Plant-based fiber, preparation method thereof and application of plant-based fiber in protective gloves
By modifying the cross-linked network structure of carbon nanotubes and quaternized lignin, the problem of severe static electricity in PET fibers was solved, achieving good application results of plant-based fibers in protective gloves, which have antistatic and flame-retardant properties.
Patent Information
- Application Number
- CN202511183283.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-22
- Publication Date
- 2025-10-31
AI Technical Summary
PET fibers suffer from severe static electricity due to their insulation properties, which affects their application in textile materials. In particular, they may cause hazards during use, such as attracting dust, causing fires due to electrostatic discharge, and damaging microelectronic components.
Plant-based fibers were prepared by reacting carbon nanotubes with sulfuric acid and nitric acid to obtain carboxylated carbon nanotubes, then reacting them with thionyl chloride to obtain acyl chloride carbon nanotubes, and reacting them with (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone to obtain modified carbon nanotubes. Simultaneously, quaternary ammonium salts were generated by reacting 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine with 6-chloro-1-hexene, which were then reacted with alkali lignin to obtain quaternized lignin, and reacted with allylphosphine dichloride and p-aminobenzoic acid to obtain a dicarboxylic acid. Finally, the modified carbon nanotubes and quaternized lignin were melt-spun to form a cross-linked network structure.
Plant-based fibers have good antistatic and flame-retardant properties, which improves the safety and effectiveness of protective gloves.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, specifically to a plant-based fiber, its preparation method, and its application in protective gloves. Background Technology
[0002] PET fiber possesses excellent mechanical properties, abrasion resistance, and creep resistance, along with high hardness, rigidity, low water absorption, and good dimensional stability, exhibiting excellent comprehensive performance and thus gaining popularity and rapid development. Therefore, since its industrial production in the 1950s, PET has been applied in many fields such as national defense, aerospace, medical and health, and communications, making it an important textile raw material. However, due to the inherent insulating properties of PET, its poor moisture absorption makes it prone to static electricity. For textile materials, static electricity mostly leaks from the surface. If the surface conductivity is poor, the charge cannot leak, leading to severe static electricity and various hazards during use, such as attracting dust, causing fires due to electrostatic discharge, and damaging microelectronic components, thereby hindering the application of this material. Therefore, this invention prepares a plant-based fiber with good antistatic and flame-retardant properties, showing good application results in protective gloves. Summary of the Invention
[0003] The purpose of this invention is to provide a plant-based fiber, its preparation method, and its application in protective gloves, so as to solve the problems existing in the prior art.
[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:
[0005] A plant-based fiber, said plant-based fiber is obtained by melt spinning polyester, modified carbon nanotubes, and quaternized lignin.
[0006] As an optimization, the polyester is prepared by polycondensation reaction of diacid, ethylene glycol, and terephthalic acid.
[0007] As an optimization, the dicarboxylic acid is prepared by reacting allylphosphine dichloride with p-aminobenzoic acid.
[0008] As an optimization, the modified carbon nanotubes are prepared by reacting carboxylated carbon nanotubes with thionyl chloride to obtain acyl chloride carbon nanotubes, and then reacting them with (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone.
[0009] As an optimization, the carboxylated carbon nanotubes are prepared by reacting carbon nanotubes with sulfuric acid and nitric acid.
[0010] As an optimization, the quaternized lignin is prepared by reacting 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine with 6-chloro-1-hexene to generate a quaternary ammonium salt, which is then reacted with alkali lignin.
[0011] A method for preparing plant-based fibers includes the following preparation steps:
[0012] (1) Carbon nanotubes, 95wt% sulfuric acid aqueous solution, and 65wt% nitric acid aqueous solution were mixed and reacted, then centrifuged, washed, and dried to obtain carboxylated carbon nanotubes; carboxylated carbon nanotubes, sulfoxide, and N,N-dimethylformamide were mixed and reacted, then centrifuged, washed, and dried to obtain acyl chloride carbon nanotubes; acyl chloride carbon nanotubes, (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone, triethylamine, and dichloromethane were mixed and reacted, then centrifuged, washed, and dried to obtain modified carbon nanotubes;
[0013] (2) 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine, 6-chloro-1-hexene and N,N-dimethylformamide were mixed and reacted, and then dried under vacuum to obtain quaternary ammonium salt; alkali lignin, 20wt% sodium hydroxide aqueous solution and quaternary ammonium salt were mixed, stirred and reacted, and then dialyzed and dried to obtain quaternized lignin;
[0014] (3) Allylphosphine dichloride, triethylamine, N,N-dimethylformamide and p-aminobenzoic acid were mixed and reacted, filtered and distilled under reduced pressure to obtain a dicarboxylic acid; the dicarboxylic acid, ethylene glycol, terephthalic acid and antimony glycol were mixed and reacted to obtain a polyester.
[0015] (4) Polyester, modified carbon nanotubes, quaternized lignin and azobisisobutyronitrile are mixed and melt-spun to obtain plant-based fibers.
