Carbon nanotube / resin composite based on acoustic resonance mixing and method of making

Abstract

Carbon nanotube / resin composite material based on acoustic resonance mixing belongs to the technical field of nanotube composite material, and comprises single-walled carbon nanotube, glass fiber, carbon fiber, spherical nanometer silicon dioxide and thermoplastic resin powder components; the preparation method of the carbon nanotube / resin composite material based on acoustic resonance mixing comprises three processes.The present application aims at the problems of traditional single-walled carbon nanotube (SWCNTs) / thermoplastic resin composite material preparation, such as uneven dispersion caused by easy agglomeration of SWCNTs, weak interface combination and performance degradation, etc., and the finished product prepared by using SWCNTs, thermoplastic resin powder, glass fiber, carbon fiber and spherical nanometer silicon dioxide as raw materials through acoustic resonance mixing equipment has the tensile strength improved by 70%, the thermal conductivity coefficient more than 80%, the surface resistivity reduced by 7-10 orders of magnitude, excellent mechanical properties, thermal conductivity and anti-static performance, and is especially suitable for application in the fields of automobile parts, electronic shell and the like.In summary, the present application has good application prospect.

Description

Technical Field

[0001] This invention relates to the field of nanotube composite materials technology, and in particular to a carbon nanotube / resin composite material based on acoustic resonance mixing and its preparation method. Background Technology

[0002] Single-walled carbon nanotubes (SWCNTs), as a one-dimensional nanomaterial, possess extremely high mechanical strength (tensile strength up to hundreds of GPa), excellent thermal conductivity (thermal conductivity 2000-6000 W / m·K), and electrical properties (including high electrical conductivity, enabling the formation of continuous conductive networks to impart antistatic properties). They are widely used in resin composites to enhance mechanical, thermal, antistatic, and functional properties. Thermoplastic resins are engineering resins widely used in the automotive, electronics, and machinery industries due to their good mechanical strength, heat resistance, and processability. However, in existing technologies, when adding SWCNTs to thermoplastic resins along with other excipients, the differences in material composition, density, and properties of the components can easily lead to uneven mixing, agglomeration, or phase separation in the final product.

[0003] Currently, the main preparation methods for single-walled carbon nanotube / thermoplastic resin composites include mechanical stirring, melt blending, and solution mixing. Mechanical stirring methods, such as high-speed shearing or ball milling, while simple, often result in stratification and incomplete dispersion due to differences in material density and affinity. They also have long processing times (several hours) and are prone to introducing defects (such as SWCNT breakage), leading to only a 10-20% increase in tensile strength, limited improvement in thermal conductivity (<30%), and insignificant antistatic properties (surface resistivity reduction of less than two orders of magnitude). Melt blending uses twin-screw extrusion, but uneven premixing can cause blockages or performance fluctuations during extrusion. It is suitable for low filler content (<1wt%), but at high filler content, agglomeration is common, making it difficult to form an effective conductive network to achieve excellent antistatic properties. Solution mixing requires organic solvents, which poses environmental risks and insufficient purity of the prepared product, and the drying process is complex. All of the above methods, coupled with the limitations of various raw material types and proportions, have the overall risks of low efficiency, narrow applicability (limited to materials of similar density), poor scalability, and damage to material integrity. These risks can affect the performance and consistency of the final composite material (including the difficulty in achieving stable antistatic properties), thus limiting the potential of composite materials in high-end applications. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies for preparing single-walled carbon nanotube / thermoplastic resin composites, as described in the background section, this invention provides a method that uses related materials and acoustic resonance technology in conjunction with the shear effect of spherical materials to achieve uniform dispersion and interfacial wetting of multi-component materials with large density differences and distinct properties (such as conductivity and insulation) at the microscale. This solves the problems of uneven raw material dispersion, weak interfacial bonding, and performance degradation in the mixing process of traditional technologies. The resulting composite material has excellent mechanical properties, thermal conductivity, and antistatic properties, and is particularly suitable for acoustic resonance-based carbon nanotube / resin composite materials and their preparation method used in automotive parts, electronic casings, and other fields.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A carbon nanotube / resin composite material based on acoustic resonance mixing comprises single-walled carbon nanotubes, glass fibers, carbon fibers, spherical nano-silica, and thermoplastic resin powder components; wherein the content of single-walled carbon nanotubes is 0.5-5 wt%, glass fibers are 1-10 wt%, carbon fibers are 0.5-5 wt%, spherical nano-silica is 0.1-2 wt%, and thermoplastic resin powder is 78-97.9 wt%; the preparation method of the carbon nanotube / resin composite material based on acoustic resonance mixing includes the following steps: S1: preparing single-walled carbon nanotubes, thermoplastic resin powder, glass fibers, carbon fibers, and spherical nano-silica in proportions. S1: Silica, and modify and pre-dry the surface of glass fiber and spherical nano silica; S2: Put the material from step S1 into the mixing chamber of the acoustic resonance mixing equipment to carry out multi-stage acoustic resonance mixing of multiple materials. The resonance cavity of the resonance mixing equipment generates a resonance frequency of 50-70Hz and an acceleration of 5-100g, forming a standing wave field in the mixing chamber to achieve microscopic uniform dispersion of multiple components, with a dispersion uniformity >96%; S3: After mixing, the material is subjected to vacuum degassing device, vacuum degassing, hot pressing equipment for pre-forming, vacuum drying equipment for drying, and twin-screw extrusion molding to obtain carbon nanotube / resin composite material.

