing the micropolymers with deionized water several times, and then drying them at room temperature for use;

[0046] S6. The PET chips are heated to a molten state, and the surface of the micropolymer is modified to make the micropolymer compatible with the PET chips. The micropolymer and the PET chips are mixed in a ratio of 8:1 to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0047] Example 2

[0048] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0049] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0050] S2. A mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol is used as a precursor solution, and a hybrid hierarchical porous material is prepared by freeze-drying technology. The hybrid hierarchical porous material is then calcined at a high temperature of 1100°C to remove organic matter, thereby finally obtaining a hierarchical porous γ-alumina.

[0051] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0052] S4, dissolving urea and a 37% formaldehyde solution in a reactor, adding melamine, and heating and stirring for 30 minutes, then adding 4% by mass of a graphene-doped porous γ-alumina composite material, and stirring the solution at a speed of 1000 rpm using a mechanical stirrer for 40 minutes to obtain a uniformly dispersed precursor mixed solution;

[0053] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 600 rpm for 110 min to obtain micropolymers, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymers, washing the micropolymers with deionized water several times, and then drying them at room temperature for use;

[0054] S6. Fiber-grade recycled PET chips are melt-blended with titanium dioxide to form a blended melt, and the micropolymer is surface-modified to make the micropolymer compatible with the blended melt. The micropolymer and PET chips are mixed in a ratio of 8:1 to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0055] Example 3

[0056] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0057] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0058] S2. A mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol is used as a precursor solution, and a hybrid hierarchical porous material is prepared by freeze-drying technology. The hybrid hierarchical porous material is then calcined at a high temperature of 1100°C to remove organic matter, thereby obtaining a hierarchical porous γ-alumina.

[0059] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0060] S4, dissolving urea and a 37% formaldehyde solution in a reactor, adding melamine, and heating and stirring for 30 minutes, then adding 4% by mass of a graphene-doped porous γ-alumina composite material, and stirring the solution at a speed of 1000 rpm using a mechanical stirrer for 40 minutes to obtain a uniformly dispersed precursor mixed solution;

[0061] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 600 rpm for 120 min to obtain micropolymers, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymers, washing the micropolymers with deionized water several times, and then drying them at room temperature for use;

[0062] S6. The PET chips are heated to a molten state, and the surface of the micropolymer is modified to make the micropolymer compatible with the PET chips. The micropolymer and the PET chips are mixed in a ratio of 8:1 to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0063] Example 4

[0064] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0065] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0066] S2. Using a mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol as a precursor solution, a hybrid hierarchical porous material is prepared by freeze-drying technology, and then calcined at high temperature to remove organic matter, ultimately obtaining a hierarchical porous γ-alumina;

[0067] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0068] S4. Add a modifier to the urea-formaldehyde resin precursor solution, heat and stir for 40 minutes, then add 6% by mass of a porous γ-alumina composite material doped with graphene, and stir the solution at 1200 rpm for 50 minutes using a mechanical stirrer to obtain a uniformly dispersed precursor mixed solution;

[0069] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 650 rpm for 115 minutes to obtain micropolymers, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymers, washing the micropolymers with deionized water several times, and then drying them at room temperature for use;

[0070] S6. The PET chips are heated to a molten state, and the surface of the micropolymer is modified to make the micropolymer compatible with the PET chips. The micropolymer and the PET chips are mixed in a ratio of 8:1 to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0071] Example 5

[0072] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0073] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0074] S2. Using a mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol as a precursor solution, a hybrid hierarchical porous material is prepared by freeze-drying technology, and then calcined at high temperature to remove organic matter, ultimately obtaining a hierarchical porous γ-alumina;

[0075] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0076] S4. Add a modifier to the urea-formaldehyde resin precursor solution, heat and stir for 40 minutes, then add 8% by mass of a porous γ-alumina composite material doped with graphene, and stir the solution at 1400 rpm for 50 minutes using a mechanical stirrer to obtain a uniformly dispersed precursor mixed solution;

[0077] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 650 rpm for 120 min to obtain micropolymers, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymers, washing the micropolymers with deionized water several times, and then drying them at room temperature for use;

