High-toughness antibacterial conductive nylon fiber composite material and preparation method thereof

Abstract

The invention discloses a high-toughness antibacterial conductive nylon fiber composite material which comprises the following raw materials: a nylon matrix, an antioxidant, a conductive filler, silver nanoparticles or a copper-based antibacterial agent, a dispersant, a silane coupling agent or a titanate coupling agent, an ultraviolet light absorber or a hindered amine light stabilizer, a plasticizer and a lubricant. The invention also comprises a preparation method of the high-toughness antibacterial conductive nylon fiber composite material, which comprises the following steps: weighing according to the proportion, drying, uniformly mixing various raw materials, carrying out extrusion processing by using a twin-screw extruder to form a composite material strip, cooling the composite material strip by using a water cooling device, and carrying out extrusion molding to obtain the high-toughness antibacterial conductive nylon fiber composite material. And the composite material strips enter a granulator to be subjected to granulation processing, and composite material particles are formed. According to the high-toughness antibacterial conductive nylon fiber composite material and the preparation method thereof disclosed by the invention, the compatibility of conductivity and antibacterial property of the composite material is solved, and meanwhile, the mechanical property is ensured.

Description

Technical Field

[0001] The invention relates to the field of plastic modification, in particular to a high-toughness antibacterial conductive nylon fiber composite material and a preparation method thereof. Background Art

[0002] With the growing demand for multifunctional materials in the fields of smart textiles, medical and health care, antistatic and electronics, nylon fiber composites that have both antibacterial and conductive properties have gradually attracted attention. However, traditional nylon materials themselves lack conductivity and antibacterial properties, and when conductive nylon materials are prepared by melt blending, conductive fillers such as carbon nanotubes are easily unevenly dispersed in the matrix, with poor interface compatibility, resulting in unsatisfactory conductivity and reduced mechanical properties. At the same time, a higher amount of filler is required, which affects the spinning processing performance; the introduction of antibacterial properties also faces the problems of uneven dispersion of antibacterial agents and poor high-temperature processing stability. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a high-toughness antibacterial conductive nylon fiber composite material and a preparation method thereof, which solves the compatibility of the composite material's conductive properties and antibacterial properties while ensuring mechanical properties.

[0004] The technical solution adopted by the present invention to solve the above problem is a high-toughness antibacterial conductive nylon fiber composite material, comprising the following raw materials:

[0005] Nylon matrix: nylon 6 or nylon 66, 90-95 parts;

[0006] Antioxidant: 0.1-0.3 parts;

[0007] Conductive filler: 0.5-5 parts;

[0008] Silver nanoparticles or copper-based antimicrobial agents: 1-3 parts;

[0009] Dispersant: 0.5-5 parts;

[0010] Silane coupling agent or titanate coupling agent: 0.5-5 parts;

[0011] UV absorber or hindered amine light stabilizer (HALS): 0.5-5 parts;

[0012] Plasticizer: 0.5-5 parts;

[0013] Lubricant: 0.5-5 parts.

[0014] Compared with the prior art, the advantages of the present invention are:

[0015] Nylon matrix: provides the basic structure and excellent mechanical properties of the composite material;

[0016] Antioxidant: used to improve the oxidation resistance of materials and extend their service life;

[0017] Conductive filler: provides conductive properties;

[0018] Antimicrobial agent: implement the antimicrobial effect of composite materials;

[0019] Dispersant: Improve the dispersion of fillers in the matrix and ensure the uniformity of the material;

[0020] Silane coupling agent or titanate coupling agent: improve the interfacial compatibility between filler and polymer matrix;

[0021] UV absorbers or hindered amine light stabilizers (HALS): enhance the material’s UV resistance and prevent photodegradation;

[0022] Plasticizer: Increase the plasticity of composite materials;

[0023] Lubricant: Reduce friction, reduce wear, improve processing performance and facilitate processing.

[0024] As an improvement of the present invention, the antioxidant is selected from at least one of the following materials: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris[2,4-di-tert-butylphenyl]phosphite, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, triphenylphosphite, and 2,6-di-tert-butyl-4-methylphenol.

[0025] As an improvement of the present invention, the conductive filler is selected from at least one of the following materials: carbon nanotubes, graphene, carbon fibers, and conductive metal powders.

[0026] As an improvement of the present invention, the dispersant is selected from at least one of the following materials: an organosilicon dispersant, a fatty acid dispersant, and a polyamide dispersant.