[0016] As an optimization, the preparation steps of the modified carbon nanotubes in step (1) are as follows: carbon nanotubes, 95wt% sulfuric acid aqueous solution, and 65wt% nitric acid aqueous solution are mixed evenly at a mass ratio of 1:(70-80):(20-30), stirred at 95-105℃ and 200-300r / min for 2-4h, centrifuged at 8000-10000rpm for 10-12min, the obtained precipitate is washed 4-6 times with deionized water, and vacuum dried at 75-85℃ for 10-12h to obtain carboxylated carbon nanotubes; carboxylated carbon nanotubes, sulfoxide, and N,N-dimethylformamide are mixed evenly at a mass ratio of 1:(10-15):(1.5-2.5), stirred at 60-80℃ and 200-300r / min for 20-12h. After 24 hours, the mixture was cooled to room temperature and centrifuged at 8000–10000 rpm for 10–12 minutes. The resulting precipitate was washed 4–6 times with dichloromethane and dried under vacuum at 40–60 °C for 10–12 hours to obtain acyl chloride carbon nanotubes. Under ice-water bath conditions, acyl chloride carbon nanotubes, (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone, triethylamine, and dichloromethane were mixed uniformly at a mass ratio of 1:(2–3):(0.9–1.1):(10–12). The mixture was stirred at 200–300 rpm for 5–7 hours at room temperature and centrifuged at 8000–10000 rpm for 10–12 minutes. The resulting precipitate was washed 4–6 times with deionized water and dried under vacuum at 20–30 °C for 10–12 hours to obtain modified carbon nanotubes.
[0017] As an optimization, the preparation steps of the quaternized lignin in step (2) are as follows: 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine, 6-chloro-1-hexene, and N,N-dimethylformamide are mixed evenly at a mass ratio of 1:(0.5~0.6):(15~20), stirred at 45~55℃ and 200~300r / min for 4~6h, and then vacuum dried at 20~30℃ for 10~12h to obtain the quaternary ammonium salt; alkali lignin and 20wt% sodium hydroxide aqueous solution are mixed evenly at a mass ratio of 1:(15~25), and 0.2~0.4 times the mass of the alkali lignin quaternary ammonium salt is added, stirred at 80~90℃ and 200~300r / min for 4~6h, cooled to room temperature, dialyzed for 70~72h, and the resulting solution is vacuum dried at 20~30℃ for 10~12h to obtain the quaternized lignin.
[0018] As an optimization, the preparation steps of the polyester in step (3) are as follows: Under a nitrogen atmosphere, allylphosphine dichloride, triethylamine, and N,N-dimethylformamide are mixed evenly in a mass ratio of 1:(0.8-1.2):(15-20), and p-aminobenzoic acid with a mass of 1.5-2 times that of allylphosphine dichloride is added. The mixture is stirred at 55-65°C and 200-300 r / min for 10-12 h. The mixture is then filtered, and N,N-dimethylformamide is removed by vacuum distillation to obtain a dicarboxylic acid. Under a nitrogen atmosphere, the dicarboxylic acid, ethylene glycol, terephthalic acid, and antimony glycol are mixed evenly in a mass ratio of 1:(0.3-0.4):(0.4-0.5):(0.001-0.002). The mixture is stirred at 250-260°C, 0.3-0.4 MPa, and 40-60 r / min for 2-3 h to obtain the polyester.
[0019] As an optimization, the preparation steps of the plant-based fiber in step (4) are as follows: polyester, modified carbon nanotubes, quaternized lignin, and azobisisobutyronitrile are mixed evenly in a mass ratio of 1:(0.06~0.08):(0.04~0.06):(0.001~0.002), added to a spinning machine, and melt-spun at the following conditions: zone 1 temperature 220~230℃, zone 2 temperature 245~255℃, zone 3 temperature 250~260℃, zone 4 temperature 250~260℃, metering pump temperature 265~275℃, spinning assembly temperature 280~285℃, and spinning speed 800m / min to obtain plant-based fiber.
[0020] As an optimization, the carbon nanotubes have a purity of 95%, a diameter of 20–40 nm, and a length of 1–2 μm, and were purchased from Shanghai Yuanye Biotechnology Co., Ltd.
[0021] As an optimization, the alkali lignin was purchased from Shanghai Nuotai Chemical Co., Ltd.
[0022] As an optimization, the dialysis uses a dialysis bag with a molecular weight cutoff of 1000 Da, and the deionized water is changed every 12 hours.
[0023] As an optimization, the reaction process of the modified carbon nanotubes in step (1) is as follows:
[0024]
[0025] As an optimization, the reaction process of the quaternary ammonium salt in step (2) is as follows:
[0026]
[0027] As an optimization, the reaction process of quaternized lignin in step (2) is as follows:
[0028]
[0029] As an optimization, the reaction process of the dicarboxylic acid in step (3) is as follows:
[0030]
[0031] Application of a plant-based fiber in protective gloves.
