Pps-based quaternary ammonium salt antistatic fiber and method for preparing the same

Abstract

The application discloses a PPS-based quaternary ammonium salt antistatic fiber and a preparation method thereof, and belongs to the field of special polymer fiber production. The preparation method of the antistatic fiber comprises the following steps: S1, preparing chloromethylated PPS fiber; S2, adding the chloromethylated PPS fiber into an aqueous solution or an aqueous dispersion liquid containing a tertiary alkylamine R1R2R3N, and reacting for 3-8 hours at 30-90 DEG C, and then taking out the fiber; and S3, sufficiently rinsing the fiber with deionized water, and drying at 30-80 DEG C to obtain the PPS-based quaternary ammonium salt antistatic fiber. Compared with the prior art, the method utilizes a chemical modification method to perform surface modification treatment on the polyphenylene sulfide fiber, so that the polyphenylene sulfide fiber has durable and stable antistatic ability and smoothness, and has good popularization and application value.

Description

Technical Field

[0001] This invention relates to the field of specialty polymer fiber production, specifically providing a PPS-based quaternary ammonium salt antistatic fiber and its preparation method. Background Technology

[0002] Polyphenylene sulfide (PPS) fibers have wide applications in many industrial fields due to their high temperature resistance, solvent resistance, chemical corrosion resistance, and excellent mechanical strength, electrical insulation properties, and dimensional stability. For example, utilizing the high temperature and acid corrosion resistance of PPS fibers, high-temperature filter belts woven from PPS fibers are used for dust removal from high-temperature acidic exhaust gases in thermal power plants; they can also be woven into filter cloths for solid-liquid separation in industrial production processes; and the high temperature resistance, solvent resistance, and dimensional stability of PPS fibers can replace ordinary cross-linked polystyrene and polyester materials in the production of ion exchange resins. After surface functionalization of the fibers, ion exchange resins are obtained for industrial water treatment or the enrichment of metal ions.

[0003] However, the electrical insulation properties of polyphenylene sulfide (PPS) fibers significantly impact their application performance. For instance, during weaving, the excellent electrical insulation properties of PPS fibers lead to static electricity buildup, resulting in low weaving efficiency, fiber fuzzing, and numerous fiber breaks, all of which affect fabric quality. While specific antistatic agents can be applied to the fiber surface to partially address static electricity accumulation, the weak physical adsorption between the antistatic agent and the PPS fiber means that the agent may detach during processing due to mechanical friction or washing. Consequently, the antistatic effect is not durable, and static electricity buildup will recur after a period of time. Therefore, obtaining PPS fibers with stable, reliable, and durable antistatic properties is a crucial issue that urgently needs to be addressed to improve the application performance of PPS fibers. Summary of the Invention

[0004] This invention addresses the shortcomings of the prior art by providing a method for preparing PPS-based quaternary ammonium salt antistatic fibers. This method utilizes chemical modification to perform surface modification treatment on polyphenylene sulfide fibers, enabling the polyphenylene sulfide fibers to possess durable and stable antistatic capabilities and smoothness.

[0005] The technical solution adopted by this invention to solve its technical problem is: a method for preparing PPS-based quaternary ammonium salt antistatic fibers, comprising: S1. Preparation of chloromethylated PPS fibers; S2. Add chloromethylated PPS fibers to an aqueous solution or aqueous dispersion containing alkyl tertiary amines R1R2R3N, react at 30℃~90℃ for 3~8 hours, remove the fibers; thoroughly rinse the fibers with deionized water, and dry at 30~80℃ to obtain PPS-based quaternary ammonium salt antistatic fibers.

[0006] Preferably, step S1 includes: immersing polyphenylene sulfide (PPS) fibers in a mixed medium composed of concentrated hydrochloric acid and zinc chloride, controlling the temperature at 20°C to 80°C for 3 to 5 hours; then gradually adding paraformaldehyde and introducing hydrogen chloride gas to react, thereby obtaining chloromethylated PPS fibers.

[0007] Preferably, in step S1, the mass percentage concentration of zinc chloride in hydrochloric acid is 10% to 15%.

[0008] Preferably, the degree of substitution (DS) of the chloromethylated PPS fiber in step S1 is 0.01 to 0.8.

