Antibacterial conductive PET composite material and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials, and provides an antibacterial conductive PET composite material and a preparation method thereof.The PET composite material is prepared from, by weight, 95-105 parts of PET matrix, 10-16 parts of functional filler and 0.1-0.5 part of antioxidant, and the functional filler is nano-copper coated polydopamine-carbon nanotube composite filler. The PET composite material prepared by the invention has excellent antibacterial property and electrical conductivity, and has wide popularization and application prospects.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and in particular to an antibacterial conductive PET composite material and a preparation method thereof. Background Art

[0002] Polyethylene terephthalate (PET) is a widely used polymer polyester resin. PET has advantages such as good fatigue resistance, good heat resistance and excellent dimensional stability. However, PET's electrical conductivity and antibacterial properties are average, which limits the application of PET materials in some specific fields, such as medical devices and packaging, flexible electronic devices, and materials for new energy lithium batteries.

[0003] To expand the application areas of PET materials, researchers are continuously improving their preparation methods. For example, patent application CN118703025A discloses an antibacterial conductive PET composite material and its preparation method. The composite material is composed of the following components by weight: 80-100 parts PET, 10-16 parts antibacterial conductive filler, and 0.1-0.5 parts antioxidant. The preparation method for the antibacterial conductive filler is as follows: gallic acid, dopamine hydrochloride, a catalyst, a crosslinking agent, an organic solvent, fullerene, and water are uniformly mixed, and the mixture is reacted at 70-90°C for 6-8 hours. The reaction solution is filtered, washed, and dried to obtain the antibacterial conductive filler. However, the fullerene used in this method is relatively expensive, and the conductivity of fullerene depends on π-π stacking. Subsequent processing of the PET material may disrupt this stacking structure, resulting in a decrease in the uniformity of the conductive properties.

[0004] For example, the patent application document with publication number CN113897701A discloses a production method for preparing PET fibers using recycled plastic bottles, wherein dopamine hydrochloride is added to deionized water, magnetically stirred for 5 minutes, then poured into an ethanol aqueous solution, ammonia is added dropwise, and magnetically stirred for 20 hours to obtain a reaction solution, which is then centrifuged, washed, and a polyhydroxy compound is added. The mixture is stirred for 30 minutes and then freeze-dried for 10 hours to obtain a composite antimicrobial agent; by weight, 55-75 parts of recycled plastic bottles, 12-25 parts of the composite antimicrobial agent, 5-10 parts of nanoparticles, and 0.1-0.3 parts of an antioxidant are mixed uniformly, then added to a twin-screw extruder for extrusion and granulation to obtain a recycled masterbatch, which is then filtered through a spinning manifold and spun into bundles to obtain PET fibers. However, during the preparation process of the above method, the composite antimicrobial agent may agglomerate in the PET matrix, affecting its dispersibility and, in turn, its antimicrobial properties. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides an antibacterial conductive PET composite material and a preparation method thereof, which has excellent antibacterial properties and electrical conductivity.

[0006] To achieve the above objectives, the present invention adopts the following technical means:

[0007] The first aspect of the present invention provides an antibacterial conductive PET composite material, comprising the following raw materials in parts by weight:

[0008] 95 to 105 parts of PET matrix, 10 to 16 parts of functional filler, 0.1 to 0.5 parts of antioxidant, wherein:

[0009] The functional filler is a nano-copper-coated polydopamine-carbon nanotube composite filler.

[0010] Furthermore, the functional filler presents a three-dimensional network structure.

[0011] Furthermore, the raw materials of the functional filler include dopamine hydrochloride, ammonia water, carbon nanotubes and copper nitrate, which are prepared by oxidative self-polymerization reaction and photochemical reduction reaction in sequence.

[0012] Furthermore, the antioxidant is selected from at least one of tris(2,4-di-tert-butyl)phenyl phosphite, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0013] A second aspect of the present invention provides a method for preparing an antibacterial conductive PET composite material, comprising the following steps:

[0014] (1) Using dopamine hydrochloride, ammonia, carbon nanotubes and copper nitrate as raw materials, functional fillers were prepared by oxidative self-polymerization and photochemical reduction reactions.

[0015] (2) The functional filler, the PET matrix and the antioxidant are mixed to obtain a mixture, and the mixture is extruded and granulated to prepare an antibacterial conductive PET composite material.

