Preparation method of wear-resistant antibacterial polyethylene plastic pipe

Abstract

The invention relates to the technical field of plastic pipes, and discloses a preparation method of a wear-resistant antibacterial polyethylene plastic pipe, and the wear-resistant antibacterial polyethylene plastic pipe is obtained by taking high-density polyethylene, thymol gemini quaternary ammonium salt modified carbon fiber, an aluminate coupling agent and the like as raw materials, uniformly mixing, extruding, granulating and mould pressing. The mechanical property of the polyethylene plastic pipe is synergistically enhanced by carbon fibers and polyphenylene sulfide contained in the polyethylene plastic pipe, and the antibacterial property of the polyethylene plastic pipe is synergistically improved by natural plant essential oil thymol and a quaternary ammonium salt antibacterial structure contained in the polyethylene plastic pipe, so that the prepared polyethylene plastic pipe has excellent wear resistance and antibacterial property; wide application prospects are realized in the field of pipes.

Description

Technical Field

[0001] The invention relates to the technical field of plastic pipes, in particular to a method for preparing a wear-resistant and antibacterial polyethylene plastic pipe. Background Art

[0002] High-density polyethylene resin has good low-temperature toughness, good chemical stability and electrical insulation, and is widely used. As a pipe material, it has the advantages of light weight and no pollution to the transported substances. It is widely used in water supply and sewage discharge, oil fields, and mine fine particle transportation.

[0003] During the use of traditional polyethylene pipes, the surface material will continue to wear out, and its wear resistance can no longer meet the needs of the current market. In addition, when the polyethylene pipe is used to transport water, although the water source has been disinfected, bacteria still exist. The bacteria form biofilms inside the pipes, which will deteriorate the water quality and endanger people's lives and property when using the water source.

[0004] As a high-strength, low-density, high-modulus ratio fiber material, carbon fiber has excellent wear resistance, heat resistance and other properties. Composite materials prepared from carbon fiber have been widely used in aerospace, automotive, sports and other industries. However, the surface of untreated carbon fiber precursor is smooth and inert, and the reaction activity is low, which leads to poor wetting and bonding between the carbon fiber and the matrix, and a weak interface bonding is formed between the carbon fiber and the matrix. However, the weak interface bonding is not conducive to the stress transfer between the matrix and the carbon fiber, so the excellent performance of the carbon fiber as a reinforcement itself cannot be fully utilized.

[0005] Thymol, also known as thymol, is a natural essential oil found in thyme. It has strong antibacterial and bactericidal activity against a variety of bacteria. However, thymol is volatile and lacks durability, and cannot form a stable antibacterial system.

[0006] For example, the patent with authorization announcement number CN102417650B discloses a wear-resistant cross-linked PE composite pipe and its preparation method. The invention uses polyethylene, carbon fiber, antioxidant, etc. as raw materials to prepare a polyethylene pipe. The prepared pipe has good wear resistance and heat resistance, but does not improve the antibacterial performance of the polyethylene pipe. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a method for preparing a wear-resistant and antibacterial polyethylene plastic pipe. The prepared polyethylene plastic pipe has excellent wear resistance and antibacterial properties.

[0008] The purpose of the present invention can be achieved through the following technical solutions: A preparation method of wear-resistant and antibacterial polyethylene plastic pipe, characterized in that the preparation method comprises the following steps: Mix the dried high-density polyethylene, thymol-based gemini quaternary ammonium salt modified carbon fiber, aluminate coupling agent, and polyphenylene sulfide evenly, then add them to a twin-screw extruder, extrude and granulate, and then mold through a flat vulcanizing machine to obtain the wear-resistant and antibacterial polyethylene plastic pipe.

[0009] Preferably, the dosage ratio of the high-density polyethylene, thymol-based gemini quaternary ammonium salt modified carbon fiber, aluminate coupling agent, and polyphenylene sulfide is 100 parts: (10-20) parts: (1-2) parts: (1-5) parts.

