Low-foam filtering polypropylene short fiber and preparation method thereof
By blending and extruding polybutadiene containing alkyl organotin acrylate with polypropylene to form hydrophilic polypropylene staple fibers and using organotin compounds under high temperature conditions, the problem of bubbles generated by the polypropylene staple fiber filter screen during the filtration process is solved, and its defoaming performance and thermal stability are improved.
Patent Information
- Application Number
- CN202411826834.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-03-18
AI Technical Summary
The polypropylene staple fiber filter is prone to bubbles during the filtration process, which affects the filtration effect, especially the defoaming performance of polypropylene staple fiber is significantly reduced under high temperature conditions.
By blending and extruding polybutadiene containing alkyl organotin acrylate with polypropylene, hydrophilic polypropylene staple fibers, and using an organotin compound under high temperature conditions to improve thermal stability.
It effectively reduces the possibility of bubbles generated by polypropylene staple fiber filter screen during the filtration process, improves its defoaming performance under high temperature conditions, and improves the filtration effect.
Smart Images
Figure BDA0005184526690000071 
Figure BDA0005184526690000081
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of functional polypropylene fibers, and more specifically, to a polypropylene staple fiber for low-foam filtration and a preparation method thereof. Background Art
[0002] Polypropylene, also known as polypropylene fiber or PP fiber, is a fiber made from isotactic polypropylene melt spinning. It has the advantages of high strength, low specific gravity, wear resistance, chemical corrosion resistance, etc., so it is widely used in civil and industrial fields. Polypropylene has two varieties: short fiber and filament. Among them, polypropylene short fiber can be used to prepare polypropylene short fiber filter net. Polypropylene short fiber filter net has excellent mechanical properties and chemical corrosion resistance. Therefore, it is widely used in water treatment and industrial filtration, which are high acid and alkali strength segments.
[0003] Industrial filtration includes chemical filtration, which is solid-liquid separation during drug extraction or preparation. However, during the filtration process, gas or air in the filter medium may be brought into the liquid, or the filter medium may contain surfactants or other foam-generating substances, causing dense bubbles to form on the polypropylene staple fiber filter, thereby affecting the filtration effect of the polypropylene staple fiber filter. Summary of the invention
[0004] In order to improve the defect that conventional polypropylene staple fiber filter nets are prone to generate bubbles during the filtration process, the present application provides a polypropylene staple fiber for low-foam filtration and a preparation method thereof.
[0005] In the first aspect, the present application provides a polypropylene staple fiber for low-foam filtration, which adopts the following technical solution:
[0006] The invention discloses a polypropylene staple fiber for low-foam filtration. The polypropylene staple fiber for low-foam filtration is obtained by blending and extruding polybutadiene grafted with organotin alkyl acrylate and polypropylene. The polybutadiene grafted with organotin alkyl acrylate is a hydrolyzed carboxyl system.
[0007] Hydrophilizing the polypropylene staple fibers is an extremely effective method for removing foam. When the polypropylene staple fibers are hydrophilic, it means that the polypropylene staple fibers can form a strong interaction with water molecules, thereby reducing the surface tension of water, resulting in a decrease in the stability of the foam, and then causing the foam to break. Moreover, the hydrophilized polypropylene staple fibers can be inserted into the liquid film of the foam and can adsorb the foam, thereby changing the properties of the liquid film and even causing the bubbles to merge, thereby causing the foam to break.
[0008] Compared with the process of impregnating the surface of polypropylene staple fibers with a hydrophilic agent, the present invention grafts the hydrophilic carboxyl group onto the polypropylene chain segment, thereby effectively improving the hydrophilic durability of the polypropylene staple fibers. Moreover, the present invention uses ester hydrolysis to form the carboxyl group, thereby avoiding the demulsification effect of the acidity of the carboxyl group on polybutadiene.
[0009] In addition, when filtering chemicals, the temperature of the filtrate is sometimes relatively high, reaching 80-100°C, and the high temperature resistance of polypropylene staple fibers is relatively poor. Therefore, when filtering the high-temperature filtrate, the polypropylene staple fibers are likely to denature, which in turn leads to a significant decrease in the defoaming performance of the polypropylene staple fibers.