[0032] Compared with the prior art, the beneficial effects achieved by the present invention are:
[0033] In preparing plant-based fibers, this invention involves reacting carbon nanotubes with sulfuric acid and nitric acid to obtain carboxylated carbon nanotubes; reacting the carboxylated carbon nanotubes with sulfoxide to obtain acyl chloride carbon nanotubes; reacting the acyl chloride carbon nanotubes with (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone to obtain modified carbon nanotubes; reacting 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine with 6-chloro-1-hexene to generate a quaternary ammonium salt; reacting the quaternary ammonium salt with alkali lignin to obtain quaternized lignin; reacting allylphosphine dichloride with p-aminobenzoic acid to obtain a dicarboxylic acid; reacting the dicarboxylic acid, ethylene glycol, and terephthalic acid in a polycondensation reaction to obtain a polyester; and melt-spinning the polyester, modified carbon nanotubes, and quaternized lignin to obtain plant-based fibers.
[0034] First, carboxylated carbon nanotubes were prepared by reacting carbon nanotubes with sulfuric acid and nitric acid. Then, the carboxylated carbon nanotubes were reacted sequentially with thionyl chloride to prepare acyl chloride carbon nanotubes. Finally, the acyl chloride carbon nanotubes were reacted with (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone to prepare modified carbon nanotubes. Carbon nanotubes are carbon molecules composed of nanoscale coaxial carbon nanotubes, possessing a graphite-like layered structure. The C-C covalent bonds they form are among the most stable chemical bonds in nature, thus giving carbon nanotubes excellent mechanical properties. Furthermore, the p-orbital electrons of the carbon atoms in the carbon nanotubes are highly delocalized outside the tube wall. The large π bond, due to its significant conjugation effect, gives carbon nanotubes excellent electrical properties. Carbon nanotubes react with sulfuric acid and nitric acid to introduce carboxyl groups, which then react with thionyl chloride to form acyl chloride groups. Modified carbon nanotubes are prepared by reacting the acyl chloride groups on acyl chloride carbon nanotubes with the hydroxyl groups on (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone. The introduction of benzophenone-type ultraviolet absorbers on carbon nanotubes improves their UV protection performance. At the same time, the introduction of double bonds on carbon nanotubes reacts with the double bonds on quaternized lignin and polyester to form a cross-linked network structure, which improves their mechanical properties.
[0035] Secondly, 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine is reacted with 6-chloro-1-hexene to generate a quaternary ammonium salt. The tertiary amine group on 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine undergoes a quaternization reaction with the chlorine on 6-chloro-1-hexene. The resulting quaternary ammonium salt can improve antistatic properties. Simultaneously, 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine contains a triazine structure and a large amount of nitrogen, which, synergistically with lignin and phosphorus, improves flame retardant properties. The quaternary ammonium salt is then reacted with alkali wood... Quaternized lignin was prepared by a reaction of alkali lignin and alkali lignin. The alkali lignin contains a benzene ring structure with good thermal stability and has good heat resistance. When it decomposes at high temperature, it can promote the formation of a char layer, thereby forming an oxygen-barrier and heat-insulating protective layer in the material, inhibiting the combustion process. When alkali lignin decomposes endothermically, it can release non-flammable gases such as carbon dioxide and water vapor, which can inhibit the spread of flame to a certain extent and improve the flame retardant performance. At the same time, the reaction of alkali lignin with quaternary ammonium salt introduces double bonds into alkali lignin, which react with double bonds on modified carbon nanotubes and polyesters to form a cross-linked network structure, improving mechanical properties.
[0036] Finally, a diacid was prepared by reacting allylphosphine dichloride with p-aminobenzoic acid; a polyester was prepared by polycondensation of the diacid, ethylene glycol, and terephthalic acid. The chlorine on allylphosphine dichloride reacted with the amino group on p-aminobenzoic acid to prepare the diacid. The prepared diacid contained phosphorus and double bonds. Phosphorus can promote the formation of the char layer and can also block the combustion reaction by capturing free radicals, thus further improving the flame retardant performance. The polyester prepared by polycondensation of the diacid, ethylene glycol, and terephthalic acid contained double bond groups, which reacted with the double bonds on modified carbon nanotubes and quaternized lignin to form a cross-linked network structure, thus improving the mechanical properties. Detailed Implementation
[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0038] Example 1:
[0039] A method for preparing plant-based fibers includes the following preparation steps:
[0040] (1) Carbon nanotubes, 95wt% sulfuric acid aqueous solution, and 65wt% nitric acid aqueous solution were mixed evenly at a mass ratio of 1:70:20. The mixture was stirred at 95℃ and 200r / min for 2h, and centrifuged at 8000rpm for 10min. The resulting precipitate was washed four times with deionized water and vacuum dried at 75℃ for 10h to obtain carboxylated carbon nanotubes. Carboxylated carbon nanotubes, sulfoxide, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:10:1.5. The mixture was stirred at 60℃ and 200r / min for 20h, and then cooled to room temperature and centrifuged at 8000rpm for 10min. The precipitate was centrifuged at 00 rpm for 10 min, washed four times with dichloromethane, and dried under vacuum at 40 °C for 10 h to obtain acyl chloride carbon nanotubes; under ice-water bath conditions, acyl chloride carbon nanotubes, (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone, triethylamine, and dichloromethane were mixed evenly at a mass ratio of 1:2:0.9:10, stirred at 200 rpm for 5 h at room temperature, centrifuged at 8000 rpm for 10 min, washed four times with deionized water, and dried under vacuum at 20 °C for 10 h to obtain modified carbon nanotubes;
[0041] (2) 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine, 6-chloro-1-hexene, and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:0.5:15, stirred at 45°C and 200 r / min for 4 h, and then dried under vacuum at 20°C for 10 h to obtain quaternary ammonium salt; alkali lignin and 20 wt% sodium hydroxide aqueous solution were mixed evenly in a mass ratio of 1:15, and 0.2 times the mass of alkali lignin quaternary ammonium salt was added, stirred at 80°C and 200 r / min for 4 h, cooled to room temperature, dialyzed for 70 h, and the resulting solution was dried under vacuum at 20°C for 10 h to obtain quaternized lignin;
[0042] (3) Under a nitrogen atmosphere, allylphosphine dichloride, triethylamine, and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:0.8:15. 1.5 times the mass of allylphosphine dichloride and p-aminobenzoic acid were added. The mixture was stirred at 55°C and 200 r / min for 10 h. After filtration, N,N-dimethylformamide was removed by vacuum distillation to obtain a diacid. Under a nitrogen atmosphere, the diacid, ethylene glycol, terephthalic acid, and antimony glycol were mixed evenly in a mass ratio of 1:0.3:0.4:0.001. The mixture was stirred at 250°C, 0.3 MPa, and 40 r / min for 2 h to obtain a polyester.