[0010] Preferably, the preparation method of the thymol-based gemini quaternary ammonium salt modified carbon fiber comprises the following steps: Step (1): Add thymol and epichlorohydrin to toluene solvent, stir and disperse, then add 20% sodium hydroxide aqueous solution and catalyst thereto, control the temperature at 80-90 °C, react for 3-5 h, after the reaction is completed, add cyclohexane thereto, stir and disperse, wash with saturated brine, separate the organic layer, dry, filter, distill under reduced pressure, and dry to obtain epoxy thymol; Further, in the step (1), the dosage ratio of thymol, epichlorohydrin, and catalyst is 1 mol: (1-1.2) mol: (0.3-0.5) mol, and the catalyst is one of tetrabutylammonium bromide and tetrabutylammonium chloride.

[0011] During the reaction process of step (1), under the catalysis of the catalyst, thymol and epichlorohydrin carry out an etherification reaction to obtain epoxy thymol, and the reaction route is: .

[0012] Step (2): Add epoxy thymol and tetramethylpropylenediamine to ethanol solvent, stir and disperse, then add hydrochloric acid thereto, react at 60-70 °C for 8-10 h, after the reaction is completed, distill, recrystallize with acetone, and dry to obtain terminal thymol-based gemini quaternary ammonium salt; Further, in the step (2), the dosage ratio of epoxy thymol, tetramethylpropylenediamine, and hydrochloric acid is (2-2.4) mol: 1 mol: (2.2-2.5) mol.

[0013] During the reaction process of step (2), by using the epoxy group contained in epoxy thymol and the tertiary amine structure in tetramethylpropylenediamine to carry out a ring-opening quaternization reaction, a terminal thymol-based gemini quaternary ammonium salt is obtained, and its structure contains a double thymol structure and a gemini quaternary ammonium salt structure, and its antibacterial performance is more excellent than that of a single thymol structure and a single quaternary ammonium salt structure. The reaction route is: 。

[0014] Step (3): Add hexamethylene diisocyanate and terminal thymol-based gemini quaternary ammonium salt into toluene solvent, stir and disperse, then add dibutyltin dilaurate into it, control the reaction temperature at 70 - 80 °C, react for 4 - 6 h. After the reaction is completed, remove toluene by rotary evaporation, wash with deionized water, and dry to obtain diisocyanate-terminated thymol-based gemini quaternary ammonium salt; Further, in the step (3), the dosage ratio of hexamethylene diisocyanate, terminal thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is (2 - 2.4) mol: 1 mol: (0.05 - 0.1) mol.

[0015] During the reaction process of step (3), under the catalysis of dibutyltin dilaurate, by controlling the dosage ratio of hexamethylene diisocyanate and terminal thymol-based gemini quaternary ammonium salt, the addition reaction occurs between the isocyanate group and the hydroxyl group, and they are linked through a urethane bond to obtain diisocyanate-terminated thymol-based gemini quaternary ammonium salt. Its reaction route is: 。

[0016] Step (4): Add oxidized carbon fiber into ethyl acetate solvent, ultrasonically disperse for 10 - 15 min, then add diisocyanate-terminated thymol-based gemini quaternary ammonium salt and dibutyltin dilaurate into it. Under a nitrogen atmosphere, react at 90 - 100 °C for 2 - 5 h. After the reaction is completed, cool to room temperature, wash with ethyl acetate, and dry to obtain thymol-based gemini quaternary ammonium salt-modified carbon fiber.

[0017] Further, in the step (4), the dosage ratio of oxidized carbon fiber, diisocyanate-terminated thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 1 g: (5 - 10) mmol: (0.2 - 0.5) mmol.

