High-strength composite antibacterial monofilament and preparation method thereof

Abstract

The invention discloses a high-strength composite antibacterial monofilament and a preparation method thereof.The high-strength composite antibacterial monofilament is of a skin-core composite structure, and a core layer is a blend of 10 parts of high-density polyethylene resin and 90 parts of ultra-high molecular weight polyethylene resin; the skin layer is a blend of 70 parts of antibacterial modified high-density polyethylene resin and 30 parts of ultra-high molecular weight polyethylene resin. The antibacterial modified high-density polyethylene resin in the skin layer is prepared by uniformly mixing 70 parts of pre-irradiated high-density polyethylene resin, 28 parts of a reactive antibacterial agent and 2 parts of a modified nano rare earth-based antibacterial agent CeO2 and carrying out reactive grafting, extrusion and granulation through double screws. The prepared composite monofilament is high in strength and good in antibacterial effect.

Description

Technical Field

[0001] This invention relates to the field of composite fiber preparation technology, specifically to a high-strength composite antibacterial monofilament and its preparation method. Background Technology

[0002] Ultra-high molecular weight polyethylene (UHMWPE) fiber backbone is a new generation of high-performance material with many excellent properties, such as high strength, high modulus, excellent corrosion resistance, and abrasion resistance. It is often used in fisheries to make fishing lines, ropes, nets, and aquaculture enclosures. However, ordinary UHMWPE fiber products are easily corroded by microorganisms when immersed in seawater for extended periods, shortening their lifespan. Therefore, developing an antibacterial UHMWPE fiber is of great significance.

[0003] Patent CN 113122949A discloses an ultra-high molecular weight polyethylene (UHMWPE) fiber for manufacturing reservoir seepage-proof lining and its preparation method. It employs inorganic toughening agents and polymeric antibacterial agents to antibacterially modify UHMWPE masterbatch. The antibacterial UHMWPE fiber is prepared through melt spinning, water bath cooling, multiple stretching, drying, and setting, effectively avoiding or suppressing the loss of antibacterial agents caused by water cooling, washing, and extraction processes in traditional gel spinning. However, directly grafting antibacterial agents onto the polymer matrix results in most of the antibacterial components being embedded within the fiber after subsequent processing, leaving less antibacterial content on the fiber surface that can contact microorganisms, thus affecting the antibacterial effect. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a long-lasting, antibacterial, and anti-adhesion high-strength monofilament for aquaculture and its preparation method. This method involves uniformly mixing ultra-high molecular weight polyethylene resin, antibacterial modified polypropylene resin, antioxidant, compatibilizer, and lubricant, followed by melt spinning, multiple stretching, oiling, and heat setting to obtain a monofilament with long-lasting antibacterial and anti-adhesion functions, which can be applied in the aquaculture field.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A high-strength composite antibacterial monofilament, characterized in that: the monofilament structure is a skin-core composite structure, the core layer is a blend of 10 parts high-density polyethylene resin and 90 parts ultra-high molecular weight polyethylene resin, and the skin layer is a blend of 70 parts antibacterial modified high-density polyethylene resin and 30 parts ultra-high molecular weight polyethylene resin. The antibacterial modified high-density polyethylene resin is prepared by uniformly mixing 70 parts of pre-irradiated high-density polyethylene resin, 28 parts of reactive antibacterial agent, and 2 parts of modified nano-rare earth-based antibacterial agent CeO2, followed by reactive grafting, extrusion, and granulation via a twin-screw extruder. The modified nano-rare earth-based antibacterial agent CeO2 is prepared by surface chemical modification of nano-CeO2 with double-bonded silane; The pre-irradiated high-density polyethylene resin is pre-irradiated in a nitrogen atmosphere using an electron accelerator as the irradiation source, with an irradiation dose of 80~120 kGy.

[0006] The ultra-high molecular weight polyethylene resin has a viscosity-average molecular weight of 1×10⁻⁶. 6 ~2×10 6 The molecular weight of high-density polyethylene resin is 4×10. 4 ~8×10 4 The melt index is 5~12 g / 10 min.

[0007] The reactive antibacterial agent is selected from one or more of allyltrimethylammonium chloride, methacryloylethyl sulfobetaine, and 2-methacryloyloxyethyl carboxylic acid betaine. The average diameter of the nano CeO2 is 10-30 nm. The double bond silane is selected from one or more of vinyltrimethoxysilane, allyltrimethoxysilane, and 3-methacryloyloxypropyltrimethoxysilane.

