High-strength polyester yarn and preparation method thereof

Abstract

The invention relates to the technical field of polyester yarns, in particular to a high-strength polyester yarn and a preparation method thereof.The method comprises the steps that PET slices with the intrinsic viscosity of 0.85-1.00 dL / g are subjected to melt spinning and cooled through circular blowing to obtain nascent fibers, the nascent fibers are subjected to surface activating treatment through low-temperature plasma or esterase bio-enzyme, and the high-strength polyester yarn is obtained; the preparation method comprises the following steps: firstly, activating fibers, then carrying out graft copolymerization reaction on the activated fibers and graft monomer solutions such as fluorinated acrylate and acrylic acid, and finally, cleaning, drying, carrying out thermal network and winding on the composite fibers, so that the prepared polyester yarn has the breaking strength of more than or equal to 7.7 g / D, the dry heat shrinkage rate of less than or equal to 3.5% and the shrinkage tension of less than or equal to 0.03 g / D, has the high functional characteristics of lasting super-hydrophobicity, antibacterial property and the like, is excellent in washing resistance, and is suitable for industrial production. The problem that functionalization is difficult due to surface inertia of the polyester fiber is solved, and the mechanical property and the surface characteristic of the polyester fiber are comprehensively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyester yarn, in particular to a high-strength polyester yarn and a preparation method thereof. BACKGROUND

[0002] As the common name of polyethylene terephthalate fiber, polyester has become the largest synthetic fiber in the world since its industrial production, with the largest output and the most widely application. Its molecular chain structure endows the fiber with high strength, excellent elastic recovery, good dimensional stability, wrinkle resistance and other outstanding advantages, making it irreplaceable in civilian fields such as clothing and home textiles.

[0003] With the rapid development of modern textile industry, especially the continuous expansion of industrial textile field, higher and more comprehensive requirements are put forward for the performance of polyester yarn. In high-end application scenarios such as safety protection, high-end sports equipment, medical health, environmental protection filtration and intelligent wear, not only is it required to maintain excellent intrinsic mechanical properties, but also is it expected to have specific surface functional properties, such as durable water and oil repellency, antistatic property, antibacterial property or stronger interfacial bonding force with composite matrix materials.

[0004] However, due to the lack of active groups in the macromolecular chain, high crystallinity and smooth surface of polyester fiber, it shows strong chemical inertness and hydrophobicity, which to some extent limits its functional development. In order to break through this bottleneck, surface modification of polyester yarn by physical or chemical methods has become the key core technology and development trend to realize its high performance and high added value, which aims to explore a new way of efficient surface functional modification of polyester yarn. SUMMARY

[0005] In order to solve the problems mentioned in the background art, the present application provides a high-strength polyester yarn and a preparation method thereof.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme: A preparation method of a high-strength polyester yarn, the preparation process comprising the following steps: S1, selecting polyethylene terephthalate chips with a specific viscosity of 0.85-1.00 dL / g, melting at 285-300℃, and then extruding through a spinneret and cooling by ring blowing to obtain primary fibers; S2, surface activation treatment of the primary fibers obtained in S1 to obtain activated fibers; S3, contacting the activated fibers obtained in S2 with a grafting monomer solution to carry out grafting polymerization reaction to obtain composite fibers with surface grafted functional polymer chains; S4, washing and drying the composite fiber after graft polymerization of S3, then heat networking and winding to obtain the high-strength polyester yarn.

[0007] Further, in S2, the surface activation treatment adopts low-temperature plasma treatment or biological enzyme treatment. The low-temperature plasma treatment is carried out in a reaction chamber with a mixed gas of argon and oxygen, the volume ratio of argon to oxygen in the mixed gas being (3:1)-(5:1), under the conditions of a discharge power of 20-50 W, a vacuum degree of 20-50 Pa, and a treatment time of 1-10 min. The biological enzyme treatment is esterase treatment, the treatment liquid containing esterase 1-2.5 U / mL and penetrant 0.2-2 g / L, and the treatment being carried out under the conditions of pH 7.0-9.0 and temperature 30-50℃ for 1-2 h.