[0027] As an improvement of the present invention, the plasticizer is selected from at least one of the following materials: phthalate plasticizers, phosphate plasticizers, and fatty acid ester plasticizers.

[0028] As an improvement of the present invention, the lubricant is selected from at least one of the following materials: stearic acid, stearate, and amide lubricant.

[0029] A method for preparing a high-toughness antibacterial conductive nylon fiber composite material, which is used to prepare a high-toughness antibacterial conductive nylon fiber composite material, and the steps are as follows:

[0030] S1: Pre-treatment of carbon nanotubes and silver nanoparticles using ultrasonic dispersion to ensure good homogeneity;

[0031] S2: Weigh various raw materials in proportion and dry them separately;

[0032] S3: Evenly mix all kinds of raw materials;

[0033] S4: using a twin-screw extruder for extrusion processing to form a composite material strip;

[0034] S5: The composite strip is cooled by a water cooling device;

[0035] S6: The composite material strips enter a pelletizer for pelletizing to form composite material particles;

[0036] S7: Collecting composite particles.

[0037] Compared with the prior art, the advantages of the present invention are as follows: the present invention introduces conductive fillers and antibacterial agents into a nylon matrix through a melt polymerization process, thereby achieving good dispersibility and interface compatibility, thereby preparing a nylon fiber composite material with excellent conductive properties, antibacterial effects and mechanical properties, overcoming the shortcomings of traditional processes and expanding the application scope of nylon; at the same time, the melt polymerization process is simple, easy to realize industrial production, and suitable for large-scale promotion. The above-mentioned various raw materials are low in cost and have significant price competitive advantages.

[0038] As an improvement of the present invention, in step S4, the twin-screw extruder includes four temperature processing zones and an extrusion temperature zone, and the temperatures of the four temperature processing zones and the extrusion temperature zone are respectively:

[0039] The first temperature zone: 220-260°C;

[0040] The second temperature zone: 230-270°C;

[0041] The third temperature zone: 240-280°C;

[0042] The fourth temperature zone: 240-280°C;

[0043] Head temperature zone: 235~275℃;

[0044] The screw speed of the twin-screw extruder is 30 to 120 revolutions per minute. Through the improvement, the stability of the composite material during the melting process can be achieved by slowly increasing the processing temperature.

[0045] As an improvement of the present invention, the injection pressure of the twin-screw extruder is 60-80MPa, and the extrusion die temperature is 40-90°C, so as to control the extrusion temperature of the composite material strip at 230-250°C, and the stretching ratio of the composite material strip is 3:1. Through the improvement, an ideal fiber diameter and strength are obtained, so that the composite material strip has good processing performance.

[0046] As an improvement of the present invention, in step S5, the water cooling device is circulating water, and the composite material strip is controlled to be maintained at 130-150°C for heat setting for 30 minutes. Through the improvement, the dimensional stability and performance of the fiber are improved, thereby improving BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is the antibacterial micrograph of Example 1 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0048] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0049] A high-tenacity antibacterial conductive nylon fiber composite material, comprising the following raw materials:

[0050] Nylon matrix: nylon 6 or nylon 66, 90-95 parts;

[0051] Antioxidant: 0.1-0.3 parts;

[0052] Conductive filler: 0.5-5 parts;

[0053] Silver nanoparticles or copper-based antimicrobial agents: 1-3 parts;

[0054] Dispersant: 0.5-5 parts;

[0055] Silane coupling agent or titanate coupling agent: 0.5-5 parts;

[0056] UV absorber or hindered amine light stabilizer (HALS): 0.5-5 parts;

[0057] Plasticizer: 0.5-5 parts;

[0058] Lubricant: 0.5-5 parts.

[0059] The antioxidant is selected from at least one of the following materials: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris[2,4-di-tert-butylphenyl]phosphite, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, triphenylphosphite, and 2,6-di-tert-butyl-4-methylphenol.

[0060] The conductive filler is selected from at least one of the following materials: carbon nanotubes, graphene, carbon fibers, and conductive metal powders.

[0061] The dispersant is selected from at least one of the following materials: an organosilicon dispersant, a fatty acid dispersant, and a polyamide dispersant.

[0062] The plasticizer is selected from at least one of the following materials: phthalate plasticizers, phosphate plasticizers, and fatty acid ester plasticizers.

[0063] The lubricant is selected from at least one of the following materials: stearic acid, stearate, and amide lubricants.

