Natural plant-based spinning yarn and preparation method thereof

Abstract

The invention discloses a natural plant-based spinning yarn and a preparation method thereof, and relates to the technical field of spinning yarns. When the natural plant-based spinning yarn is prepared, palm fibers are pretreated with a sodium chlorite solution and a sodium hydroxide solution, and pretreated palm fibers are prepared; reacting the pretreated palm fibers with ammonium dihydrogen phosphate to prepare phosphorylated modified palm fibers; reacting the phosphorylated modified palm fibers with calcium nitrate, diammonium hydrogen phosphate and allylphosphonic acid to grow hydroxyapatite in situ, so as to prepare hydroxyapatite composite palm fibers; 4-allyl thiosemicarbazide reacts with salicylaldehyde to prepare an antibacterial agent intermediate, and the antibacterial agent intermediate is complexed with copper ions to prepare an antibacterial agent; grafting an antibacterial agent and an anti-aging agent on the hydroxyapatite composite palm fibers to prepare modified palm fibers; and spinning the modified palm fiber to obtain the natural plant-based spun yarn. The prepared natural plant-based spinning yarn has the advantages of being high in breaking strength, antibacterial, flame-retardant and anti-aging.

Description

Technical Field

[0001] The invention relates to the technical field of spinning yarns, in particular to a natural plant-based spinning yarn and a preparation method thereof. Background Art

[0002] With the rapid advancement of industrialization and urbanization, oil resources are becoming increasingly depleted. The development and utilization of new biomass fibers to gradually replace synthetic fibers produced from oil is the need of the times. Cellulose is the main component of most plants and is one of the cheapest and most abundant renewable resources in nature. In addition, due to biosynthesis, the content of cellulose continues to increase. As a highly potential renewable material, cellulose has good biodegradability and environmental friendliness. my country's cellulose resources are extremely rich and the output is huge. However, this part of the resources has not been fully developed and utilized. It is mainly used for fuel, livestock feed and compost. Not only is the utilization rate low, but it also causes certain pollution to the environment.

[0003] Palmaceae is one of the three major tropical economic crop families in the world and an important source of cellulose. Palm trees are the earliest ancient tree species planted in my country. Due to their advantages such as salt-alkali tolerance, easy planting, wind-proof and sand-fixing, and ability to absorb harmful gases, they have been planted on a large scale in recent years, which has subsequently produced a large amount of biomass fiber resources. However, due to the lack of research on the structure and properties of palm fiber, the material can only be processed into low-value-added products such as ropes, brushes, and mats, so that a large amount of palm raw materials are randomly discarded as garbage after pruning, causing environmental pollution and waste of resources. Summary of the invention

[0004] The object of the present invention is to provide a natural plant-based spinning yarn and a preparation method thereof, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A natural plant-based spun yarn, wherein the natural plant-based spun yarn is obtained by spinning modified palm fiber;

[0007] The modified palm fiber is prepared by grafting an antibacterial agent and an anti-aging agent onto hydroxyapatite composite palm fiber;

[0008] The hydroxyapatite composite palm fiber is prepared by in-situ growth of hydroxyapatite by reacting phosphorylated modified palm fiber with calcium nitrate, diammonium hydrogen phosphate and allylphosphonic acid;

[0009] The phosphorylated modified palm fiber is prepared by reacting pretreated palm fiber with diammonium phosphate in the presence of urea;

[0010] The pretreated palm fiber is prepared by pretreating the palm fiber with a sodium chlorite solution to obtain a primary pretreated palm fiber, and then pretreating the palm fiber with a gradient concentration sodium hydroxide solution.

[0011] As an optimization, the antibacterial agent is prepared by reacting 4-propylenethiosemicarbazide with salicylaldehyde to obtain an antibacterial agent intermediate, which is then complexed with copper ions.

[0012] As an optimization, the anti-aging agent is 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl-2-methacrylate.

[0013] As an optimization, the palm fiber was purchased from Huzhou Fusheng Carbon Industry Co., Ltd.

[0014] A method for preparing natural plant-based spinning yarn comprises the following preparation steps:

[0015] (1) 2-3 parts of palm fiber, 20-30 parts of 1wt% sodium chlorite solution, and 20-30 parts of 2wt% glacial acetic acid solution are mixed uniformly by weight, refluxed at 80-85°C and 200-300r / min for 7-8h, filtered, washed with 1wt% sodium hydroxide solution until neutral, then washed with pure water for 4-5 times, and vacuum dried at 60-70°C for 8-10h to obtain primary pretreated palm fiber;

[0016] (2) treating the primary pretreated palm fiber with 6 wt % sodium hydroxide solution, 8 wt % sodium hydroxide solution and 10 wt % sodium hydroxide solution in sequence at a solid-liquid ratio of 1:20 g / ml, with each treatment condition being 60-70° C., 200-300 r / min, 2-3 h. After all treatments are completed, filtering, washing with pure water until neutral, and vacuum drying at 60-70° C. for 8-10 h to obtain pretreated palm fiber;

[0017] (3) immersing the pretreated palm fiber in a mixed solution of ammonium dihydrogen phosphate / urea at a material-liquid ratio of 1:20 g / ml, stirring at 200-300 r / min for 20-30 min at room temperature, baking in a 60-70° C. oven with the liquid for 2-2.5 h, then baking in a 130-135° C. oven for 90-120 min, cooling naturally to room temperature, washing alternately with boiling water and room temperature pure water for 3-4 times, and vacuum drying at 60-70° C. for 8-10 h to obtain phosphorylated modified palm fiber;