[0008] Further, in S3, the preparation and polymerization of the grafting monomer specifically include the following steps: S3.1, dipping the fiber after surface activation treatment in a solution containing vinyl silane, introducing a polymerizable vinyl group on the surface of the fiber under the conditions of pH 9-10 and temperature 30-40℃ for 1-2 h, and the mass fraction of the vinyl silane solution being 1%-5%; S3.2, preparing a mixed emulsion composed of fluorine-containing acrylic ester, acrylic acid, emulsifier, and initiator, wherein the concentration of fluorine-containing acrylic ester is 2.5-5 g / L, the concentration of acrylic acid is 1-2 g / L, the concentration of emulsifier sodium dodecyl sulfate is 0.5-1 g / L, and the initiator is potassium persulfate or ammonium persulfate, and the addition amount of the initiator is 0.5%-2.0% of the total mass of fluorine-containing acrylic ester and acrylic acid; S3.3, placing the fiber after S3.1 treatment in the mixed emulsion, and carrying out graft copolymerization under the conditions of 30-40℃ and pH 4-6 for 0.5-2 h.

[0009] Further, in S3, the grafting monomer is an organic monomer containing an ionic liquid structure, the general formula of which is [A-B]+[C]-, wherein A is an organic structural unit containing a carbon-carbon double bond, selected from an acrylate group, a methacrylate group, or a styrene group, B is a cationic group of an ionic liquid, selected from an imidazole group, a pyridine group, or a quaternary ammonium group, and C is an anionic group of an ionic liquid, selected from a halide ion, BF4-, or PF6-, and the grafting rate of the organic monomer on the textile is 0.5% to 15% by weight.

[0010] Further, the organic monomer containing the ionic liquid structure is at least one of 1-butyl-3-vinylimidazole chloride or methacryloyloxyethyl trimethyl ammonium chloride, the graft polymerization reaction is initiated by chemical initiator, ionizing radiation, ultraviolet light, plasma or ozone treatment, the reaction temperature is 10-160 DEG C, and the reaction time is 30 min to 48 h.

[0011] Further, the heat network step in S4 is specifically that: the yarn after graft polymerization is subjected to network treatment using hot air with a temperature of 90-200 DEG C before winding, and the winding is completed at a temperature of 90-160 DEG C, and the winding speed is not less than 1650 m / min.

[0012] Further, a high-strength polyester yarn prepared by the preparation method in any one of claims 1-6.

[0013] Further, the breaking strength of the yarn is not less than 7.7 g / D, the dry heat shrinkage DHS177 measured at 177 DEG C is not higher than 3.5%, and the shrinkage tension ST140 measured at 140 DEG C is not higher than 0.03 g / D.

[0014] The beneficial effects of the application are as follows: 1. In the technical scheme of the application, rigid segments and flexible segments are innovatively introduced into the polyester main chain, the rigid segments serve as firm physical crosslinking points, and the flexible segments distributed therebetween can effectively dissipate energy and inhibit micro-crack propagation through conformation change and segment motion under external force, so that the yarn has high strength and excellent toughness and fatigue resistance.

[0015] 2. In the technical scheme of the application, active sites are activated on the fiber surface through plasma treatment and the like, then silane coupling agent is used as a'molecular bridge', and finally functional monomers containing fluorine and antibacterial agents are firmly grafted to the fiber surface through copolymerization, so that the super-hydrophobic and antibacterial functions have excellent washing resistance and wear resistance.

[0016] 3. In the technical scheme of the application, the high-strength modified polyester filament is used as the core to provide core mechanical support, and the hydrophilic natural fiber is used as the sheath to endow the fabric with excellent skin-friendliness and moisture absorption, and more importantly, the fiber fineness and arrangement of the core layer and the sheath layer are accurately controlled to construct a gradient capillary channel from inside to outside in the yarn, so that efficient moisture transfer and quick drying functions are realized.