[0018] During the reaction process of step (4), under the catalysis of dibutyltin dilaurate, the hydroxyl group contained in the oxidized carbon fiber reacts with the isocyanate group contained in the diisocyanate-terminated thymol-based gemini quaternary ammonium salt to obtain thymol-based gemini quaternary ammonium salt-modified carbon fiber. In the product, on the one hand, using hexamethylene diisocyanate as a bridge, volatile thymol is confined on the surface of the carbon fiber to reduce the volatility of thymol. On the other hand, the thymol quaternary ammonium salt structure with a long-chain structure is an organic structure. Blending the prepared thymol-based gemini quaternary ammonium salt-modified carbon fiber with polyethylene, etc., can increase the compatibility between the carbon fiber and organic substances. Its reaction route is: 。

[0019] The beneficial effects of the present invention: (1) The present invention prepares a thymol-based gemini quaternary ammonium salt modified carbon fiber through a series of reactions. In this process, hexamethylene diisocyanate is used as a bridge to link the carbon fiber with the antibacterial structure, confining the antibacterial structure into the macromolecular structure formed by the carbon fiber. On the one hand, it improves the volatility of the natural antibacterial essential oil thymol, forms a stable antibacterial system with the quaternary ammonium salt structure, and enhances the persistence of its antibacterial property. On the other hand, due to the smooth surface of the carbon fiber and the poor interfacial binding force with organic substances, the diisocyanate-terminated thymol-based gemini quaternary ammonium salt is reacted with the carbon fiber, and they are linked through urethane active groups, improving the wettability between the fiber and the resin, enhancing the chemical bond force, that is, enhancing the compatibility with organic substances and improving the interfacial binding force with organic substances.

[0020] (2) The modified carbon fiber used in the present invention can be evenly dispersed in the polyethylene pipe and has good compatibility with the polyethylene substrate. During the wear process, the carbon fiber can bear most of the load, protecting the polyethylene pipe substrate from serious wear. As the frictional movement continues, the carbon fiber is ground into graphite particles with excellent lubricating effects, forming a wear-resistant transfer continuous film, further reducing the wear of the material and improving the wear resistance of the polyethylene pipe.

[0021] (3) The thymol-based gemini quaternary ammonium salt modified carbon fiber prepared in the present invention contains many polar structures (urethane structure, quaternary ammonium salt structure). When it is blended with polyethylene, etc., the polar structures can form hydrogen bonds with other polar structures, strengthening the binding between molecular chains. This can not only further enhance the compatibility between the carbon fiber and organic substances, but also when subjected to external forces, the external forces can be dispersed along the molecular chains to other molecular chains, synergistically improving its comprehensive mechanical properties with the carbon fiber. Specific Embodiments

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0023] Preparation method of oxidized carbon fiber: Place the polyacrylonitrile-based carbon fiber in acetone solution for extraction for 24 h, then wash it 3 times with deionized water and dry it. Add 5 g of the dried polyacrylonitrile-based carbon fiber to 100 mL of a concentrated phosphoric acid and concentrated nitric acid solution with a volume ratio of 1:3, react at 80 °C for 5 h, wash it with deionized water until neutral, and dry it to obtain oxidized carbon fiber. Example 1