[0007] Further, the thermoplastic resin powder is one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyamide, polycarbonate, polyoxymethylene, polybutylene terephthalate, polyethylene terephthalate, polyetheretherketone, polyimide, polyphenylene sulfide, polyethersulfone, polytetrafluoroethylene, polysulfone, polymethylpentene, ethylene-vinyl acetate copolymer, and polyphthalamide, with a density of 1.0 g / cm³-1.4 g / cm³.

[0008] Furthermore, the single-walled carbon nanotubes have a purity >80%, a diameter of 0.5nm-2nm, a length of 1μm-100μm, and a density of 1g / cm³-1.8g / cm³; the glass fibers have a density of 2g / cm³-2.6g / cm³ and a length of 1mm-10mm; the carbon fibers have a density of 1.2g / cm³-1.9g / cm³ and a length of 0.5mm-5mm; and the spherical nano-silica has a density of 1.6g / cm³-2.3g / cm³ and a particle size of 100nm-200nm.

[0009] Furthermore, in step S1, the surfaces of the glass fiber and spherical nano-silica are modified by treating with a silane coupling agent. The modification is achieved by stirring the glass fiber and spherical nano-silica with a silane coupling agent at room temperature for 20-40 minutes. The pre-drying is carried out in a drying equipment at 75°C-85°C for 2-2.5 hours.

[0010] Furthermore, in the multi-stage acoustic resonance mixing in step S2, the first stage mixes at an acceleration of 30g-80g for 8-12 minutes, and the second stage mixes at an acceleration of 60g-95g for 2-8 minutes, with a total mixing time of <40 minutes.

[0011] Further, in step S3, the vacuum degassing device has a vacuum degree of -0.1MPa to -0.2MPa and a time of 15 to 25 minutes; the hot pressing device has a pressure of 5MPa to 6MPa, a temperature of 150°C to 160°C, and a time of 10 to 15 minutes; the vacuum drying device has a material drying temperature of 60°C to 65°C and a drying time of 60 to 70 minutes; the carbon nanotube / resin composite material has a tensile strength >90MPa, a Young's modulus >4GPa, a thermal conductivity >0.5W / m•K, and a surface resistivity of 1.0×10^4-1.0×10^9Ω / sq.

[0012] Further, in step S2, the applied acoustic resonance mixing equipment includes a resonance cavity, an acoustic frequency modulation module, a mixing chamber, a control module, and a fixing device. The resonance cavity is installed in the middle of the housing via the fixing device. The acoustic frequency modulation module is installed at the lower end of the resonance cavity. The mixing chamber is installed inside the resonance cavity. The control module is installed at the front end of the housing. The power output terminal of the control module and the power input terminal of the acoustic frequency modulation module are connected to the lower interior of the acoustic frequency modulation module via wires. The vacuum degassing device is installed at the rear of the resonance cavity. The air inlet pipe of the vacuum degassing device and the exhaust pipe at the upper end of the mixing chamber are connected via pipes. The front end of the housing has a sealed soundproof door. Before mixing, the sealed door is opened to put raw materials into the mixing chamber and the sealed soundproof door is closed.

[0013] Furthermore, in step S2, the acoustic frequency modulation module of the applied acoustic resonance mixing equipment, under the control of the control module, can output different frequency signals to the resonance cavity through its own automatic frequency regulator. The resonance cavity can generate a low-frequency standing wave field that acts on the mixing chamber, realizing the acoustic flow and uniform mixing of multi-component raw materials without damaging the physical structure of the materials.

[0014] Furthermore, in step S2, the resonant acoustic wave formed by the low-frequency standing wave field, in conjunction with the spherical component shearing effect, can achieve preferential deagglomeration and interfacial fusion of raw material components with a density difference greater than 30%, without the need for additional dispersants, and maintain a purity greater than 99%.