[0018] (4) 8 to 10 parts by mass of phosphorylated modified palm fiber and 20 to 30 parts by mass of 0.2 mol / L calcium nitrate solution were mixed evenly, reacted at room temperature at 200 to 300 r / min for 30 to 40 min, pH adjusted to 10 to 12 with aqueous ammonia, then 20 to 30 parts by mass of 0.12 mol / L diammonium hydrogen phosphate solution were added dropwise at a rate of 1 drop per second, stirred at room temperature at 200 to 300 r / min for 3 to 4 h, then allowed to stand at 75 to 85° C. for 3 to 4 h, cooled naturally to room temperature, allowed to stand at room temperature for 28 to 32 h, and then added again. 10 to 20 parts of 0.2 mol / L calcium nitrate solution are added, stirred at 200 to 300 r / min for 10 to 20 minutes at room temperature, the pH is adjusted to 10 to 12 with ammonia water, 20 to 30 parts of phosphoric acid mixed solution are added dropwise at a rate of 1 drop per second, stirred at 200 to 300 r / min for 4 to 5 hours at room temperature after the addition is completed, then allowed to stand at 75 to 85° C. for 4 to 5 hours, cooled naturally to room temperature, allowed to stand at room temperature for 36 to 40 hours, filtered, washed with pure water for 2 to 3 times, and vacuum dried at 50 to 60° C. for 10 to 12 hours to obtain hydroxyapatite composite palm fiber;

[0019] (5) Mix 3-4 parts of 4-propylenethiosemicarbazide and 60-70 parts of ethanol solvent by weight, stir at 75°C and 200-300 r / min until completely dissolved, cool to 60-65°C, keep stirring, add 30-40 parts of 10 wt% salicylaldehyde ethanol solution at 2-3 drops per second, continue to react for 4-5 hours after the addition is completed, filter, wash with 80°C pure water 2-3 times, then wash with anhydrous ethanol twice, and vacuum dry at 50-60°C for 10-12 hours to obtain an antibacterial agent intermediate;

[0020] (6) 2 to 3 parts of the antibacterial agent intermediate and 30 to 40 parts of a methanol / dimethyl sulfoxide mixed solvent are mixed uniformly by weight, stirred at 200 to 300 r / min at room temperature until dissolved, 14 to 18 parts of a 10 wt% copper chloride methanol solution are added, stirred at 300 to 400 r / min at room temperature for 10 to 12 hours, and the solvent is removed by rotary evaporation and ice water treatment, filtered, washed with anhydrous ethanol for 3 to 4 times, and vacuum dried at 60 to 70° C. for 10 to 12 hours to obtain an antibacterial agent;

[0021] (7) The hydroxyapatite composite palm fiber was immersed in the antibacterial modification liquid at a bath ratio of 1:30 g / ml, and was rolled at room temperature for 30 to 40 min, with a stirring speed of 200 to 300 r / min and a rolling rate of 100%. The fiber was then pre-baked at 50 to 60 °C for 5 min, and then baked at 120 to 125 °C for 10 to 12 min. The surface was washed with acetone for 2 to 3 times, and then immersed in the anti-aging modification liquid at a bath ratio of 1:30 g / ml. The modified palm fiber is prepared by immersing the palm fiber in a liquid at room temperature for 30 to 40 minutes, stirring at a speed of 200 to 300 r / min, and a rolling rate of 100%. The palm fiber is then pre-baked at 50 to 60° C. for 5 minutes, and then baked at 120 to 125° C. for 10 to 12 minutes. The surface is washed with acetone for 2 to 3 times, and vacuum dried at 60 to 70° C. for 10 to 12 hours to obtain the modified palm fiber. The modified palm fiber is spun in a spinning machine to obtain a natural plant-based spinning yarn.

[0022] As an optimization, the content of ammonium dihydrogen phosphate in the ammonium dihydrogen phosphate / urea mixed solution in step (3) is 0.09 g / ml, and the content of urea is 0.28 g / ml.

[0023] As an optimization, the phosphoric acid mixed solution in step (4) contains 0.1 mol / L diammonium hydrogen phosphate and 0.02 mol / L allylphosphonic acid.

[0024] As an optimization, the pH value is maintained at 10-12 during the entire dropwise addition process in step (4).

[0025] As an optimization, the ethanol solvent in step (5) is a mixture of anhydrous ethanol and pure water in a volume ratio of 1:1.

[0026] As an optimization, the reaction process of the antibacterial agent intermediate in step (5) is as follows:

[0027]

[0028] As an optimization, the methanol / dimethyl sulfoxide mixed solvent in step (6) is a mixture of methanol and dimethyl sulfoxide in a volume ratio of 1:1.

[0029] As an optimization, the antibacterial modified liquid in step (7) is prepared by mixing N,N-dimethylformamide as solvent, an antibacterial agent content of 10 wt %, and a benzoyl peroxide content of 0.2 wt %.

[0030] As an optimization, the anti-aging modified liquid in step (7) is prepared by mixing N,N-dimethylformamide as solvent, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole with a content of 10 wt% and benzoyl peroxide with a content of 0.2 wt%.

[0031] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0032] When preparing the natural plant-based spinning yarn, the present invention comprises the following steps: firstly pretreating palm fibers with a sodium chlorite solution to obtain primary pretreated palm fibers, and then pretreating with a sodium hydroxide solution with a gradient concentration to obtain pretreated palm fibers; reacting the pretreated palm fibers with ammonium dihydrogen phosphate in the presence of urea to obtain phosphorylated modified palm fibers; reacting the phosphorylated modified palm fibers with calcium nitrate, diammonium hydrogen phosphate and allylphosphonic acid to in-situ grow hydroxyapatite to obtain hydroxyapatite composite palm fibers; reacting 4-propylene thiosemicarbazide with salicylaldehyde to obtain an antibacterial agent intermediate, and then complexing copper ions to obtain an antibacterial agent; grafting the antibacterial agent and the anti-aging agent onto the hydroxyapatite composite palm fibers to obtain modified palm fibers; and spinning the modified palm fibers to obtain the natural plant-based spinning yarn.

