A polyester fiber filter bag

Abstract

The invention relates to the field of filter bags, and discloses a polyester fiber filter bag. The filter bag is prepared by needle punching modified polyester fibers and natural fibers, wherein the modified polyester fibers are prepared by mixing polyester slices and modified graphene oxide into modified polyester master batches, and then melt spinning is performed to prepare the modified graphene oxide; the modified graphene oxide is prepared by grafting a modified silane coupling agent and a component three on the surface of the graphene oxide; the modified silane coupling agent is reacted with 2-octenyl succinic anhydride and 1,1,3,3-tetramethyldisiloxane, and then reacted with diisopropanolamine to obtain a component two, and then the component two is further reacted with vinyl triethoxysilane to prepare the filter bag; the component three is copolymerized by methacrylate-2-hydroxyethyl phosphate, methacrylate dodecafluoroheptyl and γ-methacryloxypropyltrimethoxysilane under the action of an initiator, and the addition of the modified graphene oxide gives the filter bag excellent high temperature resistance, acid and alkali corrosion resistance, wear resistance, water resistance and flame retardant effects.

Description

Technical Field

[0001] The invention belongs to the technical field of filter bags, and in particular relates to a polyester fiber filter bag. Background Art

[0002] With the acceleration of economic development and urbanization, air pollution has become a global problem. Bag filter is a common industrial dust removal equipment, with the advantages of high filtration efficiency, no influence from dust composition, and abundant fiber raw material sources. In industrial smoke filtration conditions such as coal-fired power plants, steel smelting, cement kilns, etc., the fiber used in the filter bag must meet the performance requirements of high temperature resistance, acid and alkali corrosion resistance, etc.

[0003] Among them, polyester fiber can be used as a common fiber raw material for industrial smoke filtration because of its advantages such as high strength, good elasticity and low cost. However, due to its own chemical composition, polyester fiber does not have flame retardant characteristics, and its limiting oxygen index is about 22%. It is a flammable material and has great safety hazards during use. The existing technology achieves flame retardant effect by adding additional flame retardants, but the added flame retardant is often added in large amounts. While ensuring the flame retardant performance, it causes a significant decrease in the mechanical properties of the material itself, and affects the feel of the material. In addition, the flame retardant is very likely to migrate on the surface of the material at high temperatures, resulting in a decrease in the flame retardant effect, which limits its large-scale production and application. In addition, the wear resistance, high temperature resistance and acid and alkali corrosion resistance of the polyester fiber used in the existing filter bags need to be further improved to expand its application range. Summary of the invention

[0004] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide a polyester fiber filter bag, which is made by needle-punching a mixture of natural fibers and modified polyester fibers, wherein the modified polyester fibers are made by melt-blending and granulating polyester chips and modified graphene oxide and then melt-spinning, so that the prepared filter bag has excellent high temperature resistance, acid and alkali corrosion resistance, wear resistance, water resistance and flame retardant effects.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A polyester fiber filter bag is made by needle-punching modified polyester fibers and natural fibers, wherein the modified polyester fibers are prepared by mixing polyester chips and modified graphene oxide into modified polyester masterbatch, and then melt-spinning the modified graphene oxide; the modified graphene oxide is prepared by grafting a modified silane coupling agent and component three onto the surface of graphene oxide by chemical reaction;

[0007] The modified silane coupling agent is prepared by reacting 2-octenylsuccinic anhydride and 1,1,3,3-tetramethyldisiloxane with diisopropanolamine to obtain component two, which is then further reacted with vinyltriethoxysilane to undergo a hydrosilylation reaction; component three is prepared by copolymerizing 2-hydroxyethyl methacrylate phosphate, dodecafluoroheptyl methacrylate and γ-methacryloxypropyltrimethoxysilane under the action of azobisisobutyronitrile.

[0008] Preferably, the natural fiber is one or more combinations of ramie fiber, jute fiber, and basalt fiber, and the mass ratio of the modified polyester fiber to the natural fiber is 3:1-2.

