Ultra-high temperature dust removal bag material and preparation method thereof

Abstract

The present invention discloses an ultra-high temperature dust bag material and a preparation method thereof, and relates to the technical field of filter materials. The present invention discloses a preparation method of an ultra-high temperature dust bag material, comprising the following steps: extruding modified polyphenylene sulfide through a twin-screw extruder and granulating to obtain a masterbatch; melt-spinning, stretching, and heat-setting the masterbatch to obtain an ultra-high temperature dust bag material; and obtaining the modified polyphenylene sulfide by grafting acetylated polyphenylene sulfide with modified nano-montmorillonite and then hydrolyzing and cross-linking. The modified nano-montmorillonite prepared in the present application is added to polyphenylene sulfide to not only improve the toughness and other mechanical properties of polyphenylene sulfide, but also effectively increase the service life of polyphenylene sulfide in a high-oxygen and high-temperature environment, so that the dust bag prepared with modified polyphenylene sulfide as raw material has oxidation resistance and excellent mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of filter materials, and in particular to an ultra-high temperature dust removal bag material and a preparation method thereof. Background Art

[0002] With the advancement of science and technology and the enhancement of people's environmental awareness, the prevention and control of air pollution, especially the filtration of high-temperature smoke from industries such as waste incineration, metallurgy, and steel, has received more attention. The industrial exhaust gas emitted by thermal power generation, steel, waste incineration, and other industries is not only high in temperature, but also contains a variety of corrosive oxidizing gases such as SO X 、NO X , HCl, dioxanes, etc., general chemical fiber filter media have poor filtering effects and short service life. Polyphenylene sulfide, the full name of polyphenylene sulfide (PPS for short), is a highly crystalline aromatic sulfur polymer. PPS is a rigid main chain formed by alternating benzene rings and sulfur atoms. The large number of benzene rings on the main chain gives the PPS macromolecule good rigidity, and the sulfur atoms give the PPS macromolecule a certain flexibility. The presence of large π bonds in the structure makes the performance of PPS very stable. The limiting oxygen index of PPS is greater than 43, and its combustion performance reaches UL94V-1 level. It has good thermal stability, excellent chemical corrosion resistance and electrical insulation. PPS has become one of the preferred filter materials for high-temperature flue gas and special heat medium filtration, such as dust removal of flue gas from coal-fired power plants and exhaust filtration of urban waste incineration plants.

[0003] Although PPS fiber is currently recognized as the most suitable material for dust removal bags, from the perspective of PPS's inherent physical properties, and due to the presence of sulfur bonds on the PPS macromolecular chain, sulfur in the molecular structure exists in a divalent state. Due to the instability of sulfur's outermost electrons, it has multiple valences and is prone to losing electrons and combining with oxygen. This makes PPS fiber susceptible to oxidation in a high-temperature environment with a high oxygen content, causing a serious loss of thermal strength. This, in turn, leads to degradation and macromolecular breakage due to oxidation, greatly reducing the overall performance of the material. When polyphenylene sulfide fiber is used as a filter material for high-temperature flue gas in power plants, steel mills, etc., the high-temperature flue gas contains 7-8% oxygen, with the maximum oxygen content reaching 14%. The temperature of the high-temperature flue gas is generally 160-180°C, and may instantly reach above 200°C. In such a long-term strong oxidizing atmosphere, the sulfur bonds of polyphenylene sulfide undergo oxidation, and the filter material ages; the fiber strength is reduced, and its products are more brittle, have poor toughness, and lack rigidity and strength. They cannot meet the strength loss requirements of the exhaust gas treatment process of power plants, cement plants, waste incineration plants and other enterprises, and the service life of the filter bag is significantly shortened, thereby reducing the scope of use and service life of the dust bag. Summary of the Invention

[0004] The purpose of the present invention is to provide an ultra-high temperature dust bag material and a preparation method thereof to solve the following technical problems:

[0005] Due to the inherent physical properties of existing PPS fibers, the mechanical properties and high-temperature resistance under oxygen-containing conditions of the materials are poor, which greatly reduces the service life of the materials.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing an ultra-high temperature dust bag material comprises the following steps:

[0008] A1: Modified polyphenylene sulfide is extruded through a twin-screw extruder and pelletized to obtain a masterbatch;

[0009] A2: Melt-spinning, stretching, and heat-setting the masterbatch to obtain ultra-high temperature dust bag material;

[0010] The preparation method of modified polyphenylene sulfide comprises the following steps:

[0011] S1: In a nitrogen atmosphere, polyphenylene sulfide and dichloromethane were added to a reaction kettle, and the mixture was allowed to stand at room temperature for 12-18 hours. The temperature was controlled at 0-5°C, and anhydrous aluminum chloride and acetyl chloride were added. The mixture was allowed to react at room temperature for 1-3 hours. The temperature was controlled at 35-45°C, and the mixture was kept warm for 2-4 hours. An icy hydrochloric acid solution was added to terminate the reaction. The mixture was filtered, washed with sodium hydroxide solution, water, ethanol, and dried to obtain component 1.

