Preparation method of polyketone fiber with good heat resistance
By adding modified boron nitride and polyethylene glycol to the preparation of polyketone fibers, the crystallization process of polyketone and the melt flowability are extended, and the problems of poor fluidity and fast crystallization speed of polyketone fibers during melt spinning are solved, and polyketone fibers with high heat resistance and physical properties are achieved.
Patent Information
- Application Number
- CN202510167236.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-15
- Publication Date
- 2025-06-17
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Polyketone fibers have poor fluidity and fast crystallization speed during melt spinning, which leads to poor spinning stability and continuity, affecting the physical properties of the fibers.
During the preparation of polyketone fibers, modified boron nitride is added to extend the nucleation and crystal growth process of polyketone through the hindering, dispersion and adsorption effects with polyketone crystals, reduce the crystallization rate, and improve the dispersion of modified boron nitride through polyethylene glycol and improve the fluidity of the melt.
It improves the heat resistance and physical properties of polyketone fibers, including break strength and elongation of break, reduces the clogging rate of spinning holes, and improves the stability and continuity of spinning.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the field of man-made fibers, and particularly relates to a method for preparing polyketone fibers with good heat resistance. Background Art
[0002] Polyketone refers to a class of polymers formed by copolymerization of CO and ethylene. Polyketone has excellent impact resistance and high wear resistance, excellent oil resistance, hydrolysis resistance, chemical reagent resistance, good low water permeability and gas barrier properties, etc., and has good application prospects in the fields of automotive industry, electronics and electrical industry, daily necessities, special engineering plastics, films and fibers, etc.
[0003] The application of polyketone in the field of fibers has shown great potential, especially in the preparation of high-strength and high-modulus fibers. However, the application of polyketone in the field of fibers also faces some difficulties. Polyketone is insoluble in common organic solvents, so the melt spinning method is usually used to prepare polyketone fibers. The melting temperature of polyketone is about 257°C, and the temperature of polyketone melt spinning is usually 20°C higher than the melting temperature. At this temperature, polyketone will undergo high-temperature degradation; during the synthesis of polyketone, introducing propylene monomer can reduce the melting temperature of polyketone, so that the temperature of polyketone melt spinning is lower than the degradation temperature of polyketone, thus obtaining polyketone fibers.
[0004] However, the melt of polyketone has poor fluidity and fast crystallization rate, which may cause clogging of the spinneret holes or slow down the spinning speed, and fiber breakage is likely to occur during the spinning process, affecting the stability and continuity of spinning. This will not only affect the appearance quality of the fibers, but also reduce the physical properties of the fibers, such as strength, elongation and wear resistance, etc.
[0005] Patent CN111411417A discloses a graphene-reinforced polyketone fiber and its preparation method. This technical solution uses graphene and polyketone to be mixed and then melt spun to obtain a graphene-reinforced polyketone fiber, which improves the tensile strength of the polyketone fiber, but has no improvement effect on the fluidity and crystallization rate of the melt during the melt spinning process. Summary of the Invention
[0006] Aiming at the problems existing in the prior art, the present invention provides a method for preparing polyketone fibers with good heat resistance, and realizes the following invention purposes: the polyketone has a low melting point and good melt fluidity, which is convenient for spinning, and the obtained polyketone fibers have good heat resistance and high strength.
[0007] To solve the above technical problems, the technical solutions adopted by the present invention are as follows: A method for preparing polyketone fibers with good heat resistance, comprising the following steps: 1. Prepare polyketone Heat the reactor to 110 - 130 °C, displace with nitrogen to remove air and water in the reactor. After the reactor cools down, inject palladium acetate, methanol, hexafluoroisopropanol, and propylene in sequence. Then inject a mixed gas of ethylene and CO into the reactor until the reactor pressure reaches 5 - 6 MPa. Then heat and stir the reactor at a rate of 2 - 4 °C / min to 80 - 100 °C, and then start timing. After reacting for 2.5 - 3.5 h (continuously inject the mixed gas of ethylene and CO during the reaction process to keep the reactor pressure stable at 5 - 6 MPa), cool the reactor to 20 - 30 °C. After slowly releasing the pressure, transfer all the substances in the reactor to methanol with a mass 4 - 6 times that of the substances. Stir and precipitate at a rate of 700 - 900 r / min, filter, and vacuum dry at 75 - 85 °C for 5.5 - 6.5 h to obtain polyketone; The mass ratio of palladium acetate, methanol, hexafluoroisopropanol, and propylene in the reactor is 0.5 - 0.7∶2.5 - 3.5∶10 - 14∶0.8 - 1.2; The mass ratio of ethylene and CO is 0.8 - 1.2∶0.9 - 1.1; The stirring rate of the reactor is 350 - 450 r / min.