[0010] In the present application, an organotin compound is added, and the organotin compound contains a tin-carbon bond, which is relatively more stable. At the same time, the tin atom of the organotin compound has a higher oxidation state, which can effectively reduce the possibility of thermal decomposition. Moreover, the coordination structure of the organotin compound can also effectively disperse heat energy, thereby improving the overall thermal stability of the polypropylene staple fiber, and indirectly improving the defoaming performance of the polypropylene staple fiber in filtering high-temperature liquids.
[0011] Compared with adding an organotin compound alone, in the present application, the organotin compound is grafted onto an alkyl acrylate and then grafted onto polypropylene via polybutadiene. This effectively improves the dispersibility of the organotin while also effectively reducing the possibility of the precipitation of the organotin, thereby further improving the thermal stability of the polypropylene staple fiber.
[0012] Preferably, the organic tin alkyl acrylate-containing material comprises the following raw materials in molar parts: 0.5-1.5 parts of hydroxyl-containing organic tin, 3-5 parts of hydroxyethyl methacrylate and 3-5 parts of toluene-3,5-diisocyanate.
[0013] Since there are two cyano groups on toluene-3,5-diisocyanate, when the hydroxyl-containing organotin, hydroxyethyl methacrylate and toluene-3,5-diisocyanate are mixed and reacted, the two cyano groups of toluene-3,5-diisocyanate will react and connect with the hydroxyl groups on the hydroxyl-containing organotin and hydroxyethyl methacrylate respectively, thereby grafting the organotin onto the alkyl acrylate.
[0014] In addition, when the components of the organotin alkyl acrylate are in the above molar ratio, since toluene-3,5-diisocyanate is in excess, the hydroxyl groups of the prepared organotin alkyl acrylate will be completely consumed, thereby reducing the impact on the subsequent hydrophilic carboxyl group acquisition.
[0015] Preferably, the preparation method of the organotin-containing alkyl acrylate is as follows: first, hydroxyl-containing organic tin, hydroxyethyl methacrylate and toluene-3,5-diisocyanate are mixed, then added to 4-6 times the volume of N,N-dimethylformamide, and continuously stirred at a temperature of 65-75°C, while adding 3-5% of the total mass of dibutyltin dilaurate, reacting for 5-8h, and finally removing N,N-dimethylformamide to obtain the organotin-containing alkyl acrylate.
[0016] Preferably, the hydroxyl-containing organic tin comprises the following raw materials in molar proportions: 1-1.4 parts of stannous ethoxide and 1-3 parts of monopentaerythritol stearate.
[0017] Preferably, the preparation method of the hydroxyl-containing organic tin is: first, stannous ethoxide and monopentaerythritol stearate are mixed, and then added to 2-4 times the volume of a solvent, the solvent is a mixture of ethanol and chloroform, and the volume ratio of ethanol to chloroform is 2: (1-1.2); then 3-5% of the total mass of catalyst acetic acid is added dropwise, and reflux reaction is carried out at a temperature of 120-140° C. for 3-4 hours, and then the solvent is removed, cooled, washed, and dried to obtain the hydroxyl-containing organic tin.
[0018] Preferably, the method for preparing the polybutadiene grafted with an organotin alkyl acrylate comprises the following steps:
[0019] S1. First, add 1-50 parts of deionized water and 0.1-5 parts of sodium dodecylbenzene sulfonate to 100 parts of polybutadiene latex, and stir evenly at 50-70°C; add 0.01-0.02 parts of cumene hydroperoxide to 10-50 parts of organic tin alkyl acrylate and mix evenly, then slowly add to the polybutadiene latex, the dropwise addition time is 1-2 hours, and finally react at 70-90°C for 1-4 hours to obtain a grafted product;
[0020] S2, adding hydrochloric acid to the grafted product until the pH is 1-5.5, keeping the temperature at 70-90°C, reacting for 1-3h, and obtaining a hydrolyzate;
[0021] S3. Add 1-3 parts of magnesium sulfate to 200 parts of deionized water, control the temperature to 70-80° C., slowly add 10-50 parts of the hydrolyzate, continue stirring for 1-3 hours, filter and dry to obtain polybutadiene grafted with organotin alkyl acrylate.
[0022] Preferably, in S1, the mass ratio of the polybutadiene latex to the organotin-containing alkyl acrylate is 100:(30-50).