[0009] Preferably, the aqueous solution or aqueous dispersion of the alkyl tertiary amine R1R2R3N in step S2 also contains an AEO surfactant.

[0010] Preferably, in step S2, the tertiary amine R1R2R3N, at least one of R1, R2, and R3 is a straight-chain alkyl group with a C3 or greater, a branched alkyl group with a C3 or greater, an aralkyl group Ar-R-, an amide alkyl group RCONHR'-, or an ester alkyl group RCOOR'-.

[0011] Compared with the prior art, the preparation method of PPS-based quaternary ammonium salt antistatic fiber of the present invention has the following outstanding advantages: (i) The method of the present invention uses chemical modification to modify the surface of polyphenylene sulfide fibers. Quaternary ammonium salt hydrophilic groups are attached to the fiber surface through chemical bonding, which endows the polyphenylene sulfide fibers with durable and stable antistatic ability, thereby improving the weaving performance of polyphenylene sulfide fibers in subsequent weaving processes. At the same time, in view of the hydrophobic properties of polyphenylene sulfide fibers, quaternization is carried out using tertiary amines with different carbon chains, which can enhance the compatibility with the fiber surface and endow the fibers with smooth properties. (ii) In the quaternization process of the present invention, long-chain alkyl tertiary amines and amide tertiary amines are used. Different carbon chain lengths and structures of tertiary amines can be adapted according to different application scenarios in order to obtain better antistatic and compliant effects. (III) In the process of chloromethylating polyphenylene sulfide fiber, the method of the present invention does not require the use of organic solvents. It directly reacts hydrogen chloride and formaldehyde in a hydrochloric acid-water medium, which is more environmentally friendly and efficient. Polyphenylene sulfide fiber can be chloromethylated quickly through a stable chloromethylation reactor, and its degree of chloromethylation substitution can be precisely controlled. Detailed Implementation

[0012] The present invention will be further described below with specific embodiments, but these are not intended to limit the invention. Unless otherwise defined, the test reagents used in the following embodiments are conventional biochemical reagents, and the experimental methods are conventional methods unless otherwise specified.

[0013] This invention obtains antistatic fibers with durable and stable antistatic properties and smoothness by a two-step chemical reaction of commercial polyphenylene sulfide fibers, including: S1. Chloromethylation of polyphenylene sulfide fibers to synthesize chloromethylated polyphenylene sulfide CM-PPS; S2. Quaternization of chloromethylated polyphenylene sulfide CM-PPS fibers.

[0014] Next, the various steps in the preparation method of PPS-based quaternary ammonium salt antistatic fiber of the present invention will be described in more detail.

[0015] First, chloromethylated polyphenylene sulfide (CM-PPS) was synthesized by chloromethylation of polyphenylene sulfide fibers.

[0016] In one embodiment of the present invention, polyphenylene sulfide (PPS) fibers are immersed in a mixed medium composed of concentrated hydrochloric acid and zinc chloride, and the temperature is controlled at 20°C to 80°C for 3 to 5 hours; then paraformaldehyde is gradually added, and hydrogen chloride gas is introduced to carry out the reaction, thereby obtaining chloromethylated PPS fibers. The reaction equation is as follows:

[0017] In a specific example, in step S1, the zinc chloride concentration in concentrated hydrochloric acid is 10%~15% by mass, wherein the concentration of concentrated hydrochloric acid is 35%. When the zinc chloride concentration is below 10%, the chloromethylation reaction proceeds slowly; when the zinc chloride concentration is above 15%, the chloromethylation reaction proceeds too quickly, causing cross-linking between different polymer chains and affecting the mechanical strength of the fiber.

[0018] In a specific example, when the polyphenylene sulfide (PPS) fibers are immersed in the mixing medium in step S1, the weight of the fibers accounts for 10% to 20% of the weight of the mixing medium to ensure sufficient mixing of the system.

[0019] In a specific example, when the polyphenylene sulfide (PPS) fibers are immersed in the mixed medium in step S1, the temperature is preferably controlled at 40~70°C, especially 50~60°C.