[0016] Furthermore, step (1) further includes:

[0017] (a) preparing tris hydrochloride buffer;

[0018] (b) mixing tris(hydroxymethylaminomethane) hydrochloride buffer, dopamine hydrochloride, ammonia water, carbon nanotubes, anhydrous ethanol, and deionized water, performing an oxidative self-polymerization reaction in a water bath, filtering, washing, and drying to obtain polydopamine-carbon nanotubes;

[0019] (c) Polydopamine-carbon nanotubes, copper nitrate, anhydrous ethanol, and deionized water are mixed, subjected to photochemical reduction reaction under laser irradiation, filtered, washed, and dried to obtain a functional filler.

[0020] Furthermore, in step (b), the mass ratio of tris(hydroxymethyl)aminomethane hydrochloride buffer, dopamine hydrochloride, ammonia water, carbon nanotubes, anhydrous ethanol and deionized water is (30-40): (24-28): (28-32): (30-36): (60-70): (90-110).

[0021] Furthermore, in step (c), the mass ratio of copper nitrate, polydopamine-carbon nanotubes, anhydrous ethanol and deionized water is (30-36): (32-36): (50-58): (80-90).

[0022] Furthermore, in step (c), the laser wavelength of the laser irradiation environment is 580 nm, and the laser emission power is 1.2 mw / cm 2 .

[0023] Furthermore, in step (c), the temperature of the laser irradiation environment is 40°C to 50°C.

[0024] The beneficial technical effects of the present invention are:

[0025] The present invention uses dopamine hydrochloride, ammonia, carbon nanotubes, and copper nitrate as raw materials to prepare a functional filler. During the preparation process, dopamine hydrochloride is dissolved in deionized water and decomposed to produce dopamine DA. Dopamine then undergoes oxidative self-polymerization in the alkaline environment provided by tris(hydroxymethyl)aminomethane hydrochloride) buffer and ammonia to form polydopamine PDA. PDA then adsorbs onto the surface of the carbon nanotubes through π-π stacking and hydrogen bonding, forming a uniform polydopamine coating, thereby producing polydopamine-carbon nanotubes.

[0026] At the same time, PDA has catechol groups that can be adsorbed on the surface of bacterial cell walls, destroying the cell wall structure and the permeability of the cell membrane, thereby achieving a bactericidal effect. Therefore, it can give functional fillers antibacterial properties. At the same time, PDA has polar groups (-OH, -NH2) that can reduce the agglomeration of carbon nanotubes (with high conductivity), allowing them to be evenly dispersed in the PET matrix, forming a more continuous conductive path. The introduction of PDA can also improve the interfacial compatibility between the functional filler and the PET matrix, making the functional filler more dispersed in the PET matrix, thereby making the PET composite material have better conductivity.

[0027] Secondly, in the laser irradiation environment, the photon energy provided by the laser is absorbed by the polydopamine-carbon nanotubes, stimulating the electron transition on its surface, thereby acting as an electron donor and transferring electrons to the Cu in the copper nitrate. 2+ , Cu2+ A photochemical reduction reaction occurs to produce copper atoms; the reduced copper atoms nucleate on the surface of the polydopamine-carbon nanotubes and gradually grow into nano-copper, which is ultimately coated on the polydopamine-carbon nanotubes to form a functional filler with a three-dimensional network structure. The present invention utilizes this functional filler to construct a conductive path with a three-dimensional network structure in the PET composite material, thereby improving its conductive performance.

[0028] Moreover, the nano-copper in the functional filler can combine with the bacterial protein to coagulate the protein, restrict bacterial activity, achieve the purpose of sterilization, and ultimately improve the antibacterial properties of the PET composite material.

[0029] Therefore, the PET composite material prepared by the present invention has excellent antibacterial properties and electrical conductivity, and has broad promotion and application prospects.

[0030] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. DETAILED DESCRIPTION

[0031] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. It should be understood that certain features of the invention (described in the context of separate embodiments for clarity) may also be provided in combination in a single embodiment. Conversely, multiple features of the invention (described in the context of a single embodiment for brevity) may also be provided separately or in any suitable combination or, where appropriate, in any other described embodiment of the invention. Certain features described in the context of various embodiments will not be considered essential features of those embodiments unless the embodiment is inoperable without those elements. The invention is further described below through specific examples, but it should be noted that the specific process conditions and results described in the examples of the invention are only for illustration of the invention and are not intended to limit the scope of protection of the invention. Any equivalent changes or modifications made in accordance with the spirit and substance of the invention should be included within the scope of protection of the invention.