[0009] Preferably, the method for preparing the modified graphene oxide comprises the following steps:

[0010] (1) 2-octenylsuccinic anhydride and an isopropanol solution containing chloroplatinic acid are stirred and mixed, the temperature is raised to 60-90° C., 1,1,3,3-tetramethyldisiloxane is added, and the mixture is stirred and reacted for 4-7 hours. After the reaction is completed, unreacted materials are removed by a rotary evaporator to prepare component 1;

[0011] (2) Component 1, diisopropanolamine, p-toluenesulfonic acid and N,N-dimethylformamide were placed in a reactor, stirred and reacted at 110-125° C. for 5-7 hours, and after the reaction was completed, the component was distilled under reduced pressure and dried to prepare component 2;

[0012] (3) Component 2 and vinyl triethoxysilane are placed in a reactor, toluene solvent is added, nitrogen is passed through the reaction, the temperature is raised to 75-90°C, Wilkinson catalyst is added, and the reaction is stirred for 5-7 hours. After the reaction is completed, the solvent is removed by vacuum rotary evaporation, and the reaction product is poured into a silica gel chromatography column, rinsed with n-hexane and ethyl acetate, and then the eluted reaction product is vacuum rotary evaporated to prepare a modified silane coupling agent;

[0013] (4) 2-Hydroxyethyl methacrylate phosphate, dodecafluoroheptyl methacrylate and γ-methacryloxypropyltrimethoxysilane were placed in a reactor, anhydrous ethanol was added and mixed evenly, nitrogen was introduced for 20-30 minutes, and then azobisisobutyronitrile was added, and the mixture was reacted at 70-80°C for 7-9 hours to prepare component three;

[0014] (5) Graphene oxide is ultrasonically dispersed in xylene, and then the temperature is raised to 120-135°C, and component three and a modified silane coupling agent are added and stirred to react for 7-9 hours. The reaction is carried out in a nitrogen atmosphere. After the reaction is completed, the modified graphene oxide is prepared by centrifugation, washing, and drying.

[0015] Preferably, in step (1), the molar ratio of 2-octenylsuccinic anhydride to 1,1,3,3-tetramethyldisiloxane is 1-1.2:1.

[0016] Preferably, in step (2), the molar ratio of component 1 to diisopropanolamine is 1:1.1-1.3.

[0017] Preferably, in step (3), the molar ratio of component 2 to vinyltriethoxysilane is 1:1-9.

[0018] Preferably, in step (4), the molar ratio of 2-hydroxyethyl methacrylate phosphate, dodecafluoroheptyl methacrylate and γ-methacryloxypropyltrimethoxysilane is 4-10:2-3:1.

[0019] Preferably, in step (5), the mass ratio of graphene oxide, component three and modified silane coupling agent is 1:0.1~0.5:0.5~1.5.

[0020] Preferably, the method for preparing the polyester fiber filter bag comprises the following steps:

[0021] S1. Dry the polyester chips in a blast oven at 75-85°C for 1-2 hours, then heat to 90-100°C and continue drying for 1-2 hours to remove free water on the surface of the polyester chips and perform pre-crystallization, then dry in a vacuum oven at 85-100°C for 1-2 hours, then heat to 110-125°C and dry for 20-24 hours to remove bound water inside the polyester chips, thereby obtaining pretreated polyester chips;

[0022] S2, mixing the pretreated polyester chips and the modified graphene oxide, and then melt-blending and granulating them using a twin-screw extruder to obtain a modified polyester masterbatch;

[0023] S3, spinning by using a melt spinning machine, keeping the barrel in a vacuum state and continuously introducing nitrogen until the spinning is completed, extruding the modified polyester masterbatch from the three-hole spinneret, and winding it through a winder to obtain a modified polyester fiber, the temperature of each section of the spinning machine is set to 260-280° C., and the winding speed of the winder is set to 500-1500 r / min;

[0024] S4. Add the modified polyester fiber and natural fiber into the opening machine and loosen them into a cotton-like state. Mix and remove impurities during the loosening process. Feed the opened and evenly mixed fiber raw materials into the carding machine by quantitative feeding method. Use cross-laying to form a fiber web with the required surface density. Then, needle-punch the fiber web to prepare a polyester fiber filter bag.

[0025] Preferably, the mass ratio of the pretreated polyester chips to the modified graphene oxide is 1:0.02-0.12.