[0012] S2: Component 1 and anhydrous toluene were added to a reaction kettle and dispersed evenly. Modified nano-montmorillonite, acetic acid, and 4A molecular sieve were added. The temperature was controlled at 90-100°C and the reaction was kept warm for 9-15 hours. The mixture was filtered, washed, extracted with ethanol, and dried to obtain component 2.

[0013] S3: Add component 2 and deionized water into a reaction kettle and disperse them evenly. Control the temperature at 90-100° C., adjust the pH to 4-5, add dibutyltin dilaurate, keep the reaction warm for 12-24 hours, filter and dry to obtain modified polyphenylene sulfide.

[0014] As a further solution of the present invention, polyphenylene sulfide is pretreated before preparing modified polyphenylene sulfide: polyphenylene sulfide is dried in a vacuum drum dryer at 140° C. and a vacuum degree of -0.08 to -0.085 MPa to control the moisture content of PPS to below 28 ppm.

[0015] As a further embodiment of the present invention, the hydrochloric acid icy aqueous solution in S1 is obtained by mixing hydrochloric acid and ice water in a volume ratio of 1:1; the addition ratio of polyphenylene sulfide, dichloromethane, anhydrous aluminum chloride, acetyl chloride, and hydrochloric acid icy aqueous solution is 10 g: 50-100 mL: 15-18 g: 5-10 mL: 50-100 mL.

[0016] As a further solution of the present invention: the addition ratio of component 1, anhydrous toluene, modified nano-montmorillonite, acetic acid, and 4A molecular sieve in S2 is 10g:150-200mL:0.8-1.5g:1-2mL:3-5g.

[0017] As a further solution of the present invention: the addition ratio of component 2, deionized water, and dibutyltin dilaurate in S3 is 10g:100-200g:1-5g.

[0018] As a further solution of the present invention: the preparation method of modified nano-montmorillonite comprises the following steps:

[0019] B1: Methanol, distilled water, and γ-aminopropyltriethoxysilane were added to a reaction flask and dispersed evenly. Glacial acetic acid was added to adjust the pH to 4-5. The temperature was controlled at 50-60°C and kept warm under stirring for 1-3 hours. Nano-montmorillonite was added and the temperature was controlled at 70-80°C. The temperature was kept warm under stirring for 1-3 hours. The mixture was washed with water and dried to obtain the organic montmorillonite.

[0020] B2: Add the organic montmorillonite, pyromellitic anhydride, and N,N-dimethylformamide into a reaction kettle and disperse them evenly. Control the temperature to 45-55°C, keep stirring for 3-6 hours, filter, and dry to obtain anhydride montmorillonite.

[0021] B3: In a nitrogen atmosphere, 4,4'-diaminodiphenyl sulfide and N,N-dimethylformamide were added to a reaction kettle and dispersed evenly. Anhydride-treated montmorillonite was added and reacted at room temperature for 3-6 hours. The mixture was filtered, washed with water, and dried to obtain modified nano-montmorillonite.

[0022] As a further solution of the present invention: the addition ratio of methanol, distilled water, γ-aminopropyltriethoxysilane and nano-montmorillonite in B1 is 20-40 mL: 80-160 mL: 4-6 g: 10 g.

[0023] As a further embodiment of the present invention, the addition ratio of the organized montmorillonite, pyromellitic anhydride, and N,N-dimethylformamide in B2 is 10 g: 20-50 g: 100-200 mL.

[0024] As a further embodiment of the present invention, the addition ratio of 4,4'-diaminodiphenyl sulfide, N,N-dimethylformamide, and anhydride-treated montmorillonite in B3 is 4.5-7.5 g: 100-200 mL: 10 g.

[0025] As a further embodiment of the present invention, the melt temperature during extrusion in the twin-screw extruder in A1 is 300-310°C and the screw speed is 180-210 rpm; the spinning speed during melt spinning in A2 is 500-600 m / min; the stretching ratio during stretching in A2 is 3-4.5 and the stretching temperature is 75-105°C; and the heat setting temperature in A2 is 185-210°C.

[0026] An ultra-high temperature dust removal bag material, made by any of the above preparation methods.