[0032] First of all, it should be noted that the raw materials used in the present invention are all commercially available, as follows:

[0033] PET substrate (model 008L): Aclo, Canada; dopamine hydrochloride: Jinan Hongshengdi New Materials Co., Ltd.; Tris (trishydroxymethylaminomethane) solution: Hubei Kewode Chemical Co., Ltd.; ammonia: Luoyang Hongchang Industry and Trade Co., Ltd.; anhydrous ethanol: Shanghai Fangye Chemical Co., Ltd.; HCL (hydrochloric acid) solution: Yangzhou Huafu Chemical Co., Ltd.; carbon nanotubes: Shanghai Lishuo Composite Materials Co., Ltd.; deionized water: Shanghai Lanyi Environmental Protection Technology Co., Ltd.

[0034] Antioxidants (model Irganox 168 (tris(2,4-di-tert-butyl)phenyl phosphite), Irganox 1010 (pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), Irganox 1330 (1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene): BASF, Germany.

[0035] The present invention provides an antibacterial conductive PET composite material, comprising the following raw materials in parts by weight:

[0036] 95 to 105 parts of PET matrix, 10 to 16 parts of functional filler, and 0.1 to 0.5 parts of antioxidant, wherein the functional filler is a nano-copper-coated polydopamine-carbon nanotube composite filler, and the functional filler presents a three-dimensional network structure.

[0037] Furthermore, the raw materials of the functional filler include dopamine hydrochloride, ammonia water, carbon nanotubes and copper nitrate, which are prepared by oxidative self-polymerization reaction and photochemical reduction reaction in sequence.

[0038] Furthermore, the antioxidant is selected from at least one of tris(2,4-di-tert-butyl)phenyl phosphite, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0039] The present invention provides a method for preparing an antibacterial conductive PET composite material, comprising the following steps:

[0040] (1) Preparation of Tris-HCl buffer:

[0041] Mix the Tris solution and the HCl solution in a flask, and stir the mixture at room temperature for 6 to 8 hours to prepare a Tris-HCl buffer solution, wherein:

[0042] The mass ratio of Tris solution to HCl solution is (30-38): (40-50).

[0043] (2) Mix Tris-HCl buffer, dopamine hydrochloride, ammonia water, carbon nanotubes, anhydrous ethanol and deionized water in a flask, and carry out oxidative self-polymerization reaction in a water bath heating environment of 50℃~70℃ for 8h~12h, filter and wash, and dry in an oven at 70℃~80℃ for 4h~8h to obtain polydopamine-carbon nanotubes, wherein,

[0044] The mass ratio of Tris-HCl buffer, dopamine hydrochloride, ammonia water, carbon nanotubes, anhydrous ethanol and deionized water is (30~40): (24~28): (28~32): (30~36): (60~70): (90~110).

[0045] (3) Polydopamine-carbon nanotubes, copper nitrate, anhydrous ethanol and deionized water are mixed and placed in a flask, and a photochemical reduction reaction is carried out under a laser irradiation environment. The reaction is stirred for 12 hours to 16 hours, filtered and washed, and dried in an oven at 60°C to 80°C for 4 hours to 6 hours to obtain a functional filler, wherein:

[0046] The mass ratio of copper nitrate, polydopamine-carbon nanotubes, anhydrous ethanol and deionized water is (30~36): (32~36): (50~58): (80~90);

[0047] The laser wavelength of the laser irradiation environment is 580nm, and the laser emission power is 1.2 mw / cm 2 ;

[0048] The temperature of the laser irradiation environment is 40℃~50℃.