[0026] Beneficial effects of the present invention:

[0027] The present invention adopts natural fiber and modified polyester fiber mixed by needle punching to form a polyester fiber filter bag with good air permeability, wherein the modified polyester fiber is made by melt spinning after melt blending and granulation of polyester chips and modified graphene oxide, so that the prepared filter bag has excellent high temperature resistance, acid and alkali corrosion resistance, wear resistance, water resistance and flame retardant effects. The invention uses a double bond group in a 2-octenylsuccinic anhydride structure and one of the silicon-hydrogen bonds in a 1,1,3,3-tetramethyldisiloxane structure to undergo a silylation reaction to prepare a component one, then reacts the cyclic anhydride group in the structure of the component one with an -OH group and an -NH group in a diisopropanolamine structure to prepare a component two with a hyperbranched structure, and uses the silicon-hydrogen bonds in the structure of the component two to undergo a silylation reaction with vinyltriethoxysilane to prepare a modified silane coupling agent, and at the same time, uses methacrylate-2-hydroxyethyl phosphate, dodecafluoroheptyl methacrylate and γ-methacryloxypropyltrimethoxysilane to undergo copolymerization under the action of azobisisobutyronitrile to prepare a component three having a phosphorus element and a fluorine-containing hydrophobic long chain, and then reacts the modified silane coupling agent with the structure of the component three. The silane alkoxy group undergoes a grafting reaction with the hydroxyl group in the graphene oxide structure to prepare modified graphene oxide, thereby introducing silicon, phosphorus and fluorine-containing hydrophobic long chains into the graphene oxide structure, increasing the interlayer spacing of the graphene oxide, making the path for the corrosive medium to reach the material tortuous, enhancing the acid and alkali corrosion resistance of the material, and at the same time being beneficial to the dispersion of the graphene oxide, improving the compatibility between the graphene oxide and the matrix, and giving full play to its mechanical properties. In addition, the dense carbon layer formed by the synergistic flame retardant effect of the silicon element and the phosphorus element blocks the heat and mass transfer between the material and the flame, giving the material excellent flame retardant properties, the introduction of fluorine-containing hydrophobic long chains enhances the water resistance of the material, and the multiple Si-O-Si bonds introduced into the modified graphene oxide can give the material excellent high temperature resistance, wear resistance and acid and alkali corrosion resistance. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1 A method for preparing modified graphene oxide comprises the following steps:

[0030] (1) 21.0 g of 2-octenylsuccinic anhydride and 17.5 mL of an isopropanol solution containing 0.14 g of chloroplatinic acid were stirred and mixed, the temperature was raised to 80° C., 13.4 g of 1,1,3,3-tetramethyldisiloxane was added, and the mixture was stirred and reacted for 5 h. After the reaction was completed, the unreacted product was removed by a rotary evaporator to prepare component 1;

[0031] (2) 31.0 g of component 1, 13.3 g of diisopropanolamine, 0.43 g of p-toluenesulfonic acid and 50 mL of N,N-dimethylformamide were placed in a reactor, stirred and reacted at 120° C. for 6 h, and after the reaction was completed, the component was distilled under reduced pressure and dried to prepare component 2;

[0032] (3) 20.8 g of component 2 and 8.6 g of vinyltriethoxysilane were placed in a reactor, 120 mL of toluene solvent was added, nitrogen was passed through the reaction, the temperature was raised to 85°C, 0.005 g of Wilkinson catalyst was added, and the reaction was stirred for 6 h. After the reaction was completed, the solvent was removed by vacuum rotary evaporation, and the reaction product was poured into a silica gel chromatography column, rinsed with 60 mL of n-hexane and 30 mL of ethyl acetate, and then the eluted reaction product was vacuum rotary evaporated to prepare a modified silane coupling agent;

[0033] (4) 3.6 g of 2-hydroxyethyl methacrylate phosphate, 2.4 g of dodecafluoroheptyl methacrylate and 0.5 g of γ-methacryloxypropyltrimethoxysilane were placed in a reactor, 20 mL of anhydrous ethanol was added and mixed evenly, nitrogen was introduced for 30 min, and then 0.02 g of azobisisobutyronitrile was added, and the mixture was reacted at 75 °C for 8 h to prepare component three;

[0034] (5) 5 g of graphene oxide was ultrasonically dispersed in 100 mL of xylene, and then the temperature was raised to 125°C. 0.5 g of component three and 5 g of modified silane coupling agent were added and stirred for 8 h. The reaction was carried out in a nitrogen atmosphere. After the reaction was completed, the modified graphene oxide was prepared by centrifugation, washing, and drying.

[0035] Example 2 A polyester fiber filter bag is made by needle-punching modified polyester fiber and basalt fiber in a mass ratio of 3:2. The modified polyester fiber is prepared by mixing polyester chips and modified graphene oxide prepared in Example 1 into modified polyester masterbatch, which is then made by melt spinning.