[0015] Compared with existing technologies, the advantages of this invention are as follows: This invention addresses the problems of uneven dispersion, weak interfacial bonding, and performance degradation caused by the easy aggregation of SWCNTs leading to unrefined composite materials, as well as in the preparation of traditional single-walled carbon nanotube (SWCNT) / thermoplastic resin composites. Using SWCNTs, thermoplastic resin powder, glass fiber, carbon fiber, and spherical nano-silica as raw materials, and through acoustic resonance equipment in synergistic mixing of the spherical components, the resulting finished product exhibits a 70% increase in tensile strength, over 80% thermal conductivity, and a 7-10 order of magnitude reduction in surface resistivity. It possesses excellent mechanical properties, thermal conductivity, and antistatic properties, making it particularly suitable for applications in automotive parts, electronic casings, and other fields. In summary, this invention has promising application prospects. Attached Figure Description

[0016] Figure 1 This is a scanning electron microscope (SEM) image of the composite material prepared using the acoustic resonance mixing equipment of this invention. Detailed Implementation

[0017] A carbon nanotube / resin composite material based on acoustic resonance hybridization comprises single-walled carbon nanotubes, glass fibers, carbon fibers, spherical nano-silica, and thermoplastic resin powder components. The single-walled carbon nanotubes comprise 0.5-5 wt%, glass fibers 1-10 wt%, carbon fibers 0.5-5 wt%, spherical nano-silica 0.1-2 wt%, and thermoplastic resin powder 78-97.9 wt%. The thermoplastic resin powder is one or more of the following: polyethylene, polypropylene, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyamide, polycarbonate, polyoxymethylene, polybutylene terephthalate, polyethylene terephthalate, polyetheretherketone, polyimide, polyphenylene sulfide, polyethersulfone, polytetrafluoroethylene, polysulfone, polymethylpentene, ethylene-vinyl acetate copolymer, and polyphthalamide, with a density of 1.0 g / cm³-1.4 g / cm³. Nanotubes with a purity >80%, diameter between 0.5nm and 2nm, length between 1μm and 100μm, and density between 1g / cm³ and 1.8g / cm³; glass fibers with a density between 2g / cm³ and 2.6g / cm³ and a length between 1mm and 10mm; carbon fibers with a density between 1.2g / cm³ and 1.9g / cm³ and a length between 0.5mm and 5mm; and spherical nano-silica with a density between 1.6g / cm³ and 2.3g / cm³ and a particle size between 100nm and 200nm.

[0018] After acoustic resonance synergistic treatment with spherical silica, single-walled carbon nanotubes can be uniformly dispersed in the thermoplastic resin matrix to construct a 3D network structure, which is conducive to the formation of a continuous mechanical reinforcement network, thermal conductivity pathway and electrical conductivity network, and achieves excellent mechanical properties, thermal conductivity and antistatic properties.

