Polyester fiber dedusting filter bag and preparation method thereof

Abstract

The invention relates to the field of dust removal filter bags, and discloses a polyester fiber dust removal filter bag and a preparation method thereof.The dust removal filter bag is prepared from modified polyester fibers and reinforced fibers through needling, the modified polyester fibers are prepared from PET slices and composite material through melt spinning, and the composite material uses DOPO-based benzoxazine derivatives as a matrix and graphene oxide as a reinforcement body; and chalcone-based benzoxazine is used as a coupling agent, and a solution blending method is adopted to prepare the composite material. The DOPO-based benzoxazine derivative is prepared by carrying out nucleophilic addition reaction on double-bond benzoxazine liquid and DOPO, wherein the double-bond benzoxazine liquid is prepared by carrying out Mannich reaction on allylamine, paraformaldehyde and cardanol; according to the chalcone benzoxazine, paeonol and terephthalaldehyde are subjected to a Claisen-Schmidt reaction to prepare a chalcone intermediate, and then the chalcone intermediate, gamma-aminopropyltriethoxysilane and paraformaldehyde are subjected to a Mannich reaction to prepare the chalcone benzoxazine. The dust removal filter bag prepared by the invention has good mechanical properties, high temperature resistance, flame retardance, antibacterial property and hydrophobicity.

Description

Technical Field

[0001] This invention belongs to the field of dust collector filter bag technology, specifically relating to a polyester fiber dust collector filter bag and its preparation method. Background Technology

[0002] Dust collector filter bags are a type of high-efficiency dust collection media. They can be made from materials such as polyester fiber, polyphenylene sulfide fiber, polytetrafluoroethylene fiber, aramid fiber, and glass fiber. Their service life is generally 2-4 years. They possess good air permeability, high dust collection rate, and are easy to clean, achieving a dust removal efficiency of up to 98.99%. Polyester fiber, in particular, has excellent abrasion resistance, light resistance, and corrosion resistance, as well as high strength and low deformation, making it increasingly used in industrial dust filtration and other applications.

[0003] However, polyester fiber has a low limiting oxygen index and is flammable. When burning, it produces a large amount of molten droplets, which can quickly spread the flame to other combustible materials. At the same time, the mechanical properties of filter media made of polyester fiber needle punching still cannot meet the requirements for long-term use at high temperatures. Furthermore, existing polyester fiber dust collector filter bags do not have antibacterial properties, but due to the high surface area of ​​the fiber, the filter media made of polyester fiber needle punching is prone to adsorbing bacteria. In addition, when existing polyester fiber dust collector filter bags are used in areas with high humidity to handle dust with high moisture content, the filter media is prone to clogging and other phenomena, which increases the pressure drop of the filter media, reduces the filtration efficiency of the dust collector, and shortens its service life. Summary of the Invention

[0004] To address the shortcomings mentioned in the background art, the present invention aims to provide a polyester fiber dust collector filter bag and its preparation method, thereby overcoming the deficiencies in the mechanical properties, high temperature resistance, flame retardancy, antibacterial properties, and hydrophobic properties of existing polyester fiber dust collector filter bags.

[0005] The objective of this invention can be achieved through the following technical solutions: A polyester fiber dust collector filter bag is made of modified polyester fiber and reinforcing fiber by needle punching. The modified polyester fiber is made by melt spinning after melt mixing of PET chips and composite material in a twin-screw extruder. The composite material is made by solution blending using DOPO-based benzoxazine derivative as matrix, graphene oxide as reinforcing agent, and chalcone-based benzoxazine as coupling agent. The DOPO-based benzoxazine derivative is prepared by a Mannich reaction of allylamine, paraformaldehyde, and cashew phenol, followed by a nucleophilic addition reaction of the prepared double-bonded benzoxazine liquid with DOPO; the chalcone-based benzoxazine is prepared by a Claisen-Schmidt reaction of paeonol and terephthalaldehyde to obtain a chalcone intermediate, followed by a Mannich reaction of the chalcone intermediate, γ-aminopropyltriethoxysilane, and paraformaldehyde.

[0006] Preferably, the reinforcing fiber is one or more of basalt fiber, polyphenylene sulfide fiber, polytetrafluoroethylene fiber, glass fiber, aramid fiber, and polyimide fiber; the mass ratio of the modified polyester fiber to the reinforcing fiber is 5~8:1~2.