[0033] Firstly, palm fiber is pretreated with sodium chlorite solution to obtain primary pretreated palm fiber, and then pretreated with gradient concentration sodium hydroxide solution to obtain pretreated palm fiber. Sodium chlorite solution is first used to remove lignin in palm fiber, and then gradient concentration sodium hydroxide solution is used to treat in sequence to continue to remove hemicellulose in palm fiber. Cell wall of pretreated palm fiber swells, the middle cavity becomes smaller, fiber diameter decreases, and breaking strength increases; pretreated palm fiber is reacted with diammonium hydrogen phosphate in the presence of urea to obtain phosphorylated modified palm fiber, and then phosphorylated modified palm fiber is reacted with calcium nitrate, diammonium hydrogen phosphate and allylphosphonic acid to in situ grow hydroxyapatite to obtain hydroxyapatite composite palm fiber. The main component of pretreated palm fiber is cellulose. Under the swelling action of urea, hydroxyl groups on cellulose react with phosphate groups. The esterification reaction grafts the phosphate groups onto the fibers. The introduced phosphate groups have better complexation effect, and can pre-absorb and complex more calcium ions in the early stage of the subsequent growth of hydroxyapatite. The calcium ions can be evenly dispersed while being reused, and the growth of hydroxyapatite is more uniform. Hydroxyapatite, as the main inorganic component in natural bone materials, interacts with palm fibers, which can effectively improve the mechanical properties of palm fibers. At the same time, allylphosphonic acid is introduced in the late growth stage of hydroxyapatite to introduce double bond functional groups on the surface of the growing hydroxyapatite, leaving reaction sites for subsequent grafting. At the same time, the hydroxyapatite grown in situ will be coated on the surface of the palm fiber to form a protective layer. At the same time, hydroxyapatite itself has good flame retardant properties, and the phosphorylation modification of palm fibers also introduces a large amount of phosphorus flame retardant elements, further improving the flame retardant effect.

[0034] Secondly, 4-propylenethiosemicarbazide is reacted with salicylaldehyde to obtain an antibacterial agent intermediate, and then the antibacterial agent is obtained after complexing copper ions. The amino group on the 4-propylenethiosemicarbazide reacts with salicylaldehyde to undergo a Schiff base reaction, thereby grafting salicylaldehyde onto the 4-propylenethiosemicarbazide to obtain an antibacterial agent intermediate. The nitrogen, oxygen, and sulfur elements contained in the antibacterial agent intermediate all have strong metal complexing capabilities, and a large amount of copper ions with good antibacterial properties can be adsorbed and complexed thereon, effectively improving the antibacterial properties. At the same time, the Schiff base bond, as a reversible covalent bond, will break in a weak acid environment to release salicylaldehyde with antibacterial properties, and the living environment of bacteria is mostly in a weak acid environment, so the release of the antibacterial agent is also pH responsive, and the thiosemicarbazide compounds themselves have excellent antibacterial properties. The antibacterial mechanisms of the three are different, and they work together to achieve better antibacterial effects.

[0035] Finally, antibacterial agents and anti-aging agents are grafted onto hydroxyapatite composite palm fibers to obtain modified palm fibers; the modified palm fibers are spun to obtain natural plant-based spun yarns, wherein the hydroxyapatite composite palm fibers contain double bond functional groups left by the aforementioned modification, and both the antibacterial agent and the anti-aging agent contain carbon-carbon double bonds, and under the action of the initiator benzoyl peroxide, the antibacterial agent and the anti-aging agent are grafted onto the surface of the hydroxyapatite composite palm fibers through free radical reactions, and both the antibacterial agent and the anti-aging agent are introduced into the palm fibers by chemical bonding, which has better stability than physical adsorption introduction, and the antibacterial The grafting of the antibacterial agent and the anti-aging agent introduces new flame retardant elements of nitrogen and sulfur. These two elements can cooperate with the phosphorus element when combustion occurs to play a synergistic flame retardant role, further improving the flame retardant properties of the natural plant-based spinning yarn; the grafting of the antibacterial agent and the anti-aging agent also gives the natural plant-based spinning yarn antibacterial and anti-aging properties. The anti-aging agent 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole contains a benzotriazole group that can absorb ultraviolet rays. At the same time, because it is grafted through chemical bonding, the migration and volatilization of the anti-aging agent in subsequent processing is avoided. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] In all the following examples and comparative examples, the pH value of the entire dropping process in the preparation steps of the hydroxyapatite-composite palm fiber was maintained at 10-12.

[0038] Embodiment 1:

[0039] A method for preparing a natural plant-based spun yarn, the method comprising the following preparation steps:

[0040] (1) By weight, 2 parts of palm fiber, 20 parts of 1wt% sodium chlorite solution, and 30 parts of 2wt% glacial acetic acid solution were mixed uniformly, refluxed at 80°C and 200r / min for 8h, filtered, washed with 1wt% sodium hydroxide solution until neutral, then washed with pure water for 4 times, and vacuum dried at 60°C for 10h to prepare a primary pretreated palm fiber;

[0041] (2) treating the primary pretreated palm fiber with 6 wt % sodium hydroxide solution, 8 wt % sodium hydroxide solution and 10 wt % sodium hydroxide solution in sequence at a solid-liquid ratio of 1:20 g / ml, with each treatment condition being 60° C., 200 r / min, 3 h. After all treatments were completed, filtering was performed, washing with pure water until neutral, and vacuum drying was performed at 60° C. for 10 h to obtain the pretreated palm fiber;

[0042] (3) The pretreated palm fiber was immersed in a mixed solution of ammonium dihydrogen phosphate / urea at a solid-liquid ratio of 1:20 g / ml, stirred at 200 r / min at room temperature for 30 min, placed in a 60°C oven with the liquid for 2.5 h, then transferred to a 130°C oven for 120 min, naturally cooled to room temperature, washed alternately with boiling water and room temperature pure water for 3 times, and vacuum dried at 60°C for 10 h to obtain phosphorylated modified palm fiber;