[0027] Beneficial effects of the present invention:

[0028] (1) The present application first uses γ-aminopropyltriethoxysilane to carry out organic treatment on nano-montmorillonite, and the Si element in the silane coupling agent effectively increases the Si element in the montmorillonite, thereby improving the thermal stability of the montmorillonite; and the montmorillonite modified with the organic silane coupling agent and the active group not only improves the lipophilicity of the material, but also increases the reaction activity of the material; the present application continues to use the anhydride group on one side of the pyromellitic anhydride to open the ring and react with the amino group between the organic montmorillonite layers, so that the anhydride groups are indirectly branched in the montmorillonite layers, which not only effectively increases the spacing between the montmorillonite layers, but also makes the surface of the material rougher, thereby improving its subsequent composite with polyphenylene sulfide; finally, the present application uses the anhydride groups in the anhydride montmorillonite to react with 4,4'-diaminodiphenyl sulfide to obtain modified nano-montmorillonite; the modified nano-montmorillonite prepared in the present application is indirectly branched with carboxyl groups, amino groups, sulfide groups and organic silicon molecular chains in the montmorillonite layers.

[0029] The present application utilizes anhydrous aluminum trichloride as a Lewis acid to complex with acetyl chloride to provide acyl cations. The acyl cations attack the benzene ring, causing a Friede-Crafts reaction, connecting the ketone carbonyl group to the benzene ring of polyphenylene sulfide. The generated aryl ketone is complexed with aluminum chloride and released during ice-water decomposition to obtain component one. The present application grafts and dopes the amino groups between the modified nano-montmorillonite layers onto the polyphenylene sulfide molecular chain through a chemical reaction, effectively solving the problem of shortened life of the polyphenylene sulfide filter material due to aerodynamic damage and mechanical damage during use, and effectively improving the toughness and strength of the polyphenylene sulfide at high temperatures.

[0030] The modified nano-montmorillonite grafted onto the polyphenylene sulfide molecular chain of the present application introduces stable and flexible SiO chains onto the polyphenylene sulfide molecular chain, which, on the one hand, is beneficial to improving the toughness of the polymer matrix; and after the grafting modification, the polarity of the polymer surface is increased, which is beneficial to compounding with some reinforcing phases with similar polarity or with coupling groups, solving the problem of compatibility between the two phases; on the other hand, the modified montmorillonite prepared in the present application is uniformly dispersed on the polyphenylene sulfide molecular chain. When subjected to axial tensile force, the polyphenylene sulfide produces slippage, thereby increasing toughness.

[0031] The present application improves the crystal morphology of polyphenylene sulfide by grafting modified montmorillonite, thereby increasing the strength of the material, improving the spinnability of the polymer, increasing the crystallization rate and crystallinity, and improving the fiber axial orientation of the polyphenylene sulfide macromolecules. The grafted sulfide structure on the modified montmorillonite prepared in the present application acts as a chain terminator for the polyphenylene sulfide macromolecules and also as a hydrogen peroxide decomposer. The montmorillonite can prevent oxygen infiltration, and the barrier effect of the montmorillonite can prevent some low-molecular degradation products from escaping from the system, thereby delaying the progress of thermal oxidative degradation and effectively improving the thermal oxidation resistance of the polyphenylene sulfide.

[0032] (2) The present application subjects the linear fiber-grade modified polyphenylene sulfide resin after melt spinning to stretching and heat setting treatment. The stretching treatment causes the macromolecular chains to be arranged in an orderly manner. This ordered arrangement effect causes the modified montmorillonite to be grafted with polyphenylene sulfide through the molecular chain, and the modified montmorillonite to be oriented along the axial direction of the fiber, thereby promoting the improvement of the fiber's crystal structure and making the fiber more stable. Moreover, under the action of stretching and heat setting, more crystal nuclei are generated in the fiber system, and the crystal nuclei form a physical cross-linked network structure with each other, thereby increasing the density of the primary fiber and the degree of crystallinity, so that the fiber has excellent mechanical properties, excellent thermal stability, flame retardancy and chemical corrosion resistance. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solutions in 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 are within the scope of protection of the present invention.

[0034] Example 1 The preparation method of modified nano-montmorillonite comprises the following steps:

[0035] B1: Add 20 mL of methanol, 80 mL of distilled water, and 4 g of γ-aminopropyltriethoxysilane to a reaction flask and disperse them evenly. Add glacial acetic acid to adjust the pH to 4, control the temperature to 50°C, and keep the mixture under stirring for 1 hour. Add 10 g of nano-montmorillonite, control the temperature to 70°C, and keep the mixture under stirring for 1 hour. Wash with water and dry to obtain organic montmorillonite.

[0036] B2: Add 10 g of organic montmorillonite, 20 g of pyromellitic anhydride, and 100 mL of N,N-dimethylformamide into a reaction kettle and disperse them evenly. Control the temperature at 45°C, keep stirring for 3 hours, filter, and dry to obtain anhydride montmorillonite.