[0007] Preferably, the mass ratio of the PET chips to the composite material is 1:0.05~0.25.

[0008] Preferably, the preparation method of the composite material includes the following steps: taking DOPO-based benzoxazine derivative and chloroform solvent and stirring to mix, then adding graphene oxide and chalcone-based benzoxazine, stirring and reacting at 75~85℃ for 2~3h, after the reaction is completed, rotary evaporation to remove the solvent and drying to prepare the composite material.

[0009] Preferably, the mass ratio of the DOPO-based benzoxazine derivative, graphene oxide, and chalcone-based benzoxazine is 1:0.03 to 0.06:1.

[0010] Preferably, the method for preparing the DOPO-based benzoxazine derivative includes the following steps: (1) Allylamine, paraformaldehyde and anhydrous ethanol were placed in a reactor, nitrogen gas was introduced and the mixture was stirred in an ice-water bath for 0.5-1h, then cashew phenol was added dropwise and the mixture was stirred at 90-95℃ for 10-12h. After the reaction was completed, the solvent was removed by rotary evaporation and the product was dried under vacuum. The product was dissolved in chloroform and purified by sodium hydroxide solution. The lower layer was taken with a separatory funnel and washed with deionized water until neutral. Finally, the solvent was removed by rotary evaporation and the product was dried to prepare double-bonded benzoxazine liquid. (2) Take double-bonded benzoxazine liquid, DOPO and anhydrous ethanol into a reactor, and stir the reaction at 60~70℃ for 7~9h under nitrogen protection. After the reaction is completed, remove the solvent by rotary evaporation and dry to prepare DOPO-based benzoxazine derivative.

[0011] Preferably, the molar ratio of allylamine, paraformaldehyde, and cashew phenol is 1:2:1; and the molar ratio of the double-bonded benzoxazine liquid and DOPO is 2:1.

[0012] Preferably, the method for preparing the chalcone-benzoxazine includes the following steps: ① Take paeonol and terephthalaldehyde in a reactor, add anhydrous ethanol, stir and dissolve at 45~55℃, then slowly add 50% sodium hydroxide solution, stir and react for 5~8h, after the reaction is completed, cool to room temperature, add dilute hydrochloric acid solution to adjust the pH of the system to 6, filter the precipitate and recrystallize with ethanol to prepare chalcone intermediate; ② Take γ-aminopropyltriethoxysilane, paraformaldehyde and chloroform in a reactor, introduce nitrogen gas and stir for 0.5-1h for pre-reaction, then add a mixed solution of chalcone intermediate and chloroform dropwise, place at 90-95℃ and stir for 7-9h. After the reaction is completed, remove the solvent by rotary evaporation and vacuum dry. The reaction product is dissolved in chloroform and purified by removing impurities with 4% sodium hydroxide solution to prepare chalcone-based benzoxazine.

[0013] Preferably, the molar ratio of paeonol to terephthalaldehyde is 2:1; and the molar ratio of γ-aminopropyltriethoxysilane, paraformaldehyde, and chalcone intermediate is 2:4:1.

[0014] The method for preparing the polyester fiber dust collector filter bag as described above includes the following steps: S1. Crush PET chips and pass them through a 30-mesh sieve. Dry the crushed and sieved PET powder and composite material at 120℃ for 12 hours. After mixing evenly, melt-mix them through a twin-screw extruder. The twin-screw temperature settings are: Zone 1 120℃, Zone 2 230℃, Zone 3 240℃, Zone 4 260℃, Zone 5 265℃, and Die head 265℃. The screw speed is 200 r / min. Then, use a melt spinning machine to spin the fibers at a spinning temperature of 270~275℃ to prepare modified polyester fibers. S2. Modified polyester fiber and reinforcing fiber are added to the opening machine and loosened into cotton-like form. At the same time, they are mixed and impurities are removed during the loosening process. The opened and mixed fiber raw materials are fed into the carding machine by quantitative feeding method. The fiber web is laid in a cross-laying manner and then needle punched to form a polyester fiber dust collector filter bag.