[0008] 2. Preparation of modified boron nitride Add urea, boron nitride, and isopropanol into a ball mill, set the rotation speed of the ball mill to 200 - 400 r / min, and continuously operate for 46 - 50 h. After ball milling, filter through a filter membrane with a pore size of 0.2 - 0.24 μm to obtain amino-functionalized boron nitride; Add amino-functionalized boron nitride, 2-furoyl chloride, and triethylamine into a closed container. React at 0 - 5 °C for 4 - 6 h under a nitrogen atmosphere. Then add maleic acid and stir and react at a rate of 75 - 85 r / min at room temperature for 0.8 - 1.2 h. Then add polyethylene glycol and react at 120 - 140 °C for 35 - 45 min. Wash the product with deionized water until clean and dry to constant weight at 55 - 65 °C to obtain modified boron nitride; The mass ratio of urea, boron nitride, and isopropanol is 3 - 5∶0.8 - 1.2∶0.5 - 0.7; The mass ratio of amino-functionalized boron nitride, 2-furoyl chloride, triethylamine, maleic acid, and polyethylene glycol is 4 - 6∶12 - 14∶1 - 3∶10 - 12∶350 - 450; The molecular weight of the polyethylene glycol is 1000 - 3000.
[0009] 3. Melt spinning The polyketone and modified boron nitride are blended for 8 - 12 min at 220 - 240 °C and a rotation speed of 45 - 55 r / min to obtain a melt, which is then added to a melt spinning machine. The temperature is set at 230 - 250 °C, and a force of 50 - 70 N is applied to extrude the melt through a die hole with a diameter of 0.8 - 1.2 mm. The nascent fibers are collected by a winding device at a rotation speed of 300 - 500 r / min, and the nascent fibers are subjected to secondary drawing under the condition of a 70 - 90 °C water bath to obtain polyketone fibers; The mass ratio of the polyketone to the modified boron nitride is 20 - 30∶0.8 - 1.2; The multiple of the secondary drawing is 2 - 4 times.
[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: For the polyketone fibers of the present invention, during the melt spinning process, modified boron nitride is added, which forms hindrance, dispersion, and adsorption effects among polyketone crystals, prolongs the nucleation and crystal growth processes of polyketone, reduces the crystallization rate, extends the spinning processing time, and polyethylene glycol improves the dispersion of modified boron nitride in the melt, improves the fluidity of the melt, and the melt flow index is 35 - 38 g / 10 min. Furthermore, the spinning stability and continuity are improved. The obtained polyketone fibers have high strength, the breaking strength is 3.76 - 3.82 cN / dtex, the elongation at break is 13 - 17%, and the heat resistance is good. The thermal weight loss at 320 °C is 1 - 1.3%. Specific Embodiments
[0011] Example 1 1. Preparation of polyketone The reaction kettle is heated to 120 °C, purged with nitrogen to remove air and water in the reaction kettle. After the reaction kettle is cooled, palladium acetate, methanol, hexafluoroisopropanol, and propylene are injected in sequence, and then a mixed gas of ethylene and CO is injected into the reaction kettle until the pressure in the reaction kettle reaches 5.5 MPa. Then, the reaction kettle is stirred and heated to 90 °C at a rate of 3 °C / min, and then the timing starts. After reacting for 3 h (during the reaction process, a mixed gas of ethylene and CO is continuously injected to keep the pressure in the reaction kettle stably at 5.5 MPa), the reaction kettle is cooled to 25 °C. After slowly releasing the pressure, all the substances in the reaction kettle are transferred to methanol with 5 times the mass, and precipitation is separated out by stirring at a rate of 800 r / min, filtered, and vacuum dried at 80 °C for 6 h to obtain polyketone; The mass ratio of palladium acetate, methanol, hexafluoroisopropanol, and propylene in the reaction kettle is 0.6∶3∶12∶1; The mass ratio of ethylene to CO is 1∶1; The stirring rate of the reaction kettle is 400 r / min.