[0024] Step (1): Add thymol and epichlorohydrin into toluene solvent, stir and disperse, then add 20% sodium hydroxide aqueous solution and tetrabutylammonium chloride catalyst, control the temperature at 80 °C, react for 4 h. After the reaction, add cyclohexane, stir and disperse, wash with saturated brine, separate the organic layer, dry, filter, distill under reduced pressure, and dry to obtain epoxy thymol; the dosage ratio of thymol, epichlorohydrin, and catalyst is 0.1 mol:0.1 mol:0.04 mol; Step (2): Add epoxy thymol and tetramethylpropylenediamine into ethanol solvent, stir and disperse, then add hydrochloric acid, react at 65 °C for 9 h. After the reaction, distill, recrystallize with acetone, and dry to obtain terminal thymol-based gemini quaternary ammonium salt; the dosage ratio of epoxy thymol, tetramethylpropylenediamine, and hydrochloric acid is 160 mmol:80 mmol:190 mmol; Step (3): Add hexamethylene diisocyanate and terminal thymol-based gemini quaternary ammonium salt into toluene solvent, stir and disperse, then add dibutyltin dilaurate, control the reaction temperature at 70 °C, react for 5 h. After the reaction, rotate and evaporate to remove toluene, wash with deionized water, and dry to obtain hexamethylene diisocyanate terminal thymol-based gemini quaternary ammonium salt; the dosage ratio of hexamethylene diisocyanate, terminal thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 110 mol:50 mmol:4 mmol; Step (4): Add oxidized carbon fiber into ethyl acetate solvent, ultrasonically disperse for 15 min, then add hexamethylene diisocyanate terminal thymol-based gemini quaternary ammonium salt and dibutyltin dilaurate, react at 90 °C for 4 h under nitrogen atmosphere. After the reaction, cool to room temperature, wash with ethyl acetate, and dry to obtain thymol-based gemini quaternary ammonium salt modified carbon fiber; the dosage ratio of oxidized carbon fiber, hexamethylene diisocyanate terminal thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 5 g:25 mmol:2.5 mmol; Step (5): By weight, mix 100 parts by weight of dried high-density polyethylene, 10 parts of thymol-based gemini quaternary ammonium salt modified carbon fiber, 1 part of aluminate coupling agent, and 1 part of polyphenylene sulfide evenly, then add them into a twin-screw extruder. The temperatures of the six zones are 120 °C, 180 °C, 200 °C, 220 °C, 180 °C, and 120 °C in sequence, the screw speed is 200 r / min, extrude and pelletize, then mold and press for 300 s by a flat vulcanizing machine with a mold temperature of 190 °C and a pressure of 5 MPa, and then cold press for 200 s to obtain wear-resistant and antibacterial polyethylene plastic pipes. Example Two

[0025] Step (1): Add thymol and epichlorohydrin into toluene solvent, stir and disperse them, then add 20% sodium hydroxide aqueous solution and tetrabutylammonium bromide catalyst, control the temperature at 85 °C, react for 4 h. After the reaction, add cyclohexane, stir and disperse, wash with saturated brine, separate the organic layer, dry, filter, distill under reduced pressure, and dry to obtain epoxy thymol; the dosage ratio of thymol, epichlorohydrin, and catalyst is 0.1 mol:0.12 mol:0.04 mol; Step (2): Add epoxy thymol and tetramethylpropylenediamine into ethanol solvent, stir and disperse them, then add hydrochloric acid, react at 70 °C for 9 h. After the reaction, distill, recrystallize with acetone, and dry to obtain terminal thymol-based gemini quaternary ammonium salt; the dosage ratio of epoxy thymol, tetramethylpropylenediamine, and hydrochloric acid is 170 mmol:80 mmol:176 mmol; Step (3): Add hexamethylene diisocyanate and terminal thymol-based gemini quaternary ammonium salt into toluene solvent, stir and disperse them, then add dibutyltin dilaurate, control the reaction temperature at 75 °C, react for 5 h. After the reaction, remove toluene by rotary evaporation, wash with deionized water, and dry to obtain diisocyanate-terminated thymol-based gemini quaternary ammonium salt; the dosage ratio of hexamethylene diisocyanate, terminal thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 100 mol:50 mmol:3 mmol; Step (4): Add oxidized carbon fiber into ethyl acetate solvent, ultrasonically disperse for 10 min, then add diisocyanate-terminated thymol-based gemini quaternary ammonium salt and dibutyltin dilaurate, react at 100 °C for 3 h under a nitrogen atmosphere. After the reaction, cool to room temperature, wash with ethyl acetate, and dry to obtain thymol-based gemini quaternary ammonium salt-modified carbon fiber; the dosage ratio of oxidized carbon fiber, diisocyanate-terminated thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 5 g:35 mmol:1 mmol; Step (5): By weight, mix 100 parts by weight of dried high-density polyethylene, 14 parts of thymol-based gemini quaternary ammonium salt-modified carbon fiber, 2 parts of aluminate coupling agent, and 2 parts of polyphenylene sulfide evenly, then add them into a twin-screw extruder. The temperatures of the six zones are 120 °C, 180 °C, 200 °C, 220 °C, 180 °C, and 120 °C in sequence, the screw speed is 200 r / min, extrude and pelletize. Then, use a flat vulcanizing machine with a molding temperature of 190 °C and a pressure of 5 MPa to mold for 300 s, and then cold press for 200 s to obtain wear-resistant and antibacterial polyethylene plastic pipes. Example 3