[0017] 4、The technical scheme of the present application, through the micro-modification of molecular chain, the functionalization of the surface and the innovation of the macro yarn structure, successfully prepares a high-performance polyester yarn with high strength, high toughness, durable multifunctionality and excellent comfort, which opens up new prospects for its application in high-end sportswear, industrial textiles and smart wear. DETAILED DESCRIPTION

[0018] The technical solutions of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0019] Unless otherwise specified, the raw materials used in the present application are all obtained from market-purchased conventional products.

[0020] Preparation Example 1 S1, raw material preparation and melt spinning: Polyethylene terephthalate (PET) chips with a specific viscosity of 0.92 dL / g (commercially available, model BG-85) were placed in a vacuum drying oven at 125℃ for 4h to reduce the moisture content to less than 50ppm. The dried PET chips were added to a screw extruder (model SJ-45) with the screw temperature zones set at: zone 1 285℃, zone 2 290℃, zone 3 295℃, zone 4 298℃, and the die temperature at 300℃. The molten polymer was accurately delivered by a metering pump and extruded through a spinneret (pore size 0.25mm, number of holes 72) to form nascent fibers. A ring blowing air cooling device was used with a cooling air temperature of 20℃, an air speed of 0.5m / s, and an air humidity of 65%, to obtain the nascent fibers.

[0021] S2, fiber surface activation treatment: The above nascent fibers were guided through a low-temperature plasma treatment device (model PT-1000, frequency 40kHz) at a speed of 500m / min. A mixture of argon and oxygen gas (volume ratio 4:1) was introduced into the treatment chamber, the vacuum degree was controlled at 35Pa, the discharge power was 40W, and the treatment time was 4min. The surface energy of the treated fibers was significantly improved, and the activated fibers were obtained.

[0022] S3, preparation and polymerization of grafting monomers: S3.1, the activated fibers were immersed in a 3% mass fraction of vinyltriethoxysilane ethanol solution with a bath ratio of 1:30, and slowly stirred at pH=9.5 and a temperature of 35℃ for 1.5h to introduce vinyl groups on the fiber surface that can participate in polymerization. After the reaction was completed, the fibers were rinsed thoroughly with deionized water and dried at 60℃.

[0023] S3.2, Preparation of grafting mixed emulsion: Deionized water was added into a reaction kettle, and emulsifier sodium dodecyl sulfate (concentration 0.8 g / L), monomer dodecafluoroheptyl methacrylate (concentration 4.0 g / L), and acrylic acid (concentration 1.5 g / L) were sequentially added. After emulsification at 40°C and 300 rpm for 30 min, a stable emulsion was formed. Subsequently, initiator potassium persulfate (concentration 1.0% of the total mass of monomers) was added.

[0024] S3.3, The fiber treated by S3.1 was immersed in the above emulsion, with a bath ratio of 1:25. Nitrogen was introduced to remove oxygen for 30 min. Subsequently, the grafting copolymerization reaction was carried out at 35°C and pH=5.0, with stirring at a speed of 150 rpm for 1.5 h. After the reaction was completed, the fiber was taken out to obtain a composite fiber with functional polymer chains grafted on the surface.

[0025] S4, Post-treatment and forming: The grafted composite fiber was sequentially cleaned with hot deionized water at 60°C and anhydrous ethanol for 15 min each time by ultrasonic cleaning to completely remove unreacted monomers and homopolymers. Subsequently, the fiber was dried in a 80°C air-drying oven until the weight was constant. The dried fiber was guided through a hot netting device, and hot air at a temperature of 150°C was used for netting treatment, with a netting point spacing of 8 mm. Finally, the fiber was wound on a winder at a temperature of 120°C, and the winding speed was set to 1800 m / min. Thus, the high-strength polyester yarn was obtained.

[0026] Example 1 S1, Raw material preparation and melt spinning: Polyethylene terephthalate chips with a specific viscosity of 0.85 dL / g were selected and dried in a vacuum drying oven at 120°C for 5 h to reduce the water content to less than 50 ppm. The dried PET chips were added to a screw extruder, and the screw temperature of each zone was set as follows: zone 1, 283°C; zone 2, 288°C; zone 3, 293°C; zone 4, 295°C; and the die temperature was 296°C. The molten polymer was accurately delivered by a metering pump and extruded through a spinneret to form nascent fibers. A ring blowing air cooling device was used, with a cooling air temperature of 18°C, an air speed of 0.4 m / s, and an air humidity of 60%. The nascent fibers were obtained.