[0043] (4) By weight, 8 parts of phosphorylated modified palm fiber and 20 parts of 0.2 mol / L calcium nitrate solution were mixed evenly, reacted at room temperature at 200 r / min for 40 min, adjusted the pH to 10 with ammonia water, and then added 20 parts of 0.12 mol / L diammonium hydrogen phosphate solution at 1 drop per second, stirred at room temperature at 200 r / min for 4 h after the addition was completed, and then stood at 75°C for 4 h, cooled naturally to room temperature, stood at room temperature for 28 h, and added 10 parts of 0.2 mol / L calcium nitrate solution again, stirred at room temperature at 200 r / min for 20 min, adjusted the pH to 10 with ammonia water, and added 20 parts of phosphoric acid mixed solution at 1 drop per second, stirred at room temperature at 200 r / min for 5 h after the addition was completed, and then stood at 75°C for 5 h, cooled naturally to room temperature, stood at room temperature for 36 h, filtered, washed twice with pure water, and vacuum dried at 50°C for 12 h to obtain hydroxyapatite composite palm fiber;

[0044] (5) Mix 3 parts of 4-propylenethiosemicarbazide and 60 parts of ethanol solvent by weight, stir at 75°C and 200 r / min until completely dissolved, cool to 60°C, keep stirring, add 30 parts of 10wt% salicylaldehyde ethanol solution at 2 drops per second, continue to react for 4 hours after the addition is completed, filter, wash twice with 80°C pure water, then wash twice with anhydrous ethanol, and vacuum dry at 50°C for 12 hours to obtain an antibacterial agent intermediate;

[0045] (6) 2 parts of the antibacterial agent intermediate and 30 parts of a methanol / dimethyl sulfoxide mixed solvent were mixed uniformly by weight, stirred at 200 r / min at room temperature until dissolved, 14 parts of a 10 wt% copper chloride methanol solution were added, stirred at 300 r / min at room temperature for 12 h, and the solvent was removed by rotary evaporation and ice water treatment, filtered, washed with anhydrous ethanol for 3 times, and vacuum dried at 60° C. for 12 h to obtain an antibacterial agent;

[0046] (7) The hydroxyapatite composite palm fiber was immersed in an antibacterial modification liquid at a bath ratio of 1:30 g / ml, and rolled at room temperature for 30 min, with a stirring speed of 200 r / min and a rolling rate of 100%. It was then pre-baked at 50°C for 5 min, and then baked at 120°C for 12 min. The surface was washed twice with acetone. It was then immersed in an anti-aging modification liquid at a bath ratio of 1:30 g / ml, and rolled at room temperature for 30 min, with a stirring speed of 200 r / min and a rolling rate of 100%. It was then pre-baked at 50°C for 5 min, and then baked at 120°C for 12 min. The surface was washed twice with acetone and vacuum dried at 60°C for 12 h to obtain modified palm fiber. The modified palm fiber was spun in a spinning machine to obtain natural plant-based yarn.

[0047] Embodiment 2:

[0048] A method for preparing a natural plant-based spun yarn, the method comprising the following preparation steps:

[0049] (1) 2.5 parts of palm fiber, 25 parts of 1wt% sodium chlorite solution, and 25 parts of 2wt% glacial acetic acid solution were mixed uniformly by weight, refluxed at 85°C and 250r / min for 7.5h, filtered, washed with 1wt% sodium hydroxide solution until neutral, then washed with pure water for 5 times, and vacuum dried at 65°C for 9h to prepare a primary pretreated palm fiber;

[0050] (2) treating the primary pretreated palm fiber with 6 wt % sodium hydroxide solution, 8 wt % sodium hydroxide solution and 10 wt % sodium hydroxide solution in sequence at a solid-liquid ratio of 1:20 g / ml, with each treatment condition being 65° C., 250 r / min, 2.5 h. After all treatments were completed, filtering was performed, washing with pure water until neutral, and vacuum drying was performed at 65° C. for 9 h to obtain pretreated palm fiber;

[0051] (3) The pretreated palm fiber was immersed in a mixed solution of ammonium dihydrogen phosphate / urea at a solid-liquid ratio of 1:20 g / ml, stirred at 250 r / min at room temperature for 25 min, placed in a 65°C oven with the liquid for 2.2 h, then transferred to a 135°C oven for 105 min, naturally cooled to room temperature, washed alternately with boiling water and room temperature pure water for 4 times, and vacuum dried at 65°C for 9 h to obtain phosphorylated modified palm fiber;

[0052] (4) According to the mass fraction, 9 parts of phosphorylated modified palm fiber and 25 parts of 0.2 mol / L calcium nitrate solution were mixed evenly, reacted at room temperature at 250 r / min for 35 min, adjusted the pH to 11 with ammonia water, and then added 25 parts of 0.12 mol / L diammonium hydrogen phosphate solution at 1 drop per second. After the addition was completed, the mixture was stirred at 250 r / min for 3.5 h at room temperature, then allowed to stand at 80°C for 3.5 h, cooled naturally to room temperature, allowed to stand at room temperature for 30 h, and 15 parts of 0.2 mol / L calcium nitrate solution were added again. At room temperature, the mixture was stirred at 250 r / min for 15 min, adjusted the pH to 11 with ammonia water, and 25 parts of the phosphoric acid mixed solution were added at 1 drop per second. After the addition was completed, the mixture was stirred at 250 r / min for 4.5 h at room temperature, then allowed to stand at 80°C for 4.5 h, cooled naturally to room temperature, allowed to stand at room temperature for 38 h, filtered, washed with pure water 3 times, and vacuum dried at 55°C for 11 h to obtain hydroxyapatite composite palm fiber;

[0053] (5) By weight, 3.5 parts of 4-propenylthiosemicarbazide and 65 parts of ethanol solvent were mixed uniformly, stirred at 75°C and 250 r / min until completely dissolved, cooled to 60°C, stirred continuously, and 35 parts of 10 wt% salicylaldehyde ethanol solution were added dropwise at a rate of 2 drops per second. After the addition was completed, the reaction was continued for 4.5 hours, filtered, washed twice with 80°C pure water, and then washed twice with anhydrous ethanol, and dried under vacuum at 55°C for 11 hours to obtain an antibacterial agent intermediate;