[0064] A method for preparing a high-toughness antibacterial conductive nylon fiber composite material, which is used to prepare a high-toughness antibacterial conductive nylon fiber composite material, and the steps are as follows:

[0065] S1: Pre-treatment of carbon nanotubes and silver nanoparticles using ultrasonic dispersion to ensure good homogeneity;

[0066] S2: Weigh various raw materials in proportion and dry them separately;

[0067] S3: Evenly mix all kinds of raw materials;

[0068] S4: using a twin-screw extruder for extrusion processing to form a composite material strip;

[0069] S5: The composite strip is cooled by a water cooling device;

[0070] S6: The composite material strips enter a pelletizer for pelletizing to form composite material particles;

[0071] S7: Collecting composite particles.

[0072] In step S4, the twin-screw extruder includes four temperature processing zones and an extrusion temperature zone, and the temperatures of the four temperature processing zones and the extrusion temperature zone are respectively:

[0073] The first temperature zone: 220-260°C;

[0074] The second temperature zone: 230-270°C;

[0075] The third temperature zone: 240-280°C;

[0076] The fourth temperature zone: 240-280°C;

[0077] Head temperature zone: 235~275℃;

[0078] The screw speed of the twin-screw extruder is 30 to 120 rpm, the injection pressure of the twin-screw extruder is 60 to 80 MPa, and the extrusion die temperature is 40 to 90°C, so as to control the extrusion temperature of the composite material strip to be 230 to 250°C, and the stretching ratio of the composite material strip is 3:1. The water cooling device is circulating water, which controls the composite material strip to be maintained at 130 to 150°C for heat setting and lasts for 30 minutes.

[0079] According to the different materials and different mass proportions of the high-toughness antibacterial conductive nylon fiber composite material, the surface resistivity test is carried out in accordance with GB / T 1410, and the test conditions are tested at 23°C and 50% humidity; the antibacterial performance test is carried out in accordance with QB / T 2591, and the test conditions are tested after being placed and cultured at 23°C and 50% humidity for 24 hours. The test data are shown in Table 1.

[0080] Table 1 Raw material ratios and conductivity performance of examples and comparative examples

[0081]

[0082]

[0083] like Figure 1 As shown, Figure (a) is the antibacterial data of Escherichia coli in comparative example 1, Figure (b) is the antibacterial data of Staphylococcus aureus in comparative example 1, Figure (c) is the antibacterial data of Escherichia coli in embodiment 1, and Figure (d) is the antibacterial data of Staphylococcus aureus in embodiment 1.

[0084] From the comparison of the above embodiments and comparative examples, it can be seen that embodiments 1-5 all exhibit excellent conductivity. Under the action of different conductive fillers, the conductive properties and antibacterial properties can meet the multi-functional requirements. Because embodiment 3 uses carbon black as a conductive filler, the conductive performance is slightly inferior, but the cost is low and it is suitable for scenes where the conductivity requirements are not high. Comparative Example 1 (without antibacterial agent): Although the conductivity is good, the antibacterial function cannot be achieved because no antibacterial agent is added. Comparative Example 2 (without conductive filler): The conductivity is extremely poor, almost an insulator, but the antibacterial performance is good.

[0085] At the same time, in Example 3: by compounding triphenylphosphite with 2,6-di-tert-butyl-4-methylphenol, the sample aging time was extended by nearly 100 hours. By compounding the antioxidant with the UV stabilizer, the following beneficial effects were achieved:

[0086] 1. Synergistic anti-aging: Antioxidants mainly delay the aging of materials by inhibiting oxidation reactions, while UV stabilizers mainly prevent UV-induced material degradation by absorbing or shielding UV rays. When the two are combined, they can provide more comprehensive aging protection for materials.

[0087] 2. Extend service life: In a high temperature and high UV environment, the synergistic effect of antioxidants and UV stabilizers can significantly improve the durability of the material and extend its service life.

[0088] In material formulations, the use of triphenylphosphite (TPP) and 2,6-di-tert-butyl-4-methylphenol (BHT) as antioxidants can provide significant advantages over either ingredient alone. This is because:

[0089] 1.TPP is an effective secondary antioxidant that can decompose peroxides and prevent the propagation of free radical chain reactions, while BHT is a phenolic antioxidant that mainly terminates free radical chain reactions by donating hydrogen atoms. The different mechanisms of action of these two ingredients can work together to form a more complete antioxidant protection system, thereby more effectively inhibiting the oxidative degradation of polymers and extending the service life of materials under stresses such as heat, oxygen and ultraviolet rays.