[0026] Step (1): Add thymol and epichlorohydrin into toluene solvent, stir and disperse, then add 20% sodium hydroxide aqueous solution and tetrabutylammonium chloride catalyst, control the temperature at 85°C, react for 5 h. After the reaction, add cyclohexane, stir and disperse, wash with saturated brine, separate the organic layer, dry, filter, distill under reduced pressure, and dry to obtain epoxy thymol; the dosage ratio of thymol, epichlorohydrin, and catalyst is 0.1 mol:0.1 mol:0.04 mol; Step (2): Add epoxy thymol and tetramethylpropylenediamine into ethanol solvent, stir and disperse, then add hydrochloric acid, react at 65°C for 9 h. After the reaction, distill, recrystallize with acetone, and dry to obtain terminal thymol-based gemini quaternary ammonium salt; the dosage ratio of epoxy thymol, tetramethylpropylenediamine, and hydrochloric acid is 192 mmol:80 mmol:200 mmol; Step (3): Add hexamethylene diisocyanate and terminal thymol-based gemini quaternary ammonium salt into toluene solvent, stir and disperse, then add dibutyltin dilaurate, control the reaction temperature at 75°C, react for 5 h. After the reaction, remove toluene by rotary evaporation, wash with deionized water, and dry to obtain diisocyanate-terminated thymol-based gemini quaternary ammonium salt; the dosage ratio of hexamethylene diisocyanate, terminal thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 100 mol:50 mmol:2.5 mmol; Step (4): Add oxidized carbon fiber into ethyl acetate solvent, ultrasonically disperse for 15 min, then add diisocyanate-terminated thymol-based gemini quaternary ammonium salt and dibutyltin dilaurate, react at 90°C for 5 h under nitrogen atmosphere. After the reaction, cool to room temperature, wash with ethyl acetate, and dry to obtain thymol-based gemini quaternary ammonium salt modified carbon fiber; the dosage ratio of oxidized carbon fiber, diisocyanate-terminated thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 5 g:40 mmol:2.5 mmol; Step (5): By weight, mix 100 parts by weight of dried high-density polyethylene, 16 parts of thymol-based gemini quaternary ammonium salt modified carbon fiber, 2 parts of aluminate coupling agent, and 3 parts of polyphenylene sulfide evenly, then add them into a twin-screw extruder. The temperatures of the six zones are 120°C, 180°C, 200°C, 220°C, 180°C, and 120°C in sequence, the screw speed is 200 r / min, extrude and pelletize. Then, use a flat vulcanizing machine with a molding temperature of 190°C and a pressure of 5 MPa to mold for 300 s, and then cold press for 200 s to obtain wear-resistant and antibacterial polyethylene plastic pipes. Example 4