[0037] B3: In a nitrogen atmosphere, 4.5 g of 4,4'-diaminodiphenyl sulfide and 100 mL of N,N-dimethylformamide were added to a reactor and dispersed evenly. 10 g of anhydride-treated montmorillonite was added and reacted at room temperature for 3 h. The mixture was filtered, washed with water, and dried to obtain modified nano-montmorillonite.

[0038] Example 2 The preparation method of modified nano-montmorillonite comprises the following steps:

[0039] B1: Add 30 mL of methanol, 120 mL of distilled water, and 5 g of γ-aminopropyltriethoxysilane to a reaction flask and disperse them evenly. Add glacial acetic acid to adjust the pH to 4, control the temperature to 55°C, and keep the mixture under stirring for 2 h. Add 10 g of nano-montmorillonite, control the temperature to 75°C, and keep the mixture under stirring for 2 h. Wash with water and dry to obtain organic montmorillonite.

[0040] B2: Add 10 g of organic montmorillonite, 35 g of pyromellitic anhydride, and 150 mL of N,N-dimethylformamide into a reaction kettle and disperse evenly. Control the temperature to 50°C, keep stirring for 4.5 hours, filter, and dry to obtain anhydride montmorillonite.

[0041] B3: In a nitrogen atmosphere, 6 g of 4,4'-diaminodiphenyl sulfide and 150 mL of N,N-dimethylformamide were added to a reactor and dispersed evenly. 10 g of anhydride-treated montmorillonite was added and reacted at room temperature for 4.5 h. The mixture was filtered, washed with water, and dried to obtain modified nano-montmorillonite.

[0042] Example 3 The preparation method of modified nano-montmorillonite comprises the following steps:

[0043] B1: Add 40 mL of methanol, 160 mL of distilled water, and 6 g of γ-aminopropyltriethoxysilane to a reaction flask and disperse them evenly. Add glacial acetic acid to adjust the pH to 5, control the temperature to 60°C, and keep the mixture under stirring for 3 h. Add 10 g of nano-montmorillonite, control the temperature to 80°C, and keep the mixture under stirring for 3 h. Wash with water and dry to obtain organic montmorillonite.

[0044] B2: Add 10 g of organic montmorillonite, 50 g of pyromellitic anhydride, and 200 mL of N,N-dimethylformamide into a reaction kettle and disperse them evenly. Control the temperature to 55°C, keep stirring for 6 hours, filter, and dry to obtain anhydride montmorillonite.

[0045] B3: In a nitrogen atmosphere, 7.5 g of 4,4'-diaminodiphenyl sulfide and 200 mL of N,N-dimethylformamide were added to a reactor and dispersed evenly. 10 g of anhydride-treated montmorillonite was added and reacted at room temperature for 6 h. The mixture was filtered, washed with water, and dried to obtain modified nano-montmorillonite.

[0046] The preparation method of modified polyphenylene sulfide in Example 4 comprises the following steps:

[0047] S1: drying the polyphenylene sulfide in a vacuum drum dryer at 140° C. and a vacuum degree of -0.08 MPa for 14 h to obtain pretreated polyphenylene sulfide;

[0048] S2: In a nitrogen atmosphere, 10 g of pretreated polyphenylene sulfide (Fortron fiber-type polyphenylene sulfide produced by Japan Polyplastics Group, Tm = 285 ° C) and 50 mL of dichloromethane were added to a reactor, and the mixture was allowed to stand at room temperature for 12 h. The temperature was controlled at 0 ° C. 15 g of anhydrous aluminum chloride and 5 mL of acetyl chloride were added, and the mixture was allowed to react at room temperature for 1 h. The temperature was controlled at 35 ° C. The mixture was kept warm for 2 h. 50 mL of hydrochloric acid and 50 mL of ice water were mixed and added to the reactor to terminate the reaction. The mixture was filtered, washed with 5% sodium hydroxide aqueous solution, washed with water, washed with ethanol, and dried to obtain component 1;

[0049] S3: 10 g of component 1 and 150 mL of anhydrous toluene were added to a reaction kettle and dispersed evenly. 0.8 g of the modified nano-montmorillonite prepared in Example 1 was added, along with 1 mL of acetic acid and 3 g of 4A molecular sieves. The temperature was controlled at 90° C. and the reaction was kept warm for 9 h. The mixture was filtered, washed, extracted with ethanol, and dried to obtain component 2.

[0050] S4: Add 10 g of component 2 and 100 g of deionized water into a reactor and disperse them evenly. Control the temperature at 90°C. Add 1 mol / L hydrochloric acid aqueous solution to adjust the pH to 4. Add 2 g of dibutyltin dilaurate. Keep the temperature and react for 18 h. Filter and dry to obtain modified polyphenylene sulfide.