[0012] 2. Preparation of modified boron nitride Urea, boron nitride, and isopropanol were added to a ball mill. The rotation speed of the ball mill was set at 300 r / min, and the operation was continued for 48 h. After the ball milling was completed, the mixture was filtered through a filter membrane with a pore size of 0.22 μm to obtain amino-functionalized boron nitride; The amino-functionalized boron nitride, 2-furoyl chloride, and triethylamine were added to a sealed container. Under a nitrogen atmosphere, the reaction was carried out at 3°C for 5 h. Then, maleic acid was added, and the reaction was stirred at a rate of 80 r / min at room temperature for 1 h. Subsequently, polyethylene glycol was added, and the reaction was carried out at 130°C for 40 min. The product was washed thoroughly with deionized water and dried to a constant weight at 60°C to obtain modified boron nitride; The mass ratio of the urea, boron nitride, and isopropanol was 4:1:0.6; The mass ratio of the amino-functionalized boron nitride, 2-furoyl chloride, triethylamine, maleic acid, and polyethylene glycol was 5:13:2:11:400; The molecular weight of the polyethylene glycol was 2000.
[0013] 3. Melt spinning The polyketone and the modified boron nitride were blended at 230°C and a rotation speed of 50 r / min for 10 min to obtain a melt. Then, the melt was added to a melt spinning machine. The temperature was set at 240°C, and a force of 60 N was applied to extrude the melt through a die hole with a diameter of 1 mm. The nascent fiber was collected by a winding device at a rotation speed of 400 r / min. The nascent fiber was subjected to secondary drawing in an 80°C water bath to obtain polyketone fiber; The mass ratio of the polyketone and the modified boron nitride was 25:1; The multiple of the secondary drawing was 3 times.
[0014] Example 2 1. Preparation of polyketone The reaction kettle was heated to 110°C and purged with nitrogen to remove the air and water in the reaction kettle. After the reaction kettle was cooled, palladium acetate, methanol, hexafluoroisopropanol, and propylene were injected in sequence. Then, a mixed gas of ethylene and CO was injected into the reaction kettle until the pressure in the reaction kettle reached 5 MPa. Then, the reaction kettle was heated with stirring at a rate of 2°C / min to 80°C, and then the timing was started. After reacting for 2.5 h (during the reaction, the mixed gas of ethylene and CO was continuously injected to keep the pressure in the reaction kettle stable at 5 MPa), the reaction kettle was cooled to 20°C. After slowly releasing the pressure, all the substances in the reaction kettle were transferred to methanol with 4 times the mass. The precipitate was precipitated by stirring at a rate of 700 r / min, filtered, and vacuum dried at 75°C for 5.5 h to obtain polyketone; The mass ratio of palladium acetate, methanol, hexafluoroisopropanol, and propylene in the reaction kettle was 0.5:2.5:10:0.8; The mass ratio of ethylene and CO was 0.8:0.9; The stirring rate of the reactor is 350 r / min.
[0015] 2. Preparation of modified boron nitride Add urea, boron nitride, and isopropanol into a ball mill, set the rotation speed of the ball mill to 200 r / min, and continuously operate for 46 h. After the ball milling is completed, filter through a filter membrane with a pore size of 0.2 μm to obtain amino-functionalized boron nitride. Add amino-functionalized boron nitride, 2-furoyl chloride, and triethylamine into a sealed container. Under a nitrogen atmosphere, react at 0 °C for 4 h, then add maleic acid, and stir and react at a rate of 75 r / min at room temperature for 0.8 h. Then add polyethylene glycol and react at 120 °C for 35 min. Wash the product with deionized water and dry it to a constant weight at 55 °C to obtain modified boron nitride. The mass ratio of urea, boron nitride, and isopropanol is 3:0.8:0.5. The mass ratio of amino-functionalized boron nitride, 2-furoyl chloride, triethylamine, maleic acid, and polyethylene glycol is 4:12:1:10:350. The molecular weight of the polyethylene glycol is 1000.
[0016] 3. Melt spinning Blend polyketone and modified boron nitride at 220 °C and a rotation speed of 45 r / min for 8 min to obtain a melt. Then add it into a melt spinning machine, set the temperature to 230 °C, apply a force of 50 N to extrude the melt from a die hole with a diameter of 0.8 mm, and collect the as-spun fiber through a winding device at a rotation speed of 300 r / min. Perform secondary drawing on the as-spun fiber under the condition of a 70 °C water bath to obtain polyketone fiber. The mass ratio of polyketone and modified boron nitride is 20:0.8. The multiple of the secondary drawing is 2 times.