[0036] The preparation method of the polyester fiber filter bag comprises the following steps:

[0037] S1, placing the polyester chips in a blast oven at 80°C for 2 hours, then heating to 100°C and continuing to dry for 1 hour to remove free water on the surface of the polyester chips and pre-crystallize, then placing in a vacuum oven at 95°C for 2 hours, and continuing to heat to 120°C and drying for 24 hours to remove bound water inside the polyester chips, thereby obtaining pretreated polyester chips;

[0038] S2, mixing the pretreated polyester chips and the modified graphene oxide prepared in Example 1 at a mass ratio of 1:0.02, and then melt-blending and granulating them using a twin-screw extruder to obtain a modified polyester masterbatch;

[0039] S3, spinning by using a melt spinning machine, keeping the barrel in a vacuum state and continuously introducing nitrogen until the spinning is completed, extruding the modified polyester masterbatch from the three-hole spinneret, and winding it through a winder to obtain a modified polyester fiber, the temperature of each section of the spinning machine is set to 275° C., and the winding speed of the winder is set to 950 r / min;

[0040] S4, add the modified polyester fiber and basalt fiber into the opening machine, and loosen them into cotton wool. At the same time, mix and remove impurities during the loosening process. Feed the opened and mixed fiber raw materials into the carding machine by quantitative feeding method, and use cross-laying to form a 125g / m 2 The fiber net is subjected to three needling passes, wherein the first needling frequency is 520 r / min, the needling depth is 6 mm, and the needling density is 580 punctures / cm²; the second needling frequency is 780 r / min, the needling depth is 8 mm, and the needling density is 700 punctures / cm²; the third needling frequency is 920 r / min, the needling depth is 14 mm, and the needling density is 850 punctures / cm², to prepare a polyester fiber filter bag.

[0041] Example 3 A polyester fiber filter bag is made by needle-punching modified polyester fiber and basalt fiber in a mass ratio of 3:2. The modified polyester fiber is prepared by mixing polyester chips and modified graphene oxide prepared in Example 1 into modified polyester masterbatch, which is then made by melt spinning.

[0042] The preparation method of the polyester fiber filter bag comprises the following steps:

[0043] Compared with Example 2, in this example, the pretreated polyester chips and the modified graphene oxide prepared in Example 1 are mixed at a mass ratio of 1:0.05, and the remaining components and operating methods are consistent with those in Example 2.

[0044] Example 4 A polyester fiber filter bag is made by needle-punching modified polyester fiber and basalt fiber in a mass ratio of 3:2. The modified polyester fiber is prepared by mixing polyester chips and the modified graphene oxide prepared in Example 1 into modified polyester masterbatch, which is then made by melt spinning.

[0045] The preparation method of the polyester fiber filter bag comprises the following steps:

[0046] Compared with Example 2, in this example, the pretreated polyester chips and the modified graphene oxide prepared in Example 1 are mixed in a mass ratio of 1:0.1, and the other components and operating methods are consistent with those in Example 2.

[0047] Comparative Example 1 A method for preparing modified graphene oxide comprises the following steps:

[0048] (1) 21.0 g of 2-octenylsuccinic anhydride and 17.5 mL of an isopropanol solution containing 0.14 g of chloroplatinic acid were stirred and mixed, the temperature was raised to 80° C., 13.4 g of 1,1,3,3-tetramethyldisiloxane was added, and the mixture was stirred and reacted for 5 h. After the reaction was completed, the unreacted product was removed by a rotary evaporator to prepare component 1;

[0049] (2) 15.6 g of component 1 and 8.6 g of vinyl triethoxysilane were placed in a reactor, 120 mL of toluene solvent was added, nitrogen was passed through the reaction, the temperature was raised to 85°C, 0.005 g of Wilkinson catalyst was added, and the reaction was stirred for 6 h. After the reaction was completed, the solvent was removed by vacuum rotary evaporation, and the reaction product was poured into a silica gel chromatography column, rinsed with 60 mL of n-hexane and 30 mL of ethyl acetate, and then the eluted reaction product was vacuum rotary evaporated to prepare a modified silane coupling agent;