[0027] S2, Fiber surface activation treatment: The above nascent fibers were guided through a low-temperature plasma treatment device at a speed of 450 m / min. A mixture of argon and oxygen gases was introduced into the treatment chamber, with a volume ratio of 3:1, a vacuum degree of 20 Pa, and a discharge power of 20 W. The treatment time was 1 min. After treatment, the fiber surface was activated, and the hydrophilicity was significantly improved. The activated fiber was obtained.

[0028] S3, Preparation and polymerization of grafting monomers: S3.1, the activated fiber is immersed in a 1% by mass fraction of vinyl triethoxysilane ethanol solution, the bath ratio is 1:25, the pH is 9.0, the temperature is 30°C, and the fiber surface is introduced with a vinyl group capable of participating in polymerization by slowly stirring for 1 h, then the fiber is rinsed with deionized water, and dried at 55°C.

[0029] S3.2, a grafting mixed emulsion is prepared: deionized water is added to a reaction kettle, and emulsifiers, dodecyl sodium sulfate, monomers dodecafluoroheptyl methacrylate and acrylic acid are sequentially added at concentrations of 0.5 g / L, 2.5 g / L and 1.0 g / L respectively, and emulsified at 35°C and 250 rpm for 40 min to form a stable emulsion, and then an initiator potassium persulfate is added in an amount of 0.8% of the total mass of the fluorine-containing acrylate and acrylic acid.

[0030] S3.3, the fiber treated in S3.1 is immersed in the above emulsion, the bath ratio is 1:20, nitrogen is introduced to remove oxygen for 20 min, then the grafting copolymerization reaction is completed by stirring at 30°C and pH=4.0 at a stirring speed of 100 rpm for 0.5 h, after the reaction is completed, the fiber is taken out, and a composite fiber with a functional polymer chain grafted on the surface is obtained.

[0031] S4, post-treatment and forming: The grafted composite fiber is sequentially ultrasonically cleaned with hot deionized water at 50°C and anhydrous ethanol for 10 min to remove unreacted monomers and homopolymers, then dried in a 70°C air-drying oven until the weight is constant, the dried fiber is guided through a hot networker, hot air at a temperature of 90°C is used for network processing, and finally winding is completed on a winder at a temperature of 90°C, and the winding speed is set to 1650 m / min, thereby obtaining the high-strength polyester yarn.

[0032] Example 2 S1, raw material preparation and melt spinning: PET chips with a specific viscosity of 0.98 dL / g are selected, dried in a vacuum drying oven at 130°C for 4 h to reduce the water content to less than 50 ppm, the dried PET chips are added to a screw extruder, the screw temperature zones are set as follows: zone 1, 287°C; zone 2, 292°C; zone 3, 297°C; zone 4, 299°C; the die temperature is 300°C, the molten polymer is accurately conveyed through a metering pump, extruded through a spinneret to form a nascent fiber, and a ring blowing air cooling device is used, the cooling air temperature is 22°C, the air speed is 0.6 m / s, and the air humidity is 70%, thereby obtaining the nascent fiber.

[0033] S2, fiber surface activation treatment: The above nascent fiber is guided through a low-temperature plasma treatment device at a speed of 550 m / min, a mixed gas of argon and oxygen is introduced into the treatment chamber, the volume ratio is controlled to be 5:1, the vacuum degree is 50 Pa, the discharge power is 50 W, and the treatment time is 10 min, a large number of active sites are generated on the surface of the fiber after treatment, and an activated fiber is obtained.

[0034] S3, grafting monomer preparation and polymerization: S3.1, the activated fiber is immersed in a 5% by mass vinyltriethoxysilane ethanol solution, the bath ratio is 1:35, the pH is 10.0, the temperature is 40°C, and slow stirring is performed for 2 hours to fully introduce vinyl groups on the surface of the fiber, after the reaction is completed, the fiber is rinsed with deionized water and dried at 65°C.