[0008] A method for preparing a high-strength composite antibacterial monofilament, characterized by comprising the following steps: Step 1: Preparation of modified nano-rare earth-based antibacterial agent CeO2 Add a dispersant to deionized water, mix well, then add nano CeO2, mechanically stir and disperse for 10-15 min, add anhydrous ethanol, ultrasonically disperse for 10-20 min, then add double-bonded silane, heat to 60℃ and react for 3-4 h, filter after the reaction is complete, repeatedly wash and dry the filter residue to obtain modified nano rare earth-based antibacterial agent CeO2. Step 2: Preparation of pre-irradiated high-density polyethylene resin Under nitrogen protection, high-density polyethylene resin was pre-irradiated using an electron accelerator to obtain pre-irradiated high-density polyethylene resin. Step 3: Antibacterial modified high-density polyethylene resin Take 70 parts of pre-irradiated high-density polyethylene resin, 28 parts of reactive antibacterial agent, and 2 parts of modified nano-rare earth-based antibacterial agent CeO2, mix them evenly, and then use a twin-screw extruder for reactive extrusion and granulation to obtain antibacterial modified high-density polyethylene resin. Step 4: Preparation of the cortex and core blend 70 parts of antibacterial modified high-density polyethylene resin and 30 parts of ultra-high molecular weight polyethylene resin were blended and extruded using a twin-screw extruder at a temperature of 270~290℃. After water cooling, drying, and pelletizing, a skin layer blend was obtained. 10 parts of high-density polyethylene resin and 90 parts of ultra-high molecular weight polyethylene resin were blended and extruded using a twin-screw extruder at a temperature of 270~290℃. After water cooling, drying, and pelletizing, a core layer blend was obtained. Step 5: Preparation of high-strength composite antibacterial monofilaments The skin and core blends prepared in the above steps are extruded by a single screw extruder, metered by a metering pump, and then transported to a composite spinning assembly. After being formed by a composite spinneret, they are cooled, stretched, and heat-set to obtain high-strength composite antibacterial monofilaments.

[0009] In step one, the mass ratio of deionized water to anhydrous ethanol is 80:20, and the dispersant used is sodium dodecylbenzenesulfonate, with the amount of dispersant being 1% of the mass of nano CeO2.

[0010] The temperature of the twin-screw extruder in step three is 190~220℃.

[0011] Step 5: The mass ratio of the metering pump supply to the skin layer and the core layer is (10:90) ~ (30:70).

[0012] In step five, the composite spinning assembly has a spinning temperature of 290℃, a water cooling temperature of 20℃, a two-stage stretching process, a first-stage stretching temperature of 90℃ with a stretching ratio of 8 times, a second-stage stretching temperature of 100℃ with a stretching ratio of 1.12 times, and a heat setting temperature of 160℃. Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] (1) This invention uses pre-irradiation technology to irradiate and modify high-density polyethylene resin to generate reactive free radicals. Then, the pre-irradiated high-density polyethylene resin, reactive antibacterial agent, and modified nano-rare earth-based antibacterial agent are fed into a twin-screw extruder for reactive extrusion grafting, thereby introducing antibacterial groups onto the high-density polyethylene macromolecular chain. A composite monofilament with antibacterial function is prepared using core-sheath composite spinning technology. The sheath provides the antibacterial properties of the monofilament, and the core provides the excellent mechanical properties of the monofilament. In traditional antibacterial modification, many antibacterial components are embedded inside the monofilament, resulting in low antibacterial efficiency. The antibacterial components of the composite monofilament prepared in this invention are uniformly distributed on the surface of the monofilament, which can maximize the antibacterial effect, reduce the amount of antibacterial agent used, and reduce production costs.

[0014] (2) The present invention utilizes silane to modify the surface of nano CeO2, reducing the aggregation effect of nanoparticles and improving dispersibility. In addition, nano CeO2 and reactive antibacterial agents can play a synergistic antibacterial role, further improving the antibacterial performance of composite monofilaments.

[0015] (3) In this invention, a blend of high-density polyethylene resin and ultra-high molecular weight polyethylene resin is used as the core layer. During the composite spinning process, high-density polyethylene can penetrate into the molecular chains of ultra-high molecular weight polyethylene with higher viscosity, relieve some physical entanglement, increase the fluidity of ultra-high molecular weight polyethylene molecular chains, improve melt processing performance, and facilitate its orientation crystallization. Detailed Implementation

[0016] To further understand the present invention, the following detailed description, in conjunction with embodiments, provides a long-lasting antibacterial and anti-adhesion high-strength fishery monofilament and its preparation method. The scope of protection of the present invention is not limited by the following embodiments.