[0027] Step (1): Add thymol and epichlorohydrin into toluene solvent, stir and disperse, then add 20% sodium hydroxide aqueous solution and tetrabutylammonium bromide catalyst, control the temperature at 80 °C, react for 5 h. After the reaction, add cyclohexane, stir and disperse, wash with saturated brine, separate the organic layer, dry, filter, distill under reduced pressure, and dry to obtain epoxy thymol; the dosage ratio of thymol, epichlorohydrin, and catalyst is 0.1 mol:0.12 mol:0.05 mol; Step (2): Add epoxy thymol and tetramethylpropylenediamine into ethanol solvent, stir and disperse, then add hydrochloric acid, react at 70 °C for 8 h. After the reaction, distill, recrystallize with acetone, and dry to obtain terminal thymol-based gemini quaternary ammonium salt; the dosage ratio of epoxy thymol, tetramethylpropylenediamine, and hydrochloric acid is 180 mmol:80 mmol:200 mmol; Step (3): Add hexamethylene diisocyanate and terminal thymol-based gemini quaternary ammonium salt into toluene solvent, stir and disperse, then add dibutyltin dilaurate, control the reaction temperature at 70 °C, react for 6 h. After the reaction, rotary evaporate to remove toluene, wash with deionized water, and dry to obtain hexamethylene diisocyanate-terminated thymol-based gemini quaternary ammonium salt; the dosage ratio of hexamethylene diisocyanate, terminal thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 110 mol:50 mmol:4 mmol; Step (4): Add oxidized carbon fiber into ethyl acetate solvent, ultrasonically disperse for 15 min, then add hexamethylene diisocyanate-terminated thymol-based gemini quaternary ammonium salt and dibutyltin dilaurate, react at 95 °C for 4 h under a nitrogen atmosphere. After the reaction, cool to room temperature, wash with ethyl acetate, and dry to obtain thymol-based gemini quaternary ammonium salt modified carbon fiber; the dosage ratio of oxidized carbon fiber, hexamethylene diisocyanate-terminated thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 5 g:50 mmol:2 mmol; Step (5): By weight, mix 100 parts by weight of dry high-density polyethylene, 18 parts of thymol-based gemini quaternary ammonium salt modified carbon fiber, 2 parts of aluminate coupling agent, and 4 parts of polyphenylene sulfide evenly, then add them into a twin-screw extruder. The temperatures of the six zones are 120 °C, 180 °C, 200 °C, 220 °C, 180 °C, and 120 °C in sequence, the screw speed is 200 r / min, extrude and pelletize. Then, use a flat vulcanizing machine with a molding temperature of 190 °C and a pressure of 5 MPa to mold for 300 s, and then cold press for 200 s to obtain wear-resistant and antibacterial polyethylene plastic pipes. Example Five

[0028] Step (1): Add thymol and epichlorohydrin into toluene solvent, stir and disperse them, then add 20% sodium hydroxide aqueous solution and tetrabutylammonium bromide catalyst, control the temperature at 90 °C, react for 3 h. After the reaction, add cyclohexane, stir and disperse, wash with saturated brine, separate the organic layer, dry, filter, distill under reduced pressure, and dry to obtain epoxy thymol; the dosage ratio of thymol, epichlorohydrin, and catalyst is 0.1 mol: 0.11 mol: 0.03 mol; Step (2): Add epoxy thymol and tetramethylpropylenediamine into ethanol solvent, stir and disperse them, then add hydrochloric acid, react at 60 °C for 10 h. After the reaction, distill, recrystallize with acetone, and dry to obtain terminal thymol-based gemini quaternary ammonium salt; the dosage ratio of epoxy thymol, tetramethylpropylenediamine, and hydrochloric acid is 160 mmol: 80 mmol: 180 mmol; Step (3): Add hexamethylene diisocyanate and terminal thymol-based gemini quaternary ammonium salt into toluene solvent, stir and disperse them, then add dibutyltin dilaurate, control the reaction temperature at 80 °C, react for 4 h. After the reaction, remove toluene by rotary evaporation, wash with deionized water, and dry to obtain diisocyanate-terminated thymol-based gemini quaternary ammonium salt; the dosage ratio of hexamethylene diisocyanate, terminal thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 120 mol: 50 mmol: 5 mmol; Step (4): Add oxidized carbon fiber into ethyl acetate solvent, ultrasonically disperse for 10 min, then add diisocyanate-terminated thymol-based gemini quaternary ammonium salt and dibutyltin dilaurate, react at 100 °C for 2 h under a nitrogen atmosphere. After the reaction, cool to room temperature, wash with ethyl acetate, and dry to obtain thymol-based gemini quaternary ammonium salt-modified carbon fiber; the dosage ratio of oxidized carbon fiber, diisocyanate-terminated thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 5 g: 50 mmol: 1.5 mmol; Step (5): By weight, mix 100 parts by weight of dry high-density polyethylene, 20 parts of thymol-based gemini quaternary ammonium salt-modified carbon fiber, 1 part of aluminate coupling agent, and 5 parts of polyphenylene sulfide evenly, then add them into a twin-screw extruder. The temperatures of the six zones are 120 °C, 180 °C, 200 °C, 220 °C, 180 °C, and 120 °C in sequence, the screw speed is 200 r / min, extrude and pelletize, and then mold and press for 300 s by a flat vulcanizing machine with a molding temperature of 190 °C and a pressure of 5 MPa, and then cold press for 200 s to obtain wear-resistant and antibacterial polyethylene plastic pipes.