[0035] S3.2, a grafting mixed emulsion is prepared: deionized water is added to a reaction kettle, and emulsifier sodium dodecyl sulfate, monomer dodecafluoroheptyl methacrylate, and acrylic acid are sequentially added at concentrations of 1.0 g / L, 5.0 g / L, and 2.0 g / L, respectively, and emulsified at 45°C and 350 rpm for 20 minutes to form a stable emulsion, and then initiator potassium persulfate is added in an amount of 1.2% of the total mass of the fluorine-containing acrylate and acrylic acid.

[0036] S3.3, the fiber treated in S3.1 is immersed in the above emulsion, the bath ratio is 1:30, nitrogen is introduced to remove oxygen for 40 minutes, and then stirring is performed at 40°C and pH=6.0 for 2 hours at a stirring speed of 200 rpm to complete the graft copolymerization reaction, after the reaction is completed, the fiber is taken out, and a composite fiber with functional polymer chains grafted on the surface is obtained.

[0037] S4, post-treatment and forming: The grafted composite fiber is sequentially cleaned with hot deionized water at 70°C and anhydrous ethanol for 20 minutes each to ensure thorough cleaning, and then dried in a 90°C air-drying oven until the weight is constant, the dried fiber is guided through a hot networker, hot air at a temperature of 200°C is used for network processing, and finally winding is completed on a winder at a temperature of 160°C, and the winding speed is set to 1950 m / min, thereby obtaining the high-strength polyester yarn.

[0038] Example 3 S1, raw material preparation and melt spinning: In this example, the same raw materials and melt spinning process as in Preparation Example 1 are used, PET chips with a specific viscosity of 1.00 dL / g are selected, dried, and then melted in a screw extruder at 285-298°C, extruded through a spinneret, and cooled under 20°C air blowing to obtain nascent fibers.

[0039] S2, fiber surface activation treatment: The nascent fiber was passed through a low-temperature plasma treatment device at a speed of 500 m / min, and the treatment conditions were as follows: argon and oxygen volume ratio 4:1, vacuum degree 35 Pa, discharge power 40 W, and treatment time 4 min, to obtain an activated fiber.

[0040] S3, grafting monomer preparation and polymerization: S3.1, the activated fiber was immersed in a 3% by mass vinyltriethoxysilane solution, and reacted at pH=9.5 and 35°C for 1.5 h to introduce a vinyl group.

[0041] S3.2, a mixed emulsion containing dodecafluoroheptyl methacrylate 4.0 g / L, acrylic acid 1.5 g / L, and sodium dodecyl sulfate 0.8 g / L was prepared, and 1.0% of the total mass of the monomers was added as an initiator.

[0042] S3.3, the fiber was placed in the emulsion, and a graft copolymerization reaction was carried out at 35°C and pH=5.0 for 1.5 h to obtain a composite fiber.

[0043] S4, post-treatment and forming: After the grafting, the fiber was washed and dried, and then subjected to a thermal network treatment at 150°C, and was formed at 120°C and a winding speed of 1800 m / min, to finally obtain the high-strength polyester yarn.

[0044] Comparative Example 1 In this comparative example, the key steps of surface activation and graft polymerization were omitted to illustrate the influence on the final performance of the yarn, and the preparation process was as follows: S1, raw material preparation and melt spinning: The same polyethylene terephthalate chip with an intrinsic viscosity of 1.00 dL / g as in Example 3 was selected, and the same pretreatment and melt spinning process was adopted. The dried PET chip was added to the screw extruder, and the screw temperature in each zone was set to be completely consistent with that in Example 3 (Zone 1 285°C, Zone 2 290°C, Zone 3 295°C, Zone 4 298°C). The melt was extruded through a spinneret and cooled at 20°C under air blowing to obtain nascent fiber.

[0045] S4, post-treatment and forming (directly): The above nascent fiber was directly subjected to post-treatment without the steps of S2 (surface activation) and S3 (graft polymerization). The fiber was guided through a thermal network device, and the network treatment was carried out using hot air at a temperature of 150°C. Finally, the winding was completed on a winder at a temperature of 120°C, and the winding speed was set to be 1800 m / min, to obtain a comparative yarn.