[0017] The breaking strength test of the monofilament was carried out in accordance with GB / T4344-2008 standard, with a tensile interval of 200 mm and a tensile speed of 200 m / min.

[0018] The antibacterial performance of the monofilament was evaluated according to the standard GB / T20944.3-2008, using the plate count method, with a contact time of 60 min, and the test strains were Escherichia coli O157: H7 and Staphylococcus aureus. Example 1

[0019] Step 1: Preparation of modified nano-rare earth-based antibacterial agent CeO2 Add 5 g sodium dodecylbenzenesulfonate to 3 L of water, mix well, then add 500 g nano CeO2, mechanically stir and disperse for 15 min, add 0.75 kg anhydrous ethanol, ultrasonically disperse for 10 min, then add 25 g double bond silane, heat to 60℃ and react for 4 h, filter after the reaction is complete, repeatedly wash and dry the filter residue to obtain modified nano rare earth-based antibacterial agent CeO2. Step 2: Preparation of pre-irradiated high-density polyethylene resin Under nitrogen protection, high-density polyethylene resin with a melt index of 10.2 g / 10 min was pre-irradiated using an electron accelerator at a dose of 100 kGy to obtain pre-irradiated high-density polyethylene resin. Step 3: Antibacterial modified high-density polyethylene resin Take 5 kg of pre-irradiated high-density polyethylene resin, 2 kg of reactive antibacterial agent, and 0.14 kg of modified nano-rare earth-based antibacterial agent CeO2, mix them evenly, and then use a twin-screw extruder for reactive extrusion and granulation to obtain antibacterial modified high-density polyethylene resin. Step 4: Preparation of the cortex and core blend 3 kg of antibacterial modified high-density polyethylene resin and 1.28 kg of ultra-high molecular weight polyethylene resin were blended and extruded using a twin-screw extruder at a temperature of 270~290℃. After water cooling, drying, and pelletizing, a skin layer blend was obtained. 0.34 kg of high-density polyethylene resin and 3 kg of ultra-high molecular weight polyethylene resin were blended and extruded using a twin-screw extruder at a temperature of 270~290℃. After water cooling, drying, and pelletizing, a core layer blend was obtained. Step 5: Preparation of high-strength composite antibacterial monofilaments The skin and core blends prepared in the above steps are extruded separately by a single screw extruder with a skin-to-core ratio of 10:90. After being metered by a metering pump, they are fed into a composite spinning assembly. The spinning temperature is 290℃, the water cooling temperature is 20℃, the first-stage stretching temperature is 90℃ with a stretching ratio of 8 times, the second-stage stretching temperature is 100℃ with a stretching ratio of 1.12 times, and the heat setting temperature is 160℃.

[0020] The strength of the antibacterial composite monofilament is 10.7 cN / tex. Example 2

[0021] Steps one, two, three and four are the same as in Example 1.

[0022] Step 5: Preparation of high-strength composite antibacterial monofilaments The skin and core blends prepared in the above steps are extruded separately by a single screw extruder with a skin-to-core ratio of 20:80. After being metered by a metering pump, they are fed into a composite spinning assembly. The spinning temperature is 290℃, the water cooling temperature is 20℃, the first-stage stretching temperature is 90℃ with a stretching ratio of 8 times, the second-stage stretching temperature is 100℃ with a stretching ratio of 1.12 times, and the heat setting temperature is 160℃.

[0023] The strength of the antibacterial composite monofilament is 9.8 cN / tex. Example 3

[0024] Steps one, two, three and four are the same as in Example 1.

[0025] Step 5: Preparation of high-strength composite antibacterial monofilaments The skin and core blends prepared in the above steps are extruded separately by a single screw extruder with a skin-to-core ratio of 30:70. After being metered by a metering pump, they are fed into a composite spinning assembly. The spinning temperature is 290℃, the water cooling temperature is 20℃, the first-stage stretching temperature is 90℃ with a stretching ratio of 8 times, the second-stage stretching temperature is 100℃ with a stretching ratio of 1.12 times, and the heat setting temperature is 160℃.

[0026] The strength of the antibacterial composite monofilament is 7.4 cN / tex.