[0023] When the polybutadiene latex and the organotin-containing alkyl acrylate are in the above-mentioned mass ratio, the prepared polypropylene staple fibers will have better thermal stability and defoaming properties.
[0024] In a second aspect, the present application provides a method for preparing polypropylene staple fibers for low-foam filtration, using the following technical solution:
[0025] A method for preparing polypropylene staple fibers for low-foam filtration comprises the following steps:
[0026] S1. Preheat the polybutadiene grafted with organotin alkyl acrylate and polypropylene at 110-130°C and continue stirring for 20-40 minutes, then cool. Then dry at 120-140°C for 3-4 hours to obtain a mixed masterbatch;
[0027] S2, the mixed masterbatch is transported to the screw extruder, and after compaction and plasticization, screw melting, and filtering, it enters the melt pipeline, and the filter mesh number of the filter is 180-220 mesh;
[0028] S3, then carry out extrusion spinning, cooling, oiling, drawing, curling, heat setting, cutting and packaging in sequence to obtain polypropylene staple fibers for low-foam filtration.
[0029] In summary, this application has the following beneficial effects:
[0030] 1. Compared with the method of impregnating the surface of polypropylene staple fibers with a hydrophilic agent, the present invention grafts the hydrophilic carboxyl group onto the polypropylene chain segment, thereby effectively improving the hydrophilic durability of the polypropylene staple fibers. Moreover, the present invention uses ester hydrolysis to form the carboxyl group, thereby avoiding the demulsification effect of the acidity of the carboxyl group on polybutadiene.
[0031] 2. In the present application, an organic tin compound is added, and the organic tin compound contains a tin-carbon bond, which is relatively more stable. At the same time, the tin atom of the organic tin compound has a higher oxidation state, which can effectively reduce the possibility of thermal decomposition. Moreover, the coordination structure of the organic tin compound can also effectively disperse heat energy, thereby improving the overall thermal stability of the polypropylene staple fiber, and indirectly improving the defoaming performance of the polypropylene staple fiber in filtering high-temperature liquids.
[0032] 3. Compared with adding organotin compounds alone, in the present application, the organotin compounds are grafted onto alkyl acrylate and then grafted onto polypropylene through polybutadiene. This effectively improves the dispersibility of the organotin while also effectively reducing the possibility of the precipitation of the organotin, further improving the thermal stability of the polypropylene staple fibers. DETAILED DESCRIPTION
[0033] The present application is further described in detail below in conjunction with embodiments.
[0034] raw material
[0035] Hydroxyethyl methacrylate CAS: 868-77-9; 3-5 parts toluene-3,5-diisocyanate CAS: 26471-62-5; N,N-dimethylformamide CAS: 68-12-2; dibutyltin dilaurate CAS: 77-58-7; stannous ethoxide CAS: 14791-99-2; monopentaerythritol stearate CAS: 115-83-3; ethanol CAS: 64-17-5 ; Chloroform CAS: 67-66-3; Acetic acid CAS: 64-19-7; Polybutadiene latex EBR of Zeon Co., Ltd.; Sodium dodecylbenzene sulfonate CAS: 25155-30-0; Isopropylbenzene hydroperoxide CAS: 80-15-9; Hydrochloric acid CAS: 7647-01-0; Magnesium sulfate CAS: 7487-88-9; Polypropylene BH Lan-Gang Petrochemical; Ethyl acrylate CAS: 140-88-5.
[0036] Example
[0037] Example 1
[0038] A polypropylene staple fiber for low-foam filtration is obtained by blending and extruding polybutadiene grafted with organotin alkyl acrylate and polypropylene, wherein the polybutadiene grafted with organotin alkyl acrylate is a hydrolyzed carboxyl system.
[0039] A method for preparing polypropylene staple fibers for low-foam filtration comprises the following steps:
[0040] S1. Preheat 13 g of polybutadiene grafted with organotin alkyl acrylate and 100 g of polypropylene at 120° C. and stir for 30 min, then cool, and then dry at 130° C. for 3.5 h to obtain a mixed masterbatch.