[0043] (4) Polyester, modified carbon nanotubes, quaternized lignin and azobisisobutyronitrile are mixed evenly in a mass ratio of 1:0.06:0.04:0.001 and added to a spinning machine. The mixture is melt-spun at a temperature of 220℃ in zone 1, 245℃ in zone 2, 250℃ in zone 3, 250℃ in zone 4, 265℃ in metering pump, 280℃ in spinning assembly, and 800m / min to obtain plant-based fiber.
[0044] Example 2:
[0045] A method for preparing plant-based fibers includes the following preparation steps:
[0046] (1) Carbon nanotubes, 95wt% sulfuric acid aqueous solution, and 65wt% nitric acid aqueous solution were mixed evenly at a mass ratio of 1:75:25, and stirred at 100℃ and 250r / min for 3h. The mixture was then centrifuged at 9000rpm for 11min, and the resulting precipitate was washed 5 times with deionized water and dried under vacuum at 80℃ for 11h to obtain carboxylated carbon nanotubes. Carboxylated carbon nanotubes, sulfoxide, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:13:2, and stirred at 70℃ and 250r / min for 22h. The mixture was then cooled to room temperature and centrifuged at 9000rpm for 11min. The precipitate was centrifuged at 00 rpm for 11 min, washed 5 times with dichloromethane, and dried under vacuum at 50 °C for 11 h to obtain acyl chloride carbon nanotubes; under ice-water bath conditions, acyl chloride carbon nanotubes, (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone, triethylamine, and dichloromethane were mixed evenly at a mass ratio of 1:2.5:1:11, stirred at 250 rpm for 6 h at room temperature, centrifuged at 9000 rpm for 11 min, washed 5 times with deionized water, and dried under vacuum at 25 °C for 11 h to obtain modified carbon nanotubes;
[0047] (2) 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine, 6-chloro-1-hexene, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:0.55:18, stirred at 50℃ and 250 r / min for 5 h, and then dried under vacuum at 25℃ for 11 h to obtain quaternary ammonium salt; alkali lignin and 20 wt% sodium hydroxide aqueous solution were mixed evenly at a mass ratio of 1:20, and 0.3 times the mass of alkali lignin quaternary ammonium salt was added, stirred at 85℃ and 250 r / min for 5 h, cooled to room temperature, dialyzed for 71 h, and the resulting solution was dried under vacuum at 25℃ for 11 h to obtain quaternized lignin;
[0048] (3) Under a nitrogen atmosphere, allylphosphine dichloride, triethylamine, and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:1:18. 1.8 times the mass of allylphosphine dichloride and p-aminobenzoic acid were added. The mixture was stirred at 60℃ and 250 r / min for 11 h. After filtration, N,N-dimethylformamide was removed by vacuum distillation to obtain a diacid. Under a nitrogen atmosphere, the diacid, ethylene glycol, terephthalic acid, and antimony glycol were mixed evenly in a mass ratio of 1:0.35:0.45:0.0015. The mixture was stirred at 255℃, 0.35 MPa, and 50 r / min for 2.5 h to obtain a polyester.
[0049] (4) Polyester, modified carbon nanotubes, quaternized lignin and azobisisobutyronitrile are mixed evenly in a mass ratio of 1:0.07:0.05:0.0015 and added to a spinning machine. The mixture is melt-spun at a temperature of 225℃ in zone 1, 250℃ in zone 2, 255℃ in zone 3, 255℃ in zone 4, 270℃ in metering pump, 283℃ in spinning assembly, and 800m / min to obtain plant-based fiber.