[0051] Example 5 The preparation method of modified polyphenylene sulfide comprises the following steps:

[0052] S1: drying the polyphenylene sulfide in a vacuum drum dryer at 140° C. and a vacuum degree of -0.08 MPa for 14 h to obtain pretreated polyphenylene sulfide;

[0053] S2: In a nitrogen atmosphere, 10 g of pretreated polyphenylene sulfide (Fortron fiber-type polyphenylene sulfide produced by Japan Polyplastics Group, Tm = 285 ° C) and 70 mL of dichloromethane were added to a reactor, and the mixture was allowed to stand at room temperature for 15 h. The temperature was controlled at 0 ° C. 15 g of anhydrous aluminum chloride and 7 mL of acetyl chloride were added, and the mixture was allowed to react at room temperature for 2 h. The temperature was controlled at 40 ° C. The mixture was kept warm for 3 h. 50 mL of hydrochloric acid and 50 mL of ice water were mixed and added to the reactor to terminate the reaction. The mixture was filtered, washed with 5% sodium hydroxide aqueous solution, washed with water, washed with ethanol, and dried to obtain component 1;

[0054] S3: 10 g of component 1 and 200 mL of anhydrous toluene were added to a reaction kettle and dispersed evenly. 1.2 g of the modified nano-montmorillonite prepared in Example 2 was added, along with 1.5 mL of acetic acid and 4 g of 4A molecular sieves. The temperature was controlled at 95°C and the reaction was kept warm for 12 h. The mixture was filtered, washed, extracted with ethanol, and dried to obtain component 2.

[0055] S4: Add 10 g of component 2 and 100 g of deionized water into a reactor and disperse them evenly. Control the temperature at 90°C. Add 1 mol / L hydrochloric acid aqueous solution to adjust the pH to 4. Add 2 g of dibutyltin dilaurate. Keep the temperature and react for 18 h. Filter and dry to obtain modified polyphenylene sulfide.

[0056] The preparation method of modified polyphenylene sulfide of Example 6 comprises the following steps:

[0057] S1: drying the polyphenylene sulfide in a vacuum drum dryer at 140° C. and a vacuum degree of -0.08 MPa for 14 h to obtain pretreated polyphenylene sulfide;

[0058] S2: In a nitrogen atmosphere, 10 g of pretreated polyphenylene sulfide (Fortron fiber-type polyphenylene sulfide produced by Japan Polyplastics Group, Tm = 285 ° C) and 100 mL of dichloromethane were added to a reactor, and the mixture was allowed to stand at room temperature for 18 h. The temperature was controlled at 5 ° C. 18 g of anhydrous aluminum chloride and 10 mL of acetyl chloride were added, and the reaction was carried out at room temperature for 3 h. The temperature was controlled at 45 ° C. and the reaction was kept warm for 4 h. 50 mL of hydrochloric acid and 50 mL of ice water were mixed and added to the reactor to terminate the reaction. The mixture was filtered, washed with 5% sodium hydroxide aqueous solution, washed with water, washed with ethanol, and dried to obtain component 1;

[0059] S3: 10 g of component 1 and 200 mL of anhydrous toluene were added to a reaction kettle and dispersed evenly. 1.5 g of the modified nano-montmorillonite prepared in Example 3 was added, along with 2 mL of acetic acid and 5 g of 4A molecular sieves. The temperature was controlled at 100° C. and the reaction was kept warm for 15 h. The mixture was filtered, washed, extracted with ethanol, and dried to obtain component 2.

[0060] S4: Add 10 g of component 2 and 100 g of deionized water into a reactor and disperse them evenly. Control the temperature at 90°C. Add 1 mol / L hydrochloric acid aqueous solution to adjust the pH to 4. Add 2 g of dibutyltin dilaurate. Keep the temperature and react for 18 h. Filter and dry to obtain modified polyphenylene sulfide.

[0061] Example 7 A method for preparing an ultra-high temperature dust bag material comprises the following steps:

[0062] A1: The modified polyphenylene sulfide prepared in Example 4 was extruded and pelletized through a twin-screw extruder at a melt temperature of 300° C. and a screw speed of 180 rpm to obtain a masterbatch;

[0063] A2: The masterbatch was melt-spun at a spinning speed of 500 m / min, stretched (stretching ratio 3.5, stretching temperature 90°C), and heat-set at 185°C to obtain an ultra-high temperature dust bag material.