[0078] S6. The PET chips are heated to a molten state, and the surface of the micropolymer is modified to make the micropolymer compatible with the PET chips. The micropolymer and the PET chips are mixed in a ratio of 8:1 to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0079] Example 6

[0080] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0081] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0082] S2. Using a mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol as a precursor solution, a hybrid hierarchical porous material is prepared by freeze-drying technology, and then calcined at high temperature to remove organic matter, ultimately obtaining a hierarchical porous γ-alumina;

[0083] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0084] S4. Add a modifier to the urea-formaldehyde resin precursor solution, heat and stir for 45 minutes, then add 8% by mass of a porous γ-alumina composite material doped with graphene, and use a mechanical stirrer to stir the solution at a speed of 1600 rpm for 60 minutes to obtain a uniformly dispersed precursor mixed solution;

[0085] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 600 rpm for 110 min to obtain micropolymers, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymers, washing the micropolymers with deionized water several times, and then drying them at room temperature for use;

[0086] S6. The PET chips are heated to a molten state, and the surface of the micropolymer is modified to make the micropolymer compatible with the PET chips. The micropolymer and the PET chips are mixed in a ratio of 8:1 to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0087] Example 7

[0088] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0089] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0090] S2. Using a mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol as a precursor solution, a hybrid hierarchical porous material is prepared by freeze-drying technology, and then calcined at high temperature to remove organic matter, ultimately obtaining a hierarchical porous γ-alumina;

[0091] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0092] S4. Add a modifier to the urea-formaldehyde resin precursor solution, heat and stir for 30 minutes, then add 6% by mass of a graphene-doped porous γ-alumina composite material, and use a mechanical stirrer to stir the solution at a speed of 1200 rpm for 50 minutes to obtain a uniformly dispersed precursor mixed solution;

[0093] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 650 rpm for 115 minutes to obtain micropolymers, wherein the weight ratio of paraffin, emulsifier, and citric acid is 25:5:0.8, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymers, washing the micropolymers with deionized water several times, and then drying them at room temperature for use;

[0094] S6. The PET chips are heated to a molten state, and the surface of the micropolymer is modified to make the micropolymer compatible with the PET chips. The micropolymer and the PET chips are mixed in a ratio of 8:1 to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0095] Example 8

[0096] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0097] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0098] S2. Using a mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol as a precursor solution, a hybrid hierarchical porous material is prepared by freeze-drying technology, and then calcined at high temperature to remove organic matter, ultimately obtaining a hierarchical porous γ-alumina;

[0099] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0100] S4. Add a modifier to the urea-formaldehyde resin precursor solution, heat and stir for 30 minutes, then add 6% by mass of a graphene-doped porous γ-alumina composite material, and use a mechanical stirrer to stir the solution at a speed of 1200 rpm for 50 minutes to obtain a uniformly dispersed precursor mixed solution;

[0101] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 650 rpm for 115 minutes to obtain micropolymers, wherein the weight ratio of paraffin, emulsifier, and citric acid is 30:7:1, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymers, washing the micropolymers with deionized water several times, and then drying them at room temperature for use;

[0102] S6. The PET chips are heated to a molten state, and the micropolymers are surface-modified to make the micropolymers compatible with the PET chips to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0103] Example 9

[0104] A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material comprises the following steps:

[0105] S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips;

[0106] S2. Using a mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol as a precursor solution, a hybrid hierarchical porous material is prepared by freeze-drying technology, and then calcined at high temperature to remove organic matter, ultimately obtaining a hierarchical porous γ-alumina;

[0107] S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material;

[0108] S4. Add a modifier to the urea-formaldehyde resin precursor solution, heat and stir for 40 minutes, then add 6% by mass of a porous γ-alumina composite material doped with graphene, and stir the solution at 1200 rpm for 50 minutes using a mechanical stirrer to obtain a uniformly dispersed precursor mixed solution;

[0109] S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 650 rpm for 115 minutes to obtain micropolymers, wherein the weight ratio of paraffin, emulsifier, and citric acid is 35:9:1.2, then adding sodium hydroxide solution to adjust the pH value to neutral, terminating the reaction, and finally filtering the micropolymers, washing the micropolymers with deionized water several times, and then drying them at room temperature for use;

[0110] S6. The PET chips are heated to a molten state, and the surface of the micropolymer is modified to make the micropolymer compatible with the PET chips. The micropolymer and the PET chips are mixed in a ratio of 8:1 to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

[0111] Comparative Example 1

[0112] The difference from Example 1 is that step S2 and step S3 are removed, and step S4 is changed to taking a urea-formaldehyde resin precursor solution and adding melamine, and heating and stirring for 40 minutes, and using a mechanical stirrer to stir the solution at a speed of 1200 rpm for 50 minutes to obtain a uniformly dispersed precursor mixed solution.