[0019] The preparation method of carbon nanotube / resin composite material based on acoustic resonance mixing works by generating low-frequency vibrations of 50-70Hz within an acoustic frequency modulation module. This vibrations form a standing wave field in the mixing chamber through a resonant cavity, applying mechanical resonance and energy superposition to multi-component materials with large density and performance differences, resulting in large-amplitude vibrations. The contents of the mixing chamber are compressed, generating acoustic flow, and the material as a whole is fully fluidized. This promotes the deagglomeration of single-walled carbon nanotubes and their uniform fusion with thermoplastic resin powder and other raw materials, avoiding the damage and unevenness of traditional methods. The process includes the following steps: (1) Prepare single-walled carbon nanotubes, thermoplastic resin powder, glass fiber, carbon fiber and spherical nano silica according to the proportions, and modify the surface of glass fiber and spherical nano silica (the density of spherical nano silica is about 2.2 g / cm³, which acts as an interface modifier to promote filler dispersion, increase fluidity and provide shear force to deagglomerate, improve the interfacial bonding between fiber / nanoparticle and resin matrix, enhance dispersibility and compatibility, prevent agglomeration, and improve the overall mechanical, electrical and thermal properties of composite materials) and pre-dry; Specifically, the surface of glass fiber and spherical nano silica is modified by silane coupling agent treatment. The modification is achieved by stirring glass fiber and spherical nano silica at room temperature with silane coupling agent for 20 to 40 minutes. Pre-drying is carried out in a drying equipment at 75°C-85°C for 2 to 2.5 hours. (2): The material in step S1 is put into the mixing chamber of the acoustic resonance mixing device to carry out multi-stage acoustic resonance mixing of multiple materials. The resonance cavity of the resonance mixing device generates a resonance frequency of 50-70Hz and an acceleration between 5-100g. A standing wave field is formed in the mixing chamber to achieve microscopic uniform dispersion of multiple components with a dispersion uniformity of >96%. In the multi-stage acoustic resonance mixing, the first stage is mixed with an acceleration of 30g-80g for 8-12 minutes, and the second stage is mixed with an acceleration of 60g-95g for 2-8 minutes. The total mixing time is <40 minutes.(3): After mixing, the material is subjected to vacuum degassing device, vacuum degassing (removing dissolved gases (such as air, hydrogen, oxygen) and bubbles in the mixture to prevent them from forming voids, cracks or defects in subsequent processing, thereby improving the density, mechanical strength and overall integrity of the composite material), hot pressing equipment for pre-forming (hot pressing combined with pressure and temperature promotes particle rearrangement, plastic flow and resin curing), vacuum drying equipment for drying and twin-screw extrusion molding to obtain carbon nanotube / resin composite material; specifically, the vacuum degree of vacuum degassing device is -0.1MPa to -0.2MPa, and the time is 15 minutes to 25 minutes; the pressure of hot pressing equipment is 5MPa to 6MPa, the temperature is 150°C to 160°C, and the time is 10 minutes to 15 minutes; the material temperature of vacuum drying equipment is 60°C to 65°C, and the drying time is 60 minutes to 70 minutes; the tensile strength of carbon nanotube / resin composite material is >90MPa, and the Young's modulus is >4G. Pa, thermal conductivity >0.5W / m•K, surface resistivity 1.0×10^4-1.0×10^9Ω / sq; the applied acoustic resonance mixing equipment includes a resonant cavity (transmitting the vibration signal of the acoustic frequency modulation module), an acoustic frequency modulation module (outputting vibration signals of different functional frequencies to the resonant cavity), a mixing chamber (mixing materials), a control module (controlling the magnitude of the vibration signal output by the acoustic frequency modulation module), and a fixing device (for fixing). The resonant cavity is installed in the middle of the shell via the fixing device, the acoustic frequency modulation module is installed at the lower end of the resonant cavity, the mixing chamber is installed inside the resonant cavity, and the control module is installed at the front end of the shell. The power output terminal of the control module and the power input terminal of the acoustic frequency modulation module are connected to the lower interior of the acoustic frequency modulation module via wires. The vacuum degassing device is installed at the rear of the resonant cavity. The air inlet pipe of the vacuum degassing device and the exhaust pipe at the upper end of the mixing chamber are connected via pipes. The front end of the shell has a sealed soundproof door. Before mixing, the sealed door is opened to put the raw materials into the mixing chamber and the sealed soundproof door is closed. The acoustic frequency modulation module of the applied acoustic resonance mixing equipment, under the control of the control module, can output different frequency signals to the resonant cavity through its own automatic frequency adjuster. The resonant cavity can generate a low-frequency standing wave field that acts on the mixing chamber, realizing the acoustic flow and uniform mixing of multi-component raw materials without damaging the physical structure of the materials. The resonant acoustic waves formed by the low-frequency standing wave field, in conjunction with the spherical component effect, can achieve preferential deagglomeration and interfacial fusion of raw material components with a density difference greater than 30%, without the need for additional dispersants, maintaining a purity greater than 99%.

[0020] Figure 1The image shows a SEM image of the composite material of this invention. As can be seen, after acoustic resonance mixing treatment, single-walled carbon nanotubes are uniformly dispersed in the thermoplastic resin matrix, exhibiting a 3D network structure. This facilitates the formation of a continuous mechanical reinforcement network, thermal conductivity pathways, and electrical conductivity network, resulting in excellent mechanical properties, thermal conductivity, and antistatic properties. In Examples 1-4 and Comparative Examples 1-2 below, the extruder screw diameter was 25 mm, L / D = 40, temperature was 180-280°C, and rotation speed was 80-250 rpm. Standard specimens were extruded. Mechanical properties were tested using a universal testing machine (ASTM D638 standard, tensile speed 5 mm / min), thermal conductivity was tested using the laser flash method (ASTM E1461 standard), and antistatic properties were tested using the surface resistivity four-probe method (ASTM D257 standard).

[0021] Example 1: (1) Take 0.5wt% single-walled carbon nanotube powder (relative to PP mass), 2wt% glass fiber, 0.5wt% carbon fiber, 0.2wt% spherical nano-silica, and PP powder (thermoplastic resin powder), totaling 100g for later use. (2) Modify the surface of glass fiber and spherical nano-silica (specifically, modify the surface of glass fiber and spherical nano-silica by silane coupling agent) and pre-dry. (3) Place the above materials in the mixing chamber of the acoustic resonance mixing equipment, start the equipment, set the acceleration to a low level of 30g, mix for 8 minutes in the first stage, and adjust the acceleration to 60g for 2 minutes in the second stage. (4) After mixing, the materials are degassed under vacuum, pre-formed by hot pressing, and dried under vacuum. Figure 1 As can be seen, SEM observation shows that each component is evenly distributed among the PP components without agglomeration. (5) The carbon nanotube / resin composite material obtained by the above steps after twin-screw extrusion molding has the following test performance results: tensile strength is 87MPa (pure PP is 55MPa, an increase of 58%), Young's modulus is 2.9GPa (pure PP is 1.8GPa, an increase of 61%), thermal conductivity is 0.34W / m·K (pure PP is 0.20W / m·K, an increase of 70%), and surface resistivity is 1.0×10^9Ω / sq (pure PP is 1.0×10^15Ω / sq, a decrease of 6 orders of magnitude). This example proves that acoustic resonance mixing can effectively handle materials with different densities but different properties, is suitable for low-reinforcement composite material applications, and initially imparts antistatic properties.