[0041] S2, the mixed masterbatch is transported to the screw extruder, and after compaction and plasticization, screw melting, and filtering, it enters the melt pipeline, and the filter mesh number of the filter is 200 meshes;
[0042] S3, then carry out extrusion spinning, cooling, oiling, drawing, curling, heat setting, cutting and packaging in sequence to obtain polypropylene staple fibers for low-foam filtration.
[0043] The filter mesh number is 200 mesh (180-220 mesh is suitable), and the temperatures of the five zones of the screw are: Zone 1: 305°C; Zone 2: 300°C; Zone 3: 295°C; Zone 4: 280°C; Zone 5: 275°C. Flange zone: 275°C, elbow zone: 270°C, spinning box: 267°C, ring blowing speed: 0.45m / min, wind temperature: 16°C, spinning speed: 750m / min, pre-spinning oiling: 1.5%; original yarn oiling wet rate: 15%.
[0044] Total denier of bundle: 660,000 denier, total drafting multiple: 4; drawing speed: 90m / min, drawing temperature: oil bath 56℃, superheated steam: 110℃, crimping machine main pressure: 1.8kg / cm 2 , back pressure: 1.2kg / cm 2 , the temperature of the four heat setting zones: Zone 1: 100℃, Zone 2: 115℃, Zone 3: 125℃, Zone 4: 95℃; cut and pack at 95℃, cutting length 35mm.
[0045] The preparation method of polybutadiene grafted with organotin alkyl acrylate comprises the following steps:
[0046] S1. First, add 10g of deionized water and 1g of sodium dodecylbenzene sulfonate to 100g of polybutadiene latex, and stir evenly at 60°C; add 0.015g of cumene hydroperoxide to 40g of organic tin alkyl acrylate and mix evenly, then slowly add to the polybutadiene latex, dropwise for 1.5h, and finally react at 80°C for 3h to obtain a grafted product;
[0047] S2, adding hydrochloric acid to the grafted product until the pH is 1, keeping the temperature at 80°C, reacting for 3 hours, and obtaining a hydrolyzate;
[0048] S3. Add 2 g of magnesium sulfate to 200 g of deionized water, control the temperature to 75° C., slowly add 30 g of the hydrolyzate, continue stirring for 2 h, filter and dry to obtain polybutadiene grafted with organotin alkyl acrylate.
[0049] The organic tin alkyl acrylate includes the following raw materials in moles: 1 mol of organic tin containing hydroxyl group, 4 mol of hydroxyethyl methacrylate and 4 mol of toluene-3,5-diisocyanate.
[0050] The preparation method of organic tin alkyl acrylate is as follows:
[0051] First, hydroxyl-containing organic tin, hydroxyethyl methacrylate and toluene-3,5-diisocyanate are mixed, then added to 5 times the volume of N,N-dimethylformamide, and stirred continuously at a temperature of 70°C. While stirring, 4% of the total mass of dibutyltin dilaurate is added, and the reaction is carried out for 7 hours. Finally, N,N-dimethylformamide is removed to obtain an organic tin-containing alkyl acrylate.
[0052] The hydroxyl-containing organic tin comprises the following raw materials in molar proportions: 1.2 mol of stannous ethoxide and 2 mol of monopentaerythritol stearate.
[0053] The preparation method of hydroxyl-containing organic tin is as follows: first, stannous ethoxide and monopentaerythritol stearate are mixed, and then added into 3 times volume of solvent, the solvent is a mixture of ethanol and chloroform, and the volume ratio of ethanol to chloroform is 2:1.1; then, 4% of the total mass of catalyst acetic acid is added dropwise, and reflux reaction is carried out at a temperature of 130°C for 4 hours, and then the solvent is removed, cooled, washed and dried to obtain hydroxyl-containing organic tin.
[0054] Example 2-3
[0055] The difference from Example 1 is that in S1, the mass ratio of the polybutadiene latex to the organotin-containing alkyl acrylate is different, as shown in Table 1.
[0056] Example 1 Example 2 Example 3 Polybutadiene latex 100 100 100 Contains organotin alkyl acrylate 40 30 50
[0057] Embodiment 4-5
[0058] The difference from Example 1 is that the molar ratios of the components containing the organotin alkyl acrylate are different, as shown in Table 2.
[0059] Table 2 Molar ratio of each component of organic tin alkyl acrylate in Example 1 and Examples 4-5
[0060]
[0061]
[0062] Embodiment 6-7
[0063] The difference from Example 1 is that the molar ratios of the components of the hydroxyl-containing organic tin are different, as shown in Table 3.