[0049] (4) Weigh the following weight parts: 95 to 105 parts of PET matrix, 10 to 16 parts of functional filler, and 0.1 to 0.5 parts of antioxidant, mix and stir evenly to obtain a mixture, wherein:

[0050] The antioxidant is at least one selected from tris(2,4-di-tert-butyl)phenyl phosphite, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene;

[0051] The mixed material is then put into the hopper of a twin-screw extruder for extrusion and granulation to obtain an antibacterial conductive PET composite material. The twin-screw extruder includes six temperature zones arranged in sequence, with a temperature of 240°C to 260°C in zone one, a temperature of 280°C to 300°C in zone two, a temperature of 280°C to 300°C in zone three, a temperature of 280°C to 300°C in zone four, a temperature of 280°C to 300°C in zone five, a temperature of 280°C to 300°C in zone six, a die head temperature of 280°C to 300°C, and a screw speed of 200 rpm to 280 rpm.

[0052] Furthermore, step (3) of the present application also contains a polypyrrole-chitosan polymer (PPy-CS polymer), and the preparation process is as follows:

[0053] (a) Chitosan, carboxylated polypyrrole, and crosslinker glutaraldehyde were blended and grafted under UV light to form PPy-CS polymer.

[0054] (b) Copper nitrate, polydopamine-carbon nanotubes, PPy-CS polymer, anhydrous ethanol and deionized water are mixed in a flask, and a photochemical reduction reaction and a Schiff base reaction are carried out under laser irradiation. The mixture is stirred for 16 to 20 hours, filtered and washed, and dried in an oven at 60° C. to 80° C. for 4 to 6 hours to obtain a functional filler, wherein:

[0055] The mass ratio of copper nitrate, polydopamine-carbon nanotubes, PPy-CS polymer, anhydrous ethanol and deionized water is (30~36): (42~46): (18~25): (50~58): (80~90);

[0056] The laser wavelength of the laser irradiation environment is 580nm, and the laser emission power is 1.2 mw / cm 2 ;

[0057] The temperature of the laser irradiation environment is 40℃~50℃.

[0058] Furthermore, the present application utilizes natural antibacterial agents to graft with conductive polymer carboxylated polypyrrole to obtain PPy-CS polymer, wherein the carboxylated polypyrrole can provide an electron conduction path through its π-π conjugated structure, and the amino group of chitosan can participate in the protonation reaction to form a double conductive network.

[0059] Furthermore, under laser irradiation, the quinone group of polydopamine can also combine with the amino group of chitosan through a Schiff base reaction. Therefore, the functional filler presents a complex three-dimensional network structure. Nanocopper grows on polydopamine-carbon nanotubes, and the PPy-CS polymer is firmly bound to the polydopamine-carbon nanotubes, which further enhances the antibacterial and electrical conductivity of the functional filler.

[0060] The present invention is described in detail below by way of specific examples. It should also be understood that the following examples are only used to specifically illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the scope of protection of the present invention. The specific process parameters and the like in the following examples are only examples within a suitable range, and those skilled in the art can make selections within a suitable range through the description herein, and are not to be limited to the specific numerical values exemplified below.

[0061] Example 1

[0062] (1) Prepare Tris-HCl buffer:

[0063] 300 g of Tris solution and 400 g of HCl solution were mixed in a flask and stirred at room temperature for 6 h to prepare a Tris-HCl buffer solution;

[0064] (2) 300 g of Tris-HCl buffer, 240 g of dopamine hydrochloride, 280 g of ammonia water, 300 g of carbon nanotubes, 600 g of anhydrous ethanol and 900 g of deionized water were mixed in a flask and subjected to oxidative self-polymerization reaction in a 50 °C water bath for 8 h. The mixture was filtered and washed, and dried in an oven at 70 °C for 4 h to obtain polydopamine-carbon nanotubes (PDA-carbon nanotubes).

[0065] (3) 300 g of copper nitrate, 320 g of PDA-carbon nanotubes, 500 g of anhydrous ethanol and 800 g of deionized water were mixed and placed in a flask, and a photochemical reduction reaction was carried out under laser irradiation. The mixture was stirred for 12 h, filtered and washed, and dried in an oven at 60 ° C for 4 h to obtain a functional filler, wherein:

[0066] The laser wavelength of the laser irradiation environment is 580nm, and the laser emission power is 1.2 mw / cm 2 ;

[0067] The temperature of the laser irradiation environment was 40°C;

[0068] (4) Weigh the following weight parts: 95 parts of PET matrix, 10 parts of functional filler, and 0.1 parts of Irganox 1010, mix and stir evenly to obtain a mixture;

[0069] The mixed material is then put into the hopper of a twin-screw extruder for extrusion and granulation to obtain an antibacterial conductive PET composite material, wherein the twin-screw extruder includes six temperature zones arranged in sequence, with a temperature of 240°C in zone 1, a temperature of 280°C in zone 2, a temperature of 280°C in zone 3, a temperature of 280°C in zone 4, a temperature of 280°C in zone 5, a temperature of 280°C in zone 6, a head temperature of 280°C, and a screw speed of 200 r / min.