[0046] Comparative Example 2 In this comparative example, the effect of not containing fluorine-containing monomer in the grafting monomer mixture on the function durability was investigated, and the preparation process was different from S3.2 and Example 3, as follows: S1, raw material preparation and melt spinning: This step is exactly the same as Example 3, using PET chips with a specific viscosity of 1.00 dL / g, and the same drying, melting (285-298℃), spinning and air cooling (20℃) process, to obtain the as-spun fiber.

[0047] S2, fiber surface activation treatment: This step is exactly the same as Example 3, and the as-spun fiber is treated by low temperature plasma (argon:oxygen=4:1, vacuum degree 35Pa, power 40W, time 4min) to obtain the activated fiber.

[0048] S3, preparation and polymerization of grafting monomer: S3.1, this step is exactly the same as Example 3, and the activated fiber is treated in a 3% vinyltriethoxysilane solution (pH=9.5, 35℃) for 1.5h to introduce vinyl groups.

[0049] S3.2, preparation of grafting mixed emulsion: add deionized water in the reaction kettle, and then add emulsifier sodium dodecyl sulfate (concentration 0.8g / L), acrylic acid (concentration 1.5g / L), Omit adding fluorine-containing monomer dodecafluoroheptyl methacrylate, emulsify at 40℃ under 300rpm stirring for 30min to form emulsion, and then add initiator potassium persulfate (concentration is 1.0% of the mass of acrylic acid).

[0050] S3.3, this step is exactly the same as Example 3, and the fiber is placed in the above emulsion, stirred at 35℃ and pH=5.0 for 1.5h to complete the grafting copolymerization reaction, and the composite fiber is obtained.

[0051] S4, post-treatment and forming: This step is exactly the same as Example 3, and the grafted fiber is washed, dried, heat networked at 150℃, and wound at 120℃ and 1800m / min to obtain the comparative yarn.

[0052] Comparative Example 3 In this comparative example, the effect of the type of silane coupling agent on the interfacial bonding strength was investigated, and the reactive vinyl silane was replaced by non-reactive amino silane, and the preparation process was different from S3.1 and Example 3, as follows: S1, raw material preparation and melt spinning: This step is exactly the same as Example 3.

[0053] S2, fiber surface activation treatment: This step is exactly the same as example 3.

[0054] S3, graft monomer preparation and polymerization: S3.1, the activated fiber is immersed in a 3% mass fraction of aminopropyl triethoxysilane (KH-550) ethanol solution, the bath ratio is 1:30, and the reaction is slowly stirred at pH=9.5 and temperature 35℃ for 1.5h. The silane molecule does not contain a carbon-carbon double bond, and its amino functional group cannot copolymerize with the subsequent monomer, but can only be attached to the fiber surface by physical adsorption or hydrogen bonding. After the reaction is completed, the fiber is rinsed with deionized water and dried.

[0055] S3.2, this step is exactly the same as example 3, and a mixed emulsion containing dodecafluoroheptyl methacrylate (4.0g / L) and acrylic acid (1.5g / L) is prepared.

[0056] S3.3, this step is exactly the same as example 3, and the fiber treated by S3.1 is placed in the emulsion and reacted at 35℃ and pH=5.0 for 1.5h.

[0057] S4, post-treatment and forming: This step is exactly the same as example 3, and the treated fiber is cleaned, dried, heat networked and wound, and the comparative yarn is obtained.

[0058] Effect verification example The yarns prepared in examples 1-3 and comparative examples 1-3 are tested for the following properties, and the test methods and standards are as follows: Mechanical properties: the yarn breaking strength and elongation at break are tested according to GB / T 3916-2013 Textiles Wound Yarns Determination of Breaking Force and Elongation at Break of Single Yarns.

[0059] Wear resistance: the yarn wear resistance (to break) is tested according to GB / T 21196.2-2007 Textiles Determination of the Wear Resistance of Fabrics by the Martindale Method.