[0050] (3) 3.6 g of 2-hydroxyethyl methacrylate phosphate, 2.4 g of dodecafluoroheptyl methacrylate and 0.5 g of γ-methacryloxypropyltrimethoxysilane were placed in a reactor, 20 mL of anhydrous ethanol was added and mixed evenly, nitrogen was introduced for 30 min, and then 0.02 g of azobisisobutyronitrile was added, and the mixture was reacted at 75 °C for 8 h to prepare component 2;

[0051] (4) 5 g of graphene oxide was ultrasonically dispersed in 100 mL of xylene, and then the temperature was raised to 125°C. 0.5 g of component 2 and 5 g of modified silane coupling agent were added and stirred for 8 h. The reaction was carried out in a nitrogen atmosphere. After the reaction was completed, the modified graphene oxide was prepared by centrifugation, washing, and drying.

[0052] Comparative Example 2 A method for preparing modified graphene oxide comprises the following steps:

[0053] (1) 21.0 g of 2-octenylsuccinic anhydride and 17.5 mL of an isopropanol solution containing 0.14 g of chloroplatinic acid were stirred and mixed, the temperature was raised to 80° C., 13.4 g of 1,1,3,3-tetramethyldisiloxane was added, and the mixture was stirred and reacted for 5 h. After the reaction was completed, the unreacted product was removed by a rotary evaporator to prepare component 1;

[0054] (2) 31.0 g of component 1, 13.3 g of diisopropanolamine, 0.43 g of p-toluenesulfonic acid and 50 mL of N,N-dimethylformamide were placed in a reactor, stirred and reacted at 120° C. for 6 h, and after the reaction was completed, the component was distilled under reduced pressure and dried to prepare component 2;

[0055] (3) 20.8 g of component 2 and 8.6 g of vinyltriethoxysilane were placed in a reactor, 120 mL of toluene solvent was added, nitrogen was passed through the reaction, the temperature was raised to 85°C, 0.005 g of Wilkinson catalyst was added, and the reaction was stirred for 6 h. After the reaction was completed, the solvent was removed by vacuum rotary evaporation, and the reaction product was poured into a silica gel chromatography column, rinsed with 60 mL of n-hexane and 30 mL of ethyl acetate, and then the eluted reaction product was vacuum rotary evaporated to prepare a modified silane coupling agent;

[0056] (4) 5 g of graphene oxide was ultrasonically dispersed in 100 mL of xylene, and then the temperature was raised to 125°C, and 5 g of modified silane coupling agent was added and stirred for reaction for 8 h. The reaction was carried out in a nitrogen atmosphere. After the reaction was completed, the modified graphene oxide was prepared by centrifugation, washing, and drying.

[0057] Comparative Example 3 A polyester fiber filter bag is made by needle-punching modified polyester fiber and basalt fiber in a mass ratio of 3:2. The modified polyester fiber is prepared by mixing polyester chips and modified graphene oxide prepared in Comparative Example 1 into modified polyester masterbatch, which is then made by melt spinning.

[0058] The preparation method of the polyester fiber filter bag comprises the following steps:

[0059] Compared with Example 2, in this example, the pretreated polyester chips and the modified graphene oxide prepared in Comparative Example 1 are mixed in a mass ratio of 1:0.1, and the remaining components and operating methods are consistent with those in Example 2.

[0060] Comparative Example 4 A polyester fiber filter bag is made by needle-punching modified polyester fiber and basalt fiber in a mass ratio of 3:2. The modified polyester fiber is prepared by mixing polyester chips and modified graphene oxide prepared in Comparative Example 2 into modified polyester masterbatch, which is then made by melt spinning.

[0061] The preparation method of the polyester fiber filter bag comprises the following steps:

[0062] Compared with Example 2, in this example, the pretreated polyester chips and the modified graphene oxide prepared in Comparative Example 2 are mixed in a mass ratio of 1:0.1, and the remaining components and operating methods are consistent with those in Example 2.

[0063] Comparative Example 5 A polyester fiber filter bag is made by needle-punching modified polyester fiber and basalt fiber in a mass ratio of 3:2, wherein the modified polyester fiber is prepared by mixing polyester chips and graphene oxide into modified polyester masterbatch, and then made by melt spinning.

[0064] The preparation method of the polyester fiber filter bag comprises the following steps:

[0065] Compared with Example 2, in this example, the pretreated polyester chips and graphene oxide are mixed in a mass ratio of 1:0.1, and the remaining components and operating methods are consistent with those in Example 2.