[0070] Example 2

[0071] (1) Prepare Tris-HCl buffer:

[0072] Mix 380g of Tris solution and 500g of HCl solution in a flask and stir at room temperature for 8h to prepare Tris-HCl buffer;

[0073] (2) 400 g of Tris-HCl buffer, 280 g of dopamine hydrochloride, 320 g of ammonia water, 360 g of carbon nanotubes, 700 g of anhydrous ethanol and 1.1 kg of deionized water were mixed in a flask and subjected to oxidative self-polymerization reaction in a 70 °C water bath for 12 h. The mixture was filtered and washed, and dried in an 80 °C oven for 8 h to obtain PDA-carbon nanotubes.

[0074] (3) 360 g of copper nitrate, 360 g of PDA-carbon nanotubes, 580 g of anhydrous ethanol and 900 g of deionized water were mixed in a flask and subjected to a photochemical reduction reaction under laser irradiation. The mixture was stirred for 16 h, filtered and washed, and dried in an oven at 80 ° C for 6 h to obtain a functional filler, wherein:

[0075] The laser wavelength of the laser irradiation environment is 580nm, and the laser emission power is 1.2 mw / cm 2 ;

[0076] The temperature of the laser irradiation environment is 50°C;

[0077] (4) Weigh the following weight parts: 105 parts of PET matrix, 16 parts of functional filler, 0.1 parts of Irganox 1010, and 0.2 parts of Irganox 168, mix and stir evenly to obtain a mixture;

[0078] The mixed material is then put into the hopper of a twin-screw extruder for extrusion and granulation to obtain an antibacterial conductive PET composite material. The twin-screw extruder includes six temperature zones arranged in sequence, with a temperature of 260°C in zone one, a temperature of 300°C in zone two, a temperature of 300°C in zone three, a temperature of 300°C in zone four, a temperature of 300°C in zone five, a temperature of 300°C in zone six, a head temperature of 300°C, and a screw speed of 280 r / min.

[0079] Example 3

[0080] (1) Prepare Tris-HCl buffer:

[0081] Mix 340 g of Tris solution and 450 g of HCl solution in a flask and stir at room temperature for 7 h to prepare Tris-HCl buffer;

[0082] (2) 350 g of Tris-HCl buffer, 260 g of dopamine hydrochloride, 300 g of ammonia water, 330 g of carbon nanotubes, 650 g of anhydrous ethanol and 1.0 kg of deionized water were mixed in a flask and subjected to oxidative self-polymerization reaction in a 60 °C water bath for 10 h. The mixture was filtered and washed, and dried in an oven at 75 °C for 6 h to obtain PDA-carbon nanotubes.

[0083] (3) 330 g of copper nitrate, 340 g of PDA-carbon nanotubes, 540 g of anhydrous ethanol and 850 g of deionized water were mixed and placed in a flask, and a photochemical reduction reaction was carried out under laser irradiation. The mixture was stirred for 14 h, filtered and washed, and dried in an oven at 70 ° C for 5 h to obtain a functional filler, wherein:

[0084] The laser wavelength of the laser irradiation environment is 580nm, and the laser emission power is 1.2 mw / cm 2 ;

[0085] The temperature of the laser irradiation environment was 45°C;

[0086] (4) Weigh the following weight parts: 100 parts of PET matrix, 13 parts of functional filler, 0.2 parts of Irganox 1010, 0.1 parts of Irganox 168, and 0.2 parts of Irganox 1330, mix and stir evenly to obtain a mixture;

[0087] The mixed material is then put into the hopper of a twin-screw extruder for extrusion and granulation to obtain an antibacterial conductive PET composite material, wherein the twin-screw extruder includes six temperature zones arranged in sequence, with a temperature of 250°C in zone 1, a temperature of 290°C in zone 2, a temperature of 290°C in zone 3, a temperature of 290°C in zone 4, a temperature of 290°C in zone 5, a temperature of 290°C in zone 6, a head temperature of 290°C, and a screw speed of 240 r / min.

