A method for producing a polyphenylene sulfide sulfone ketone fiber

Abstract

This invention discloses a method for preparing polyphenylene sulfone ketone (PPS) fibers. First, using a metal oxide as a catalyst, PPS resin, the metal oxide, and dicarboxylic acids or polycarboxylic acids are reacted by screw extrusion to prepare ketone-containing PPS tows. Then, the ketone-containing PPS tows are placed in an oxidation system and subjected to an oxidation reaction under the action of an oxidation catalyst to obtain nascent PPS fibers. After impurity removal, the nascent PPS fibers are dried to obtain PPS fibers. This invention achieves Friedel-Crafts acylation crosslinking between PPS molecular chains in the molten state, realizing intermolecular crosslinking or chain extension of PPS molecules and introducing ketone groups into the PPS molecules. Then, the ketone-crosslinked or chain-extended PPS fibers are oxidized to achieve controlled oxidation of sulfur atoms, thereby introducing sulfone and sulfoxide groups, resulting in high-toughness and high-strength PPS modified fibers containing ketones or sulfoxides, exhibiting high temperature resistance, solvent resistance, creep resistance, drip resistance, and oxidation resistance.

Description

Technical Field

[0001] This invention relates to the field of PPS modification technology, specifically a method for preparing polyphenylene sulfone ketone fiber. Background Technology

[0002] Polyphenylene sulfide (PPS) is a thermoplastic resin with phenyl sulfide groups in its molecular backbone. Due to its excellent high-temperature resistance, corrosion resistance, radiation resistance, and flame retardancy, it is widely used in harsh high-temperature environments. However, PPS fibers are prone to creep shrinkage, exhibit dripping, and are not resistant to oxidation and have low temperature resistance, limiting their use in environments above 180°C. Although domestic and international research and development have been active, and a certain production capacity for PPS fibers or modified fibers has been initially established (ZL201510631820.5 and ZL201510350644.8), PPS-derived fiber products still suffer from problems such as poor toughness, low strength, poor UV resistance, and a lack of high-performance products.

[0003] Currently, PPS is generally used as a special engineering plastic after being filled and modified, and then spun into PPS composite fibers. However, the addition of modification technology cannot effectively improve the oxidation resistance and high temperature resistance of PPS fibers. PPS oxidation modification technology can greatly improve the oxidation resistance and temperature resistance of fibers, but the oxidation of PPS fibers alone causes a significant decrease in the mechanical properties of the fibers, and cannot effectively improve the strength and toughness of the modified fibers.

[0004] Currently, the structurally modified PPS resins that have been developed mainly include polyphenylene sulfide ketone (PPSK), polyphenylene sulfide sulfone, polyphenylene sulfide amide, and polyphenylene nitrile sulfide. These PPS derivatives are primarily introduced through copolymerization with a third monomer containing special functional groups, thereby introducing special modifying groups into the PPS molecular chain. However, monomer copolymerization is costly, and the introduction of the third monomer significantly reduces the average molecular weight of the target compound. While polyphenylene sulfide sulfone possesses excellent high-temperature resistance, its solvent resistance is slightly inferior to crystalline polyaryl sulfide resins. Polyphenylene sulfide ketone is also a high-temperature and corrosion-resistant material, exhibiting high strength, high modulus crystallinity, and high-temperature thermoplasticity at high temperatures. Compared to the former two, polyphenylene sulfide ketone combines the advantages of polyphenylene sulfide sulfone and polyphenylene sulfide ketone. Compared to PPS, its mechanical properties, high-temperature resistance, and solvent resistance are superior, with a heat distortion temperature exceeding 300℃. It has significant potential application value in related industries such as automotive, chemical, electronics, electrical appliances, precision machinery, and aerospace.

[0005] Currently, there is only one method for preparing polyphenylene sulfone ketone resin: direct polymerization using sodium sulfide, 4,4'-dichlorodiphenyl sulfone, and 4,4'-dichlorobenzophenone as raw materials, N-methylpyrrolidone as solvent, sodium hydroxide as an additive, and sodium benzoate as a catalyst (invention application No. 201610753506.9). However, this modification method is complex, difficult to control, results in low average molecular weight of the polymerized product, and relatively high polymerization cost, making it difficult to industrialize high-quality products. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a method for preparing polyphenylene sulfone ketone fiber.

[0007] The technical solution of the present invention to solve the aforementioned technical problem is to provide a method for preparing polyphenylene sulfone ketone fiber, characterized in that the method includes the following steps:

[0008] (1) Using metal oxide as a catalyst, PPS resin, metal oxide and carboxylic acid are blended and melt-spun in one step by screw extrusion to prepare ketone-containing PPS tow; or PPS resin, metal oxide and carboxylic acid are blended and melt-granulated by screw extrusion to prepare ketone-containing PPS particles, and then the ketone-containing PPS particles are used as raw materials for particle melt spinning to prepare ketone-containing PPS tow; wherein the carboxylic acid is a dicarboxylic acid or a polycarboxylic acid;

[0009] (2) The ketone-containing PPS tow obtained in step (1) is placed in an oxidation system and subjected to oxidation reaction under the action of an oxidation catalyst to obtain polyphenylene sulfone ketone nascent fiber.

[0010] (3) After removing impurities from the polyphenylene sulfone ketone nascent fiber obtained in step (2), it is dried to obtain polyphenylene sulfone ketone fiber.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] (1) This invention uses PPS resin as raw material, carboxylic acid as modifier, and adds nano-micro metal oxide as Friedel-Crafts acylation catalyst to realize Friedel-Crafts cross-linking reaction between PPS molecular chains in the molten state (i.e. screw extrusion reaction), realize cross-linking or chain extension between PPS molecules, and introduce ketone groups into PPS molecules; then oxidize the PPS fiber with ketone cross-linking or chain extension to realize the controllable oxidation of S atoms, realize the introduction of sulfone and sulfoxide groups, and obtain high toughness and high strength PPS modified fibers containing ketone and sulfone or containing ketone and sulfoxide with high temperature resistance, solvent resistance, creep resistance, drip resistance, and oxidation resistance.