[0029] Comparative Example 1 The difference between this comparative example and Example 1 is that: in step (5), thymol is used instead of thymol-based gemini quaternary ammonium salt-modified carbon fiber.

[0030] Comparative Example 2 The difference between this comparative example and Example 1 is that: in step (5), carbon fiber is used instead of thymol-based gemini quaternary ammonium salt modified carbon fiber.

[0031] Refer to the standard method of GB / T 31402-2023 to test the antibacterial rate, and the test strain is Escherichia coli ATCC8739.

[0032] Table 1: Test results of antibacterial properties of each example and comparative example

[0033] As can be seen from the above table, the polyethylene pipe prepared by the present invention has excellent antibacterial properties, and the highest antibacterial rate can reach 99.9%. From Example 1 and Comparative Example 1, it can be seen that due to the volatility of thymol, when unmodified thymol is directly added to the polyethylene pipe, due to its volatility, thymol volatilizes and is lost during the preparation of the polyethylene pipe, and the purpose of excellent antibacterial properties cannot be achieved. However, the grafted thymol is firmly fixed on the carbon fiber and can cooperate with the quaternary ammonium salt structure to antibacterial, improving the antibacterial properties of the polyethylene pipe, and the highest antibacterial rate reaches 99.9%.

[0034] Refer to the standard method of GB / T 3960-2016 and use a microcomputer-controlled friction testing machine to test the wear resistance, and the test load is 150N.

[0035] Refer to the standard method of GB / T1040.2-2006 and use an electronic universal testing machine to test the tensile mechanical properties, and the tensile rate is 50mm / min.

[0036] Table 2: Test results of mechanical properties of each example and comparative example

[0037] The smaller the wear rate, the better the wear resistance. As can be seen from Table 2, the polyethylene plastic pipe prepared by the present invention has good wear resistance. And from Comparative Example 2 and Example 1, it can be seen that the interfacial bonding force between the modified carbon fiber and the polyethylene substrate is stronger, which can limit the movement of the polyethylene molecular chain, disperse the stress received on the surface of the composite material during friction, has a higher load-bearing capacity, can reduce the wear degree of the material, and improve the wear resistance and tensile properties.

[0038] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should all belong to the protection scope of the present invention.