[0088] Example 4

[0089] (1) Prepare Tris-HCl buffer:

[0090] Mix 333 g of Tris solution and 456 g of HCl solution in a flask and stir at room temperature for 7.5 h to prepare Tris-HCl buffer;

[0091] (2) 365 g of Tris-HCl buffer, 278 g of dopamine hydrochloride, 315 g of ammonia water, 355 g of carbon nanotubes, 635 g of anhydrous ethanol and 999 g of deionized water were mixed in a flask and subjected to oxidative self-polymerization reaction in a water bath at 65 °C for 11 h. The mixture was filtered and washed, and dried in an oven at 77 °C for 6.6 h to obtain PDA-carbon nanotubes.

[0092] (3) 345 g of copper nitrate, 360 g of PDA-carbon nanotubes, 555 g of anhydrous ethanol and 835 g of deionized water were mixed in a flask and subjected to a photochemical reduction reaction under laser irradiation. The mixture was stirred for 15 h, filtered and washed, and dried in an oven at 78 ° C for 6 h to obtain a functional filler, wherein:

[0093] The laser wavelength of the laser irradiation environment is 580nm, and the laser emission power is 1.2 mw / cm 2 ;

[0094] The temperature of the laser irradiation environment was 48°C;

[0095] (4) Weigh the following weight parts: 98 parts of PET matrix, 15 parts of functional filler, 0.1 parts of Irganox 1010, and 0.2 parts of Irganox 1330, mix and stir evenly to obtain a mixture;

[0096] The mixed material is then put into the hopper of a twin-screw extruder for extrusion and granulation to obtain an antibacterial conductive PET composite material, wherein the twin-screw extruder includes six temperature zones arranged in sequence, with a temperature of 245°C in zone 1, a temperature of 285°C in zone 2, a temperature of 285°C in zone 3, a temperature of 285°C in zone 4, a temperature of 285°C in zone 5, a temperature of 285°C in zone 6, a head temperature of 285°C, and a screw speed of 255 r / min.

[0097] Example 5

[0098] (1) Prepare Tris-HCl buffer:

[0099] Mix 366g of Tris solution and 435g of HCl solution in a flask and stir at room temperature for 8h to prepare Tris-HCl buffer;

[0100] (2) 375 g of Tris-HCl buffer, 275 g of dopamine hydrochloride, 315 g of ammonia water, 348 g of carbon nanotubes, 666 g of anhydrous ethanol and 965 g of deionized water were mixed in a flask and subjected to oxidative self-polymerization reaction in a water bath at 66 °C for 11 h. The mixture was filtered and washed, and dried in an oven at 73 °C for 5 h to obtain PDA-carbon nanotubes.

[0101] (3) 322 g of copper nitrate, 338 g of PDA-carbon nanotubes, 575 g of anhydrous ethanol and 888 g of deionized water were mixed in a flask and subjected to a photochemical reduction reaction under laser irradiation. The mixture was stirred for 15.5 h, filtered and washed, and dried in an oven at 73 ° C for 5.5 h to obtain a functional filler, wherein:

[0102] The laser wavelength of the laser irradiation environment is 580nm, and the laser emission power is 1.2 mw / cm 2 ;

[0103] The temperature of the laser irradiation environment was 44°C;

[0104] (4) Weigh the following weight parts: 96 parts of PET matrix, 12 parts of functional filler, 0.1 parts of Irganox 1010, and 0.1 parts of Irganox 168, mix and stir evenly to obtain a mixture;

[0105] The mixed material is then put into the hopper of a twin-screw extruder for extrusion and granulation to obtain an antibacterial conductive PET composite material, wherein the twin-screw extruder includes six temperature zones arranged in sequence, with a temperature of 250°C in zone 1, a temperature of 295°C in zone 2, a temperature of 295°C in zone 3, a temperature of 295°C in zone 4, a temperature of 295°C in zone 5, a temperature of 295°C in zone 6, a head temperature of 295°C, and a screw speed of 270 r / min.