[0013] (2) By modifying PPS with ketone groups, the flexibility of the molecular chain is effectively improved, the interaction force between the molecular chains is increased, and the mechanical properties of PPS fibers or resins, such as tensile strength, tensile toughness, and cohesion between fibers, are greatly improved. At the same time, the oxidative breakage of PPS molecular chains can be greatly inhibited, and the mechanical properties of ketone-containing PPS tows are well maintained during the catalytic oxidation process.

[0014] (3) The sulfur atoms (S) in PPS are selectively oxidized to sulfone (SO2) or sulfoxide (SO) through an oxidation process. The catalytic oxidation conditions, the types of oxidants and catalysts are controlled to prepare ketone- and sulfone-modified PPS fibers in a targeted manner.

[0015] (4) The addition of carboxylic acid and metal oxides improves the overall performance of the fiber on the one hand, and reduces the influence of high-temperature volatiles on spinning on the other hand (the residual N-methylpyrrolidone and ethylene glycol in PPS volatiles), which greatly improves the fiber formation rate.

[0016] (5) The presence of metal oxides catalyzes the Friedel-Crafts acylation reaction between organic acids and PPS molecules, and also improves the UV resistance of modified fibers. Furthermore, the presence of metal oxides also improves the mechanical properties of fibers.

[0017] (6) The polyphenylene sulfone ketone fiber prepared by this method has a high glass transition temperature (above 150℃, or even no glass transition temperature, while the glass transition temperature of PPS is around 93℃). At high temperatures, the polyphenylene sulfone ketone fiber does not exhibit dripping or creep, which overcomes the disadvantages of PPS, such as low glass transition temperature, poor temperature resistance, poor oxidation resistance, poor toughness, high brittleness, easy generation of static electricity, poor cohesion between monofilaments, loose filaments, high coefficient of friction, and difficult post-processing.

[0018] The polyphenylene sulfone ketone (PPS) fibers prepared by this method exhibit superior resistance to creep, dripping, shrinkage, oxidation, and UV radiation, and in particular, excellent mechanical properties. Furthermore, the surface properties of the PPS fibers are improved using appropriate fiber oiling agents, enhancing their wettability, high-temperature adhesion, and electrical conductivity. This reduces fiber fuzzing and breakage during processing, improves tensile and post-processing properties, and allows the fibers to successfully pass through various processing steps.

[0019] The polyphenylene sulfone ketone fiber prepared by this method has a large polymer molecular weight and good controllability of fiber structure, which is conducive to large-scale industrial production. It can be used in protective equipment such as fire suits, furnace work clothes, welding work clothes, special military uniforms, fire curtains, fireproof felt, and fireproof gloves. It can also be used in high-end filter materials, such as high-temperature flue dust collector filter bags and chemical filter cloths. Attached Figure Description

[0020] Figure 1XPS image of sulfur element in polyphenylene sulfone ketone fiber prepared in Example 1 of this invention;

[0021] Figure 2 This is a comparison chart of the corrosion resistance and high temperature resistance of polyphenylene sulfone ketone fiber and PPS fiber prepared in Example 1 of the present invention.

[0022] Figure 3 This is a comparison chart of combustion test results between polyphenylene sulfone ketone fiber and PPS fiber prepared in Example 1 of this invention.

[0023] Figure 4 The image shows the DSC test result of the polyphenylene sulfone ketone fiber prepared in Example 1 of this invention.

[0024] Figure 5 The image shows the UV resistance test results for PPS fibers.

[0025] Figure 6 The image shows the UV resistance test results of the polyphenylene sulfone ketone fiber prepared in Example 1 of this invention.

[0026] Figure 7 Thermogravimetric analysis (TGA) of the polyphenylene sulfone ketone fibers prepared in Examples 2-7 of this invention;

[0027] Figure 8 XPS elemental analysis results for the polyphenylene sulfone ketone fibers prepared in Examples 2-7 of this invention;

[0028] Figure 9 This is a 1000x SEM image of the surface of the polyphenylene sulfone ketone fiber prepared in Example 9 of the present invention.

[0029] Figure 10 This is a 2000x SEM image of the surface of the polyphenylene sulfone ketone fiber prepared in Example 9 of the present invention. Detailed Implementation

[0030] Specific embodiments of the present invention are given below. These specific embodiments are only used to further illustrate the present invention and do not limit the scope of protection of the claims of this application.

[0031] This invention provides a method for preparing polyphenylene sulfone ketone fiber (hereinafter referred to as the method), characterized in that the method includes the following steps:

[0032] (1) Ketogenic PPS: Using metal oxide as a catalyst, fiber-grade PPS resin, metal oxide, and carboxylic acid are blended and melt-spun in a screw extruder in a one-step in-situ spinning process to prepare ketone-containing PPS tow; or fiber-grade PPS resin, metal oxide, and carboxylic acid are blended and melt-granulated in a screw extruder to prepare ketone-containing PPS particles, and then the ketone-containing PPS particles are used as raw materials for particle melt spinning to prepare ketone-containing PPS tow; the carboxylic acid is a dicarboxylic acid or a polycarboxylic acid;

[0033] Preferably, in step (1), the dicarboxylic acid is terephthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, or biphenyl dicarboxylic acid; the polycarboxylic acid is a tricarboxylic acid containing a benzene ring, preferably trimellitic acid or biphenyl tricarboxylic acid; the metal oxide is at least one of TiO2, SiO2, ZrO2, ZnO, SnO2, Al2O3, MoO3, WO3, CdO, GeO2, or Ga2O3;

[0034] Preferably, in step (1), the mass of the carboxylic acid is 0.01 to 10 wt% of the total mass of PPS resin, metal oxide and carboxylic acid, preferably 0.01 to 2 wt%, more preferably 0.1 to 2 wt%; the mass of the metal oxide is 0.01 to 5 wt% of the total mass of PPS resin, metal oxide and carboxylic acid, preferably 0.01 to 1 wt%.