[0066] Performance Testing

[0067] The filter bags prepared in Examples 2-4 and Comparative Examples 3-5 were tested for performance:

[0068] (1) Mechanical properties and acid and alkali corrosion resistance testing: The breaking strength and breaking elongation were tested in accordance with GB / T 24218.3-2010; 40% by mass sodium hydroxide solution and 60% by mass sulfuric acid solution were prepared respectively, and the samples were immersed in water at room temperature for 24 h. After washing and drying, the breaking strength of the samples before and after treatment was tested using a YG065H electronic fabric strength tester. The data results are shown in Table 1.

[0069] (2) High temperature resistance test: The filter bag was placed in an oven, heated to 220°C at a rate of 2°C / min, and then kept at a constant temperature for 24 hours. The breaking strength of the samples before and after treatment was measured, and the breaking strength retention rate was used as an indicator for evaluating the temperature resistance. The data results are shown in Table 1.

[0070] (3) Wear resistance and flame retardant performance testing: YG (B) 522 fabric wear tester filter bag was used for wear resistance testing, with a test area of ​​20 cm 2 The friction times were set to 400 times, the mass of the sample before and after friction was recorded, and the average wear amount per unit area was used to characterize the wear resistance of the filter bag; the limiting oxygen index was used to evaluate the flame retardant performance, and the data results are shown in Table 1.

[0071] (4) Water resistance test: 20 g of the modified polyester fiber prepared in Examples 2-4 and Comparative Examples 3-5 was taken, rinsed with ethanol twice, and then placed in an oven to dry to constant weight, with the mass being recorded as M0. The fiber was then immersed in a beaker filled with deionized water, allowed to stand for 48 h, taken out, placed on a 100-mesh standard sieve, allowed to stand for 30 min until no liquid droplets were left, and then weighed, with the mass being recorded as M1. The water absorption rate was tested, and the water absorption rate was calculated according to the following formula: Water absorption rate = (M1-M0) / M0×100%. The data results are shown in Table 1.

[0072]

[0073] As can be seen from the data in Table 1, the filter bags prepared in Examples 2-4 of the present invention have good mechanical properties, and are resistant to high temperature, acid and alkali corrosion, wear and water resistance, and excellent flame retardant effects. Among them, the modified graphene oxide added in Comparative Example 3 does not introduce the component 2 of the hyperbranched structure, and its measured high temperature resistance, wear resistance, acid and alkali corrosion resistance, and flame retardant properties are lower than those of Examples 2-4. The reason is due to the reduction of Si-O-Si bonds introduced in the graphene oxide. The modified graphene oxide added in Comparative Example 4 does not introduce the component 3 with phosphorus elements and fluorine-containing hydrophobic long chains, and its measured flame retardant properties and water resistance are lower than those of Examples 2-4. In Comparative Example 5, graphene oxide is not modified, and its measured various properties are most significantly reduced compared with Examples 2-4, indicating that modifying graphene oxide can improve the material's high temperature resistance, acid and alkali corrosion resistance, wear and water resistance, and flame retardant effects, and its mechanical properties are improved.