[0106] Example 6

[0107] (1) Prepare Tris-HCl buffer:

[0108] 300 g of Tris solution and 400 g of HCl solution were mixed in a flask and stirred at room temperature for 6 h to prepare a Tris-HCl buffer solution;

[0109] (2) 300 g of Tris-HCl buffer, 240 g of dopamine hydrochloride, 280 g of ammonia water, 300 g of carbon nanotubes, 600 g of anhydrous ethanol and 900 g of deionized water were mixed in a flask and subjected to oxidative self-polymerization reaction in a 50 °C water bath for 8 h. The mixture was filtered and washed, and dried in an oven at 70 °C for 4 h to obtain polydopamine-carbon nanotubes (PDA-carbon nanotubes).

[0110] (3) Chitosan, carboxylated polypyrrole and crosslinker glutaraldehyde were blended and grafted under ultraviolet light to form PPy-CS polymer;

[0111] 300 g of copper nitrate, 400 g of polydopamine-carbon nanotubes, 200 g of PPy-CS polymer, 580 g of anhydrous ethanol and 900 g of deionized water were mixed and placed in a flask, and subjected to photochemical reduction reaction and Schiff base reaction under laser irradiation environment. The mixture was stirred for 20 h, filtered and washed, and dried in an oven at 60°C to 80°C for 6 h to obtain a functional filler, wherein:

[0112] The laser wavelength of the laser irradiation environment is 580nm, and the laser emission power is 1.2 mw / cm 2 ;

[0113] The temperature of the laser irradiation environment is 40℃~50℃.

[0114] (4) Weigh the following weight parts: 95 parts of PET matrix, 10 parts of functional filler, and 0.1 parts of Irganox 1010, mix and stir evenly to obtain a mixture;

[0115] The mixed material is then put into the hopper of a twin-screw extruder for extrusion and granulation to obtain an antibacterial conductive PET composite material, wherein the twin-screw extruder includes six temperature zones arranged in sequence, with a temperature of 240°C in zone 1, a temperature of 280°C in zone 2, a temperature of 280°C in zone 3, a temperature of 280°C in zone 4, a temperature of 280°C in zone 5, a temperature of 280°C in zone 6, a head temperature of 280°C, and a screw speed of 200 r / min.

[0116] Comparative Example 1

[0117] (1) Weigh 96 parts of PET matrix, 0.1 parts of Irganox 1010, and 0.2 parts of Irganox 168 in the following weight parts, mix and stir evenly to obtain a mixture;

[0118] (2) The mixed material is fed into the hopper of a twin-screw extruder for extrusion and granulation to obtain a PET composite material, wherein the twin-screw extruder includes six temperature zones arranged in sequence, with a temperature of 250°C in zone 1, a temperature of 295°C in zone 2, a temperature of 295°C in zone 3, a temperature of 295°C in zone 4, a temperature of 295°C in zone 5, a temperature of 295°C in zone 6, a head temperature of 295°C, and a screw speed of 270 r / min.

[0119] Comparative Example 2

[0120] (1) Weigh the following weight parts: 96 parts of PET matrix, 15 parts of commercially available carbon nanotubes, 0.1 parts of Irganox 1010, and 0.1 parts of Irganox 1330, mix and stir evenly to obtain a mixture;

[0121] (2) The mixed material is fed into the hopper of a twin-screw extruder for extrusion and granulation to obtain a PET composite material, wherein the twin-screw extruder includes six temperature zones arranged in sequence, with a temperature of 255°C in zone 1, a temperature of 290°C in zone 2, a temperature of 290°C in zone 3, a temperature of 290°C in zone 4, a temperature of 290°C in zone 5, a temperature of 290°C in zone 6, a head temperature of 290°C, and a screw speed of 260 r / min.

[0122] Performance testing

[0123] Antibacterial Properties: According to JIS Z 2801:2010, Antibacterial Products - Antibacterial Activity and Effectiveness Test, the antibacterial conductive PET composite materials of Examples 1 to 6 and the PET composite materials of Comparative Examples 1 to 2 were tested, and Staphylococcus aureus and Escherichia coli were used as test bacteria. The sterilization rates of the test materials against the test bacteria were measured. The test results are shown in Table 1.

[0124] Conductivity: According to ASTM D257, Standard Test Method for DC Resistance or Conductance of Insulating Materials, the antibacterial conductive PET composite materials of Examples 1 to 6 and the PET composite materials of Comparative Examples 1 and 2 were tested for surface resistivity. The test results are shown in Table 1.