[0020] In a specific example, when the polyphenylene sulfide (PPS) fibers are immersed in the mixed medium in step S1, the immersion time is preferably 3 to 5 hours, especially 3 to 4 hours.

[0021] In a specific example, the degree of substitution (DS) of the chloromethylated PPS fiber in step S1 is 0.01~0.8, especially 0.1~0.5, and particularly 0.15~0.45, to ensure that the mechanical strength of the polyphenylene sulfide fiber is not affected. The degree of substitution (DS) of the chloromethylation reaction of the polyphenylene sulfide fiber can be adjusted by controlling the amount of paraformaldehyde and hydrogen chloride, as well as the temperature and time of the chloromethylation reaction. Generally speaking, the more paraformaldehyde and hydrogen chloride gas added, the more complete the reaction and the higher the degree of substitution (DS); conversely, the degree of substitution (DS) is lower. Lower temperatures result in a slower reaction rate, leading to a lower degree of substitution for the same ratio of paraformaldehyde to hydrogen chloride. Increasing the temperature allows the fiber to swell in an acidic medium, increasing the rate of the chloromethylation reaction and thus the degree of substitution (DS).

[0022] In this specific example, the degree of substitution (DS) of the chloromethylated PPS fiber is calculated by analyzing the chloride ion content in the generated CM-PPS fiber. The formula for calculating the degree of substitution (DS) of chloromethylation is as follows:

[0023] in: M0: The mass of chloromethylated PPS fiber CM-PPS taken for chlorine content analysis, in grams; M Cl Mass of chloride ions analyzed from 0 g of chloromethylated PPS fiber CM-PPS, in grams; N Cl Take m0 grams of chloromethylated PPS fiber and analyze the number of moles of chloride ions. M pps unit : The mass of the repeating unit of PPS polymer, taken as 108; M CH2Cl : Molar mass of the chloromethyl substituent, taken as 49.5.

[0024] Secondly, the quaternization of chloromethyl polyphenylene sulfide (CM-PPS) fibers.

[0025] In one embodiment of the present invention, chloromethylated PPS fibers are added to an aqueous solution or dispersion containing alkyl tertiary amines R1R2R3N, reacted at 30°C to 90°C for 3 to 8 hours, and then the fibers are removed. The fibers are thoroughly rinsed with deionized water and dried at 30 to 80°C to obtain PPS-based quaternary ammonium salt antistatic fibers. The reaction equation is as follows:

[0026] In one specific example, the aqueous solution or dispersion containing alkyl tertiary amines R1R2R3N also contains a surfactant to improve the grafting uniformity of quaternary ammonium groups and enhance the final flexibility of the fiber.

[0027] The surfactant is preferably AEO-9 surfactant (fatty alcohol polyoxyethylene ether).

[0028] In a specific example, in the tertiary amine R1R2R3N, R1, R2, and R3 can be the same or different; two of the alkyl groups can be the same, while the third alkyl group can be different.

[0029] In a specific example, at least one alkyl group among R1, R2, and R3 needs to meet the following condition: it can be a straight-chain alkyl group with more than three carbon atoms, an aralkyl group (Ar-R-), an amide alkyl group (RCONHR'-), or an ester alkyl group (RCOOR'-). Amide alkyl groups offer better antistatic properties, while long-chain straight-chain alkyl groups provide better smoothing and compliance properties. To simultaneously achieve both "smoothing properties" and "antistatic properties," the optimal choice is an asymmetric tertiary amine. For example, R1 and R2 can be methyl groups, resulting in higher quaternization reactivity; R3 can be a long alkyl group containing an amide, ensuring both hygroscopic conductivity (antistatic properties) and providing lubricity (smoothing) through its long-chain structure. Branched alkyl groups with more than three carbon atoms and aralkyl groups (Ar-R-) are less effective.