[0035] Preferably, in step (1), the one-step in-situ spinning process of blending and melting is as follows: mixing or not mixing - screw extruder melting - melt metering pump - forced filtration - spinneret - nascent filament - hot stretching - ketone-containing PPS tow. Specifically, PPS powder or granules, carboxylic acid and metal oxides are directly fed into a twin-screw extruder or a single-screw extruder through a feeder, or PPS powder or granules, carboxylic acid and metal oxides are fully mixed in a mixer to form a mixture, and then the mixture is fed into the feeder. The material is fed into a twin-screw extruder or a single-screw extruder; then, during the screw extrusion process, the material reacts at high temperature to form the target substance; the feed port temperature (i.e., zone 1) is 265-310℃, the intermediate zone temperature is 300-335℃, and the die temperature is 295-320℃; under the action of the melt metering pump, the melt is forcibly filtered by a metal mesh to remove gels or large-sized metal oxides. The filtered melt is then controlled to spin by a spinneret to form nascent filaments, which are then subjected to a hot stretching process to obtain ketone-containing PPS tow.

[0036] Preferably, in step (1), the process of blending melt granulation is as follows: mixing or not mixing - screw extruder melting - melt metering pump - forced filtration - drawing and pelletizing - ketone-containing PPS granules. Specifically, PPS powder or granules, carboxylic acid and metal oxides are directly fed into a twin-screw extruder or a single-screw extruder through a feeder, or PPS powder or granules, carboxylic acid and metal oxides are fully mixed in a mixer to form a mixture, and then the mixture is fed into a twin-screw extruder or a single-screw extruder through a feeder; then the material reacts at high temperature during screw extrusion to form the target substance; the feed port temperature (i.e., zone 1) is 250-295℃, the intermediate zone temperature is 290-340℃, and the die temperature is 280-320℃; under the action of the melt metering pump, the melt is forcibly filtered by a metal mesh to obtain gel or large-sized metal oxides in the melt, and the filtered melt is drawn and pelletized to obtain ketone-containing PPS granules.

[0037] Preferably, in step (1), the process of granule melt spinning is as follows: drying of ketone-containing PPS granules - melting in a screw extruder - melt metering pump - forced filtration - spinneret assembly - nascent filament - hot stretching - ketone-containing PPS tow. Specifically, ketone-containing PPS granules are fed into a twin-screw extruder or a single-screw extruder through a feeder; then the material reacts at high temperature during screw extrusion to form the target substance; the feed port temperature is 270-310℃, the intermediate zone temperature is 290-340℃ (zone 290-330℃, zone 315-340℃, zone 420-340℃), and the die temperature is 300-320℃; under the action of the melt metering pump, the melt is forcibly filtered by a metal mesh to remove gel or large-sized metal oxides. The filtered melt is then controlled to spin by the spinneret assembly to form nascent filament, and then hot stretching is performed to obtain ketone-containing PPS tow.

[0038] Preferably, in step (1), the hot stretching process is performed at a temperature of 90 to 200°C and a stretching ratio of 2 to 10 times; preferably, the hot stretching is carried out in water vapor at 70 to 100°C and the stretching ratio is 3 to 8 times, so that the crystallinity of the ketone-containing PPS tow is 80% to 96%.

[0039] (2) In-situ oxidation or post-oxidation of ketone-containing PPS tow: The ketone-containing PPS tow obtained in step (1) is placed in an oxidation system and an oxidation reaction is carried out under the action of an oxidation catalyst to obtain polyphenylene sulfone ketone nascent fiber.

[0040] Preferably, in step (2), the mass of the ketone-containing PPS tow accounts for 0.1 to 40 wt% (preferably 5 to 15 wt%) of the total mass of the ketone-containing PPS tow and the oxidation system; the mass concentration of the oxidation catalyst in the oxidation system is 0.1 to 40 wt% (preferably 1 to 20 wt%).

[0041] Preferably, in step (2), the fineness of the ketone-containing PPS tow is 1D to 3D;

[0042] Preferably, in step (2), the oxidation catalyst is an inorganic acid and / or an organic acid; the inorganic acid is sulfuric acid, hydrochloric acid, carbonic acid, heteropoly acid, boric acid, phosphoric acid, nitric acid, molybdic acid, tungstic acid, or an acidic molecular sieve; the organic acid is formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, decanoic acid, benzoic acid, naphthoic acid, benzenesulfonic acid, naphthalenesulfonic acid, oxalic acid, malonic acid, succinic acid, adipic acid, or pimelic acid, etc., fatty acids and aromatic acids. The function of the oxidation catalyst is to keep the pH of the oxidation system in the range of 1 to 8 (preferably 4 to 8), which facilitates the oxidation reaction.

[0043] Preferably, in step (2), the oxidation system is an oxidant solution, an electrolyte, an oxygen-saturated solution of water, or an ozone aqueous solution;

[0044] When using an oxidizing agent solution, the ketone-containing PPS tow obtained in step (1) is immersed in the oxidizing agent solution and oxidized at 0–140°C (preferably 35–90°C) for 0.1 min–24 h (preferably 1 min–6 h, more preferably 0.5–2 h) under the action of an oxidation catalyst to obtain polyphenylene sulfone ketone nascent fibers; the oxidizing agent solution is an oxidizing agent solution with a mass concentration of 0.1–40 wt% (preferably 0.5–40 wt%, more preferably 5–15 wt%) formed by dissolving or dispersing the oxidizing agent in a solvent; the oxidizing agent The solvent is at least one of H2O2, Na2O2, NaClO, KClO, HClO, KMnO4, K2Cr2O7, MnO2, FeCl3, NO2, HNO3, peracetic acid, performic acid, dicumyl peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, tert-butanol peroxide, or perbenzoic acid; the solvent is at least one of water, benzene, toluene, ketones, organic alcohols, amides, dimethyl sulfoxide, tetrahydrofuran, diethyl ether, dimethyl ether, cyclohexane, n-hexane, organic acids, or halogenated hydrocarbons.