[0022] Example 2: (1) Take 1 wt% single-walled carbon nanotube powder, 4 wt% glass fiber, 1 wt% carbon fiber, 0.5 wt% spherical nano-silica and PP powder, with a total mass of 200 g. (2) Modify the surface of glass fiber and spherical nano-silica (specifically, modify the surface of glass fiber and spherical nano-silica by treating with silane coupling agent) and pre-dry. (3) Place the above materials in the mixing chamber of the acoustic resonance mixing equipment, start the equipment, set the acceleration to a medium level of 50 g, mix for 10 minutes in the first stage, and increase the acceleration to 60 g in the second stage for 5 minutes. (4) After mixing, the materials are degassed under vacuum, pre-formed by hot pressing and vacuum dried, and the materials are uniformly fused. (5) The carbon nanotube / resin composite material obtained by twin-screw extrusion molding of the material obtained in the above steps has the following test performance results: tensile strength of 95 MPa (73% improvement), Young's modulus of 3.6 GPa (100% improvement), thermal conductivity of 0.45 W / m·K (125% improvement), and surface resistivity of 1.0 × 10^7 Ω / sq (pure PP is 1.0 × 10^15 Ω / sq, a decrease of 8 orders of magnitude). Data logic shows that the performance improvement is linear with the increase of filler content (correlation coefficient R² = 0.97), which is attributed to the uniform dispersion of acoustic resonance avoiding stress concentration caused by agglomeration. This embodiment is suitable for electronic casing material applications with medium strength requirements and provides significant antistatic properties.

[0023] Example 3: Preparation and performance testing of carbon nanotube / resin composite material with high filling amount based on acoustic resonance mixing. (1) Take 3wt% single-walled carbon nanotube powder, 8wt% glass fiber, 3wt% carbon fiber, 1wt% spherical nano silica and PP powder, with a total mass of 500g. (2) Modify the surface of glass fiber and spherical nano silica (specifically, the surface of glass fiber and spherical nano silica is modified by silane coupling agent) and pre-dry. (3) Place the above materials in the mixing chamber of the acoustic resonance mixing equipment, start the equipment, set the acoustic resonance mixing acceleration intensity to a high level of 80g, mix for 12 minutes in the first stage, and adjust to 95g for 8 minutes in the second stage. After mixing, the material is degassed under vacuum, pre-formed by hot pressing and vacuum dried. Although the density difference makes it easy for traditional methods to separate into layers, the acoustic resonance achieves >98% uniformity (the distribution is verified by X-ray CT scanning). (5) The carbon nanotube / resin composite material obtained by the above steps through twin-screw extrusion molding has the following test performance results: tensile strength is 100MPa (increased by 82%), Young's modulus is 4.3GPa (increased by 139%), thermal conductivity is 0.58W / m·K (increased by 190%), and surface resistivity is 1.0×10^4Ω / sq (pure PP is 1.0×10^15Ω / sq, reduced by 11 orders of magnitude). The performance data are positively correlated with the filling amount, but the growth rate is slowing down (threshold effect), which proves the robustness of the technology under high filling. This embodiment is suitable for automotive parts applications with high thermal management requirements and provides an excellent antistatic conductive network.

[0024] Example 4: (1) Take 1.5wt% single-walled carbon nanotube powder (relative to the mass of PP), 5wt% glass fiber, 1.5wt% carbon fiber, 0.6wt% spherical nano-silica, and PP powder, with a total mass of 200g. (2) Modify the surface of the glass fiber and spherical nano-silica (specifically, modify the surface of the glass fiber and spherical nano-silica by treating with a silane coupling agent) and pre-dry. (3) Place the above materials in the mixing chamber of the acoustic resonance mixing equipment, start the equipment, set the acceleration to a medium level of 50g, mix for 10 minutes in the first stage, and increase to 60g for 5 minutes in the second stage. (4) After mixing, the materials are vacuum degassed, hot-pressed pre-formed, and vacuum dried, and the materials are uniformly fused. (5) The carbon nanotube / resin composite material obtained by the above steps through twin-screw extrusion molding has the following test performance results: tensile strength of 93 MPa (55 MPa for pure PP, an increase of 69%), Young's modulus of 3.7 GPa (1.8 GPa for pure PP, an increase of 106%), thermal conductivity of 0.47 W / m·K (0.20 W / m·K for pure PP, an increase of 135%), and surface resistivity of 1.0 × 10^6 Ω / sq (1.0 × 10^15 Ω / sq for pure PP, a decrease of 9 orders of magnitude) measured using the four-probe method (ASTM D257 standard). Compared with Example 2, this example further enhances the formation of conductive network by optimizing the ratio of carbon nanotubes and fibers, improving antistatic performance by one order of magnitude, while maintaining high levels of mechanical and thermal conductivity. This example demonstrates that the synergy between acoustic resonance mixing and spherical nano-silica can efficiently construct continuous conductive paths, suitable for fields such as electronic packaging and precision instrument housings.