[0030] In a specific instance, tertiary amines with R1 = R2 ≠ R3 include: ① Long-chain alkyl dimethyl tertiary amines such as octyl dimethyl tertiary amine, decyl dimethyl tertiary amine, dodecyl dimethyl tertiary amine, tetradecyl dimethyl tertiary amine, hexadecyl dimethyl tertiary amine, and octadecyl dimethyl tertiary amine; ② Tertiary amines with R1=R2=CH3 and R3=aralkyl groups: such as benzyl dimethyl tertiary amine; ③R1=R2=CH3, R3=fatty acid amide alkyl tertiary amines (amide tertiary amines): octamidoethyl dimethyl tertiary amine, decanamidoethyl dimethyl tertiary amine, lauramidoethyl dimethyl tertiary amine, myristamidoethyl dimethyl tertiary amine, palmitamidoethyl dimethyl tertiary amine, oleamide ethyl dimethyl tertiary amine, stearamidoethyl dimethyl tertiary amine, octamidopropyl dimethyl tertiary amine, decanamidopropyl dimethyl tertiary amine, lauramidopropyl dimethyl tertiary amine, myristamidopropyl dimethyl tertiary amine, palmitamidopropyl dimethyl tertiary amine, oleamide propyl dimethyl tertiary amine, stearamidopropyl dimethyl tertiary amine; ④R1=R2=CH3, R3=tertiary amines of fatty acid acyloxyalkyl groups (ester tertiary amines): octanoyloxyethyl dimethyl tertiary amine, decanoyloxyethyl dimethyl tertiary amine, lauroyloxyethyl dimethyl tertiary amine, myristoyloxyethyl dimethyl tertiary amine, palmitoyloxyethyl dimethyl tertiary amine, oleoyloxyethyl dimethyl tertiary amine and stearoyloxyethyl dimethyl tertiary amine; and octanoyloxypropyl dimethyl tertiary amine, decanoyloxypropyl dimethyl tertiary amine, lauroyloxypropyl dimethyl tertiary amine, myristoyloxypropyl dimethyl tertiary amine, palmitoyloxypropyl dimethyl tertiary amine, oleoyloxypropyl dimethyl tertiary amine and stearoyloxypropyl dimethyl tertiary amine.

[0031] When long-chain alkyl groups, amide tertiary amines, or ester tertiary amines are used as quaternizing agents, compared with trimethylamine, their long-chain structure can form a hydrophobic lubricating pad similar to an "oil film" on the surface. This can significantly reduce the coefficient of friction on the fiber surface and reduce mechanical triboelectric charging during weaving. If amide tertiary amines are used, the amide bond (-CONH-) can also form certain hydrogen bonds with the polar regions inside the PPS matrix or fiber, which increases the adhesion of functional groups to the fiber surface, making it more wear-resistant and wash-resistant.

[0032] In one specific instance, a short-chain tertiary amine dissolves in water and undergoes a quaternization reaction in the resulting aqueous solution.

[0033] In one specific instance, long-chain alkyl tertiary amines, which are insoluble in water, undergo quaternization in a formed aqueous emulsion medium.

[0034] In one specific example, the quaternization reaction was carried out at 50–80 °C.

[0035] In one specific instance, the quaternization reaction time was 3 to 6 hours, particularly 5 to 6 hours.

[0036] Example:

[0037] S1: General Operating Procedures for the Synthesis of CM-PPS Fibers by Chloromethylation of PPS Fibers

[0038] Add 200 ml of concentrated hydrochloric acid and 25 g of anhydrous zinc chloride to a quartz reactor, mix thoroughly and dissolve evenly to obtain a hydrochloric acid-zinc chloride mixed medium; take 21.6 g of commercial polyphenylene sulfide fiber, put it into the mixed medium composed of concentrated hydrochloric acid-zinc chloride, and keep it at room temperature for 3 hours for immersion.

[0039] The mixed medium was heated to a certain temperature, paraformaldehyde was added in batches, and dry hydrogen chloride gas was continuously bubbled through to carry out the chloromethylation reaction for 3-6 hours. After the reaction was completed, the PPS fibers were cooled and removed, washed three times with 200 ml of deionized water, and then dried at 50°C to obtain chloromethylated PPS fibers CM-PPS; its chlorine content was analyzed and the degree of chloromethylation substitution was calculated.

[0040] The chloromethylation test data for Examples 1-15 are shown in Table 1:

[0041] Note: The numbers in CM-PPS-XXX represent the degree of substitution (DS), expressed in parts per thousand. For example, CM-PPS-030 indicates a degree of substitution of 30‰ for the chloromethylation reaction.