[0015] The beneficial effects of this invention are: This invention utilizes allylamine, paraformaldehyde, and cashew nut shell phenol to undergo a Mannich reaction to prepare a double-bonded benzoxazine liquid. Then, a nucleophilic addition reaction is performed between the -PH bond in DOPO and the double-bonded benzoxazine liquid to prepare a DOPO-based benzoxazine derivative. Simultaneously, this invention uses paeonol and terephthalaldehyde as starting materials to prepare a chalcone intermediate via a Claisen-Schmidt reaction. Then, a Mannich reaction is performed between the phenolic hydroxyl group on the chalcone intermediate, γ-aminopropyltriethoxysilane, and paraformaldehyde to prepare a chalcone-based benzoxazine. Furthermore, this invention uses the DOPO-based benzoxazine derivative as a matrix, graphene oxide as a reinforcing agent, and chalcone-based benzoxazine as a coupling agent to prepare a DOPO-based benzoxazine derivative / graphene oxide / chalcone-based benzoxazine composite material using a solution blending method. The composite material is then melt-mixed with PET chips using a twin-screw extruder under high temperature conditions. During the curing process, the oxazine rings in the DOPO-based benzoxazine derivative and the chalcone intermediate open, generating -OH groups. The chalcone intermediate itself also undergoes ring-opening polymerization. Simultaneously, the silanol groups in the chalcone intermediate react and crosslink with the carboxyl groups on the graphene oxide surface and the -OH groups formed by the DOPO-based benzoxazine derivative, thus constructing the composite material. The oxazine rings, phosphaphenanthrene groups, and chalcone structure introduced into this composite material endow the fiber material with excellent flame retardant, high-temperature resistance, and antibacterial properties. It also improves the dispersibility of graphene oxide in the matrix, avoiding performance defects caused by graphene oxide agglomeration, and imparts good mechanical properties to the fiber material. Furthermore, the DOPO-based benzoxazine derivative has a long aliphatic chain. The low surface energy of the DOPO-based benzoxazine derivative and the synergistic effect from the rough structure of the composite material endow the fiber material with excellent hydrophobic properties. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1: A method for preparing a DOPO-based benzoxazine derivative includes the following steps: (1) Take 5.7g of allylamine, 6.6g of paraformaldehyde and 100mL of anhydrous ethanol into a reactor, introduce nitrogen gas and stir in an ice-water bath for 1h, then add 30.4g of cashew phenol dropwise, stir at 95℃ for 10h, remove the solvent by rotary evaporation and dry under vacuum, dissolve the reaction product in chloroform, remove impurities and purify with 4% sodium hydroxide solution, take the lower layer liquid with a separatory funnel and wash with deionized water until neutral, finally remove the solvent by rotary evaporation and dry to prepare double bonded benzoxazine liquid; (2) Take 19.3g of double-bonded benzoxazine liquid, 5.4g of DOPO and 200mL of anhydrous ethanol into a reactor, and stir the reaction at 65℃ for 8h under nitrogen protection. After the reaction is completed, remove the solvent by rotary evaporation and dry to prepare DOPO-based benzoxazine derivative.

[0018] Example 2 A method for preparing a chalcone-based benzoxazine includes the following steps: ① Take 0.83g of paeonol and 0.67g of terephthalaldehyde in a reactor, add 15mL of anhydrous ethanol, stir and dissolve at 50℃, then slowly add 1.5mL of 50% sodium hydroxide solution, stir and react for 6h. After the reaction is completed, cool to room temperature, add 6mol / L dilute hydrochloric acid solution to adjust the pH of the system to 6, filter the precipitate and recrystallize with 95% ethanol to prepare chalcone intermediate; ② The reaction was carried out at a molar ratio of γ-aminopropyltriethoxysilane, paraformaldehyde, and chalcone intermediate of 2:4:1. First, γ-aminopropyltriethoxysilane, paraformaldehyde, and 200 mL of chloroform were placed in a reactor, and nitrogen gas was introduced and the mixture was stirred for 1 h for pre-reaction. Then, the corresponding amount of chalcone intermediate and 20 mL of chloroform were added dropwise, and the mixture was stirred at 95 °C for 8 h. After the reaction was completed, the solvent was removed by rotary evaporation and the product was dried under vacuum. The reaction product was dissolved in chloroform and purified by removing impurities with a 4% sodium hydroxide solution to prepare chalcone-based benzoxazine.

[0019] Example 3 A method for preparing a composite material includes the following steps: 5g of DOPO-based benzoxazine derivative prepared in Example 1 and 100mL of chloroform solvent are mixed and stirred. Then, 0.2g of graphene oxide and 5g of chalcone-based benzoxazine prepared in Example 2 are added and stirred at 80°C for 3h. After the reaction is completed, the solvent is removed by rotary evaporation and dried to obtain the composite material.