[0027] Comparative Example 1 Step 1: Preparation of modified nano-rare earth-based antibacterial agent CeO2 Add 3 g sodium dodecylbenzenesulfonate to 2 kg of water, mix well, then add 300 g nano CeO2, mechanically stir and disperse for 15 min, add 0.5 kg of anhydrous ethanol, ultrasonically disperse for 10 min, then add 20 g double bond silane, heat to 60℃ and react for 3 h. After the reaction is complete, filter, wash and dry to obtain modified nano rare earth-based antibacterial agent CeO2. Step 2: Preparation of pre-irradiated high-density polyethylene resin In a nitrogen atmosphere, high-density polyethylene resin with a melt index of 11 g / 10 min was pre-irradiated using an electron accelerator at a dose of 120 kGy to obtain pre-irradiated high-density polyethylene resin. Step 3: Antibacterial modified high-density polyethylene resin Take 3 kg of pre-irradiated high-density polyethylene resin, 1.2 kg of reactive antibacterial agent, and 0.09 kg of modified nano-rare earth-based antibacterial agent CeO2, mix them evenly, and then use a twin-screw extruder for reactive extrusion and granulation to obtain antibacterial modified high-density polyethylene resin. Step 4: Preparation of the cortex and core blend 3 kg of antibacterial modified high-density polyethylene resin and 1.28 kg of ultra-high molecular weight polyethylene resin were blended and extruded using a twin-screw extruder at a temperature of 270~290℃. After water cooling, drying, and pelletizing, a skin layer blend was obtained. 0.34 kg of high-density polyethylene resin and 3 kg of ultra-high molecular weight polyethylene resin were blended and extruded using a twin-screw extruder at a temperature of 270~290℃. After water cooling, drying, and pelletizing, a core layer blend was obtained. Step 5: Preparation of high-strength composite antibacterial monofilaments The skin and core blends prepared in the above steps are extruded separately by a single screw extruder with a skin-to-core ratio of 50:50. After being metered by a metering pump, they are fed into a composite spinning assembly. The spinning temperature is 290℃, the water cooling temperature is 20℃, the first-stage stretching temperature is 90℃ with a stretching ratio of 5, the second-stage stretching temperature is 100℃ with a stretching ratio of 1.1, and the heat setting temperature is 160℃.

[0028] The strength of the antibacterial composite monofilament is 5.6 cN / tex.

[0029] Comparative Example 2 Step 3: Take 4 kg of pre-irradiated high-density polyethylene resin and 1.7 kg of reactive antibacterial agent, mix them evenly, and then use a twin-screw extruder for reactive extrusion and granulation to obtain antibacterial modified high-density polyethylene resin.

[0030] The rest is the same as in Example 1.

[0031] The strength of the antibacterial composite monofilament is 9.7 cN / tex.

[0032] Comparative Example 3 Step 3: Take 4 kg of pre-irradiated high-density polyethylene resin and 0.1 kg of modified nano-rare earth-based antibacterial agent CeO2, mix them evenly, and then use a twin-screw extruder for reactive extrusion and granulation to obtain antibacterial modified high-density polyethylene resin.

[0033] The rest is the same as in Example 1.

[0034] The strength of the antibacterial composite monofilament is 9.6 cN / tex.

[0035] Table 1. Test results of antibacterial properties of monofilaments Table 1 shows the antibacterial test results. The higher the cortex content, the better the antibacterial effect of the composite monofilament. When the ratio of cortex to core is 30:70, the antibacterial rate of the composite monofilament against the two bacteria reaches more than 98%. Compared with Example 1, Comparative Example 2 did not add modified nano-rare earth-based antibacterial agent CeO2, and Comparative Example 3 did not add reactive antibacterial agent. The antibacterial rate was low, and the antibacterial effect against the two bacteria was poor. This indicates that nano-CeO2 and reactive antibacterial agent have a good synergistic antibacterial effect.

Claims

1. A high-strength composite antimicrobial monofilament, characterized by: The monofilament structure is a skin-core composite structure, the core layer is a blend of 10 parts of high-density polyethylene resin and 90 parts of ultra-high molecular weight polyethylene resin, and the skin layer is a blend of 70 parts of antibacterial modified high-density polyethylene resin and 30 parts of ultra-high molecular weight polyethylene resin; The antibacterial modified high-density polyethylene resin is prepared by uniformly mixing 70 parts of pre-irradiated high-density polyethylene resin, 28 parts of reactive antibacterial agent and 2 parts of modified nano-rare earth-based antibacterial agent CeO2, and then performing reactive grafting by a double screw, extruding and granulating; The modified nano-rare earth-based antibacterial agent CeO2 is prepared by surface chemical modification of nano CeO2 with double-bond silane; The pre-irradiated high-density polyethylene resin is prepared by pre-irradiating high-density polyethylene resin under a nitrogen atmosphere using an electron accelerator as an irradiation source, and the irradiation dose is 80-120 kGy.