[0064] Example 8 A method for preparing an ultra-high temperature dust bag material comprises the following steps:

[0065] A1: The modified polyphenylene sulfide prepared in Example 5 was extruded and pelletized through a twin-screw extruder at a melt temperature of 300° C. and a screw speed of 180 rpm to obtain a masterbatch;

[0066] A2: The masterbatch was melt-spun at a spinning speed of 500 m / min, stretched (stretching ratio 3.5, stretching temperature 90°C), and heat-set at 185°C to obtain an ultra-high temperature dust bag material.

[0067] Example 9 A method for preparing an ultra-high temperature dust bag material comprises the following steps:

[0068] A1: The modified polyphenylene sulfide prepared in Example 6 was extruded and pelletized through a twin-screw extruder at a melt temperature of 300°C and a screw speed of 180 rpm to obtain a masterbatch;

[0069] A2: The masterbatch was melt-spun at a spinning speed of 500 m / min, stretched (stretching ratio 3.5, stretching temperature 90°C), and heat-set at 185°C to obtain an ultra-high temperature dust bag material.

[0070] Comparative Example 1 The preparation method of modified nano-montmorillonite comprises the following steps:

[0071] 30 mL of methanol, 120 mL of distilled water, and 5 g of γ-aminopropyltriethoxysilane were added to the reaction flask and dispersed evenly. Glacial acetic acid was added to adjust the pH to 4, the temperature was controlled at 55°C, and the mixture was kept warm for 2 h under stirring. 10 g of nano-montmorillonite was added, the temperature was controlled at 75°C, and the mixture was kept warm for 2 h under stirring. The mixture was washed with water and dried to obtain modified nano-montmorillonite.

[0072] Comparative Example 2 The preparation method of modified polyphenylene sulfide comprises the following steps:

[0073] S1: drying the polyphenylene sulfide in a vacuum drum dryer at 140° C. and a vacuum degree of -0.08 MPa for 14 h to obtain pretreated polyphenylene sulfide;

[0074] S2: In a nitrogen atmosphere, 10 g of pretreated polyphenylene sulfide (Fortron fiber-type polyphenylene sulfide produced by Japan Polyplastics Group, Tm = 285 ° C) and 70 mL of dichloromethane were added to a reactor, and the mixture was allowed to stand at room temperature for 15 h. The temperature was controlled at 0 ° C. 15 g of anhydrous aluminum chloride and 7 mL of acetyl chloride were added, and the mixture was allowed to react at room temperature for 2 h. The temperature was controlled at 40 ° C. The mixture was kept warm for 3 h. 50 mL of hydrochloric acid and 50 mL of ice water were mixed and added to the reactor to terminate the reaction. The mixture was filtered, washed with 5% sodium hydroxide aqueous solution, washed with water, washed with ethanol, and dried to obtain component 1;

[0075] S3: 10 g of component 1 and 200 mL of anhydrous toluene were added to a reaction kettle and dispersed evenly. 1.2 g of the modified nano-montmorillonite prepared in Comparative Example 1 was added, along with 1.5 mL of acetic acid and 4 g of 4A molecular sieves. The temperature was controlled at 95° C. and the reaction was kept warm for 12 h. The mixture was filtered, washed, extracted with ethanol, and dried to obtain component 2.

[0076] S4: Add 10 g of component 2 and 100 g of deionized water into a reactor and disperse them evenly. Control the temperature at 90°C. Add 1 mol / L hydrochloric acid aqueous solution to adjust the pH to 4. Add 2 g of dibutyltin dilaurate. Keep the temperature and react for 18 h. Filter and dry to obtain modified polyphenylene sulfide.

[0077] Comparative Example 3 The preparation method of modified polyphenylene sulfide comprises the following steps:

[0078] S1: drying the polyphenylene sulfide in a vacuum drum dryer at 140° C. and a vacuum degree of -0.08 MPa for 14 h to obtain pretreated polyphenylene sulfide;

[0079] S2: 10 g of pretreated polyphenylene sulfide (Fortron fiber-type polyphenylene sulfide, Tm = 285° C., manufactured by Polyplastics Japan) and 200 mL of anhydrous toluene were added to a reaction kettle and dispersed evenly. 1.2 g of the modified nano-montmorillonite prepared in Example 2 was added, along with 1.5 mL of acetic acid and 4 g of 4A molecular sieves. The temperature was controlled at 95° C. and the reaction was kept warm for 12 h. The mixture was filtered, washed, extracted with ethanol, and dried to obtain component 2.

[0080] S3: Add 10 g of component 2 and 100 g of deionized water into a reactor and disperse them evenly. Control the temperature at 90°C. Add 1 mol / L hydrochloric acid aqueous solution to adjust the pH to 4. Add 2 g of dibutyltin dilaurate. Keep the reaction warm for 18 h. Filter and dry to obtain modified polyphenylene sulfide.