[0064] Table 3 Molar ratio of each component of hydroxyl-containing organotin in Example 1 and Examples 6-7
[0065] Example 1 Example 6 Example 7 Stannous Ethoxide 1.2 1 1.4 Monopentaerythritol stearate 2 2 2
[0066] Comparative Example
[0067] Comparative Example 1
[0068] The difference from Example 1 is that the polybutadiene grafted with the organotin alkyl acrylate is not added.
[0069] Comparative Example 2
[0070] The difference from Example 1 is that hydroxyethyl methacrylate is replaced by the same molar amount of ethyl acrylate.
[0071] Comparative Example 3
[0072] The difference from Example 1 is that the organotin-containing alkyl acrylate is replaced by the same mass portion of ethyl acrylate.
[0073] Performance testing
[0074] Detection Methods
[0075] 1. Defoaming performance test
[0076] Three samples were taken from Examples 1-7 and Comparative Examples 1-3, respectively, and the samples were then processed to obtain non-woven fabrics, each of which had a weight per unit area of 13 g / m 2 , the average flow pore size of the non-woven fabric is 10μm, the specification is 5cm×5cm, and then pour 100ml of detergent aqueous solution on the non-woven fabric, the detergent is selected with Liby, the detergent content is 1%, and then observe whether there are bubbles on the non-woven fabric.
[0077] The test was performed 1000 times to obtain the defoaming rate, where defoaming rate = number of times no bubbles appeared / total number of times × 100%. If all bubbles burst within 3 seconds, it was also determined that there were no bubbles.
[0078] 2. Thermal stability test
[0079] Three samples were taken from Examples 1-7 and Comparative Examples 1-3, respectively, and the samples were then processed to obtain non-woven fabrics, each of which had a weight per unit area of 13 g / m 2 , the average flow pore size of the non-woven fabric is 10μm, the specification is 5cm×5cm, and then pour 100ml of detergent aqueous solution on the non-woven fabric, the detergent is selected with Liby, the detergent content is 1%, the detergent aqueous solution temperature is 90℃, and then observe whether there are bubbles on the non-woven fabric.
[0080] The test was performed 1000 times, and the number of times bubbles appeared was recorded to obtain the hot water defoaming rate, which was calculated as follows: hot water defoaming rate = number of times no bubbles appeared / total number of times × 100%. If all bubbles burst within 3 seconds, it was considered as no bubbles.
[0081] The test data are shown in Table 4.
[0082] Table 4 Test data table of Examples 1-7 and Comparative Examples 1-3
[0083] Defoaming rate / % High temperature defoaming rate / % Example 1 99.7％ 96.1％ Example 2 96.5％ 92.0％ Example 3 99.8％ 96.2％ Example 4 97.6％ 95.1％ Example 5 99.4％ 95.4％ Example 6 99.6％ 95.3％ Example 7 99.5％ 95.9％ Comparative Example 1 1.3％ 0.9％ Comparative Example 2 98.3％ 79.9％ Comparative Example 3 98.9％ 51.8％
[0084] Referring to Example 1 and Comparative Example 1 and in combination with Table 4, it can be seen that relative to Comparative Example 1, the defoaming rate and high-temperature defoaming rate of Example 1 are significantly improved, which indicates that the addition of polybutadiene grafted with organotin alkyl acrylate can effectively inhibit the generation of bubbles in the polypropylene staple fiber filter during the filtration process, and at the same time, the polypropylene staple fiber filter has an excellent defoaming effect when filtering high-temperature filtrate.
[0085] Referring to Example 1 and Comparative Examples 1-3 and in combination with Table 4, it can be seen that compared with Comparative Example 1, the defoaming rate and high-temperature defoaming rate of Comparative Example 3 and Example 1 are significantly improved, which shows that, however, compared with Comparative Example 3, the high-temperature defoaming rate of Example 1 is further improved, which shows that the selection of organic tin alkyl acrylate and ethyl acrylate can effectively inhibit the polypropylene staple fiber filter from easily generating bubbles during the filtration process, and the selection of organic tin alkyl acrylate can further inhibit the polypropylene staple fiber filter from easily generating bubbles when filtering the high-temperature filtrate.