[0045] When using an electrolyte, the ketone-containing PPS tow obtained in step (1) is immersed in the electrolyte of the electrolytic oxidation device. The initial pH of the electrolytic oxidation reaction is 4-7, both the anode and cathode are inert electrodes, the voltage is 2-380V, and the current density is 10-1000A / m. 2 (Preferred 300~400A / m) 2 The electrolytic oxidation process takes place over a period of 0.1 min to 10 h (preferably 5 to 7 h) under the action of an oxidation catalyst to obtain polyphenylene sulfone ketone nascent fibers. The electrolyte is a potassium bisulfate solution. The oxidation capacity is controlled by adjusting the current intensity and voltage of the electrolytic oxidation device, achieving online controllable oxidation. The active oxygen generated during electrolysis includes hydroxyl radicals, superoxide, peroxide, or oxygen radicals.

[0046] When using an oxygen-saturated solution of water, oxygen or air is continuously introduced into the deionized water, and aryl alcohols are added to the deionized water as oxidation aids to obtain an oxygen-saturated solution of water. The ketone-containing PPS tow obtained in step (1) is then immersed in the oxygen-saturated solution of water. Under the action of an oxidation catalyst, it undergoes an oxidation reaction with air or oxygen at 40-44°C for 1 min-24 h (preferably 10 min-2 h) to achieve online oxidation of the ketone-containing PPS tow, resulting in polyphenylene sulfone ketone nascent fiber. The aryl alcohol is ethyl anthraquinone, phenol, naphthol, phenylene sulfone, anthraquinone, or phenanthrene alcohol. The mass of the aryl alcohol accounts for 1 wt%-40 wt% (preferably 5 wt%-20 wt%) of the mass of the oxygen-saturated solution of water. The aryl alcohol is oxidized by air to quinone, and the quinone is then oxidized to sulfone and sulfoxide, and is itself reduced back to the aryl alcohol. Therefore, there is no requirement for the amount of oxygen or air added.

[0047] When using an ozone aqueous solution, ozone generated by an ozone oxidation device (i.e., an ozone generator) is continuously introduced into deionized water, and TiO2, SnO2, ZrO2, MoO3, or WO3 are added to the deionized water as auxiliary oxidants to obtain an ozone aqueous solution. The ketone-containing PPS tow obtained in step (1) is then immersed in the ozone aqueous solution and oxidized at 40–95°C for 0.1–24 h under the action of an oxidation catalyst to achieve online oxidation of the ketone-containing PPS tow, obtaining polyphenylene sulfone ketone nascent fibers. The mass ratio of ozone to ketone-containing PPS tow is 48–96:108. The mass of the auxiliary oxidant accounts for 0.1–5 wt% (preferably 0.5–2 wt%) of the mass of the ozone aqueous solution.

[0048] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) is washed with deionized water to remove residual impurities (including oxidation system and oxidation catalyst), and then dried to obtain polyphenylene sulfone ketone fiber with anti-oxidation, high temperature resistance, no melting shrinkage and self-extinguishing properties.

[0049] Preferably, in step (3), the drying temperature is 30–240°C (preferably 60–200°C, more preferably 140–200°C), and the drying time is 0.1–24 h (preferably 0.1–2 h). Appropriate drying temperature can achieve self-repair of defects in polyphenylene sulfone ketone fibers, that is, at higher temperatures, the content or ratio of sulfones and sulfoxides in the fiber molecules is optimized, ultimately improving the mechanical properties of the polyphenylene sulfone ketone fibers.

[0050] Preferably, the above steps (1) to (3) are all carried out at atmospheric pressure to 30 standard atmospheres.

[0051] Example 1

[0052] (1) 5g terephthalic acid, 1g TiO2 and 494g PPS resin were blended and melted in a twin-screw extruder at high temperature and granulated. The feed port temperature of the screw extruder was 265℃, the die head temperature was 310℃, and the temperature of the middle zone of the spinning screw was controlled at 300~325℃ to prepare ketone-containing PPS resin chips.

[0053] The ketone-containing PPS resin chips are then subjected to granular melt spinning to obtain ketone-containing PPS filaments; the feed port temperature is 305℃, zone 2 is 320~330℃, zone 3 is 325~335℃, zone 4 is 325~335℃, and the die head temperature is 315℃; the hot stretching temperature is 95℃, and the stretching ratio is 3.5 times.

[0054] (2) The ketone-containing PPS tow (tensile strength 5.5 CN / dt, elongation at break 28%) was immersed in water containing 10 wt% H2O2, 10 wt% acetic acid, and 0.1 wt% HCl. The mass ratio of the ketone-containing PPS tow to the oxidant solution was 1:5. The solution was immersed at 60°C for 30 min. The solution was then filtered through a 200-400 mesh steel wire mesh to obtain polyphenylene sulfone ketone nascent fiber.

[0055] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) is washed three times with deionized water and then vacuum dried at 140°C for 2 hours to obtain polyphenylene sulfone ketone fiber.

[0056] The prepared polyphenylene sulfone ketone fiber exhibits an oxidative weight gain of 18 wt%, and demonstrates excellent oxidation resistance, high temperature resistance, self-extinguishing properties, and exhibits no melting shrinkage, dripping, or self-extinguishing phenomena. Its glass transition temperature reaches 182–185℃, its tensile strength is 4.5 CN / dt, and its elongation at break is 18%. Compared to PPS precursor fibers, the polyphenylene sulfone ketone fiber shows significantly improved temperature resistance, UV resistance, and oxidation resistance.

[0057] Depend on Figure 1 It can be seen that after ketone-containing PPS is oxidized, the S atom becomes a sulfone group, proving that the prepared modified fiber is polyphenylene sulfone ketone fiber.