[0050] Example 3:
[0051] A method for preparing plant-based fibers includes the following preparation steps:
[0052] (1) Carbon nanotubes, 95wt% sulfuric acid aqueous solution, and 65wt% nitric acid aqueous solution were mixed evenly at a mass ratio of 1:80:30. The mixture was stirred at 105℃ and 300r / min for 4h. The mixture was then centrifuged at 10000rpm for 12min. The resulting precipitate was washed 6 times with deionized water and dried under vacuum at 85℃ for 12h to obtain carboxylated carbon nanotubes. Carboxylated carbon nanotubes, sulfoxide, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:15:2.5. The mixture was stirred at 80℃ and 300r / min for 24h. The mixture was cooled to room temperature and then centrifuged at 10000rpm for 12min. The precipitate was centrifuged at 10000 rpm for 12 min, washed 6 times with dichloromethane, and dried under vacuum at 60℃ for 12 h to obtain acyl chloride carbon nanotubes; under ice-water bath conditions, acyl chloride carbon nanotubes, (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone, triethylamine, and dichloromethane were mixed evenly at a mass ratio of 1:3:1.1:12, stirred at 300 rpm for 7 h at room temperature, centrifuged at 10000 rpm for 12 min, washed 6 times with deionized water, and dried under vacuum at 30℃ for 12 h to obtain modified carbon nanotubes;
[0053] (2) 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine, 6-chloro-1-hexene, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:0.6:20, stirred at 55℃ and 300 r / min for 6 h, and then dried under vacuum at 30℃ for 12 h to obtain quaternary ammonium salt; alkali lignin and 20 wt% sodium hydroxide aqueous solution were mixed evenly at a mass ratio of 1:25, and 0.4 times the mass of alkali lignin quaternary ammonium salt was added, stirred at 90℃ and 300 r / min for 6 h, cooled to room temperature, dialyzed for 72 h, and the resulting solution was dried under vacuum at 30℃ for 12 h to obtain quaternized lignin;
[0054] (3) Under a nitrogen atmosphere, allylphosphine dichloride, triethylamine, and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:1.2:20. P-aminobenzoic acid with a mass of 2 times that of allylphosphine dichloride was added. The mixture was stirred at 65°C and 300 r / min for 12 h. The mixture was filtered and N,N-dimethylformamide was removed by vacuum distillation to obtain a diacid. Under a nitrogen atmosphere, the diacid, ethylene glycol, terephthalic acid, and antimony glycol were mixed evenly in a mass ratio of 1:0.4:0.5:0.002. The mixture was stirred at 260°C, 0.4 MPa, and 60 r / min for 3 h to obtain a polyester.
[0055] (4) Polyester, modified carbon nanotubes, quaternized lignin and azobisisobutyronitrile are mixed evenly in a mass ratio of 1:0.08:0.06:0.002 and added to a spinning machine. The mixture is melt-spun at a temperature of 230℃ in zone 1, 255℃ in zone 2, 260℃ in zone 3, 260℃ in zone 4, 275℃ in metering pump, 285℃ in spinning assembly, and 800m / min to obtain plant-based fiber.
[0056] Comparative Example 1:
[0057] The difference between the preparation method of plant-based fibers in Comparative Example 1 and Example 2 lies in step (1). Step (1) is modified as follows: carbon nanotubes, 95wt% sulfuric acid aqueous solution, and 65wt% nitric acid aqueous solution are mixed evenly at a mass ratio of 1:75:25, stirred at 100℃ and 250r / min for 3h, centrifuged at 9000rpm for 11min, the resulting precipitate is washed 5 times with deionized water, and vacuum dried at 80℃ for 11h to obtain carboxylated carbon nanotubes; carboxylated carbon nanotubes, sulfoxide, and N,N-dimethylformamide are mixed evenly at a mass ratio of 1:13:2, stirred at 70℃ and 250r / min for 22h, cooled to room temperature, centrifuged at 9000rpm for 11min, the resulting precipitate is washed 5 times with dichloromethane, and vacuum dried at 50℃ for 11h to obtain modified carbon nanotubes. The remaining steps are the same as in Example 2.
[0058] Comparative Example 2:
[0059] The difference between the preparation method of the plant-based fiber in Comparative Example 2 and Example 2 is that step (1) is omitted, and step (4) is modified as follows: polyester, quaternized lignin, and azobisisobutyronitrile are mixed evenly at a mass ratio of 1:0.05:0.0015, added to a spinning machine, and melt-spun under the following conditions: zone 1 temperature 225℃, zone 2 temperature 250℃, zone 3 temperature 255℃, zone 4 temperature 255℃, metering pump temperature 270℃, spinning assembly temperature 283℃, and spinning speed 800m / min to obtain plant-based fiber. The remaining steps are the same as in Example 2.
[0060] Comparative Example 3:
[0061] The difference between the preparation method of the plant-based fiber in Comparative Example 3 and Example 2 is that step (2) is omitted, and step (4) is modified as follows: polyester, modified carbon nanotubes, alkali lignin, and azobisisobutyronitrile are mixed evenly in a mass ratio of 1:0.07:0.05:0.0015, added to a spinning machine, and melt-spun under the following conditions: zone 1 temperature 225℃, zone 2 temperature 250℃, zone 3 temperature 255℃, zone 4 temperature 255℃, metering pump temperature 270℃, spinning assembly temperature 283℃, and spinning speed 800m / min to obtain plant-based fiber. The remaining steps are the same as in Example 2.