[0113] Comparative Example 2

[0114] The difference from Example 1 is that: step S2 and step S3 are removed, and step S4 is changed to disperse graphene oxide in deionized water to form a uniform suspension, take a urea-formaldehyde resin precursor solution, add melamine and the suspension, use a mechanical stirrer to stir the solution at a speed of 1200 rpm for 50 minutes to obtain a uniformly dispersed precursor mixed solution, heat to 90°, react for 1 hour, and then cool for use.

[0115] The performance of the light-absorbing and heat-generating regenerated polyester fibers prepared in Examples 1-9 and Comparative Examples 1-2 of the present application was tested.

[0116] The fiber was subjected to comparative tests under outdoor sunlight and far-infrared light. The results are shown in the following table:

[0117] Table 1

[0118] Test products Outdoor sunlight exposure for 4 minutes Outdoor sunlight for 10 minutes Far infrared light for 10 minutes <![CDATA[ 对比例1 ]]> <![CDATA[ 27 °]]> <![CDATA[ 32 °]]> <![CDATA[ 31 °]]> <![CDATA[ 对比例2 ]]> <![CDATA[ 28 °]]> <![CDATA[ 33 °]]> <![CDATA[ 32 °]]> <![CDATA[ 实施例1 ]]> <![CDATA[ 29 °]]> <![CDATA[ 34 °]]> <![CDATA[ 33 °]]> <![CDATA[ 实施例2 ]]> <![CDATA[ 33 °]]> <![CDATA[ 39 °]]> <![CDATA[ 38 °]]> <![CDATA[ 实施例3 ]]> <![CDATA[ 31 °]]> <![CDATA[ 36 °]]> <![CDATA[ 35.5 °]]> <![CDATA[ 实施例4 ]]> <![CDATA[ 30 °]]> <![CDATA[ 35 °]]> <![CDATA[ 35 ° <!-- 8 -->]]> <![CDATA[ 实施例5 ]]> <![CDATA[ 30 °]]> <![CDATA[ 36 °]]> <![CDATA[ 35 °]]> <![CDATA[ 实施例6 ]]> <![CDATA[ 31 °]]> <![CDATA[ 36 °]]> <![CDATA[ 35 °]]> <![CDATA[ 实施例7 ]]> <![CDATA[ 30 °]]> <![CDATA[ 35 °]]> <![CDATA[ 34.5 °]]> <![CDATA[ 实施例8 ]]> <![CDATA[ 30 °]]> <![CDATA[ 35 °]]> <![CDATA[ 35 °]]> <![CDATA[ 实施例9 ]]> <![CDATA[ 30 °]]> <![CDATA[ 34 °]]> <![CDATA[ 34 °]]>

[0119] It can be seen from the results shown in Examples 1-9 and Comparative Examples 1-2 of the present application that the porous γ-type alumina composite material doped with graphene used in the present application as the shell of the micropolymer enhances the heat conduction efficiency and improves the photothermal conversion efficiency of the fiber. The present application uses titanium dioxide and fiber-grade recycled PET chips for melt blending, which can give full play to the light absorption and heat generation function of the photothermal powder and improve the tensile strength and modulus of the fiber-grade recycled PET chips.