[0058] Figure 2 In the diagram, the test conditions corresponding to the horizontal axis 1 are: 85℃ and 98% H2SO4 treatment for 24 hours; the test conditions corresponding to the horizontal axis 2 are: 85℃ and 60% H2SO4 treatment for 24 hours; the test conditions corresponding to the horizontal axis 3 are: 85℃ and 60% HNO3 treatment for 24 hours; the test conditions corresponding to the horizontal axis 4 are: 85℃ and 40% NaOH treatment for 24 hours; the test conditions corresponding to the horizontal axis 5 are: 50℃ and 30% H2O2 treatment for 24 hours; and the test condition corresponding to the horizontal axis 6 is the high-temperature resistance test, which is: treatment at 230℃ for 24 hours. Figure 2It can be seen that PPS has poor high temperature resistance and oxidation resistance, while the polyphenylene sulfone ketone fiber of the present invention has better temperature resistance, especially excellent oxidation resistance. Therefore, the polyphenylene sulfone ketone fiber of the present invention has excellent high temperature resistance, oxidation resistance and acid and alkali resistance.

[0059] Depend on Figure 3 As can be seen from the combustion experiment, PPS fiber exhibits significant melt shrinkage and combustion dripping properties upon contact with fire, while the polyphenylene sulfone ketone fiber of this invention shows no melt shrinkage and no combustion dripping properties. Currently, no method has been found to simultaneously determine the melt shrinkage and combustion dripping properties of fibers and fabrics.

[0060] Combustion experiments involve observing the carbonization process of fibers or fabrics under ignition or combustion conditions. If the fibers shrink or form droplets upon heating, the carbon residue after combustion will differ in shape or size from the original material before combustion. If they do not shrink upon heating and do not form droplets during combustion, the carbon residue will be approximately the same shape or size as the original material before combustion. The specific method involves burning the fiber fabric or fiber over an alcohol lamp flame without removing it from the flame until complete carbonization. Polyphenylene sulfone ketone fiber has an extremely high limiting oxygen index (32–34) and is self-extinguishing upon removal from the flame.

[0061] Depend on Figure 4 It can be seen that the melting point of PPS is 280-300℃, while the polyphenylene sulfone ketone fiber of the present invention has basically no observed melting point, indicating that the polyphenylene sulfone ketone fiber has excellent temperature resistance.

[0062] Depend on Figure 5 It can be seen that the PPS fiber structure is severely damaged after ultraviolet radiation. Figure 6 It can be seen that the polyphenylene sulfone ketone fiber has good UV resistance (containing nano-UV anti-additives). The polyphenylene sulfone ketone fiber is less affected by UV, indicating that it has good UV resistance. Therefore, the polyphenylene sulfone ketone fiber of the present invention has excellent UV resistance.

[0063] Example 2

[0064] (1) 3g of malonic acid, 0.5g of SnO2 and 496.5g of PPS resin were blended and melted in a twin-screw extruder at high temperature and granulated. The feed port temperature of the screw extruder was 260℃, the die temperature was 315℃, and the temperature of the middle zone of the spinning screw was 295~320℃. Ketone-containing PPS resin chips were prepared.

[0065] The ketone-containing PPS resin chips are then melt-spun into ketone-containing PPS filaments; the feed port temperature is 305℃, zone 2 is 325℃, zone 3 is 325℃, zone 4 is 330℃, and the die temperature is 315℃; the hot stretching temperature is 100℃, and the stretching ratio is 4 times.

[0066] (2) The ketone-containing PPS tow (tensile strength 5.3 CN / dt, elongation at break 32%) was immersed in benzene containing 15 wt% benzoyl peroxide, 5 wt% butyric acid and 0.1 wt% benzenesulfonic acid. The mass ratio of the ketone-containing PPS tow to the oxidant solution was 1:11. The solution was immersed at 60°C for 10 min. The solution was then filtered through a 200-400 mesh steel wire mesh to obtain polyphenylene sulfone ketone nascent fiber.

[0067] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) is washed twice with deionized water and then vacuum dried at 140°C for 2 hours to obtain polyphenylene sulfone ketone fiber.

[0068] The prepared polyphenylene sulfone ketone fiber has an oxidation weight gain of 15 wt%, and exhibits oxidation resistance, high temperature resistance, self-extinguishing properties, no melting shrinkage, no melting dripping, and no self-extinguishing phenomenon. The glass transition temperature reaches 171-175℃, the fiber tensile strength is 4.6 CN / dt, and the elongation at break is 20%.

[0069] Example 3

[0070] (1) 4g adipic acid, 1g ZrO2 and 495g PPS resin were blended and melted in a twin-screw extruder at high temperature and granulated. The feed port temperature of the screw extruder was 265℃, the die head temperature was 310℃, and the temperature of the middle zone of the spinning screw was 300~330℃. Ketone-containing PPS resin chips were prepared.

[0071] The ketone-containing PPS resin chips are then melt-spun into granules to obtain ketone-containing PPS filaments; the feed port temperature is 300℃, zone 2 temperature is 330℃, zone 3 temperature is 330℃, zone 4 temperature is 330℃, and the die temperature is 310℃; the hot stretching temperature is 95℃, and the stretching ratio is 3 times.

[0072] (2) A ketone-containing PPS tow (tensile strength 5.3 CN / dt, elongation at break 32%) was immersed in an electrolytic oxidation device. The electrolyte, potassium hydrogen sulfate solution, contained 2 wt% acetic acid and 0.1 wt% sulfuric acid. Both the anode and cathode were inert electrodes. The voltage was 380 V and the current density was 500 A / m. 2 Electrolytic oxidation for 1 hour yields polyphenylene sulfone ketone nascent fibers;

[0073] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) is washed three times with deionized water and then vacuum dried at 160°C for 2 hours to obtain polyphenylene sulfone ketone fiber.

[0074] The prepared polyphenylene sulfone ketone fiber has an oxidation weight gain of 12.5 wt%, and exhibits oxidation resistance, high temperature resistance, self-extinguishing properties, no melting shrinkage, no melting dripping, and self-extinguishing phenomena. The glass transition temperature reaches 165-170℃, the fiber tensile strength is 4.4 CN / dt, and the elongation at break is 20%.