[0060] Hydrophobicity: the yarn water contact angle is tested according to GB / T 30413-2013 Textiles Determination of Static Contact Angle.

[0061] Antibacterial property: the yarn antibacterial rate against Staphylococcus aureus is tested according to GB / T 20944.3-2008 Textiles Evaluation of Antibacterial Property Part 3: Oscillation Method.

[0062] Functional durability (wash durability): first, the yarn was subjected to 50 times of standard washing according to AATCC 135-2018 Test Method for Colorfastness to Home Laundering of Textiles, and then the water contact angle was measured again according to GB / T 30413-2013 to evaluate the functional durability by the change of the water contact angle before and after washing.

[0063] The mechanical properties and wear resistance test results of the yarns are shown in Table 1, and the hydrophobic, antibacterial and wash resistance test results are shown in Table 2.

[0064] Table 1. Yarn performance test results of Examples 1-3 and Comparative Examples 1-3 Sample Breaking strength (cN / dtex) Elongation at break (%) Wear resistance (times) Example 1 8.0 20.1 18000 Example 2 8.3 20.8 19000 Example 3 8.5 21.2 19500 Comparative Example 1 6.5 18.5 8500 Comparative Example 2 7.9 20.5 18500 Comparative Example 3 7.0 19 10000 Table 2. Yarn performance test results of Examples 1-3 and Comparative Examples 1-3 Sample Water contact angle (°) Washing resistance (°) Antibacterial rate (%) Example 1 142 135 92.5 Example 2 148 142 95.8 Example 3 145 140 94.1 Comparative Example 1 75 72 0 Comparative Example 2 78 70 90.2 Comparative Example 3 105 88 60.3 From the data in Tables 1 and 2, it can be seen that the high-strength polyester yarns prepared in Examples 1-3 are significantly superior to the comparative examples in terms of mechanical properties, hydrophobicity, wash resistance and antibacterial properties.

[0065] Comparative Example 1 has no surface activation and grafting, and its performance is the same as that of ordinary polyester yarn. The water contact angle has no change after 50 times of washing, but it is always low, which proves that the surface lacks a functional grafting layer.

[0066] Although Comparative Example 2 is activated and grafted, it does not use fluorine-containing monomer dodecafluoroheptyl methacrylate, so its initial hydrophobicity is poor, and the water contact angle further decreases after 50 times of washing, indicating that it lacks the low surface energy characteristics provided by the fluorine component, and the hydrophobicity of the grafting layer is not durable.

[0067] Comparative Example 3 uses amino silane, which can form a certain initial hydrophobicity (water contact angle 105°) by physical adsorption or weak interaction to combine part of the polymer, but it cannot form a firm covalent bond grafting layer, resulting in a large amount of grafting layer falling off after 50 times of washing, and the water contact angle decreases significantly to 88°, and the wear resistance and functional durability are both greatly reduced.

[0068] Examples 1-3 have a very small decrease (≤5°) in water contact angle after 50 times of washing, which indicates that the grafting layer formed by bridging with vinyl triethoxysilane and subsequent copolymerization is combined with the surface of the polyester fiber through a firm Si-O-C covalent bond, showing excellent durability, and the stable arrangement of the fluorine-containing segment on the surface also ensures the persistent superhydrophobicity.

[0069] In summary, the application successfully prepares high-performance polyester yarns with high strength, high toughness, excellent wear resistance, long-lasting super-hydrophobicity and high-efficiency antibacterial property by strictly controlling process steps and parameters such as plasma activation, silane coupling agent bridging and functional monomer grafting copolymerization, and fully embodies the importance of the synergistic effect of each step.

[0070] In the description of the specification, the description referring to the terms "preparation example", "embodiment", "each embodiment" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or preparation example are included in at least one embodiment or preparation example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or preparation example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or preparation examples in a suitable manner.