[0054] (6) 2.5 parts of the antibacterial agent intermediate and 35 parts of a methanol / dimethyl sulfoxide mixed solvent were mixed uniformly by weight, stirred at 250 r / min at room temperature until dissolved, 16 parts of a 10 wt% copper chloride methanol solution were added, stirred at 350 r / min at room temperature for 11 h, and the solvent was removed by rotary evaporation and ice water treatment, filtered, washed with anhydrous ethanol for 3 times, and vacuum dried at 65° C. for 11 h to obtain an antibacterial agent;

[0055] (7) The hydroxyapatite composite palm fiber was immersed in an antibacterial modification liquid at a bath ratio of 1:30 g / ml, and rolled at room temperature for 35 min, with a stirring speed of 250 r / min and a rolling rate of 100%. It was then pre-baked at 55°C for 5 min, and then baked at 120°C for 11 min. The surface was washed with acetone three times. It was then immersed in an anti-aging modification liquid at a bath ratio of 1:30 g / ml, and rolled at room temperature for 35 min, with a stirring speed of 250 r / min and a rolling rate of 100%. It was then pre-baked at 55°C for 5 min, and then baked at 120°C for 11 min. The surface was washed with acetone three times and vacuum dried at 65°C for 11 h to obtain modified palm fiber. The modified palm fiber was spun in a spinning machine to obtain natural plant-based yarn.

[0056] Embodiment 3:

[0057] A method for preparing a natural plant-based spun yarn, the method comprising the following preparation steps:

[0058] (1) 3 parts of palm fiber, 30 parts of 1 wt% sodium chlorite solution, and 20 parts of 2 wt% glacial acetic acid solution were mixed uniformly by weight, refluxed at 85° C. and 300 r / min for 7 h, filtered, washed with 1 wt% sodium hydroxide solution until neutral, then washed with pure water for 5 times, and vacuum dried at 70° C. for 8 h to obtain a primary pretreated palm fiber;

[0059] (2) treating the primary pretreated palm fiber with 6 wt % sodium hydroxide solution, 8 wt % sodium hydroxide solution and 10 wt % sodium hydroxide solution in sequence at a solid-liquid ratio of 1:20 g / ml, with each treatment condition being 70° C., 300 r / min, 2 h. After all treatments were completed, filtering was performed, washing with pure water until neutral, and vacuum drying was performed at 70° C. for 8 h to obtain the pretreated palm fiber;

[0060] (3) The pretreated palm fiber was immersed in a mixed solution of ammonium dihydrogen phosphate / urea at a solid-liquid ratio of 1:20 g / ml, stirred at 300 r / min at room temperature for 20 min, placed in a 70°C oven with the liquid for 2 h, and then transferred to a 135°C oven for 90 min, cooled naturally to room temperature, washed alternately with boiling water and room temperature pure water for 4 times, and vacuum dried at 70°C for 8 h to obtain phosphorylated modified palm fiber;

[0061] (4) According to the mass fraction, 10 parts of phosphorylated modified palm fiber and 30 parts of 0.2 mol / L calcium nitrate solution were mixed evenly, reacted at 300 r / min for 30 min at room temperature, adjusted the pH to 12 with ammonia water, and then added 30 parts of 0.12 mol / L diammonium hydrogen phosphate solution at 1 drop per second, stirred at 300 r / min for 3 h at room temperature after the addition was completed, and then stood at 85°C for 3 h, cooled naturally to room temperature, and stood at room temperature for 32 h, and then 20 parts of 0.2 mol / L calcium nitrate solution were added again, stirred at 300 r / min for 10 min at room temperature, adjusted the pH to 12 with ammonia water, and added 30 parts of phosphoric acid mixed solution at 1 drop per second, stirred at 300 r / min for 4 h at room temperature after the addition was completed, and then stood at 85°C for 4 h, cooled naturally to room temperature, and stood at room temperature for 40 h, filtered, washed with pure water 3 times, and vacuum dried at 60°C for 10 h to obtain hydroxyapatite composite palm fiber;

[0062] (5) Mix 4 parts of 4-propylenethiosemicarbazide and 70 parts of ethanol solvent by weight, stir at 75°C and 300 r / min until completely dissolved, cool to 65°C, keep stirring, add 40 parts of 10 wt% salicylaldehyde ethanol solution at 3 drops per second, continue to react for 4 hours after the addition is completed, filter, wash 3 times with 80°C pure water, wash 2 times with anhydrous ethanol, and vacuum dry at 60°C for 10 hours to obtain an antibacterial agent intermediate;

[0063] (6) 3 parts of the antibacterial agent intermediate and 40 parts of a methanol / dimethyl sulfoxide mixed solvent were mixed uniformly by weight, stirred at 300 r / min at room temperature until dissolved, 18 parts of a 10 wt% copper chloride methanol solution were added, stirred at 400 r / min at room temperature for 10 h, and the solvent was removed by rotary evaporation and ice water treatment, filtered, washed with anhydrous ethanol 4 times, and vacuum dried at 70° C. for 10 h to obtain an antibacterial agent;

[0064] (7) The hydroxyapatite composite palm fiber was immersed in an antibacterial modification liquid at a bath ratio of 1:30 g / ml, and rolled at room temperature for 40 min, with a stirring speed of 300 r / min and a rolling rate of 100%. It was then pre-baked at 60°C for 5 min, and then baked at 125°C for 10 min. The surface was washed with acetone three times. It was then immersed in an anti-aging modification liquid at a bath ratio of 1:30 g / ml, and rolled at room temperature for 40 min, with a stirring speed of 300 r / min and a rolling rate of 100%. It was then pre-baked at 60°C for 5 min, and then baked at 125°C for 10 min. The surface was washed with acetone three times and vacuum dried at 70°C for 10 h to obtain modified palm fiber. The modified palm fiber was spun in a spinning machine to obtain natural plant-based yarn.