Claims

1. A preparation method of wear-resistant and antibacterial polyethylene plastic pipe, characterized in that, The preparation method comprises the following steps: Mix the dry high-density polyethylene, thymol-based gemini quaternary ammonium salt modified carbon fiber, aluminate coupling agent, and polyphenylene sulfide evenly, then add them into a twin-screw extruder, extrude and granulate, and then carry out compression molding through a flat vulcanizing machine to obtain wear-resistant and antibacterial polyethylene plastic pipes; The preparation method of the thymol-based gemini quaternary ammonium salt modified carbon fiber comprises the following steps: Add the oxidized carbon fiber into an ethyl acetate solvent, ultrasonically disperse for 10 - 15 min, then add diisocyanate-terminated thymol-based gemini quaternary ammonium salt and dibutyltin dilaurate thereto, and react at 90 - 100 °C for 2 - 5 h under a nitrogen atmosphere. After the reaction, cool to room temperature, wash with ethyl acetate, and dry to obtain the thymol-based gemini quaternary ammonium salt modified carbon fiber.

2. The preparation method of the wear-resistant and antibacterial polyethylene plastic pipe according to claim 1, wherein The weight part usage ratio of the high-density polyethylene, thymol-based gemini quaternary ammonium salt modified carbon fiber, aluminate coupling agent, and polyphenylene sulfide is 100 parts : (10 - 20) parts : (1 - 2) parts : (1 - 5) parts.

3. The preparation method of the wear-resistant and antibacterial polyethylene plastic pipe according to claim 1, characterized in that, The usage ratio of the oxidized carbon fiber, diisocyanate-terminated thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is 1 g : (5 - 10) mmol : (0.2 - 0.5) mmol.

4. The preparation method of the wear-resistant and antibacterial polyethylene plastic pipe according to claim 1, characterized in that, The preparation method of the diisocyanate-terminated thymol-based gemini quaternary ammonium salt comprises the following steps: Step (1), add thymol and epichlorohydrin into a toluene solvent, stir and disperse, then add a 20% sodium hydroxide aqueous solution and a catalyst thereto, control the temperature at 80 - 90 °C, react for 3 - 5 h. After the reaction, add cyclohexane thereto, stir and disperse, wash with saturated brine, separate the organic layer, dry, filter, carry out vacuum distillation, and dry to obtain epoxy thymol; Step (2), add epoxy thymol and tetramethylpropylenediamine into an ethanol solvent, stir and disperse, then add hydrochloric acid thereto, react at 60 - 70 °C for 8 - 10 h. After the reaction, distill, recrystallize with acetone, and dry to obtain terminal thymol-based gemini quaternary ammonium salt; Step (3), add hexamethylene diisocyanate and terminal thymol-based gemini quaternary ammonium salt into a toluene solvent, stir and disperse, then add dibutyltin dilaurate thereto, control the reaction temperature at 70 - 80 °C, react for 4 - 6 h. After the reaction, rotate and evaporate to remove toluene, wash with deionized water, and dry to obtain diisocyanate-terminated thymol-based gemini quaternary ammonium salt.

5. The preparation method of the wear-resistant and antibacterial polyethylene plastic pipe according to claim 4, characterized in that, In the step (1), the usage ratio of thymol, epichlorohydrin, and the catalyst is 1 mol : (1 - 1.2) mol : (0.3 - 0.5) mol.

6. The preparation method of the wear-resistant and antibacterial polyethylene plastic pipe according to claim 4, characterized in that, In the step (1), the catalyst is one of tetrabutylammonium bromide and tetrabutylammonium chloride.

7. The preparation method of the wear-resistant and antibacterial polyethylene plastic pipe according to claim 4, characterized in that, In the step (2), the usage ratio of epoxy thymol, tetramethylpropylenediamine, and hydrochloric acid is (2 - 2.4) mol : 1 mol : (2.2 - 2.5) mol.

8. The preparation method of the wear-resistant and antibacterial polyethylene plastic pipe according to claim 4, characterized in that In the step (3), the usage ratio of hexamethylene diisocyanate, terminal thymol-based gemini quaternary ammonium salt, and dibutyltin dilaurate is (2 - 2.4) mol : 1 mol : (0.05 - 0.1) mol.

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