[0025] Comparative Example 1: Using the same materials (1 wt% single-walled carbon nanotubes + 4 wt% glass fiber + 1 wt% carbon fiber + 0.5 wt% spherical nano-silica + PP, total mass 100 g), two composite materials were obtained by extrusion after premixing using acoustic resonance mixing (acceleration 30 g, first stage 10 minutes, second stage 5 minutes, including complete pretreatment and posttreatment) and conventional high-speed stirring (5000 rpm, 40 minutes). The data obtained are as follows: the tensile strength of the acoustic resonance sample is 90 MPa, and the Young's modulus is 3.6 GPa (pure P). The tensile strength of the P sample is 1.8 GPa (a 100% improvement), thermal conductivity is 0.48 W / m·K, and surface resistivity is 1.0 × 10^7 Ω / sq (compared to 1.0 × 10^15 Ω / sq for pure PP, a decrease of 8 orders of magnitude). The traditional sample has a tensile strength of 70 MPa (a 27% improvement), a Young's modulus of 2.4 GPa (compared to 1.8 GPa for pure PP, a 33% improvement), thermal conductivity of 0.30 W / m·K (a 50% improvement), and surface resistivity of 1.0 × 10^10 Ω / sq (compared to 1.0 × 10^15 Ω / sq for pure PP, a decrease of 5 orders of magnitude). The difference between the two is attributed to the acoustic flow of acoustic resonance, which better handles the heterogeneity of material properties and avoids damage. This embodiment logically demonstrates the superiority of the invention, including a significant improvement in antistatic properties.

[0026] Comparative Example 2: (1) Take 1 wt% of single-walled carbon nanotube powder (relative to the mass of PP), 4 wt% of glass fiber, 1 wt% of carbon fiber and PP powder (without adding spherical nano silica), with a total mass of 200g for later use. (2) Modify the surface of the glass fiber (specifically, the surface of the glass fiber is modified by silane coupling agent) and pre-dry it. (3) Place the above materials in the mixing chamber of the acoustic resonance mixing equipment, start the equipment, set the acceleration to a medium level of 50g, mix for 10 minutes in the first stage, and increase the acceleration to 60g in the second stage for 5 minutes. (4) After mixing, the materials are degassed under vacuum, pre-formed by hot pressing and vacuum dried. It is observed that the materials are basically uniformly fused, but SEM shows that there is slight agglomeration of carbon nanotubes and fibers between PP particles. (5) The carbon nanotube / resin composite material obtained by the above steps through twin-screw extrusion molding has the following test performance results: tensile strength is 78 MPa (pure PP is 55 MPa, an increase of 42%), Young's modulus is 2.7 GPa (pure PP is 1.8 GPa, an increase of 50%), thermal conductivity is 0.32 W / m·K (pure PP is 0.20 W / m·K, an increase of 60%), and surface resistivity is 1.0 × 10^9 Ω / sq (pure PP is 1.0 × 10^15 Ω / sq, a decrease of 6 orders of magnitude). Compared with Example 2, the performance improvement of this comparative example is significantly reduced (tensile strength is reduced by 18%, Young's modulus by 25%, thermal conductivity by 29%, and surface resistivity by 2 orders of magnitude), proving that although acoustic resonance mixing alone can improve dispersion, the lack of spherical nano-silica as a dispersing aid cannot fully suppress agglomeration, resulting in an incomplete conductive network and heat conduction path, and a lack of synergistic effect. The comparative logic shows that spherical nano-silica is a key synergistic component for achieving high performance, and is suitable for verifying the importance of multi-component synergy in the invention.

[0027]