[0071] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes to the technical solutions and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method of making high strength polyester yarns, characterized by, The preparation process comprises the following steps: S1, selecting polyethylene terephthalate chips with intrinsic viscosity of 0.85-1.00 dL / g, melting at 285-300℃, extruding through a spinneret, and then cooling by ring blowing to obtain primary fibers; S2, performing surface activation treatment on the primary fibers obtained in S1 to obtain activated fibers; S3, contacting the activated fibers obtained in S2 with a grafting monomer solution to perform grafting polymerization reaction, thereby obtaining composite fibers with functional polymer chains grafted on the surface; S4, performing cleaning and drying on the composite fibers after grafting polymerization in S3, and then performing heat network and winding to obtain the high-strength polyester yarn.

2. The method for preparing high-strength polyester yarn according to claim 1, characterized in that, In S2, the surface activation treatment is performed by low-temperature plasma treatment or biological enzyme treatment; In the low-temperature plasma treatment, argon and oxygen mixed gas is introduced into the reaction chamber, the volume ratio of argon to oxygen in the mixed gas is (3:1)-(5:1), the discharge power is 20-50 W, the vacuum degree is 20-50 Pa, and the treatment time is 1-10 min; In the biological enzyme treatment, the treatment liquid comprises esterase 1-2.5 U / mL and penetrant 0.2-2 g / L, the pH is 7.0-9.0, the temperature is 30-50℃, and the treatment time is 1-2 h.

3. The method for preparing high-strength polyester yarn according to claim 1, characterized in that, In S3, the preparation and polymerization of the grafting monomer specifically comprise the following steps: S3.1, immersing the fibers after surface activation treatment in a solution containing vinylsilane, reacting at pH 9-10 and temperature 30-40℃ for 1-2 h to introduce vinyl groups on the fiber surface which can participate in polymerization, and the mass fraction of the vinylsilane solution is 1%-5%; S3.2, preparing a mixed emulsion composed of fluorine-containing acrylate, acrylic acid, emulsifier, and initiator, wherein the concentration of fluorine-containing acrylate is 2.5-5 g / L, the concentration of acrylic acid is 1-2 g / L, the concentration of emulsifier sodium dodecyl sulfate is 0.5-1 g / L, the initiator is potassium persulfate or ammonium persulfate, and the addition amount of the initiator is 0.5%-2.0% of the total mass of fluorine-containing acrylate and acrylic acid; S3.3, placing the fibers after S3.1 treatment in the mixed emulsion to perform grafting copolymerization reaction at 30-40℃ and pH 4-6 for 0.5-2 h.

4. The method for preparing high-strength polyester yarn according to claim 1, characterized in that, In S3, the grafting monomer is an organic monomer containing ionic liquid structure, with a general formula of [A-B] + [C] - , wherein A is an organic structural unit containing carbon-carbon double bond, selected from acrylate group, methacrylate group or styryl group, B is a cationic group of ionic liquid, selected from imidazolium group, pyridinium group or quaternary ammonium group, and C is an anionic group of ionic liquid, selected from halide ion, BF4 - or PF6 - , and the grafting rate of the organic monomer on the textile is 0.5% to 15% by weight.

5. The method for preparing high-strength polyester yarn according to claim 4, characterized in that, The organic monomer containing ionic liquid structure is at least one of 1-butyl-3-vinylimidazole chloride or methacryloyloxyethyl trimethyl ammonium chloride, the grafting polymerization reaction is initiated by chemical initiator, ionizing radiation, ultraviolet light, plasma or ozone treatment, the reaction temperature is 10-160℃, and the reaction time is 30 min to 48 h.

6. The method for preparing high-strength polyester yarn according to claim 1, characterized in that, The heat network step in S4 is specifically as follows: before winding, the yarn after grafting polymerization is subjected to network treatment using hot air with a temperature of 90-200℃, and the winding is completed at a temperature of 90-160℃, and the winding speed is not less than 1650 m / min.

7. A high-strength polyester yarn prepared by the preparation method of any one of claims 1-6.

8. A high tenacity polyester yarn as claimed in claim 7, wherein, The yarn has a breaking strength of not less than 7.7 g / D, a dry heat shrinkage DHS177 of not more than 3.5% measured at 177 DEG C, and a shrinkage tension ST140 of not more than 0.03 g / D measured at 140 DEG C.