[0125] The experimental data and analysis are as follows:

[0126] Table 1 Performance test of composite materials in various embodiments and comparative examples

[0127]

[0128] As can be seen from Table 1, the bactericidal rates of the PET composite materials prepared in each embodiment of the present application against Staphylococcus aureus and Escherichia coli are higher than those of the PET composite materials in each comparative example, and the surface resistivity of the PET composite materials prepared in each embodiment of the present application is much lower than that of the PET composite materials in each comparative example. The lower the surface resistivity, the better the conductivity, which indicates that the PET composite materials prepared in each embodiment of the present application have excellent antibacterial properties and electrical conductivity.

[0129] However, Comparative Example 1 only uses a PET matrix and an antioxidant to compound, which lacks antibacterial active groups and thus has poor antibacterial properties. Moreover, PET is a polar polymer and cannot form a conductive path, thus having poor conductivity.

[0130] Comparative Example 2 uses a PET matrix, an antioxidant and commercially available carbon nanotubes for compounding. The commercially available carbon nanotubes are easily agglomerated due to van der Waals forces, forming local aggregations in the PET matrix, thereby hindering the continuity of the conductive network; and the unmodified commercially available carbon nanotubes have poor compatibility with the PET matrix, insufficient interfacial bonding force, and affect electron mobility; in addition, the PET matrix, antioxidant and unmodified commercially available carbon nanotubes have no active antibacterial components, so the antibacterial and electrical conductivity of the PET composite material in Comparative Example 2 are poor.

[0131] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An antibacterial conductive PET composite material, characterized in that: The PET composite material comprises the following raw materials in parts by weight: 95 to 105 parts of PET matrix, 10 to 16 parts of functional filler, 0.1 to 0.5 parts of antioxidant, wherein: The functional filler is a nano-copper-coated polydopamine-carbon nanotube composite filler.

2. The PET composite material according to claim 1, characterized in that The functional filler presents a three-dimensional network structure.

3. The PET composite material according to claim 1 or 2, characterized in that The raw materials of the functional filler include dopamine hydrochloride, ammonia water, carbon nanotubes and copper nitrate, and are prepared through oxidative self-polymerization reaction and photochemical reduction reaction in sequence.

4. The PET composite material according to claim 3, characterized in that The antioxidant is selected from at least one of tris(2,4-di-tert-butyl)phenyl phosphite, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

5. A method for preparing an antibacterial conductive PET composite material, characterized in that: The following steps are involved: (1) Using dopamine hydrochloride, ammonia, carbon nanotubes and copper nitrate as raw materials, functional fillers were prepared by oxidative self-polymerization and photochemical reduction reactions. (2) The functional filler, the PET matrix and the antioxidant are mixed to obtain a mixture, and the mixture is extruded and granulated to prepare an antibacterial conductive PET composite material.

6. The preparation method according to claim 5, characterized in that The step (1) further includes: (a) preparing tris hydrochloride buffer; (b) mixing the tris(hydroxymethylaminomethane) hydrochloride buffer, the dopamine hydrochloride, the ammonia water, the carbon nanotubes, anhydrous ethanol and deionized water, performing an oxidative self-polymerization reaction in a water bath, filtering, washing and drying to obtain polydopamine-carbon nanotubes; (c) mixing the polydopamine-carbon nanotubes, the copper nitrate, anhydrous ethanol and deionized water, performing a photochemical reduction reaction under a laser irradiation environment, filtering, washing and drying to obtain the functional filler.

7. The preparation method according to claim 6, characterized in that In the step (b), the mass ratio of the tris(hydroxymethyl)aminomethane hydrochloride buffer, the dopamine hydrochloride, the ammonia water, the carbon nanotubes, the anhydrous ethanol and the deionized water is (30-40): (24-28): (28-32): (30-36): (60-70): (90-110).

8. The preparation method according to claim 6, characterized in that In the step (c), the mass ratio of the copper nitrate, the polydopamine-carbon nanotubes, the anhydrous ethanol and the deionized water is (30-36): (32-36): (50-58): (80-90).

9. The preparation method according to claim 6, characterized in that In the step (c), the laser wavelength of the laser irradiation environment is 580 nm, and the laser emission power is 1.2 mw / cm 2 .

10. The preparation method according to claim 6, characterized in that In the step (c), the temperature of the laser irradiation environment is 40°C to 50°C.

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