[0028] Table 1

[0029] As shown in Table 1, the present invention utilizes an acoustic resonance mixing device to generate a standing wave field with a resonance frequency of 50-70Hz. The acceleration can be set to 5-100g (1g=9.8m / s²), thereby applying acoustic flow to multi-component materials with different materials, densities, and properties (such as high-density, high thermal / electrical conductivity single-walled carbon nanotubes, low-density, insulating thermoplastic resin powder, high-density glass fiber / carbon fiber, and spherical nano-silica). The material as a whole is fully fluidized. This resonance enables energy superposition and mechanical vibration to drive the interaction between particles, achieving rapid and uniform mixing without damaging the material structure. In composite carbon nanotube / resin composite materials, the filling amount of single-walled carbon nanotubes can reach 0.5-5wt%, glass fiber 1-10wt%, carbon fiber 0.5-5wt%, and spherical nano-silica 0.1-2wt%, with a dispersion uniformity of >96% (no obvious agglomeration observed by SEM). The mechanical properties are significantly improved (tensile strength >90MPa, modulus >4GPa), with excellent thermal conductivity (thermal conductivity >0.5W / m·K) and outstanding antistatic properties (surface resistivity reduced by 7-10 orders of magnitude). Among them, (1) SWCNTs can provide excellent mechanical reinforcement effect (tensile strength of hundreds of GPa), electrical and thermal conductivity (thermal conductivity of 2000-6000W / m·K, high conductivity) and antistatic properties. By forming a continuous conductive network and thermal conduction path in the matrix, it can improve the overall strength and thermal conductivity efficiency, and reduce the surface resistivity to prevent static electricity accumulation. (2) Thermoplastic resin powder, as the matrix phase, has good mechanical toughness, molding processability and insulation properties, supports extrusion molding and other processes, and can use acoustic resonance to induce surface micro-vibration and interface activation to promote wetting and fusion with fillers. (3) Glass fiber can improve mechanical strength, heat resistance and rigidity. By forming a fiber reinforcement network, it can improve stress transmission and fatigue resistance. It can use acoustic resonance to achieve uniform mixing with a density difference of 10-50%, avoiding the random impact and damage of traditional stirring. (4) Carbon fiber can improve thermal conductivity and rigidity. By constructing thermal conduction path, it can reduce interfacial thermal resistance. At the same time, it can assist the conductive network to enhance antistatic properties. It can use the standing wave field to drive random collisions between particles to achieve high filling and uniform dispersion. (5) Spherical nano silica, as an interface modifier (particle size 100-200nm, surface can be treated with silane coupling agent), can promote filler dispersion and interface bonding. Through its spherical structure, it increases powder flowability and provides shear force to deagglomerate, forming an optimized layer to reduce thermal resistance and electrostatic risks. It can achieve uniform distribution by using acoustic resonance mechanical vibration (no obvious agglomeration in SEM), enhance interface wetting, avoid the environmental risks of traditional solution mixing, and improve the purity of composite materials (>99%).In summary, carbon nanotube / resin composites possess high mechanical strength, excellent thermal conductivity, and antistatic properties (attributed to the formation of a continuous conductive network, fiber-reinforced network, and interface optimization layer by single-walled carbon nanotubes and additives within the thermoplastic resin matrix, effectively reducing the risk of static electricity accumulation, while simultaneously constructing a mechanically reinforced network and thermally conductive pathways to achieve stress transfer and reduce interfacial thermal resistance). Therefore, they can be widely applied in the automotive industry (e.g., heat-resistant components around engines, lightweight structural parts), the electronics and information technology field (e.g., electronic casings with high heat dissipation requirements, integrated circuit packaging materials), and the precision machinery field (e.g., wear-resistant transmission components). They can meet the comprehensive requirements of high-end manufacturing for materials with "high strength, high thermal conductivity, antistatic properties, and easy molding." Furthermore, the preparation process is highly controllable and industrially adaptable, including pretreatment, mixing, and post-treatment, which can effectively improve the production efficiency and quality stability of composite materials. This provides technical support for the high-performance and low-cost industrialization of polymer composites, demonstrating significant economic value and application prospects.

[0030] This invention applies acoustic resonance technology to the mixing of materials with multiple densities, materials, and properties, avoiding the random impacts and delamination risks of traditional mechanical methods. It generates precise standing waves through low-frequency resonance (50-70Hz), driving particle redistribution through inter-particle collisions. The completely random particle motion prevents delamination, achieving selective deagglomeration and interface fusion. Compared to other technical solutions, this invention offers advantages including short processing time (<40 minutes), high energy efficiency (consumption <40% of traditional methods), no need for dispersants (maintaining purity >99%), wide applicability (can handle multiphase systems with density differences >30% and strong performance contrasts, such as conductive, insulating, and reinforcing materials); powerful capabilities, simple details yet broad application, supporting expansion from small-batch laboratory production to continuous industrial production, and the ability to handle high-filler materials, improving the performance of composite materials in automotive lightweighting, thermal management, and antistatic applications. It is also important to emphasize that all other types of composite materials prepared based on acoustic resonance mixing fall within the scope of this application.