[0075] Example 4

[0076] (1) 4g adipic acid, 1g Al2O3 and 495g PPS resin were blended and melted in a twin-screw extruder at high temperature and granulated. The feed port temperature of the screw extruder was 260℃, the die head temperature was 310℃, and the temperature of the middle zone of the spinning screw was 295~320℃. Ketone-containing PPS resin chips were prepared.

[0077] The ketone-containing PPS resin chips are then melt-spun into ketone-containing PPS filaments; the feed port temperature is 305℃, zone 2 is 325℃, zone 3 is 330℃, zone 4 is 330℃, and the die temperature is 310℃; the hot stretching temperature is 100℃, and the stretching ratio is 3.8 times.

[0078] (2) Ozone generated by the ozone oxidation device is introduced into deionized water, and 5wt% acetic acid, 0.1wt% sulfuric acid and 0.5wt% auxiliary oxidant nano-TiO2 are added; then ketone-containing PPS tow (tensile strength 5.3CN / dt, elongation at break 32%) is immersed in it, the mass ratio of ketone-containing PPS to ozone aqueous solution is 1:5, and it is oxidized at 40℃ for 60min to obtain polyphenylene sulfone ketone nascent fiber; the mass ratio of ozone to ketone-containing PPS tow is 72:108;

[0079] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) is washed three times with deionized water and then vacuum dried at 160°C for 2 hours to obtain polyphenylene sulfone ketone fiber.

[0080] The prepared polyphenylene sulfone ketone fiber has an oxidation weight gain of 14 wt%, and exhibits oxidation resistance, high temperature resistance, self-extinguishing properties, no melting shrinkage, no melting dripping, and self-extinguishing phenomena. Its glass transition temperature reaches 165-170℃, fiber tensile strength is 4.2 CN / dt, and elongation at break is 22%.

[0081] Example 5

[0082] (1) 4g biphenyl tricarboxylic acid, 1g Ga2O3 and 495g PPS resin were blended and melted in a twin-screw extruder at high temperature and granulated. The feed port temperature of the screw extruder was 275℃, the die head temperature was 315℃, and the temperature of the middle zone of the spinning screw was 300~330℃. Ketone-containing PPS resin chips were prepared.

[0083] The ketone-containing PPS resin chips are then melt-spun into granules to obtain ketone-containing PPS filaments; the feed port temperature is 300℃, zone 2 is 325℃, zone 3 is 330℃, zone 4 is 330℃, and the die temperature is 320℃; the hot drawing temperature is 105℃, and the drawing ratio is 3 times.

[0084] (2) Ozone generated by the ozone oxidation device is introduced into deionized water, and 5 wt% propionic acid, 0.2 wt% hydrochloric acid and 1 wt% auxiliary oxidant heteropoly acid are added; then ketone-containing PPS tow (tensile strength 5.0 CN / dt, elongation at break 26%) is immersed in it, the mass ratio of ketone-containing PPS to ozone aqueous solution is 1:5, and it is oxidized at 45℃ for 30 min to obtain polyphenylene sulfone ketone nascent fiber; the mass ratio of ozone to ketone-containing PPS tow is 72:108;

[0085] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) is washed 4 times with deionized water and then vacuum dried at 150°C for 1 hour to obtain polyphenylene sulfone ketone fiber.

[0086] The polyphenylene sulfone ketone fiber produced has an oxidation weight gain of 12 wt%, and exhibits oxidation resistance, high temperature resistance, self-extinguishing properties, no melting shrinkage, no melting dripping, and self-extinguishing phenomena. Its glass transition temperature reaches 174-178℃, the fiber tensile strength is 4.3 CN / dt, and the elongation at break is 20%.

[0087] Example 6

[0088] (1) 3g oxalic acid, 1g ZnO and 496g PPS resin were blended and melted in a twin-screw extruder at high temperature and granulated. The feed port temperature of the screw extruder was 255℃, the die head temperature was 305℃, and the temperature of the middle zone of the spinning screw was 290~315℃. Ketone-containing PPS resin chips were prepared.

[0089] The ketone-containing PPS resin chips are then melt-spun into ketone-containing PPS filaments; the feed port temperature is 295℃, zone 2 is 325℃, zone 3 is 325℃, zone 4 is 320℃, and the die temperature is 315℃; the hot stretching temperature is 95℃, and the hot stretching is 3.5 times.

[0090] (2) A ketone-containing PPS tow (tensile strength 5.0 CN / dt, elongation at break 30%) was immersed in an electrolytic oxidation device. The electrolyte, a potassium bisulfate solution, contained 5 wt% acetic acid and 1 wt% phosphoric acid. Both the anode and cathode were inert electrodes. The voltage was 380 V and the current density was 600 A / m. 2 Electrolytic oxidation for 20 minutes yields polyphenylene sulfone ketone nascent fibers;

[0091] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) is washed three times with deionized water and then vacuum dried at 160°C for 2 hours to obtain polyphenylene sulfone ketone fiber.

[0092] The prepared polyphenylene sulfone ketone fiber has an oxidation weight gain of 17 wt%, a glass transition temperature of 201-205℃, and exhibits oxidation resistance, high temperature resistance, self-extinguishing properties, no melting shrinkage, no dripping, and no self-extinguishing phenomenon. The fiber tensile strength is 4.1 CN / dt, and the elongation at break is 20%.

[0093] Example 7

[0094] (1) 5g biphenyl dicarboxylic acid, 1g TiO2 and 495g PPS resin were blended and melted in a twin-screw extruder at high temperature and granulated. The feed port temperature of the screw extruder was 275℃, the die head temperature was 315℃, and the temperature of the middle zone of the spinning screw was 300~330℃. Ketone-containing PPS resin chips were prepared.

[0095] The ketone-containing PPS resin chips are then melt-spun into granules to obtain ketone-containing PPS filaments; the feed port temperature is 305℃, zone 2 temperature is 325℃, zone 3 temperature is 325℃, zone 4 temperature is 325℃, and the die temperature is 320℃; the hot drawing temperature is 110℃, and the hot drawing ratio is 3.5 times.