[0020] Example 4: A method for preparing a polyester fiber dust collector filter bag, comprising the following steps: S1. Crush PET chips and pass them through a 30-mesh sieve. Dry the crushed and sieved PET powder and the composite material prepared in Example 3 at 120°C for 12 hours. Mix them evenly at a mass ratio of 1:0.06 and then melt-mix them through a twin-screw extruder. The twin-screw temperature settings are: Zone 1 120°C, Zone 2 230°C, Zone 3 240°C, Zone 4 260°C, Zone 5 265°C, and Die Head 265°C. The screw speed is 200 r / min. Then, the fibers are spun using a melt spinning machine at a spinning temperature of 270°C to obtain modified polyester fibers. S2. Modified polyester fiber and basalt fiber are added to the opening machine at a mass ratio of 5.2:1.3 and loosened into a cotton-like state. Simultaneously, mixing and impurity removal are carried out during the loosening process. The loosened and uniformly mixed fiber raw material is then fed into the carding machine using a quantitative feeding method, and a cross-laid web is used. The fiber web is then needle-punched to form an areal density of 500 g / m². 2 2.2mm thick polyester fiber dust collector filter bag.

[0021] Example 5: A method for preparing a polyester fiber dust collector filter bag, comprising the following steps: S1. Crush PET chips and pass them through a 30-mesh sieve. Dry the crushed and sieved PET powder and the composite material prepared in Example 3 at 120°C for 12 hours. Mix them evenly at a mass ratio of 1:0.15 and then melt-mix them through a twin-screw extruder. The twin-screw temperature settings are: Zone 1 120°C, Zone 2 230°C, Zone 3 240°C, Zone 4 260°C, Zone 5 265°C, and Die Head 265°C. The screw speed is 200 r / min. Then, use a melt spinning machine to spin the fibers at a spinning temperature of 270°C to obtain modified polyester fibers. S2. Modified polyester fiber and basalt fiber are added to the opening machine at a mass ratio of 6.7:1.6 and loosened into a cotton-like state. Simultaneously, mixing and impurity removal are carried out during the loosening process. The opened and uniformly mixed fiber raw material is then fed into the carding machine using a quantitative feeding method, and a cross-laid web is used. The fiber web is then needle-punched to form an areal density of 500 g / m². 2 2.2mm thick polyester fiber dust collector filter bag.

[0022] Example 6 A method for preparing a polyester fiber dust collector filter bag, comprising the following steps: S1. Crush PET chips and pass them through a 30-mesh sieve. Dry the crushed and sieved PET powder and the composite material prepared in Example 3 at 120°C for 12 hours. Mix them evenly at a mass ratio of 1:0.22 and then melt-mix them through a twin-screw extruder. The twin-screw temperature settings are: Zone 1 120°C, Zone 2 230°C, Zone 3 240°C, Zone 4 260°C, Zone 5 265°C, and Die Head 265°C. The screw speed is 200 r / min. Then, use a melt spinning machine to spin the fibers at a spinning temperature of 270°C to obtain modified polyester fibers. S2. Modified polyester fiber and basalt fiber are added to the opening machine at a mass ratio of 7.7:1.8 and loosened into a cotton-like state. Simultaneously, mixing and impurity removal are performed during the loosening process. The opened and uniformly mixed fiber raw material is then fed into the carding machine using a quantitative feeding method, and a cross-laid web is constructed. The fiber web is then needle-punched to form a surface density of 500 g / m². 2 2.2mm thick polyester fiber dust collector filter bag.

[0023] Comparative Example 1: A method for preparing a paeonol-benzoxazine includes the following steps: The reaction was carried out with γ-aminopropyltriethoxysilane, paraformaldehyde, and paeonol in a molar ratio of 1:2:1. First, γ-aminopropyltriethoxysilane, paraformaldehyde, and 200 mL of chloroform were placed in a reactor and stirred under nitrogen for 1 h for pre-reaction. Then, the corresponding amount of a mixed solution of paeonol and 20 mL of chloroform was added dropwise, and the mixture was stirred at 95 °C for 8 h. After the reaction was completed, the solvent was removed by rotary evaporation and the product was dried under vacuum. The reaction product was dissolved in chloroform and purified by removing impurities with a 4% sodium hydroxide solution to prepare paeonol-based benzoxazine.