[0081] Comparative Example 4: A method for preparing an ultra-high temperature dust bag material comprises the following steps:

[0082] A1: The modified polyphenylene sulfide prepared in Comparative Example 2 was extruded and pelletized through a twin-screw extruder at a melt temperature of 300°C and a screw speed of 180 rpm to obtain a masterbatch;

[0083] A2: The masterbatch was melt-spun at a spinning speed of 500 m / min, stretched (stretching ratio 3.5, stretching temperature 90°C), and heat-set at 185°C to obtain an ultra-high temperature dust bag material.

[0084] Comparative Example 5: A method for preparing an ultra-high temperature dust bag material comprises the following steps:

[0085] A1: The modified polyphenylene sulfide prepared in Comparative Example 3 was extruded and pelletized through a twin-screw extruder at a melt temperature of 300°C and a screw speed of 180 rpm to obtain a masterbatch;

[0086] A2: The masterbatch was melt-spun at a spinning speed of 500 m / min, stretched (stretching ratio 3.5, stretching temperature 90°C), and heat-set at 185°C to obtain an ultra-high temperature dust bag material.

[0087] Performance testing

[0088] (1) Mechanical properties:

[0089] ① Tests were conducted in accordance with GB / T 14344-1993, Test Method for Breaking Strength and Elongation at Break of Synthetic Filament and Textured Yarn; Test Conditions: 23°C, 65% RH; Test Method: Filaments were tensile tested using a GY(B)021 semi-automatic tensile tester with a clamping length of 200 mm, a pre-tension of 0.05 cN / dtex, and a tensile speed of 165 mm / min. The breaking strength and elongation were measured. The test results are shown in Table 1.

[0090] ② The modified polyphenylene sulfide fibers prepared in Examples 7-9 and Comparative Examples 4-5 were subjected to a constant temperature treatment at 280° C. for 24 h in an air environment, and then the breaking strength and elongation of the materials were tested according to the above steps. The test results are shown in Table 1;

[0091] Table 1: Statistical table of mechanical properties test data of Examples 7-9 and Comparative Examples 4-5

[0092]

[0093]

[0094] It can be seen from Table 1 that the modified polyphenylene sulfide fiber prepared in the present application has good mechanical properties under normal temperature environment; by adding the modified montmorillonite grafted polyphenylene sulfide prepared in the present application, the modified polyphenylene sulfide material still maintains good mechanical properties after being treated in a high temperature environment, so that the modified polyphenylene sulfide fiber prepared in the present application is used as an ultra-high temperature dust bag material in high-temperature flue gas dust removal filter bags, which has the advantages of long service life and good filtration effect.

[0095] (2) Thermal Oxidation Stability: The oxidation induction temperature of the material was measured by differential scanning calorimetry. The specific steps included placing 5 mg of the samples prepared in Examples 7-9 and Comparative Examples 3-4 in aluminum crucibles, respectively, placing the crucibles in a differential scanning calorimeter (DSC) test chamber produced by Mettler, purging the sample with oxygen for 5 min at room temperature, controlling the heating rate to 10°C / min and the oxygen rate to 50 mL / min, heating from room temperature to 550°C in an oxygen atmosphere, cooling the instrument to room temperature, and calculating the oxidation induction temperature by tangent analysis based on the obtained curve. The test results are shown in Table 2.

[0096] (3) Thermogravimetric performance: A thermogravimetric analyzer manufactured by Mettler was used. 10 mg of the samples prepared in Examples 7-9 and Comparative Examples 3-4 were placed in the instrument. The temperature was raised from room temperature to 600°C at a controlled heating rate of 10°C / min. The mass retention was calculated. The test results are shown in Table 2.

[0097] Table 2: Statistical table of thermal oxidation stability test performance test data of Examples 7-9 and Comparative Examples 4-5

[0098] Oxidation induction temperature / ℃ Quality retention rate / ℃ Example 7 501 55.3 Example 8 512 56.1 Example 9 509 54.6 Comparative Example 4 464 40.2 Comparative Example 5 478 44.6

[0099] As can be seen from Table 2, the modified montmorillonite prepared in the present application is added to polyphenylene sulfide to prepare modified polyphenylene sulfide, which effectively improves the material's resistance to thermal oxidative decomposition. The thermal oxidative weight loss temperature of the modified polyphenylene sulfide is effectively improved. At 600°C in air, the mass retention rate is as high as over 54%. The modified polyphenylene sulfide resin has excellent thermal oxidative resistance.