[0074] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0075] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A polyester fiber filter bag, characterized in that: The modified polyester fiber is made by needle punching modified polyester fiber and natural fiber, wherein the modified polyester fiber is prepared by mixing polyester chips and modified graphene oxide into modified polyester masterbatch, and then made by melt spinning; the modified graphene oxide is made by grafting modified silane coupling agent and component three on the surface of graphene oxide by chemical reaction; The modified silane coupling agent is prepared by reacting 2-octenyl succinic anhydride and 1,1,3,3-tetramethyldisiloxane with diisopropanolamine to obtain component two, and then further reacting component two with vinyl triethoxysilane to undergo a hydrosilylation reaction; component three is prepared by copolymerizing 2-hydroxyethyl methacrylate phosphate, dodecafluoroheptyl methacrylate and γ-methacryloxypropyl trimethoxysilane under the action of azobisisobutyronitrile; The preparation method of the modified graphene oxide comprises the following steps: (1) 2-octenylsuccinic anhydride and an isopropanol solution containing chloroplatinic acid are stirred and mixed, the temperature is raised to 60-90° C., 1,1,3,3-tetramethyldisiloxane is added, and the mixture is stirred and reacted for 4-7 hours. After the reaction is completed, unreacted materials are removed by a rotary evaporator to prepare component 1; (2) Component 1, diisopropanolamine, p-toluenesulfonic acid and N,N-dimethylformamide were placed in a reactor, stirred and reacted at 110-125° C. for 5-7 hours, and after the reaction was completed, the component was distilled under reduced pressure and dried to prepare component 2; (3) Component 2 and vinyl triethoxysilane are placed in a reactor, toluene solvent is added, nitrogen is passed through the reaction, the temperature is raised to 75-90°C, Wilkinson catalyst is added, and the reaction is stirred for 5-7 hours. After the reaction is completed, the solvent is removed by vacuum rotary evaporation, and the reaction product is poured into a silica gel chromatography column, rinsed with n-hexane and ethyl acetate, and then the eluted reaction product is vacuum rotary evaporated to prepare a modified silane coupling agent; (4) 2-Hydroxyethyl methacrylate phosphate, dodecafluoroheptyl methacrylate and γ-methacryloxypropyltrimethoxysilane were placed in a reactor, anhydrous ethanol was added and mixed evenly, nitrogen was introduced for 20-30 minutes, and then azobisisobutyronitrile was added, and the mixture was reacted at 70-80°C for 7-9 hours to prepare component three; (5) Graphene oxide is ultrasonically dispersed in xylene, and then the temperature is raised to 120-135°C, and component three and a modified silane coupling agent are added and stirred to react for 7-9 hours. The reaction is carried out in a nitrogen atmosphere. After the reaction is completed, the modified graphene oxide is prepared by centrifugation, washing, and drying.

2. The polyester fiber filter bag according to claim 1, characterized in that: The natural fiber is one or more combinations of ramie fiber, jute fiber, and basalt fiber, and the mass ratio of the modified polyester fiber to the natural fiber is 3:1-2.

3. The polyester fiber filter bag according to claim 1, characterized in that: In the step (1), the molar ratio of 2-octenylsuccinic anhydride to 1,1,3,3-tetramethyldisiloxane is 1-1.2:

1.

4. The polyester fiber filter bag according to claim 1, characterized in that: In the step (2), the molar ratio of component 1 to diisopropanolamine is 1:1.1-1.

3.

5. The polyester fiber filter bag according to claim 1, characterized in that: In the step (3), the molar ratio of component 2 to vinyltriethoxysilane is 1:1-9.

6. The polyester fiber filter bag according to claim 1, characterized in that: In the step (4), the molar ratio of 2-hydroxyethyl methacrylate phosphate, dodecafluoroheptyl methacrylate and γ-methacryloxypropyltrimethoxysilane is 4-10:2-3:

1.

7. The polyester fiber filter bag according to claim 1, characterized in that: In the step (5), the mass ratio of graphene oxide, component three and modified silane coupling agent is 1:0.1~0.5:0.5~1.

5.

8. The polyester fiber filter bag according to claim 1, characterized in that: The preparation method of the polyester fiber filter bag comprises the following steps: S1. Dry the polyester chips in a blast oven at 75-85°C for 1-2 hours, then heat to 90-100°C and continue drying for 1-2 hours to remove free water on the surface of the polyester chips and perform pre-crystallization, then dry in a vacuum oven at 85-100°C for 1-2 hours, then heat to 110-125°C and dry for 20-24 hours to remove bound water inside the polyester chips, thereby obtaining pretreated polyester chips; S2, mixing the pretreated polyester chips and the modified graphene oxide, and then melt-blending and granulating them using a twin-screw extruder to obtain a modified polyester masterbatch; S3, spinning by using a melt spinning machine, keeping the barrel in a vacuum state and continuously introducing nitrogen until the spinning is completed, extruding the modified polyester masterbatch from the three-hole spinneret, and winding it through a winder to obtain a modified polyester fiber, the temperature of each section of the spinning machine is set to 260-280° C., and the winding speed of the winder is set to 500-1500 r / min; S4. Add the modified polyester fiber and natural fiber into the opening machine and loosen them into a cotton-like state. Mix and remove impurities during the loosening process. Feed the opened and evenly mixed fiber raw materials into the carding machine by quantitative feeding method. Use cross-laying to form a fiber web with the required surface density. Then, needle-punch the fiber web to prepare a polyester fiber filter bag.

9. The polyester fiber filter bag according to claim 8, characterized in that: The mass ratio of the pretreated polyester chips to the modified graphene oxide is 1:0.02-0.12.

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