[0017] Example 3 1. Preparation of polyketone Heat the reactor to 130 °C, use nitrogen for replacement to remove the air and water in the reactor. After the reactor cools down, inject palladium acetate, methanol, hexafluoroisopropanol, and propylene in sequence. Then inject a mixed gas of ethylene and CO into the reactor until the pressure in the reactor reaches 6 MPa. Then heat the reactor with stirring at a rate of 4 °C / min to 100 °C, and then start timing. After reacting for 3.5 h (continuously inject the mixed gas of ethylene and CO during the reaction process to keep the pressure in the reactor stable at 6 MPa), cool the reactor to 30 °C, slowly release the pressure, and then transfer all the substances in the reactor to methanol with 6 times the mass. Stir and precipitate at a rate of 900 r / min, filter, and vacuum dry at 85 °C for 6.5 h to obtain polyketone. The mass ratio of palladium acetate, methanol, hexafluoroisopropanol and propylene in the reactor is 0.7:3.5:14:1.2; The mass ratio of ethylene to CO is 1.2:1.1; The stirring rate of the reactor is 450 r / min.
[0018] 2. Preparation of modified boron nitride Add urea, boron nitride and isopropanol into a ball mill, set the speed of the ball mill to 400 r / min, and continue operating for 50 hours. After the ball milling is completed, filter through a 0.24 μm pore size filter membrane to obtain amino boron nitride; Add amination boron nitride, 2-furoyl chloride and triethylamine into a sealed container, react at 5°C for 6 hours under a nitrogen atmosphere, add butenedioic acid, stir and react at a rate of 85r / min at room temperature for 1.2 hours, then add polyethylene glycol, react at 140°C for 45 minutes, wash the product with deionized water, and dry at 65°C to constant weight to obtain modified boron nitride; The mass ratio of urea, boron nitride and isopropanol is 5:1.2:0.7; The mass ratio of the amidated boron nitride, 2-furoyl chloride, triethylamine, maleic acid and polyethylene glycol is 6:14:3:12:450; The molecular weight of the polyethylene glycol is 3000.
[0019] 3. Melt spinning The polyketone and modified boron nitride were blended at 240°C and a rotation speed of 55 r / min for 12 minutes to obtain a melt, which was then added to a melt spinning machine, the temperature was set to 250°C, and a force of 70N was applied to extrude the melt from a die hole with a diameter of 1.2 mm. The spun fibers were collected by a winding device at a rotation speed of 500 r / min, and the spun fibers were secondary drawn in a water bath at 90°C to obtain polyketone fibers. The mass ratio of the polyketone to the modified boron nitride is 30:1.2; The multiple of the secondary drafting is 4 times.
[0020] Comparative Example 1 On the basis of Example 1, the preparation of modified boron nitride in step 2 is omitted, the modified boron nitride in step 3 is replaced with boron nitride, and the remaining steps are the same.
[0021] Comparative Example 2 On the basis of Example 1, the preparation of modified boron nitride in step 2 is omitted, the addition of modified boron nitride in step 3 is omitted, and the remaining steps are the same.
[0022] Test Example 1 Using ASTM D3849-92(2008)e1, the thermogravimetric test was carried out on the polyketone fibers prepared in Examples 1 to 3 and Comparative Examples 1 to 2, and the test results are shown in Table 1.
[0023] Table 1
[0024] Test Example 2 Using GB / T3682-2000, the melt flow index of the melt in Step 3 of Examples 1 to 3 and Comparative Examples 1 to 2 was measured, and the spinneret clogging rate during the melt spinning process was observed and calculated. The measurement results are shown in Table 2.
[0025] Table 2
[0026] Test Example 3 Using GB / T14337-2022 "Test Method for Tensile Properties of Chemical Fiber Staple Fibers", with a pre-tension of 0.15 cN / dtex, a gauge length of 20 mm, and a tensile speed of 40 mm / min, the elongation at break and breaking strength of the polyketone fibers prepared in Step 3 of Examples 1 to 3 and Comparative Examples 1 to 2 were measured at room temperature using a universal testing machine. The measurement results are shown in Table 3.