[0100] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing an ultra-high temperature dust bag material, characterized in that: The steps include: A1: Modified polyphenylene sulfide is extruded through a twin-screw extruder and pelletized to obtain a masterbatch; A2: Melt-spinning, stretching, and heat-setting the masterbatch to obtain ultra-high temperature dust bag material; The preparation method of the modified polyphenylene sulfide comprises the following steps: S1: In a nitrogen atmosphere, polyphenylene sulfide and dichloromethane were added to a reaction kettle, and the mixture was allowed to stand at room temperature for 12-18 hours. The temperature was controlled at 0-5°C, and anhydrous aluminum chloride and acetyl chloride were added. The mixture was allowed to react at room temperature for 1-3 hours. The temperature was controlled at 35-45°C, and the mixture was kept warm for 2-4 hours. An icy hydrochloric acid solution was added to terminate the reaction. The mixture was filtered, washed with sodium hydroxide solution, water, ethanol, and dried to obtain component 1. S2: Component 1 and anhydrous toluene were added to a reaction kettle and dispersed evenly. Modified nano-montmorillonite, acetic acid, and 4A molecular sieve were added. The temperature was controlled at 90-100°C and the reaction was kept warm for 9-15 hours. The mixture was filtered, washed, extracted with ethanol, and dried to obtain component 2. S3: Add component 2 and deionized water into a reaction kettle and disperse them evenly. Control the temperature to 90-100°C, adjust the pH to 4-5, add dibutyltin dilaurate, keep the reaction warm for 12-24 hours, filter and dry to obtain modified polyphenylene sulfide. The preparation method of the modified nano-montmorillonite comprises the following steps: B1: Methanol, distilled water, and γ-aminopropyltriethoxysilane were added to a reaction flask and dispersed evenly. Glacial acetic acid was added to adjust the pH to 4-5. The temperature was controlled at 50-60°C and kept warm under stirring for 1-3 hours. Nano-montmorillonite was added and the temperature was controlled at 70-80°C. The temperature was kept warm under stirring for 1-3 hours. The mixture was washed with water and dried to obtain the organic montmorillonite. B2: Add the organic montmorillonite, pyromellitic anhydride, and N,N-dimethylformamide into a reaction kettle and disperse them evenly. Control the temperature to 45-55°C, keep stirring for 3-6 hours, filter, and dry to obtain anhydride montmorillonite. B3: In a nitrogen atmosphere, 4,4'-diaminodiphenyl sulfide and N,N-dimethylformamide were added to a reaction kettle and dispersed evenly. Anhydride-treated montmorillonite was added and reacted at room temperature for 3-6 hours. The mixture was filtered, washed with water, and dried to obtain modified nano-montmorillonite.

2. The method for preparing an ultra-high temperature dust bag material according to claim 1, characterized in that: The hydrochloric acid ice water solution in S1 is obtained by mixing hydrochloric acid and ice water in a volume ratio of 1:1; the addition ratio of polyphenylene sulfide, dichloromethane, anhydrous aluminum chloride, acetyl chloride, and hydrochloric acid ice water solution is 10g:50-100mL:15-18g:5-10mL:50-100mL.

3. The method for preparing an ultra-high temperature dust bag material according to claim 1, characterized in that: The addition ratio of component 1, anhydrous toluene, modified nano-montmorillonite, acetic acid, and 4A molecular sieve in S2 is 10 g: 150-200 mL: 0.8-1.5 g: 1-2 mL: 3-5 g.

4. The method for preparing an ultra-high temperature dust bag material according to claim 1, characterized in that: The addition ratio of component 2, deionized water, and dibutyltin dilaurate in S3 is 10g:100-200g:1-5g.

5. The method for preparing an ultra-high temperature dust bag material according to claim 1, characterized in that: The addition ratio of methanol, distilled water, γ-aminopropyltriethoxysilane, and nano-montmorillonite in B1 is 20-40 mL: 80-160 mL: 4-6 g: 10 g.

6. The method for preparing an ultra-high temperature dust bag material according to claim 1, characterized in that: The addition ratio of the organized montmorillonite, pyromellitic anhydride, and N,N-dimethylformamide in B2 is 10 g: 20-50 g: 100-200 mL.

7. The method for preparing an ultra-high temperature dust bag material according to claim 1, characterized in that: The addition ratio of 4,4'-diaminodiphenyl sulfide, N,N-dimethylformamide, and anhydride-treated montmorillonite in B3 is 4.5-7.5 g: 100-200 mL: 10 g.

8. The method for preparing an ultra-high temperature dust bag material according to claim 1, characterized in that: In A1, the melt temperature during extrusion by the twin-screw extruder is 300-310°C and the screw speed is 180-210 rpm; in A2, the spinning speed during melt spinning is 500-600 m / min; in A2, the stretching ratio is 3-4.5 and the stretching temperature is 75-105°C; and in A2, the heat setting temperature is 185-210°C.

9. An ultra-high temperature dust bag material, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.

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