[0062] Comparative Example 4:
[0063] The difference between the preparation method of the plant-based fiber in Comparative Example 4 and Example 2 is that step (2) is omitted, and step (4) is modified as follows: polyester, modified carbon nanotubes, and azobisisobutyronitrile are mixed evenly at a mass ratio of 1:0.07:0.0015, added to a spinning machine, and melt-spun under the following conditions: zone 1 temperature 225℃, zone 2 temperature 250℃, zone 3 temperature 255℃, zone 4 temperature 255℃, metering pump temperature 270℃, spinning assembly temperature 283℃, and spinning speed 800m / min to obtain plant-based fiber. The remaining steps are the same as in Example 2.
[0064] Comparative Example 5:
[0065] The difference between the preparation method of the plant-based fiber in Comparative Example 5 and Example 2 lies in step (3). Step (3) is modified as follows: under a nitrogen atmosphere, ethylene glycol, terephthalic acid, and antimony glycol are mixed evenly in a mass ratio of 1:2.5:0.0015, and the mixture is stirred at 255°C, 0.35 MPa, and 50 r / min for 2.5 h to obtain polyester. The remaining steps are the same as in Example 2.
[0066] Test Example 1:
[0067] Flame retardant performance test:
[0068] The plant-based fibers prepared in each example and comparative example were tested according to GB / T5454-1997 to determine the minimum oxygen concentration required to maintain flaming combustion of the plant-based fibers.
[0069] The results are shown in Table 1.
[0070] Table 1
[0071] Limiting oxygen index Limiting oxygen index Example 1 36.9％ Comparative Example 1 36.3％ Example 2 37.7％ Comparative Example 2 35.9％ Example 3 36.4％ Comparative Example 3 30.2％ Comparative Example 4 27.7％ Comparative Example 5 25.3％
[0072] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-5 in Table 1 reveals that the plant-based fibers prepared by this invention have good flame-retardant properties.
[0073] By comparison, the limiting oxygen index of Examples 1-3 is greater than that of Comparative Example 3, indicating that the reaction of 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine with 6-chloro-1-hexene to generate a quaternary ammonium salt, 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine contains a triazine structure and a large amount of nitrogen element, which, in synergy with lignin and phosphorus elements, improves the flame retardant properties of plant-based fibers.
[0074] By comparison, the limiting oxygen index of Examples 1-3 is greater than that of Comparative Example 4, indicating that the quaternized lignin prepared by reacting quaternary ammonium salt with alkali lignin contains a benzene ring structure with good thermal stability, has good heat resistance, and can promote the formation of a char layer when it decomposes at high temperature, thereby forming an oxygen-barrier and heat-insulating protective layer in the material, inhibiting the combustion process. In addition, when alkali lignin decomposes endothermically, it can release non-flammable gases such as carbon dioxide and water vapor, which can inhibit the spread of flame to a certain extent and improve the flame retardant performance of plant-based fibers.
[0075] By comparison, the limiting oxygen index of Examples 1-3 is greater than that of Comparative Example 5, indicating that the dicarboxylic acid is prepared by reacting allylphosphine dichloride with p-aminobenzoic acid. The dicarboxylic acid is prepared by reacting the chlorine on allylphosphine dichloride with the amino group on p-aminobenzoic acid. The prepared dicarboxylic acid contains phosphorus, which can promote the formation of char layer and can also block the combustion reaction by capturing free radicals, thereby improving the flame retardant properties of plant-based fibers.
[0076] Test Example 2:
[0077] Mechanical property testing:
[0078] The breaking strength of the plant-based fibers prepared in each embodiment and comparative example was tested using an XL-2 multifunctional yarn filament tensile strength tester. Following GB / T3916-2013, the following settings were used: clamping distance 250 mm, tensile speed 250 mm / min, pre-tension 0.05 cN / dtex, test temperature 20℃, and relative humidity 65%. Each sample was tested 15 times, and the average value was taken.
[0079] The results are shown in Table 2.
[0080] Table 2
[0081] Fracture strength (cN / dtex) Fracture strength (cN / dtex) Example 1 4.15 Comparative Example 1 2.03 Example 2 4.18 Comparative Example 2 1.71 Example 3 4.09 Comparative Example 3 2.12 Comparative Example 4 2.09 Comparative Example 5 2.22
[0082] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-5 in Table 2 reveals that the plant-based fibers prepared by this invention possess excellent mechanical properties.
[0083] By comparison, the fracture strength of Examples 1-3 is greater than that of Comparative Examples 1 and 3-5, indicating that the double bonds on the modified carbon nanotubes, quaternized lignin, and polyester react under the action of a catalyst to form a cross-linked network structure, which improves the mechanical properties of plant-based fibers.
[0084] By comparison, the tensile strength of Examples 1-3 is greater than that of Comparative Example 2, indicating that carbon nanotubes are carbon molecules composed of nanoscale coaxial carbon tubes, which have a graphite-like layered structure. The C-C covalent bonds they form are the most stable chemical bonds in nature, thus giving carbon nanotubes excellent mechanical properties. The reaction of modified carbon nanotubes with polyester and quaternized lignin further improves the mechanical properties of plant-based fibers.