[0042] S2: General Operation Method for Quaternization of CM-PPS Fibers

[0043] Add 500 mL of deionized water and 0.1 mol of tertiary amine to the reactor (in some examples, 0.1 g of fatty alcohol polyoxyethylene ether surfactant is also added), and mix thoroughly. Add 15 g of chloromethylated PPS fiber (CM-PPS) to the mixture, ensuring that the amount of tertiary amine in the reaction system is much greater than the amount of chloromethyl crown groups in CM-PPS, and that the solution or emulsion containing the tertiary amine fully submerges the CM-PPS fiber. Turn on the liquid phase circulation pump to maintain sufficient flow of liquid phase material and full submersion of the fiber. Turn on the reactor heating, gradually raise the temperature to the process temperature, and maintain this temperature for the quaternization reaction until completion.

[0044] The reacted fibers are removed, thoroughly washed with deionized water, and dried at 50-80℃ to obtain quaternized phenyl sulfide fibers, denoted as Q-PPS. The quaternization reaction efficiency is calculated using the nitrogen content method, and the surface resistivity (GB / T14342-2015), fiber strength (GB / T 14337-2022), and coefficient of friction (GB / T45179—2024) of the fibers are measured.

[0045] The data results for the quaternization reaction under different conditions are detailed in Table 2:

[0046] The data in the table above shows that the quaternization reaction is quite effective for long-chain alkyl tertiary amines within the range of patented process parameters; however, the quaternization reaction efficiency is slightly worse for low-carbon tertiary amines. This is mainly because the low-carbon tertiary amines volatilize significantly during the reaction process, making it impossible to guarantee a relative excess in the reaction system.

[0047] In addition, it can be seen that asymmetric tertiary amines can achieve better smoothing and antistatic properties, especially when R1 and R2 are methyl groups and R3 is an amide-containing long alkyl group, which has the best effect.

[0048] The embodiments described above are merely preferred embodiments of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solutions of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing PPS-based quaternary ammonium salt antistatic fibers, characterized in that, include: S1. Preparation of chloromethylated PPS fibers; S2. Add chloromethylated PPS fibers to an aqueous solution or aqueous dispersion containing alkyl tertiary amines R1R2R3N, react at 30℃~90℃ for 3~8 hours, remove the fibers; thoroughly rinse the fibers with deionized water, and dry at 30~80℃ to obtain PPS-based quaternary ammonium salt antistatic fibers.

2. The preparation method according to claim 1, characterized in that, Step S1 includes: Polyphenylene sulfide (PPS) fibers are immersed in a mixed medium consisting of concentrated hydrochloric acid and zinc chloride, and the temperature is controlled at 20℃~80℃ for 3~5 hours. Then, paraformaldehyde is gradually added and hydrogen chloride gas is introduced to carry out the reaction, thus obtaining chloromethylated PPS fibers.

3. The preparation method according to claim 1 or 2, characterized in that, Step S2 contains an aqueous solution or dispersion of alkyl tertiary amines R1R2R3N, which also contains AEO surfactant.

4. The preparation method according to claim 1 or 2, characterized in that, In step S2, the tertiary amine R1R2R3N, at least one of R1, R2, and R3 is a straight-chain alkyl group with a C3 or larger, an aralkyl group Ar-R-, an amide alkyl group RCONHR'-, or an ester alkyl group RCOOR'-.

5. The preparation method according to claim 1 or 2, characterized in that, The quaternization reaction in step S2 is carried out at a temperature of 50-80℃ for 3-6 hours.

6. The preparation method according to claim 2, characterized in that, In step S1, the mass percentage concentration of zinc chloride in hydrochloric acid is 10%~15%.

7. The preparation method according to claim 2, characterized in that, In step S1, when the polyphenylene sulfide (PPS) fiber is immersed in the mixed medium, the temperature is controlled at 40~70℃.

8. The preparation method according to claim 2, characterized in that, In step S1, the degree of substitution (DS) of the chloromethylated PPS fiber is 0.01~0.

8.

9. PPS-based quaternary ammonium salt antistatic fiber, prepared by the preparation method according to any one of claims 1-8.

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