[0096] (2) The ketone-containing PPS tow (tensile strength 4.8 CN / dt, elongation at break 30%) was immersed in N,N-dimethylacetamide containing 10 wt% cyclohexanone peroxide, 10 wt% acetic acid and 2 wt% naphthalenesulfonic acid. The mass ratio of the ketone-containing PPS tow to the oxidant solution was 1:10. The immersion was carried out at 60℃ for 30 min. The solution was then filtered through a 200-400 mesh steel wire mesh to obtain polyphenylene sulfone ketone nascent fiber.

[0097] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) was washed with deionized water 4 times and then vacuum dried at 150°C for 5 hours to obtain polyphenylene sulfone ketone fiber.

[0098] The prepared polyphenylene sulfone ketone fiber has an oxidation weight gain of 18 wt%, a glass transition temperature of 178-182℃, and exhibits oxidation resistance, high temperature resistance, self-extinguishing properties, no melting shrinkage, no dripping, and no self-extinguishing phenomenon. The fiber tensile strength is 4.0 CN / dt, and the elongation at break is 19%.

[0099] Depend on Figure 7 It can be seen that polyphenylene sulfone ketone fiber has good temperature resistance, with thermal decomposition temperatures all exceeding 370℃. Figure 8 It can be seen that polyphenylene sulfone ketone fiber contains a large amount of oxygen, and the oxygen is mainly in the form of sulfone.

[0100] Example 8

[0101] (1) 5g naphthalene dicarboxylic acid, 1g Al2O3 and 494g PPS resin were blended and melted in a twin-screw extruder at high temperature and granulated. The feed port temperature of the screw extruder was 270℃, the die head temperature was 315℃, and the temperature of the middle zone of the spinning screw was 300~330℃. Ketone-containing PPS resin chips were prepared.

[0102] The ketone-containing PPS resin chips are then melt-spun into ketone-containing PPS filaments; the feed port temperature is 295℃, zone 2 temperature is 325℃, zone 3 temperature is 325℃, zone 4 temperature is 325℃, and the die temperature is 315℃; the hot stretching temperature is 100℃, and the hot stretching ratio is 3.5 times.

[0103] (2) The ketone-containing PPS tow (tensile strength 4.9 CN / dt, elongation at break 29%) was immersed in water containing 13 wt% NaClO, 3 wt% acetic acid and 1 wt% boric acid. The mass ratio of the ketone-containing PPS tow to the oxidant solution was 1:6. The solution was immersed at 60℃ for 30 min. The solution was then filtered through a 200-400 mesh steel wire mesh to obtain polyphenylene sulfone ketone nascent fiber.

[0104] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) is washed three times with deionized water and then vacuum dried at 140°C for 1 hour to obtain polyphenylene sulfone ketone fiber.

[0105] The prepared polyphenylene sulfone ketone fiber has an oxidation weight gain of 12 wt%, a glass transition temperature of 200-205℃, and exhibits oxidation resistance, high temperature resistance, self-extinguishing properties, no melting shrinkage, no dripping, and no self-extinguishing phenomenon. The fiber tensile strength is 3.8 CN / dt, and the elongation at break is 17%.

[0106] Example 9

[0107] (1) 5g of naphthalene dicarboxylic acid, 1g of Al2O3 and 494g of PPS resin were blended and melt-spun in a twin-screw extruder to prepare ketone-containing PPS tow; the feed port temperature was 285℃, zone 2 was 320℃, zone 3 was 325℃, zone 4 was 330℃, and the die temperature was 315℃; the hot stretching temperature was 100℃ and the hot stretching ratio was 3.5 times.

[0108] (2) The ketone-containing PPS tow (tensile strength 5.2 CN / dt, elongation at break 27%) was immersed in water containing 13 wt% NaClO, 3 wt% acetic acid and 1 wt% boric acid. The mass ratio of the ketone-containing PPS tow to the oxidant solution was 1:6. The solution was immersed at 60°C for 30 min. The solution was then filtered through a 200-400 mesh steel wire mesh to obtain polyphenylene sulfone ketone nascent fiber.

[0109] (3) The polyphenylene sulfone ketone nascent fiber obtained in step (2) is washed three times with deionized water and then vacuum dried at 140°C for 1 hour to obtain polyphenylene sulfone ketone fiber.

[0110] The prepared polyphenylene sulfone ketone fiber has an oxidation weight gain of 13 wt%, a glass transition temperature of 200-205℃, and exhibits oxidation resistance, high temperature resistance, self-extinguishing properties, no melting shrinkage, no dripping, and no self-extinguishing phenomenon. The fiber tensile strength is 4.0 CN / dt, and the elongation at break is 17%.

[0111] Depend on Figure 9 and 10 It is evident that the fiber morphology is well preserved. Figure 9 It can be seen that the surface of the polyphenylene sulfone ketone fiber contains inorganic nanoparticles. (The text abruptly ends here.) Figure 10 It can be seen that the one-step spinning method can also achieve uniform dispersion of nanoparticles, which also proves that Friedel-Crafts acylation can be effectively carried out in the one-step spinning method.

[0112] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A method for preparing polyphenylene sulfone ketone fiber, characterized in that, The method includes the following steps: (1) Using metal oxide as a catalyst, PPS resin, metal oxide and carboxylic acid are blended and melt-spun in one step by screw extrusion to prepare ketone-containing PPS tow; or PPS resin, metal oxide and carboxylic acid are blended and melt-granulated by screw extrusion to prepare ketone-containing PPS particles, and then the ketone-containing PPS particles are used as raw materials for particle melt spinning to prepare ketone-containing PPS tow; wherein the carboxylic acid is a dicarboxylic acid or a polycarboxylic acid; (2) The ketone-containing PPS tow obtained in step (1) is placed in an oxidation system and subjected to oxidation reaction under the action of an oxidation catalyst to obtain polyphenylene sulfone ketone nascent fiber. (3) After removing impurities from the polyphenylene sulfone ketone nascent fiber obtained in step (2), it is dried to obtain polyphenylene sulfone ketone fiber.