[0085] Test Example 3:
[0086] Antistatic performance test:
[0087] Referring to GB / T14342-2015 "Test Method for Resistivity of Short Chemical Fibers", the plant-based fibers prepared in each example and comparative example were equilibrated at 20°C and 65% relative humidity for 5 hours. 15g of the plant-based fibers obtained in each example and comparative example were weighed and placed into the mass resistivity meter test box to test their fiber mass resistivity.
[0088] The results are shown in Table 3.
[0089] Table 3
[0090] <![CDATA[Mass specific resistance (Ω·g / cm 2 )]]> <![CDATA[Mass specific resistance (Ω·g / cm 2 )]]> Example 1 <![CDATA[2.257×10 8 ]]> Comparative Example 1 <![CDATA[2.756×10 8 ]]> Example 2 <![CDATA[2.086×10 8 ]]> Comparative Example 2 <![CDATA[1.369×10 10 ]]> Example 3 <![CDATA[2.432×10 8 ]]> Comparative Example 3 <![CDATA[8.457×10 10 ]]> Comparative Example 4 <![CDATA[7.935×10 10 ]]> Comparative Example 5 <![CDATA[2.528×10 8 ]]>
[0091] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-5 in Table 3 reveals that the plant-based fibers prepared by this invention have good antistatic properties.
[0092] By comparison, the resistivity of Examples 1-3 is lower than that of Comparative Example 2, indicating that the highly delocalized large π bonds formed by the p orbital electrons of carbon atoms outside the tube wall in carbon nanotubes have excellent electrical properties due to their significant conjugation effect. The reaction of modified carbon nanotubes with polyester and quaternized lignin improves the antistatic properties of plant-based fibers.
[0093] By comparison, the resistivity of Examples 1-3 was lower than that of Comparative Examples 3-4, indicating that the reaction of 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine with 6-chloro-1-hexene to generate a quaternary ammonium salt, and the tertiary amine group on 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine undergoes a quaternization reaction with the chlorine on 6-chloro-1-hexene, and the generated quaternary ammonium salt improves the antistatic properties of plant-based fibers.
[0094] Test Example 4:
[0095] UV protection test:
[0096] The plant-based fibers obtained from each embodiment and comparative example were used to calculate the UPF value by setting the wavelength range to 290-400 nm and the wavelength interval to 5 nm, in accordance with GB / T18830-2009 "Evaluation of UV Protection Performance of Textiles".
[0097] The results are shown in Table 4.
[0098] Table 4
[0099] UPF UPF Example 1 46 Comparative Example 1 33 Example 2 48 Comparative Example 2 31 Example 3 45 Comparative Example 3 46 Comparative Example 4 44 Comparative Example 5 45
[0100] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-5 in Table 4 reveals that the plant-based fibers prepared by this invention have excellent UV protection properties.
[0101] By comparison, the resistivity of the mass of Examples 1-3 was greater than that of Comparative Examples 1-2, indicating that the modified carbon nanotubes were prepared by reacting the acyl chloride groups on the acyl chloride carbon nanotubes with the hydroxyl groups on (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone. The introduction of benzophenone-type ultraviolet absorbers onto the carbon nanotubes improved the UV protection performance of the plant-based fibers.
[0102] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A plant-based fiber, characterized in that, The plant-based fiber is obtained by melt spinning polyester, modified carbon nanotubes, and quaternized lignin. The polyester is prepared by polycondensation reaction of diacid, ethylene glycol and terephthalic acid; The dicarboxylic acid is prepared by reacting allylphosphine dichloride with p-aminobenzoic acid. The modified carbon nanotubes are prepared by reacting carboxylated carbon nanotubes with thionyl chloride to obtain acyl chloride carbon nanotubes, and then reacting them with (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone. The carboxylated carbon nanotubes are prepared by reacting carbon nanotubes with sulfuric acid and nitric acid. The quaternized lignin is prepared by reacting 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine with 6-chloro-1-hexene to generate a quaternary ammonium salt, which is then reacted with alkali lignin.
2. A method for preparing plant-based fibers, characterized in that, The preparation steps include the following: (1) Carbon nanotubes, 95wt% sulfuric acid aqueous solution, and 65wt% nitric acid aqueous solution were mixed and reacted, then centrifuged, washed, and dried to obtain carboxylated carbon nanotubes; carboxylated carbon nanotubes, sulfoxide, and N,N-dimethylformamide were mixed and reacted, then centrifuged, washed, and dried to obtain acyl chloride carbon nanotubes; acyl chloride carbon nanotubes, (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone, triethylamine, and dichloromethane were mixed and reacted, then centrifuged, washed, and dried to obtain modified carbon nanotubes; (2) 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine, 6-chloro-1-hexene and N,N-dimethylformamide were mixed and reacted, and then dried under vacuum to obtain quaternary ammonium salt; alkali lignin, 20wt% sodium hydroxide aqueous solution and quaternary ammonium salt were mixed, stirred and reacted, and then dialyzed and dried to obtain quaternized lignin; (3) Allylphosphine dichloride, triethylamine, N,N-dimethylformamide and p-aminobenzoic acid were mixed and reacted, filtered and distilled under reduced pressure to obtain a dicarboxylic acid; the dicarboxylic acid, ethylene glycol, terephthalic acid and antimony glycol were mixed and reacted to obtain a polyester. (4) Polyester, modified carbon nanotubes, quaternized lignin and azobisisobutyronitrile are mixed and melt-spun to obtain plant-based fibers.