[0065] Comparative Example 1:

[0066] The difference between the preparation method of the natural plant-based spun yarn of Comparative Example 1 and Example 2 is that step (3) is not performed, and step (4) is modified as follows: 9 parts of pretreated palm fiber and 25 parts of 0.2 mol / L calcium nitrate solution are mixed uniformly by mass, reacted at room temperature at 250 r / min for 35 min, the pH is adjusted to 11 with ammonia water, and then 25 parts of 0.12 mol / L diammonium hydrogen phosphate solution are added dropwise at a rate of 1 drop per second. After the addition is completed, the mixture is stirred at room temperature at 250 r / min for 3.5 h, and then allowed to stand at 80 ° C for 3.5 h. h, naturally cooled to room temperature, stood at room temperature for 30 h, added 15 parts of 0.2 mol / L calcium nitrate solution again, stirred at 250 r / min for 15 min at room temperature, adjusted the pH to 11 with ammonia water, added 25 parts of phosphoric acid mixed solution at 1 drop per second, stirred at 250 r / min for 4.5 h at room temperature after the addition was completed, then stood at 80°C for 4.5 h, naturally cooled to room temperature, stood at room temperature for 38 h, filtered, washed with pure water 3 times, and vacuum dried at 55°C for 11 h to obtain hydroxyapatite composite palm fiber. The remaining steps are the same as in Example 2.

[0067] Comparative Example 2:

[0068] The method for preparing the natural plant-based spinning yarn of Comparative Example 2 is different from that of Example 2 in that step (4) is not performed, and the content of dihydrogen phosphate / urea mixed solution used in step (3) is 0.09 g / ml of dihydrogen phosphate, 0.28 g / ml of urea, and 10 mg / ml of allylphosphonic acid. The remaining steps are the same as those of Example 2.

[0069] Comparative Example 3:

[0070] The difference between the preparation method of the natural plant-based spinning yarn of Comparative Example 3 and that of Example 2 lies in the difference in step (4), and step (4) is modified as follows: 9 parts of phosphorylated modified palm fiber and 40 parts of 0.2 mol / L calcium nitrate solution are mixed uniformly by mass, reacted at 250 r / min for 45 min at room temperature, adjusted to pH 11 with aqueous ammonia, and then added dropwise with 50 parts of 0.12 mol / L diammonium hydrogen phosphate solution at 1 drop per second, stirred at room temperature at 250 r / min for 5 h, then allowed to stand at 80 ° C for 5.5 h, cooled naturally to room temperature, allowed to stand at room temperature for 60 h, filtered, washed with pure water 3 times, and vacuum dried at 55 ° C for 11 h to obtain hydroxyapatite composite palm fiber. The remaining steps are the same as those of Example 2.

[0071] Comparative Example 4:

[0072] The difference between the preparation method of the natural plant-based spinning yarn of Comparative Example 4 and Example 2 is that step (6) is not performed, and the antibacterial modified liquid used in step (7) is prepared by mixing N,N-dimethylformamide as a solvent, an antibacterial agent intermediate content of 10wt%, and a benzoyl peroxide content of 0.2wt%. The remaining steps are the same as Example 2.

[0073] Comparative Example 5:

[0074] The method for preparing the natural plant-based spun yarn of Comparative Example 5 is different from that of Example 2 in that steps (5) and (6) are not performed, and the antibacterial modified liquid used in step (7) is prepared by mixing N,N-dimethylformamide as a solvent, 10 wt% 4-propylenethiosemicarbazide, and 0.2 wt% benzoyl peroxide. The remaining steps are the same as those of Example 2.

[0075] Comparative Example 6:

[0076] The difference between the preparation method of the natural plant-based spun yarn of Comparative Example 6 and that of Example 2 is that steps (5) and (6) are not performed, and step (7) is modified as follows: immersing the hydroxyapatite composite palm fiber in an anti-aging modification solution at a bath ratio of 1:30 g / ml, padding at room temperature, the soaking time is 35 min, the stirring speed is 250 r / min, the rolling rate is 100%, and then pre-baking at 55°C for 5 min, then baking at 120°C for 11 min, washing the surface with acetone 3 times, and vacuum drying at 65°C for 11 h to obtain modified palm fiber; spinning the modified palm fiber in a spinning machine to obtain natural plant-based spun yarn. The remaining steps are the same as in Example 2.

[0077] Comparative Example 7:

[0078] The difference between the preparation method of the natural plant-based spun yarn of Comparative Example 7 and that of Example 2 lies in the difference in step (7), where step (7) is modified as follows: immersing the hydroxyapatite composite palm fiber in an antibacterial modified liquid at a bath ratio of 1:30 g / ml, padding at room temperature, the soaking time is 35 min, the stirring speed is 250 r / min, the rolling rate is 100%, and then pre-baking at 55°C for 5 min, then baking at 120°C for 11 min, washing the surface with acetone 3 times, and vacuum drying at 65°C for 11 h to obtain modified palm fiber; spinning the modified palm fiber in a spinning machine to obtain natural plant-based spun yarn. The remaining steps are the same as in Example 2.

[0079] Test Example 1:

[0080] Mechanical properties and anti-aging performance test: The breaking strength of the prepared natural plant-based yarn and the breaking strength change rate after ultraviolet aging were tested to evaluate its mechanical properties and anti-aging performance. Referring to GB / T3916-2013, the breaking strength A of the prepared natural plant-based yarn was tested using a YG061F electronic single yarn strength tester; the prepared natural plant-based yarn was artificially accelerated aged for 10 days using a FR-1205-QUV ultraviolet aging tester in accordance with the standard of GB / T 16422.3-2022, and the breaking strength B of the sample after ultraviolet treatment was tested, and the breaking strength change rate of the sample before and after ultraviolet aging treatment was calculated; breaking strength change rate = (AB) / A×100%. Each group of samples was tested 5 times, and the average value was recorded.

[0081] The results are shown in Table 1.