2. A high strength composite antimicrobial monofilament according to claim 1, characterized in that: The ultra-high molecular weight polyethylene resin has a viscosity average molecular weight of 1 x 10 6 2 x 10 6 , a high-density polyethylene resin has a molecular weight of 4 x 10 4 8 x 10 4 , and a melt index of 5 to 12 g / 10 min.

3. A high strength composite antimicrobial monofilament according to claim 1, characterized in that: The reactive antibacterial agent is selected from one or more of allyltrimethylammonium chloride, methacryloyl ethyl sulfobetaine and 2-methacryloyloxyethyl carboxylbetaine, the average diameter of nano CeO2 is 10-30 nm, and the double-bond silane is selected from one or more of vinyltrimethoxysilane, allyltrimethoxysilane and 3-methacryloyloxypropyltrimethoxysilane.

4. A method for producing a high-strength composite antibacterial monofilament, characterized by, The method comprises the following steps: Step one: preparation of modified nano-rare earth-based antibacterial agent CeO2 Deionized water is added with a dispersant, and after being uniformly mixed, nano CeO2 is added, mechanically stirred and dispersed for 10-15 min, anhydrous ethanol is added, ultrasonic dispersion is performed for 10-20 min, then double-bond silane is added, the temperature is raised to 60℃, and reaction is performed for 3-4 h; after the reaction is completed, filtration is performed, the filter residue is repeatedly washed and dried to obtain the modified nano-rare earth-based antibacterial agent CeO2; Step two: preparation of pre-irradiated high-density polyethylene resin Under the protection of nitrogen, an electron accelerator is used to pre-irradiate high-density polyethylene resin to obtain the pre-irradiated high-density polyethylene resin; Step three: antibacterial modified high-density polyethylene resin After 70 parts of pre-irradiated high-density polyethylene resin, 28 parts of reactive antibacterial agent and 2 parts of modified nano-rare earth-based antibacterial agent CeO2 are uniformly mixed, reactive extrusion is performed by a double screw, and granulation is performed to obtain the antibacterial modified high-density polyethylene resin; Step four: preparation of skin layer and core layer blend After 70 parts of antibacterial modified high-density polyethylene resin and 30 parts of ultra-high molecular weight polyethylene resin are blended, a double screw extruder is used, the extrusion temperature is 270-290℃, water cooling and drying are performed, and then granulation is performed to obtain the skin layer blend; after 10 parts of high-density polyethylene resin and 90 parts of ultra-high molecular weight polyethylene resin are blended, a double screw extruder is used, the extrusion temperature is 270-290℃, water cooling and drying are performed, and then granulation is performed to obtain the core layer blend; Step five: preparation of high-strength composite antibacterial monofilament The skin layer and core layer blends prepared in the above steps are respectively subjected to single screw extrusion, metering by a metering pump, and then conveyed to a composite spinning assembly; after molding by a composite spinneret, cooling, stretching and heat setting, the high-strength composite antibacterial monofilament is obtained.

5. The method for preparing a high-strength composite antibacterial monofilament according to claim 4, characterized in that: In the step one, the mass ratio of deionized water to anhydrous ethanol is 80:20, the dispersing agent used is sodium dodecyl benzene sulfonate, the amount of dispersing agent is 0.5-1% of the mass of nano CeO2, and the amount of double bond silane is 5-8% of the mass of nano CeO2.

6. The method for preparing a high-strength composite antibacterial monofilament according to claim 4, characterized in that: In the step three, the temperature of the double-screw extruder is 190-220℃.

7. The method for preparing a high-strength composite antibacterial monofilament according to claim 4, characterized in that: In the step five, the mass ratio of the pump supply amount of the skin layer to the core layer is (10:90)-(30:70).

8. The method for preparing a high-strength composite antibacterial monofilament according to claim 4, characterized in that: In the step five, the spinning temperature of the composite spinning assembly is 290℃, the water cooling temperature is 20℃, the stretching process is a two-stage stretching process, the first-stage stretching temperature is 90℃, the first-stage stretching ratio is 8 times, the second-stage stretching temperature is 100℃, the second-stage stretching ratio is 1.12 times, and the heat setting temperature is 160℃.

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