[0090] 2.TPP has excellent stability at higher temperatures, while BHT performs well in the range of room temperature to medium temperature. The combination of the two can cover a wider temperature range and provide continuous antioxidant protection.

[0091] 3. BHT's ability to absorb UV rays can protect the material from UV degradation, while TPP can further prevent UV-induced oxidation. The combination of the two helps to enhance the light stability of the material.

[0092] The above description is only for the best embodiment of the present invention, but it should not be understood as limiting the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to be changed. All changes made within the scope of protection of the independent claims of the present invention are within the scope of protection of the present invention.

Claims

1. A high-toughness antibacterial conductive nylon fiber composite material, characterized in that: Including the following raw materials: Nylon matrix: nylon 6 or nylon 66, 90-95 parts; Antioxidant: 0.1-0.3 parts; Conductive filler: 0.5-5 parts; Silver nanoparticles or copper-based antimicrobial agents: 1-3 parts; Dispersant: 0.5-5 parts; Silane coupling agent or titanate coupling agent: 0.5-5 parts; UV absorber or hindered amine light stabilizer (HALS): 0.5-5 parts; Plasticizer: 0.5-5 parts; Lubricant: 0.5-5 parts.

2. The high-toughness antibacterial conductive nylon fiber composite material according to claim 1, characterized in that: The antioxidant is selected from at least one of the following materials: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris[2,4-di-tert-butylphenyl]phosphite, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, triphenylphosphite, and 2,6-di-tert-butyl-4-methylphenol.

3. The high-toughness antibacterial conductive nylon fiber composite material according to claim 1, characterized in that: The conductive filler is selected from at least one of the following materials: carbon nanotubes, graphene, carbon fibers, and conductive metal powders.

4. The high-toughness antibacterial conductive nylon fiber composite material according to claim 1, characterized in that: The dispersant is selected from at least one of the following materials: an organosilicon dispersant, a fatty acid dispersant, and a polyamide dispersant.

5. The high-toughness antibacterial conductive nylon fiber composite material according to claim 1, characterized in that: The plasticizer is selected from at least one of the following materials: phthalate plasticizers, phosphate plasticizers, and fatty acid ester plasticizers.

6. The high-toughness antibacterial conductive nylon fiber composite material according to claim 1, characterized in that: The lubricant is selected from at least one of the following materials: stearic acid, stearate, and amide lubricants.

7. A method for preparing a high-toughness antibacterial conductive nylon fiber composite material, characterized in that: The steps for preparing a high-toughness antibacterial conductive nylon fiber composite material according to any one of claims 1 to 6 are as follows: S1: Pre-treatment of carbon nanotubes and silver nanoparticles using ultrasonic dispersion to ensure good homogeneity; S2: Weigh various raw materials in proportion and dry them separately; S3: Evenly mix all kinds of raw materials; S4: using a twin-screw extruder for extrusion processing to form a composite material strip; S5: The composite strip is cooled by a water cooling device; S6: The composite material strips enter a pelletizer for pelletizing to form composite material particles; S7: Collecting composite particles.

8. The method for preparing a high-toughness antibacterial conductive nylon fiber composite material according to claim 7, characterized in that: In step S4, the twin-screw extruder includes four temperature processing zones and an extrusion temperature zone, and the temperatures of the four temperature processing zones and the extrusion temperature zone are respectively: The first temperature zone: 220-260°C; The second temperature zone: 230-270°C; The third temperature zone: 240-280°C; The fourth temperature zone: 240-280°C; Head temperature zone: 235~275℃; The screw speed of the twin-screw extruder is 30 to 120 rpm.

9. The method for preparing a high-toughness antibacterial conductive nylon fiber composite material according to claim 8, characterized in that: The injection pressure of the twin-screw extruder is 60-80 MPa, and the extrusion die temperature is 40-90° C., so as to control the extrusion temperature of the composite material strip to be 230-250° C., and the stretching ratio of the composite material strip is 3:

1.

10. The method for preparing a high-toughness antibacterial conductive nylon fiber composite material according to claim 7, characterized in that: In step S5, the water cooling device is circulating water, and the composite material strip is controlled to be maintained at 130-150° C. for heat setting for 30 minutes.

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