[0082] Table 1

[0083] Breaking strength (cN / tex) Breaking strength change rate Example 1 27.15 1.17％ Example 2 27.39 1.02％ Example 3 27.19 1.06％ Comparative Example 1 21.47 1.15％ Comparative Example 2 15.96 2.51％ Comparative Example 3 26.17 7.95％ Comparative Example 4 27.04 1.19％ Comparative Example 5 25.38 1.28％ Comparative Example 6 26.15 1.33％ Comparative Example 7 26.58 8.62％

[0084] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 7 in Table 1, it can be found that the natural plant-based spun yarn prepared by the present invention has higher breaking strength and good anti-aging performance.

[0085] By comparing the data in the table, it is shown that the phosphorylation modification of palm fiber makes the growth of hydroxyapatite more uniform and obtains higher breaking strength. The growth of hydroxyapatite also effectively improves the breaking strength of palm fiber. Allylphosphonic acid is also successfully introduced into the surface of hydroxyapatite, providing sites for the subsequent grafting of antibacterial agents and anti-aging agents. The introduction of anti-aging agents effectively improves the anti-aging properties of natural plant-based yarns.

[0086] Test Example 2:

[0087] Flame retardant performance test: The limiting oxygen index and UL 94 combustion rating of the prepared natural plant-based yarn are tested to evaluate its flame retardant effect. The specific test method is as follows:

[0088] Limiting oxygen index test: According to GB / T 2406.1-2008, the limiting oxygen index of the embodiment and the comparative example was tested with an oxygen index instrument, and 5 samples were tested in each group and the average value was recorded;

[0089] Vertical combustion test: According to ASTM D3801-2010, the test was carried out using a vertical-horizontal combustion tester, and 5 samples were tested in each group and the average value was recorded.

[0090] The results are shown in Table 2.

[0091] Table 2

[0092] Limiting oxygen index UL94 rating Example 1 36.53％ V-0 Example 2 37.24％ V-0 Example 3 36.88％ V-0 Comparative Example 1 31.15％ V-1 Comparative Example 2 26.14％ V-1 Comparative Example 3 32.19％ V-1 Comparative Example 4 36.28％ V-0 Comparative Example 5 35.76％ V-0 Comparative Example 6 34.38％ V-0 Comparative Example 7 34.96％ V-0

[0093] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 7 in Table 2, it can be found that the natural plant-based spun yarn prepared by the present invention has good flame retardant properties.

[0094] By comparing the data in the table, it can be seen that the phosphorylation modification of palm fiber and the growth of hydroxyapatite have effectively improved its flame retardant properties, and the flame retardant elements contained in the antibacterial agent and anti-aging agent have also played a synergistic flame retardant role, further improving the flame retardant effect.

[0095] Test Example 3:

[0096] Antibacterial performance test: using the oscillation method in GB / T 20944.3-2008, the prepared natural plant-based yarn was cut into 0.75±0.05g samples and mixed with the bacterial solution for oscillation for 5 minutes. The bacterial solution after oscillation was cultured in agar medium, and the antibacterial rate of the natural plant-based yarn against Escherichia coli and Staphylococcus aureus was determined by the number of growing colonies. Each group of samples was tested 5 times, and the average value was recorded.

[0097] The results are shown in Table 3.

[0098] Table 3

[0099]

[0100]

[0101] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 7 in Table 3, it can be found that the natural plant-based yarn prepared by the present invention has good antibacterial properties.

[0102] By comparing the data in the table, it is shown that the complexation of copper ions in the antibacterial agent and the covalent bond introduction of salicylaldehyde both effectively improve the antibacterial effect of the prepared natural plant-based spinning yarn. The copper ion itself has a good antibacterial effect. Salicylaldehyde is bound through Schiff base bonds. In a weakly acidic environment, the Schiff base bonds are broken to release salicylaldehyde for antibacterial effect, which effectively improves the antibacterial effect. Thioaminourea itself also has a good antibacterial effect. The three play a synergistic antibacterial role, further improving the antibacterial effect.

[0103] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method 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 in the scope of protection of the present invention.

Claims

1. A natural plant-based spinning yarn, characterized in that: The natural plant-based spinning yarn is obtained by spinning modified palm fiber; The modified palm fiber is prepared by grafting an antibacterial agent and an anti-aging agent onto hydroxyapatite composite palm fiber; The hydroxyapatite composite palm fiber is prepared by in-situ growth of hydroxyapatite by reacting phosphorylated modified palm fiber with calcium nitrate, diammonium hydrogen phosphate and allylphosphonic acid; The phosphorylated modified palm fiber is prepared by reacting pretreated palm fiber with diammonium phosphate in the presence of urea; The pretreated palm fiber is prepared by pretreating the palm fiber with a sodium chlorite solution to obtain a primary pretreated palm fiber, and then pretreating the palm fiber with a gradient concentration sodium hydroxide solution.

2. A natural plant-based spinning yarn according to claim 1, characterized in that: The antibacterial agent is prepared by reacting 4-propylene thiosemicarbazide with salicylaldehyde to obtain an antibacterial agent intermediate, and then complexing copper ions to obtain the antibacterial agent intermediate.

3. A natural plant-based spinning yarn according to claim 1, characterized in that: The anti-aging agent is 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl-2-methacrylate.