[0027]
[0028] It can be seen from the above results that: During the polyketone melt spinning process, modified boron nitride was added, thus improving the melt fluidity and reducing the melt crystallization rate; compared with Comparative Examples 1 and 2, Example 1 had better melt fluidity, which in turn improved the stability and continuity of the spinning process. Therefore, the obtained polyketone fibers had a higher breaking strength and a lower elongation at break than those of Comparative Examples 1 and 2; the crystallization rate was low, so the spinneret was not easily clogged and the spinneret clogging rate was low; the heat resistance was good, and the thermogravimetric loss at 320 °C was 1-1.3%.
Claims
1. A method for preparing a polyketone fiber with good heat resistance, characterized in that: The preparation method comprises preparing polyketone, preparing modified boron nitride, and melt spinning; The method for preparing modified boron nitride comprises the following steps: adding urea, boron nitride and isopropanol into a ball mill, and continuously operating the ball mill for 46 to 50 hours, and then filtering the ball mill through a filter membrane with a pore size of 0.2 to 0.24 μm to obtain amino boron nitride; adding amino boron nitride, 2-furancarbonyl chloride and triethylamine into a sealed container, and reacting the ball mill at 0 to 5° C. for 4 to 6 hours under a nitrogen atmosphere; then adding butenedioic acid, and stirring the ball mill at room temperature for 0.8 to 1.2 hours; and then adding polyethylene glycol, and reacting the ball mill at 120 to 140° C. for 35 to 45 minutes. The product is washed and dried to obtain modified boron nitride.
2. The method for preparing a polyketone fiber with good heat resistance according to claim 1, characterized in that: In the method for preparing modified boron nitride, the mass ratio of urea, boron nitride and isopropanol is 3-5:0.8-1.2:0.5-0.7, the mass ratio of amination boron nitride, 2-furoyl chloride, triethylamine, butenedioic acid and polyethylene glycol is 4-6:12-14:1-3:10-12:350-450, and the molecular weight of polyethylene glycol is 1000-3000.
3. The method for preparing a polyketone fiber with good heat resistance according to claim 1, characterized in that: In the method for preparing modified boron nitride, the rotation speed of the ball mill is 200-400 r / min, and the stirring reaction rate at room temperature is 75-85 r / min.
4. The method for preparing a polyketone fiber with good heat resistance according to claim 1, characterized in that: The method for preparing polyketone comprises the following steps: removing air and water from a reaction kettle, then sequentially injecting palladium acetate, methanol, hexafluoroisopropanol, and propylene, and then injecting a mixed gas of ethylene and CO into the reaction kettle until the pressure of the reaction kettle reaches 5 to 6 MPa, stirring and heating the reaction kettle to 80 to 100° C., and then starting timing. After reacting for 2.5 to 3.5 hours, the mixed gas of ethylene and CO is continuously injected during the reaction process to stably maintain the pressure of the reaction kettle at 5 to 6 MPa, cooling the reaction kettle to 20 to 30° C., slowly releasing the pressure, transferring all the materials in the reaction kettle to 4 to 6 times the mass of methanol, stirring to precipitate, filtering, and drying to obtain polyketone.
5. The method for preparing a polyketone fiber with good heat resistance according to claim 4, characterized in that: In the method for preparing polyketone, the mass ratio of palladium acetate, methanol, hexafluoroisopropanol and propylene in the reaction kettle is 0.5-0.7:2.5-3.5:10-14:0.8-1.2, the mass ratio of ethylene and CO is 0.8-1.2:0.9-1.1, the stirring rate of the reaction kettle is 350-450 r / min, and the heating rate of the reaction kettle is 2-4°C / min.
6. The method for preparing a polyketone fiber with good heat resistance according to claim 1, characterized in that: The melt spinning method comprises the following steps: blending polyketone and modified boron nitride at 220-240° C. and a rotation speed of 45-55 r / min for 8-12 minutes to obtain a melt, then adding the melt into a melt spinning machine, setting the temperature at 230-250° C., applying a force of 50-70 N to extrude the melt from a die hole with a diameter of 0.8-1.2 mm, collecting the spun fibers through a winding device at a rotation speed of 300-500 r / min, and performing secondary drawing on the spun fibers in a water bath at 70-90° C. to obtain polyketone fibers.
7. The method for preparing a polyketone fiber with good heat resistance according to claim 6, characterized in that: In the melt spinning method, the mass ratio of polyketone to modified boron nitride is 20-30:0.8-1.2, and the multiple of secondary drawing is 2-4 times.