[0086] The reason is that hydrophilizing the polypropylene staple fibers is an extremely effective way to remove foam. When the polypropylene staple fibers are hydrophilic, it means that the polypropylene staple fibers can form a strong interaction with water molecules, thereby reducing the surface tension of water, resulting in a decrease in the stability of the foam, and then causing the foam to break. Moreover, the hydrophilized polypropylene staple fibers can be inserted into the liquid film of the foam and can adsorb the foam, thereby changing the properties of the liquid film and even causing the bubbles to merge, thereby causing the foam to break.
[0087] Compared with the impregnation treatment of the surface of the polypropylene staple fiber by a hydrophilic agent, Example 1 and Comparative Example 3 graft the hydrophilic group carboxyl group onto the polypropylene chain segment, thereby effectively improving the hydrophilic durability of the polypropylene staple fiber. Moreover, both Example 1 and Comparative Example 3 use ester hydrolysis to form the carboxyl group, avoiding the demulsification effect of the acidity of the carboxyl group on the polybutadiene.
[0088] Compared with Comparative Example 3, the high-temperature defoaming rate of Comparative Example 2 is also significantly improved. The reason is that when filtering chemicals, the temperature of the filtrate is sometimes relatively high, reaching 80-100°C, and the high-temperature resistance of polypropylene staple fibers is relatively poor. Therefore, when filtering the high-temperature filtrate, the polypropylene staple fibers are likely to be denatured, which leads to a significant decrease in the defoaming performance of the polypropylene staple fibers.
[0089] In Example 1 and Comparative Example 2, an organotin compound is added, and the organotin compound contains a tin-carbon bond, which is relatively more stable. At the same time, the tin atom of the organotin compound has a higher oxidation state, which can effectively reduce the possibility of thermal decomposition. Moreover, the coordination structure of the organotin compound can also effectively disperse heat energy, thereby improving the overall thermal stability of the polypropylene staple fiber, and indirectly improving the defoaming performance of the polypropylene staple fiber in filtering high-temperature liquids.
[0090] However, compared with Comparative Example 2, the high-temperature defoaming performance of Example 1 is further improved, which indicates that compared with the use of ethyl acrylate, the use of hydroxyethyl methacrylate can further enhance the effect of organic tin compounds on the thermal stability of polypropylene staple fibers.
[0091] The reason is that in Example 1, the organotin compound is grafted onto alkyl acrylate and then grafted onto polypropylene through polybutadiene, which effectively improves the dispersibility of the organotin while effectively reducing the possibility of the precipitation of the organotin, further improving the thermal stability of the polypropylene staple fiber.
[0092] Specifically, there are two cyano groups on toluene-3,5-diisocyanate. Therefore, when the hydroxyl-containing organotin, hydroxyethyl methacrylate and toluene-3,5-diisocyanate are mixed and reacted, the two cyano groups of toluene-3,5-diisocyanate will react and connect with the hydroxyl groups on the hydroxyl-containing organotin and hydroxyethyl methacrylate, respectively, thereby grafting the organotin onto the alkyl acrylate.
[0093] With reference to Examples 1-3 and in combination with Table 4, it can be seen that, relative to Example 1, the defoaming rate and high-temperature defoaming rate of Example 2 are significantly reduced, while the defoaming rate and high-temperature defoaming rate of Example 3 are only slightly improved. Considering the cost, the mass ratio of polybutadiene latex and organic tin alkyl acrylate using Example 1 is relatively better.
[0094] With reference to Example 1 and Examples 4-5 and in combination with Table 4, it can be seen that relative to Example 1, the defoaming rate and high-temperature defoaming rate of Examples 4-5 are significantly reduced. This indicates that when the components of the organotin alkyl acrylate adopt the molar ratio of Example 1, the prepared organotin alkyl acrylate will promote the polypropylene staple fiber to have a better defoaming effect and thermal stability.
[0095] Referring to Example 1 and Examples 6-7 and in combination with Table 4, it can be seen that relative to Example 1, the high-temperature defoaming rates of Examples 6-7 are slightly reduced, which indicates that when the components of the hydroxyl-containing organic tin adopt the molar ratio of Example 1, the prepared hydroxyl-containing organic tin will promote the polypropylene staple fiber to have better thermal stability.