[0024] Comparative Example 2: A method for preparing a composite material includes the following steps: 5g of DOPO-based benzoxazine derivative prepared in Example 1 and 100mL of chloroform solvent are mixed and stirred. Then, 0.2g of graphene oxide and 5g of paeonol-based benzoxazine prepared in Comparative Example 1 are added and stirred at 80°C for 3h. After the reaction is completed, the solvent is removed by rotary evaporation and dried to obtain the composite material.

[0025] Comparative Example 3: A method for preparing a composite material includes the following steps: 5g of the DOPO-based benzoxazine derivative prepared in Example 1 and 100mL of chloroform solvent are mixed and stirred, then 0.2g of graphene oxide is added, and the mixture is stirred and reacted at 80℃ for 3h. After the reaction is completed, the solvent is removed by rotary evaporation and dried to obtain the composite material.

[0026] Comparative Example 4: A method for preparing a composite material includes the following steps: 5g of chalcone-benzoxazine prepared in Example 2 and 100mL of chloroform solvent are mixed and stirred, then 0.2g of graphene oxide is added, and the mixture is stirred at 80℃ for 3h. After the reaction is completed, the solvent is removed by rotary evaporation and dried to obtain the composite material.

[0027] Comparative Example 5: A method for preparing a polyester fiber dust collector filter bag, comprising the following steps: S1. Crush PET chips and pass them through a 30-mesh sieve. Dry the crushed and sieved PET powder and the composite material prepared in Comparative Example 2 at 120℃ for 12 hours. Mix them evenly at a mass ratio of 1:0.22 and then melt-mix them through a twin-screw extruder. The twin-screw temperature settings are: Zone 1 120℃, Zone 2 230℃, Zone 3 240℃, Zone 4 260℃, Zone 5 265℃, and Die Head 265℃. The screw speed is 200 r / min. Then, use a melt spinning machine to spin the fibers at a spinning temperature of 270℃ to obtain modified polyester fibers. S2. Modified polyester fiber and basalt fiber are added to the opening machine at a mass ratio of 7.7:1.8 and loosened into a cotton-like state. Simultaneously, mixing and impurity removal are performed during the loosening process. The opened and uniformly mixed fiber raw material is then fed into the carding machine using a quantitative feeding method, and a cross-laid web is constructed. The fiber web is then needle-punched to form a surface density of 500 g / m². 2 2.2mm thick polyester fiber dust collector filter bag.

[0028] Comparative Example 6: A method for preparing a polyester fiber dust collector filter bag, comprising the following steps: S1. Crush PET chips and pass them through a 30-mesh sieve. Dry the crushed and sieved PET powder and the composite material prepared in Comparative Example 3 at 120℃ for 12 hours. Mix them evenly at a mass ratio of 1:0.22 and then melt-mix them through a twin-screw extruder. The twin-screw temperature settings are: Zone 1 120℃, Zone 2 230℃, Zone 3 240℃, Zone 4 260℃, Zone 5 265℃, and Die Head 265℃. The screw speed is 200 r / min. Then, use a melt spinning machine to spin the fibers at a spinning temperature of 270℃ to obtain modified polyester fibers. S2. Modified polyester fiber and basalt fiber are added to the opening machine at a mass ratio of 7.7:1.8 and loosened into a cotton-like state. Simultaneously, mixing and impurity removal are performed during the loosening process. The opened and uniformly mixed fiber raw material is then fed into the carding machine using a quantitative feeding method, and a cross-laid web is constructed. The fiber web is then needle-punched to form a surface density of 500 g / m². 2 2.2mm thick polyester fiber dust collector filter bag.

[0029] Comparative Example 7: A method for preparing a polyester fiber dust collector filter bag, comprising the following steps: S1. Crush PET chips and pass them through a 30-mesh sieve. Dry the crushed and sieved PET powder and the composite material prepared in Comparative Example 4 at 120℃ for 12 hours. Mix them evenly at a mass ratio of 1:0.22 and then melt-mix them through a twin-screw extruder. The twin-screw temperature settings are: Zone 1 120℃, Zone 2 230℃, Zone 3 240℃, Zone 4 260℃, Zone 5 265℃, and Die Head 265℃. The screw speed is 200 r / min. Then, use a melt spinning machine to spin the fibers at a spinning temperature of 270℃ to prepare modified polyester fibers. S2. Modified polyester fiber and basalt fiber are added to the opening machine at a mass ratio of 7.7:1.8 and loosened into a cotton-like state. Simultaneously, mixing and impurity removal are performed during the loosening process. The opened and uniformly mixed fiber raw material is then fed into the carding machine using a quantitative feeding method, and a cross-laid web is constructed. The fiber web is then needle-punched to form a surface density of 500 g / m². 2 2.2mm thick polyester fiber dust collector filter bag.