[0120] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a light-absorbing and heat-generating regenerated polyester fiber material, characterized in that: The following steps are involved: S1. Crushing recycled plastic bottles into small pieces, depolymerizing them using ethylene glycol as a reaction medium to obtain dimethyl terephthalate and ethylene glycol, transesterifying dimethyl terephthalate with methanol, and then polymerizing them to prepare fiber-grade recycled PET chips; S2. Using a mixed aqueous solution of aluminum isopropoxide, acetic acid, and polyvinyl alcohol as a precursor solution, a hybrid hierarchical porous material is prepared by freeze-drying technology, and then calcined at high temperature to remove organic matter, ultimately obtaining a hierarchical porous γ-alumina; S3, immersing the hierarchical porous γ-alumina in a solution containing graphene, and uniformly dispersing the graphene into the pores of the porous γ-alumina by ultrasonic dispersion or high shear stirring to obtain a graphene-doped porous γ-alumina composite material, and then heat treating the graphene-doped porous γ-alumina composite material; S4. Add melamine to a urea-formaldehyde resin precursor solution, heat and stir for 30-45 minutes, then add a certain mass fraction of a graphene-doped porous γ-alumina composite material, and use a mechanical stirrer to stir the solution at a speed of 300 to 2000 rpm for 30-60 minutes to obtain a uniformly dispersed precursor mixed solution; S5, heating paraffin to a molten state and mixing it with the precursor mixed solution, and using an emulsifier and a mechanical stirrer to form an emulsion, continuing to adjust the pH value by adding a pH regulator, wherein the pH regulator includes citric acid, heating the reaction system, and stirring the mechanical stirrer at a speed of 600-700 rpm for 110-125 minutes to obtain a micropolymer solution, then adding a pH regulator to adjust the pH value of the micropolymer solution to neutral, terminating the reaction, and finally filtering the micropolymer, washing the micropolymer with deionized water several times, and then drying at room temperature for use; S6. Heating the fiber-grade recycled PET chips to a molten state, and performing surface modification on the micropolymer to make the micropolymer compatible with the PET chips to form a molten mixture. The molten mixture is filtered through a filter and then cooled to a temperature suitable for spinning to form a spinning solution, which is then wet-spun to obtain fibers.

2. The method for preparing a light-absorbing and heat-generating regenerated polyester fiber material according to claim 1, characterized in that: The urea-formaldehyde resin precursor solution is prepared by dissolving urea and a formaldehyde solution with a concentration of 37% in a reactor.

3. The method for preparing a light-absorbing and heat-generating regenerated polyester fiber material according to claim 2, characterized in that: The urea-formaldehyde resin precursor solution is prepared by adding triethanolamine to adjust the pH value of the solution.

4. The method for preparing a light-absorbing and heat-generating regenerated polyester fiber material according to claim 1, characterized in that: In the step S3, the weight ratio of graphene to hierarchical porous γ-alumina is (1-3): (110-180).

5. The method for preparing a light-absorbing and heat-generating regenerated polyester fiber material according to claim 1, characterized in that: The graphene solution in S3 is prepared by the following steps: (1) Graphene oxide is obtained by oxidizing graphite using the Hummers method; (2) removing the oxygen-containing groups of graphene oxide by chemical reduction to obtain reduced graphene oxide; (3) Reduced graphene oxide powder is added to a solvent and subjected to long-term ultrasonic treatment using an ultrasonic processor.

6. The method for preparing a light-absorbing and heat-generating regenerated polyester fiber material according to claim 1, characterized in that: The mass fraction of the graphene-doped porous gamma-alumina composite material relative to the micropolymer is 1%-8%.

7. The method for preparing a light-absorbing and heat-generating regenerated polyester fiber material according to claim 1, characterized in that: In step S5, the weight ratio of paraffin wax, emulsifier and citric acid is (20-40): (3-10): (0.3-1.8).

8. The method for preparing a light-absorbing and heat-generating regenerated polyester fiber material according to claim 1, characterized in that: The paraffin is replaced by one or more of nano zirconium carbide, polyethylene glycol, hydrocarbon wax, and carbon nanotubes.

9. The method for preparing a light-absorbing and heat-generating regenerated polyester fiber material according to claim 1, characterized in that: The molten mixture filtered in step S6 is melted by a screw extruder and quantitatively fed into a spinning assembly through a spinning pump. The mixture is then extruded from the capillaries of a spinneret to form liquid filaments. The liquid filaments are then cooled and formed, stretched into filaments at high speed by a winding device, and then heat-set to obtain fibers.

10. The method for preparing a light-absorbing and heat-generating regenerated polyester fiber material according to claim 1, wherein the fiber-grade regenerated PET chips in step S6 are melt-blended with titanium dioxide and then combined with the micropolymer.