[0031] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. It will be apparent to those skilled in the art that the present invention is limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or basic characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0032] Furthermore, it should be understood that although this specification describes the embodiments, the embodiments do not necessarily contain only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A carbon nanotube / resin composite material based on acoustic resonance mixing, characterized in that, The composite material comprises single-walled carbon nanotubes, glass fibers, carbon fibers, spherical nano-silica, and thermoplastic resin powder. The single-walled carbon nanotubes contain 0.5-5 wt%, glass fibers 1-10 wt%, carbon fibers 0.5-5 wt%, spherical nano-silica 0.1-2 wt%, and thermoplastic resin powder 78-97.9 wt%. The preparation method of the carbon nanotube / resin composite material based on acoustic resonance mixing includes the following steps: S1: preparing single-walled carbon nanotubes, thermoplastic resin powder, glass fibers, carbon fibers, and spherical nano-silica according to their proportions, and modifying and pre-drying the surfaces of the glass fibers and spherical nano-silica. S2: The materials from step S1 are fed into the mixing chamber of the acoustic resonance mixing equipment for multi-stage acoustic resonance mixing of multiple materials. The resonance cavity of the mixing equipment generates a resonance frequency of 50Hz-70Hz and an acceleration of 5-100g, forming a standing wave field in the mixing chamber to achieve microscopic uniform dispersion of multiple components, with a dispersion uniformity >96%. S3: After mixing, the materials are subjected to vacuum degassing, hot pressing pre-forming, vacuum drying, and twin-screw extrusion molding to obtain carbon nanotube / resin composite materials. In step S2, the acoustic frequency modulation module of the acoustic resonance mixing equipment, under the control of the control module, can output different frequency signals to the resonance cavity through its own frequency automatic regulator. The resonance cavity can generate a low-frequency standing wave field that acts on the mixing chamber, realizing the acoustic flow and uniform mixing of multi-component raw materials without damaging the physical structure of the materials. The resonant sound waves formed by the low-frequency standing wave field can achieve the mixing of raw material components with a density difference greater than 30% in spherical carbon dioxide. Silicon preferentially deagglomerates and fuses at the interface under shear force without the need for additional dispersants, maintaining a purity greater than 99%; single-walled carbon nanotubes have a purity >80%, a diameter of 0.5nm-2nm, a length of 1μm-100μm, and a density of 1g / cm³-1.8g / cm³; glass fibers have a density of 2g / cm³-2.6g / cm³ and a length of 1mm-10mm; carbon fibers have a density of 1.2g / cm³-1.9g / cm³ and a length of 0.5... mm-5mm; the density of spherical nano-silica is 1.6g / cm³-2.3g / cm³, and the particle size is 100nm-200nm; in step S1, the surface of glass fiber and spherical nano-silica is modified by silane coupling agent treatment. The modification is achieved by stirring glass fiber and spherical nano-silica at room temperature with silane coupling agent for 20-40 minutes. Pre-drying is carried out in a drying equipment at 75°C-85°C for 2-2.5 hours.

2. The carbon nanotube / resin composite material based on acoustic resonance mixing according to claim 1, characterized in that, The thermoplastic resin powder is one or more of the following: polyethylene, polypropylene, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyamide, polycarbonate, polyoxymethylene, polybutylene terephthalate, polyethylene terephthalate, polyetheretherketone, polyimide, polyphenylene sulfide, polyethersulfone, polytetrafluoroethylene, polysulfone, polymethylpentene, ethylene-vinyl acetate copolymer, and polyphthalamide, with a density of 1.0 g / cm³ to 1.4 g / cm³.

3. The carbon nanotube / resin composite material based on acoustic resonance mixing according to claim 1, characterized in that, In the multi-stage acoustic resonance mixing in step S2, the first stage mixes at an acceleration of 30g-80g for 8-12 minutes, and the second stage mixes at an acceleration of 60g-95g for 2-8 minutes, with a total mixing time of <40 minutes.

4. The carbon nanotube / resin composite material based on acoustic resonance mixing according to claim 1, characterized in that, In step S3, the vacuum degassing device operates at a vacuum level of -0.1MPa to 0.2MPa for 15 to 25 minutes; the hot pressing device operates at a pressure of 5MPa to 6MPa, a temperature of 150°C to 160°C for 10 to 15 minutes; the vacuum drying device operates at a material temperature of 60°C to 65°C for 60 to 70 minutes; and the carbon nanotube / resin composite material exhibits tensile strength >90MPa, Young's modulus >4GPa, thermal conductivity >0.5W / m•K, and surface resistivity of 1.0×10^4-1.0×10^9Ω / sq.

5. The carbon nanotube / resin composite material based on acoustic resonance mixing according to claim 1, characterized in that, In step S2, the applied acoustic resonance mixing equipment includes a resonant cavity, an acoustic frequency modulation module, a mixing chamber, a control module, and a fixing device. The resonant cavity is installed in the middle of the housing via the fixing device. The acoustic frequency modulation module is installed at the lower end of the resonant cavity. The mixing chamber is installed inside the resonant cavity. The control module is installed at the front end of the housing. The power output terminal of the control module and the power input terminal of the acoustic frequency modulation module are connected to the lower interior of the frequency modulation module via wires. The vacuum degassing device is installed at the rear of the resonant cavity. The air inlet pipe of the vacuum degassing device and the exhaust pipe at the upper end of the mixing chamber are connected via pipes. The front end of the housing has a sealed soundproof door. Before mixing, the sealed door is opened to put raw materials into the mixing chamber and the sealed soundproof door is closed.

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