[0030] Performance testing The performance of the polyester fiber dust collector filter bags prepared in Examples 4-6 and Comparative Examples 5-7 was tested: (1) Mechanical property testing: The breaking strength and elongation at break were tested in accordance with GB / T 24218.3-2010, and the data results are shown in Table 1.

[0031] (2) High temperature resistance test: The filter bag was placed in the oven and heated to 220℃ at a rate of 2℃ / min and then kept at the temperature for 24h. The breaking strength of the sample before and after treatment was measured. The high temperature resistance of the sample was evaluated by the breaking strength retention rate. The data results are shown in Table 1.

[0032] (3) Flame retardant performance test: The limiting oxygen index was used to evaluate the flame retardant performance, and the data results are shown in Table 1.

[0033] (4) Antibacterial performance test: The antibacterial rate was tested according to GB / T 20944.3-2008. The test species were Escherichia coli and Staphylococcus aureus. The data results are shown in Table 1.

[0034] (5) Hydrophobicity test: After rinsing the sample twice with ethanol, dry it in an oven until constant weight and record the mass M0. Then immerse it in a beaker containing deionized water and let it stand for 48 hours. Take it out, place it on a 100-mesh standard sieve and let it stand for 30 minutes until no liquid drops fall. Then weigh it and record the mass M1. Perform water absorption test. The water absorption rate is calculated by the following formula: water absorption rate = (M1-M0) / M0×100%. The data results are shown in Table 1.

[0035] As can be seen from the data in Table 1, the polyester fiber dust collector filter bags prepared in Examples 4-6 of this invention possess good mechanical properties, high-temperature resistance, flame retardancy, antibacterial properties, and hydrophobic properties. In Comparative Example 5, the composite material added replaced an equal amount of chalcone-based benzoxazine with paeonol-based benzoxazine, while the composite material added in Comparative Example 6 did not contain chalcone-based benzoxazine. The measured antibacterial rates of *Escherichia coli* and *Staphylococcus aureus* in Comparative Examples 5-6 were lower than those in Examples 4-6, indicating that the chalcone structure and the introduction of paeonol both improved the antibacterial properties of the samples to some extent. Furthermore, the measured tensile strength, elongation at break, high-temperature tensile strength retention rate, limiting oxygen index, and hydrophobic properties in Comparative Example 6 were significantly lower than those in Examples 4-6. This is because the chalcone structure... DOPO-based benzoxazine can act as a coupling agent to react and crosslink with the carboxyl groups on the surface of graphene oxide and the -OH groups formed by DOPO-based benzoxazine derivatives, thereby further improving the mechanical properties, high-temperature resistance, flame retardancy, and hydrophobicity of the sample. The composite material added in Comparative Example 7 did not contain DOPO-based benzoxazine derivatives, and its measured high-temperature breaking strength retention rate, limiting oxygen index, and hydrophobicity were lower than those in Examples 4-6, indicating that the introduction of DOPO-based benzoxazine derivatives is beneficial to improving the high-temperature resistance, flame retardancy, and hydrophobicity of the sample.

[0036] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0037] The foregoing has shown and described 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. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A dust filter bag of polyester fiber, characterized by, The modified polyester fiber and the reinforcing fiber are needled, the modified polyester fiber is made by melting and spinning after PET chip and composite material are melt-mixed by a double screw extruder; the composite material is made by solution blending method using DOPO-based benzoxazine derivative as matrix, graphene oxide as reinforcing body and chalcone-based benzoxazine as coupling agent; The DOPO-based benzoxazine derivative is made by Mannich reaction of allylamine, paraformaldehyde and cardanol, then nucleophilic addition reaction of the prepared double-bonded benzoxazine liquid and DOPO; the chalcone-based benzoxazine is made by Claisen-Schmidt reaction of paeonol and p-xylene glycol, then Mannich reaction of the chalcone intermediate, γ-aminopropyl triethoxysilane and paraformaldehyde.

2. The polyester fiber dedusting filter bag according to claim 1, characterized in that, The reinforcing fiber is one or more combinations of basalt fiber, polyphenylene sulfide fiber, polytetrafluoroethylene fiber, glass fiber, aramid fiber and polyimide fiber; the mass ratio of the modified polyester fiber and the reinforcing fiber is 5-8:1-2.