2. The method for preparing polyphenylene sulfone ketone fiber according to claim 1, characterized in that, In step (1), the dicarboxylic acid is terephthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, or biphenyl dicarboxylic acid; the polycarboxylic acid is tricarboxylic acid containing a benzene ring; and the metal oxide is at least one of TiO2, SiO2, ZrO2, ZnO, SnO2, Al2O3, MoO3, WO3, CdO, GeO2, or Ga2O3.

3. The method for preparing polyphenylene sulfone ketone fiber according to claim 1, characterized in that, In step (1), the mass of the carboxylic acid is 0.01 to 10 wt% of the total mass of PPS resin, metal oxide, and carboxylic acid; the mass of the metal oxide is 0.01 to 5 wt% of the total mass of PPS resin, metal oxide, and carboxylic acid.

4. The method for preparing polyphenylene sulfone ketone fiber according to claim 1, characterized in that, In step (1), the process of one-step in-situ spinning of blended melt is: mixing or not mixing - screw extruder melting - melt metering pump - forced filtration - spinneret - nascent filament - hot stretching - ketone-containing PPS tow; The process of blending melt granulation is as follows: mixing or not mixing - screw extruder melting - melt metering pump - forced filtration - drawing and pelletizing - ketone-containing PPS granules; The process of granule melt spinning is as follows: drying of ketone-containing PPS granules - melting in a screw extruder - melt metering pump - forced filtration - spinneret - nascent filament - hot stretching - ketone-containing PPS filament bundle; The hot stretching process involves a hot stretching temperature of 90–200℃ and a stretching ratio of 2–10 times.

5. The method for preparing polyphenylene sulfone ketone fiber according to claim 1, characterized in that, In step (2), the mass of the ketone-containing PPS tow accounts for 0.1 to 40 wt% of the total mass of the ketone-containing PPS tow and the oxidation system; the mass concentration of the oxidation catalyst in the oxidation system is 0.1 to 40 wt%.

6. The method for preparing polyphenylene sulfone ketone fiber according to claim 1, characterized in that, In step (2), the oxidation catalyst is an inorganic acid and / or an organic acid; the inorganic acid is sulfuric acid, hydrochloric acid, carbonic acid, heteropoly acid, boric acid, phosphoric acid, nitric acid, molybdic acid, tungstic acid or acidic molecular sieve; the organic acid is formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, decanoic acid, benzoic acid, naphthoic acid, benzenesulfonic acid, naphthalenesulfonic acid, oxalic acid, malonic acid, succinic acid, adipic acid or pimelic acid.

7. The method for preparing polyphenylene sulfone ketone fiber according to claim 1, characterized in that, In step (2), the oxidation system is an oxidant solution, an electrolyte, an oxygen-saturated solution of water, or an ozone aqueous solution; When using an oxidizing agent solution, the ketone-containing PPS tow obtained in step (1) is immersed in the oxidizing agent solution and oxidized at 0-140°C for 0.1 min-24 h under the action of an oxidation catalyst to obtain polyphenylene sulfone ketone nascent fiber. When using an electrolyte, the ketone-containing PPS tow obtained in step (1) is immersed in the electrolyte of the electrolytic oxidation device. The initial pH of the electrolytic oxidation reaction is 4-7, both the anode and cathode are inert electrodes, the voltage is 2-380V, and the current density is 10-1000A / m. 2 The electrolytic oxidation time is 0.1 min to 10 h. Under the action of an oxidation catalyst, polyphenylene sulfone ketone nascent fibers are obtained. When using an oxygen-saturated solution of water, oxygen or air is continuously introduced into the deionized water, and aryl alcohols are added to the deionized water as an oxidation aid to obtain an oxygen-saturated solution of water; then the ketone-containing PPS tow obtained in step (1) is immersed in the oxygen-saturated solution of water, and under the action of an oxidation catalyst, it is oxidized at 40-44°C for 1 min-24 h to obtain polyphenylene sulfone ketone nascent fiber; When using an ozone aqueous solution, ozone generated by the ozone oxidation device is continuously passed into deionized water, and an auxiliary oxidant is added to the deionized water to obtain an ozone aqueous solution; then the ketone-containing PPS tow obtained in step (1) is immersed in the ozone aqueous solution, and oxidized at 40-95°C for 0.1-24 hours under the action of an oxidation catalyst to obtain polyphenylene sulfone ketone nascent fiber.

8. The method for preparing polyphenylene sulfone ketone fiber according to claim 7, characterized in that, In step (2), the oxidant solution is a solution with a mass concentration of 0.1 to 40 wt% formed by dissolving or dispersing the oxidant in a solvent; the oxidant is at least one of H2O2, Na2O2, NaClO, KClO, HClO, KMnO4, K2Cr2O7, MnO2, FeCl3, NO2, HNO3, peracetic acid, performic acid, dicumyl peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, tert-butanol peroxide, or perbenzoic acid; the solvent is at least one of water, benzene, toluene, ketones, organic alcohols, amides, dimethyl sulfoxide, tetrahydrofuran, diethyl ether, dimethyl ether, cyclohexane, n-hexane, organic acids, or halogenated hydrocarbons.

9. The method for preparing polyphenylene sulfone ketone fiber according to claim 7, characterized in that, In step (2), the electrolyte is a potassium hydrogen sulfate solution; The aryl alcohols are ethyl anthraquinol, phenol, naphthol, phenyl ketone, anthraquinol, or phenanthrene alcohol; the mass of the aryl alcohols accounts for 1 wt% to 40 wt% of the mass of the oxygen-saturated water solution. The auxiliary oxidant is TiO2, SnO2, ZrO2, MoO3 or WO3; the mass ratio of ozone to ketone-containing PPS tow is 48-96:108; the mass of the auxiliary oxidant accounts for 0.1-5 wt% of the mass of the ozone aqueous solution.

10. The method for preparing polyphenylene sulfone ketone fiber according to claim 1, characterized in that, In step (3), the drying temperature is 30 to 240°C and the drying time is 0.1 to 24 hours.

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