[0096] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.
Claims
1. A polypropylene staple fiber for low foam filtration, characterized in that: The low-foam filtration polypropylene staple fibers are obtained by blending and extruding polybutadiene grafted with organotin alkyl acrylate and polypropylene, and the polybutadiene grafted with organotin alkyl acrylate is a hydrolyzed carboxyl system.
2. The low-foam filtration polypropylene staple fiber according to claim 1, characterized in that: The organic tin alkyl acrylate comprises the following raw materials in molar parts: 0.5-1.5 parts of hydroxyl-containing organic tin, 3-5 parts of hydroxyethyl methacrylate and 3-5 parts of toluene-3,5-diisocyanate.
3. The low-foam filtration polypropylene staple fiber according to claim 2, characterized in that: The preparation method of the organotin-containing alkyl acrylate is as follows: First, hydroxyl-containing organic tin, hydroxyethyl methacrylate and toluene-3,5-diisocyanate are mixed, then added to 4-6 times the volume of N,N-dimethylformamide, and continuously stirred at a temperature of 65-75°C. While stirring, 3-5% of the total mass of dibutyltin dilaurate is added, and the reaction is carried out for 5-8 hours. Finally, N,N-dimethylformamide is removed to obtain an organic tin-containing alkyl acrylate.
4. The low-foam filtration polypropylene staple fiber according to claim 2, characterized in that: The hydroxyl-containing organic tin comprises the following raw materials in molar proportions: 1-1.4 parts of stannous ethoxide and 1-3 parts of monopentaerythritol stearate.
5. The low-foam filtration polypropylene staple fiber according to claim 4, characterized in that: The preparation method of the hydroxyl-containing organic tin is as follows: First, stannous ethoxide and monopentaerythritol stearate are mixed, and then added to 2-4 times the volume of a solvent, wherein the solvent is a mixture of ethanol and chloroform, and the volume ratio of ethanol to chloroform is 2:(1-1.2); then 3-5% of the total mass of catalyst acetic acid is added dropwise, and the mixture is refluxed at a temperature of 120-140° C. for 3-4 hours, and then the solvent is removed, and the mixture is cooled, washed, and dried to obtain a hydroxyl-containing organic tin.
6. The low-foam filtration polypropylene staple fiber according to claim 1, characterized in that: The preparation method of the polybutadiene grafted with organotin alkyl acrylate comprises the following steps: S1. First, add 1-50 parts of deionized water and 0.1-5 parts of sodium dodecylbenzene sulfonate to 100 parts of polybutadiene latex, and stir evenly at 50-70°C; add 0.01-0.02 parts of cumene hydroperoxide to 10-50 parts of organic tin alkyl acrylate and mix evenly, then slowly add to the polybutadiene latex, the dropwise addition time is 1-2 hours, and finally react at 70-90°C for 1-4 hours to obtain a grafted product; S2, adding hydrochloric acid to the grafted product until the pH is 1-5.5, keeping the temperature at 70-90°C, reacting for 1-3h, and obtaining a hydrolyzate; S3. Add 1-3 parts of magnesium sulfate to 200 parts of deionized water, control the temperature to 70-80° C., slowly add 10-50 parts of the hydrolyzate, continue stirring for 1-3 hours, filter and dry to obtain polybutadiene grafted with organotin alkyl acrylate.
7. The low-foam filtration polypropylene staple fiber according to claim 6, characterized in that: In S1, the mass ratio of the polybutadiene latex to the organotin-containing alkyl acrylate is 100:(30-50).
8. A method for preparing the low-foam filtration polypropylene staple fiber according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Preheating the polybutadiene grafted with the organotin alkyl acrylate and the polypropylene at a temperature of 110-130° C. and continuously stirring for 20-40 minutes, followed by cooling, and then drying at 120-140° C. for 3-4 hours to obtain a mixed masterbatch; S2, the mixed masterbatch is transported to the screw extruder, and after compaction and plasticization, screw melting, and filtering, it enters the melt pipeline, and the filter mesh number of the filter is 180-220 mesh; S3, then carry out extrusion spinning, cooling, oiling, drawing, curling, heat setting, cutting and packaging in sequence to obtain polypropylene staple fibers for low-foam filtration.