3. The polyester fiber dedusting filter bag according to claim 1, characterized in that, The mass ratio of the PET chip and the composite material is 1:0.05-0.

25.

4. The polyester fiber dust filtration bag according to claim 1, wherein The preparation method of the composite material comprises the following steps: stirring and mixing DOPO-based benzoxazine derivative and chloroform solvent, then adding graphene oxide and chalcone-based benzoxazine, stirring and reacting at 75-85 DEG C for 2-3 h, removing the solvent by rotary evaporation after the reaction is completed and drying to prepare the composite material.

5. The polyester fiber dust filtration bag according to claim 4, wherein The mass ratio of the DOPO-based benzoxazine derivative, graphene oxide and chalcone-based benzoxazine is 1:0.03-0.06:

1.

6. The polyester fiber dust filtration bag of claim 1, wherein The preparation method of the DOPO-based benzoxazine derivative comprises the following steps: (1) putting allylamine, paraformaldehyde and anhydrous ethanol into a reactor, bubbling nitrogen and stirring in an ice water bath for 0.5-1 h, then adding cardanol drop by drop, stirring and reacting at 90-95 DEG C for 10-12 h, removing the solvent by rotary evaporation after the reaction is completed and vacuum drying, dissolving the reaction product in chloroform, purifying by sodium hydroxide solution, taking the lower layer liquid by a separatory funnel and washing with deionized water until neutral, finally removing the solvent by rotary evaporation and drying to prepare double-bonded benzoxazine liquid; (2) putting double-bonded benzoxazine liquid, DOPO and anhydrous ethanol into a reactor, protecting in nitrogen and stirring and reacting at 60-70 DEG C for 7-9 h, removing the solvent by rotary evaporation after the reaction is completed and drying to prepare DOPO-based benzoxazine derivative.

7. The polyester fiber dust filtration bag according to claim 6, wherein The molar ratio of the allylamine, paraformaldehyde and cardanol is 1:2:1; the molar ratio of the double-bonded benzoxazine liquid and DOPO is 2:

1.

8. The polyester fiber dust filtration bag of claim 1, wherein, The preparation method of the chalcone-based benzoxazine comprises the following steps: ① putting paeonol and p-xylene glycol into a reactor, adding anhydrous ethanol, stirring and dissolving at 45-55 DEG C, then slowly adding 50% mass fraction sodium hydroxide solution, stirring and reacting for 5-8 h, cooling to room temperature after the reaction is completed, adding dilute hydrochloric acid solution to adjust the pH value of the system to 6, filtering the precipitated product and recrystallizing with ethanol to prepare chalcone intermediate; ②Take γ-aminopropyl triethoxysilane, paraformaldehyde and chloroform in a reactor, stir and pre-react for 0.5-1h under nitrogen, then add the mixed solution of chalcone intermediate and chloroform drop by drop, stir and react at 90-95℃ for 7-9h, remove the solvent by rotary evaporation after the reaction is completed, and dry in vacuum, dissolve the reaction product in chloroform, purify by using 4% sodium hydroxide solution, and obtain chalcone-based benzoxazine.

9. The polyester fiber dust filtration bag according to claim 8, wherein, The molar ratio of the paeonol and p-xylylene is 2:1; the molar ratio of the γ-aminopropyl triethoxysilane, paraformaldehyde and chalcone intermediate is 2:4:

1.

10. A method of manufacturing the polyester fiber dedusting filter bag according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: S1, crush the PET chips through a 30-mesh screen, dry the crushed and screened PET powder and the composite material at 120℃ for 12h, mix them uniformly, melt mix them through a double-screw extruder, set the double-screw temperature as follows: zone 1, 120℃; zone 2, 230℃; zone 3, 240℃; zone 4, 260℃; zone 5, 265℃; and the die head, 265℃, the screw rotation speed is 200r / min, then spin the mixture through a melt spinning machine, the spinning temperature is 270-275℃, and obtain the modified polyester fiber; S2, add the modified polyester fiber and the reinforcing fiber into an opener, and make them into cotton-like shape by loosening, at the same time, mix and remove impurities during the loosening process, feed the opened and mixed fiber raw material into a carding machine through a quantitative feeding method, adopt cross-laying, then needle punch the fiber web, and obtain the polyester fiber dust removal filter bag.

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