3. The method for preparing plant-based fibers according to claim 2, characterized in that, The preparation steps of the modified carbon nanotubes in step (1) are as follows: carbon nanotubes, 95wt% sulfuric acid aqueous solution, and 65wt% nitric acid aqueous solution are mixed evenly at a mass ratio of 1:(70-80):(20-30), and stirred at 95-105℃ and 200-300r / min for 2-4h. The mixture is then centrifuged at 8000-10000rpm for 10-12min, and the resulting precipitate is washed 4-6 times with deionized water and vacuum dried at 75-85℃ for 10-12h to obtain carboxylated carbon nanotubes. Carboxylated carbon nanotubes, sulfoxide, and N,N-dimethylformamide are mixed evenly at a mass ratio of 1:(10-15):(1.5-2.5), and stirred at 60-80℃ and 200-300r / min for 20-24h. The mixture was cooled to room temperature and centrifuged at 8000–10000 rpm for 10–12 min. The resulting precipitate was washed 4–6 times with dichloromethane and dried under vacuum at 40–60 °C for 10–12 h to obtain acyl chloride carbon nanotubes. Under ice-water bath conditions, acyl chloride carbon nanotubes, (2,4-dihydroxyphenyl)(4-vinylphenyl) methyl ketone, triethylamine, and dichloromethane were mixed evenly at a mass ratio of 1:(2–3):(0.9–1.1):(10–12). The mixture was stirred at 200–300 rpm for 5–7 h at room temperature and centrifuged at 8000–10000 rpm for 10–12 min. The resulting precipitate was washed 4–6 times with deionized water and dried under vacuum at 20–30 °C for 10–12 h to obtain modified carbon nanotubes.
4. The method for preparing plant-based fibers according to claim 2, characterized in that, The preparation steps of the quaternized lignin in step (2) are as follows: 4-chloro-N,N-diethyl-6-methyl-1,3,5-triazine-2-amine, 6-chloro-1-hexene, and N,N-dimethylformamide are mixed evenly at a mass ratio of 1:(0.5~0.6):(15~20), stirred at 45~55℃ and 200~300r / min for 4~6h, and then vacuum dried at 20~30℃ for 10~12h to obtain the quaternary ammonium salt; alkali lignin and 20wt% sodium hydroxide aqueous solution are mixed evenly at a mass ratio of 1:(15~25), and 0.2~0.4 times the mass of the alkali lignin quaternary ammonium salt is added. The mixture is stirred at 80~90℃ and 200~300r / min for 4~6h, cooled to room temperature, dialyzed for 70~72h, and the resulting solution is vacuum dried at 20~30℃ for 10~12h to obtain the quaternized lignin.
5. The method for preparing plant-based fibers according to claim 2, characterized in that, The preparation steps of the polyester in step (3) are as follows: Under a nitrogen atmosphere, allylphosphine dichloride, triethylamine, and N,N-dimethylformamide are mixed evenly in a mass ratio of 1:(0.8-1.2):(15-20), and p-aminobenzoic acid with a mass of 1.5-2 times that of allylphosphine dichloride is added. The mixture is stirred at 55-65°C and 200-300 r / min for 10-12 h. The mixture is then filtered, and N,N-dimethylformamide is removed by vacuum distillation to obtain a diacid. Under a nitrogen atmosphere, the diacid, ethylene glycol, terephthalic acid, and antimony glycol are mixed evenly in a mass ratio of 1:(0.3-0.4):(0.4-0.5):(0.001-0.002). The mixture is stirred at 250-260°C, 0.3-0.4 MPa, and 40-60 r / min for 2-3 h to obtain the polyester.
6. The method for preparing plant-based fibers according to claim 2, characterized in that, The preparation steps of the plant-based fiber in step (4) are as follows: polyester, modified carbon nanotubes, quaternized lignin and azobisisobutyronitrile are mixed evenly in a mass ratio of 1:(0.06~0.08):(0.04~0.06):(0.001~0.002), added to a spinning machine, and melt-spun at the following conditions: zone 1 temperature 220~230℃, zone 2 temperature 245~255℃, zone 3 temperature 250~260℃, zone 4 temperature 250~260℃, metering pump temperature 265~275℃, spinning assembly temperature 280~285℃, and spinning speed 800m / min to obtain plant-based fiber.
7. A method for preparing plant-based fibers according to claim 2 or 3, characterized in that, The carbon nanotubes have a purity of 95%, a diameter of 20–40 nm, and a length of 1–2 μm.
8. A method for preparing plant-based fibers according to claim 2 or 4, characterized in that, The dialysis was performed using a dialysis bag with a molecular weight cutoff of 1000 Da.
9. The application of plant-based fibers prepared by the method of any one of claims 2 to 8 in protective gloves.