4. A method for preparing natural plant-based spinning yarn, characterized in that: The method comprises the following preparation steps: (1) 2-3 parts of palm fiber, 20-30 parts of 1wt% sodium chlorite solution, and 20-30 parts of 2wt% glacial acetic acid solution are mixed uniformly by weight, refluxed at 80-85°C and 200-300r / min for 7-8h, filtered, washed with 1wt% sodium hydroxide solution until neutral, then washed with pure water for 4-5 times, and vacuum dried at 60-70°C for 8-10h to obtain primary pretreated palm fiber; (2) treating the primary pretreated palm fiber with 6 wt % sodium hydroxide solution, 8 wt % sodium hydroxide solution and 10 wt % sodium hydroxide solution in sequence at a solid-liquid ratio of 1:20 g / ml, with each treatment condition being 60-70° C., 200-300 r / min, 2-3 h. After all treatments are completed, filtering, washing with pure water until neutral, and vacuum drying at 60-70° C. for 8-10 h to obtain pretreated palm fiber; (3) immersing the pretreated palm fiber in a mixed solution of ammonium dihydrogen phosphate / urea at a material-liquid ratio of 1:20 g / ml, stirring at 200-300 r / min for 20-30 min at room temperature, baking in a 60-70° C. oven with the liquid for 2-2.5 h, then baking in a 130-135° C. oven for 90-120 min, cooling naturally to room temperature, washing alternately with boiling water and room temperature pure water for 3-4 times, and vacuum drying at 60-70° C. for 8-10 h to obtain phosphorylated modified palm fiber; (4) 8 to 10 parts by mass of phosphorylated modified palm fiber and 20 to 30 parts by mass of 0.2 mol / L calcium nitrate solution were mixed evenly, reacted at room temperature at 200 to 300 r / min for 30 to 40 min, pH adjusted to 10 to 12 with aqueous ammonia, then 20 to 30 parts by mass of 0.12 mol / L diammonium hydrogen phosphate solution were added dropwise at a rate of 1 drop per second, stirred at room temperature at 200 to 300 r / min for 3 to 4 h, then allowed to stand at 75 to 85° C. for 3 to 4 h, cooled naturally to room temperature, allowed to stand at room temperature for 28 to 32 h, and then added again. 10 to 20 parts of 0.2 mol / L calcium nitrate solution are added, stirred at 200 to 300 r / min for 10 to 20 minutes at room temperature, the pH is adjusted to 10 to 12 with ammonia water, 20 to 30 parts of phosphoric acid mixed solution are added dropwise at a rate of 1 drop per second, stirred at 200 to 300 r / min for 4 to 5 hours at room temperature after the addition is completed, then allowed to stand at 75 to 85° C. for 4 to 5 hours, cooled naturally to room temperature, allowed to stand at room temperature for 36 to 40 hours, filtered, washed with pure water for 2 to 3 times, and vacuum dried at 50 to 60° C. for 10 to 12 hours to obtain hydroxyapatite composite palm fiber; (5) Mix 3-4 parts of 4-propylenethiosemicarbazide and 60-70 parts of ethanol solvent by weight, stir at 75°C and 200-300 r / min until completely dissolved, cool to 60-65°C, keep stirring, add 30-40 parts of 10 wt% salicylaldehyde ethanol solution at 2-3 drops per second, continue to react for 4-5 hours after the addition is completed, filter, wash with 80°C pure water 2-3 times, then wash with anhydrous ethanol twice, and vacuum dry at 50-60°C for 10-12 hours to obtain an antibacterial agent intermediate; (6) 2 to 3 parts of the antibacterial agent intermediate and 30 to 40 parts of a methanol / dimethyl sulfoxide mixed solvent are mixed uniformly by weight, stirred at 200 to 300 r / min at room temperature until dissolved, 14 to 18 parts of a 10 wt% copper chloride methanol solution are added, stirred at 300 to 400 r / min at room temperature for 10 to 12 hours, and the solvent is removed by rotary evaporation and ice water treatment, filtered, washed with anhydrous ethanol for 3 to 4 times, and vacuum dried at 60 to 70° C. for 10 to 12 hours to obtain an antibacterial agent; (7) The hydroxyapatite composite palm fiber was immersed in the antibacterial modification liquid at a bath ratio of 1:30 g / ml, and was rolled at room temperature for 30 to 40 min, with a stirring speed of 200 to 300 r / min and a rolling rate of 100%. The fiber was then pre-baked at 50 to 60 °C for 5 min, and then baked at 120 to 125 °C for 10 to 12 min. The surface was washed with acetone for 2 to 3 times, and then immersed in the anti-aging modification liquid at a bath ratio of 1:30 g / ml. The modified palm fiber is prepared by immersing the palm fiber in a liquid at room temperature for 30 to 40 minutes, stirring at a speed of 200 to 300 r / min, and a rolling rate of 100%. The palm fiber is then pre-baked at 50 to 60° C. for 5 minutes, and then baked at 120 to 125° C. for 10 to 12 minutes. The surface is washed with acetone for 2 to 3 times, and vacuum dried at 60 to 70° C. for 10 to 12 hours to obtain the modified palm fiber. The modified palm fiber is spun in a spinning machine to obtain a natural plant-based spinning yarn.

5. The method for preparing a natural plant-based spinning yarn according to claim 4, characterized in that: In the diammonium phosphate / urea mixed solution of step (3), the content of diammonium phosphate is 0.09 g / ml, and the content of urea is 0.28 g / ml.

6. The method for preparing a natural plant-based spinning yarn according to claim 4, characterized in that: The phosphoric acid mixed solution in step (4) contains 0.1 mol / L diammonium hydrogen phosphate and 0.02 mol / L allylphosphonic acid.

7. The method for preparing a natural plant-based spinning yarn according to claim 4, characterized in that: The ethanol solvent in step (5) is a mixture of anhydrous ethanol and pure water in a volume ratio of 1:

1.

8. The method for preparing a natural plant-based spinning yarn according to claim 4, characterized in that: The methanol / dimethyl sulfoxide mixed solvent in step (6) is a mixture of methanol and dimethyl sulfoxide in a volume ratio of 1:

1.

9. The method for preparing a natural plant-based spinning yarn according to claim 4, characterized in that: The antibacterial modified liquid in step (7) is prepared by mixing N,N-dimethylformamide as solvent, an antibacterial agent content of 10wt% and a benzoyl peroxide content of 0.2wt%.

10. The method for preparing a natural plant-based spinning yarn according to claim 4, characterized in that: The anti-aging modified liquid in step (7) is prepared by mixing N,N-dimethylformamide as solvent, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole with a content of 10 wt % and benzoyl peroxide with a content of 0.2 wt %.

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