Polypropylene composite material and preparation method and application thereof

Abstract

This application discloses a polypropylene composite material, its preparation method, and its application, relating to the field of polymer materials technology. This application provides a polypropylene composite material comprising the following components in parts by weight: 40-95 parts PP resin, 1-5 parts silica gel adsorbent, 1-5 parts carbon nanotubes, and 1-20 parts filler; wherein the pore size of the silica gel adsorbent is D1, and the outer diameter (D50) of the carbon nanotubes is D2, with 0 ≤ D1 - D2 ≤ 17 nm. This application provides a polypropylene composite material that, through the synergistic effect of the silica gel adsorbent and carbon nanotubes, solves the material emission problem and forms a physically cross-linked structure in the system to achieve a low linear expansion coefficient and excellent scratch resistance.

Description

Technical Field

[0001] This application relates to the field of polymer materials technology, and in particular to a polypropylene composite material, its preparation method and application. Background Technology

[0002] Polypropylene has become one of the mainstream materials for the production of automotive interior and exterior parts due to its excellent comprehensive properties such as light weight, balanced mechanical properties, convenient processing and molding, and controllable cost. It is widely used in the manufacturing of various interior parts such as dashboards, door panels, and pillars, and plays an important role in promoting the lightweight and low-cost development of automotive interiors.

[0003] However, existing polypropylene materials still suffer from numerous technical defects that urgently need to be addressed in practical automotive applications, severely hindering their application effectiveness and future development. On one hand, the linear coefficient of thermal expansion (CLTE) of existing polypropylene materials is generally high, making automotive interior parts prone to thermal deformation under harsh conditions such as high temperatures and direct sunlight in summer. This leads to decreased dimensional stability of components, resulting in warping, increased gaps, and other problems, affecting the assembly precision and reliability of the interior components. On the other hand, the material releases a large amount of volatile organic compounds (VOCs) during processing and molding. These VOCs emit irritating odors, directly damaging the air quality inside the vehicle and harming the health of passengers, failing to meet the stringent environmental performance requirements of the current automotive industry. To address these issues, the industry has conducted relevant research and proposed two main improvement solutions: First, adjusting the CLTE value by adding fillers, modifiers, and other components to the polypropylene substrate. However, this approach often comes at the cost of sacrificing other key properties such as material toughness and processing fluidity, making it difficult to achieve a balance in overall performance. Second, using low-odor raw materials or adding odor adsorbents to reduce VOC content and odor. However, the selection range of existing low-odor raw materials is narrow, and adsorbents suffer from problems such as unreasonable formulation design and imperfect preparation processes. Their ability to remove odor and total volatile organic compounds (TVOC) is limited, and they also increase the material preparation cost, making it impossible to achieve large-scale application.

[0004] In conclusion, developing a polypropylene composite material that combines low CLTE value, low odor, and good scratch resistance has become an urgent technological need in the field of automotive interior materials. Summary of the Invention

[0005] Based on this, the purpose of this application is to overcome the shortcomings of the prior art and provide a polypropylene composite material with low CLTE value, low odor, and good scratch resistance, as well as its preparation method and application.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: a polypropylene composite material comprising the following components in parts by weight: 40-95 parts of PP resin, 1-5 parts of silica gel adsorbent, 1-5 parts of carbon nanotubes, and 1-20 parts of filler; wherein the pore size of the silica gel adsorbent is D1, the outer diameter of the carbon nanotubes is D2, and 0≤D1-D2≤17nm.

[0007] In one embodiment, D1-D2 is a range of one or any two of the following: 0 nm, 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm, 5.5 nm, 6 nm, 5.5 nm, 7 nm, 7.5 nm, 8 nm, 9 nm, 9.5 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, and 17 nm.

[0008] Wherein, the pore size D1 of the silica gel adsorbent is the average diameter of the pores in the porous structure inside the silica gel adsorbent; the test method is to use a pore size analyzer to calculate the specific surface area, pore size distribution, and total pore volume of the material through nitrogen adsorption-desorption isotherms, and the test standard is GB / T 21650.2-2008. The silica gel described in this application is an inorganic silica gel with a porous structure, CAS number 112926-00-8. The outer diameter D2 of the carbon nanotube refers to the diameter of the carbon nanotube from the outer surface to the outer surface, that is, the distance between the two farthest points on the outer periphery of the carbon nanotube; the method used is based on direct imaging and image analysis using transmission electron microscopy (TEM), and the relevant standard is GB / T 26826-2011; As an embodiment of this application, the particle size D50 of the silica gel adsorbent is ≤50μm; in one embodiment, the particle size D50 of the silica gel adsorbent is ≤30μm; in another embodiment, the particle size D50 of the silica gel adsorbent is a range of one or any two of the following: 1μm, 2μm, 5μm, 8μm, 10μm, 15μm, 18μm, 20μm, 25μm, 28μm, 30μm, 35μm, 38μm, 40μm, 45μm, 48μm, and 50μm. The particle size of the silica gel adsorbent is determined by using a Malvern laser particle size analyzer with a laser beam of 630nm wavelength, a scattering angle of 90°, and a testing time of 300s, measuring the angle and intensity distribution of the scattered light to calculate the particle size.

[0009] As an embodiment of this application, the carbon nanotube can be a single-walled carbon nanotube or a multi-walled carbon nanotube.

[0010] As an embodiment of this application, the length of the carbon nanotube is 3-55 μm; in one embodiment, the length of the carbon nanotube is one or any two of the following: 3 μm, 5 μm, 8 μm, 10 μm, 15 μm, 18 μm, 20 μm, 25 μm, 28 μm, 30 μm, 35 μm, 38 μm, 40 μm, 45 μm, 48 μm, 50 μm, and 55 μm.

[0011] As an embodiment of this application, the specific surface area of ​​the silica gel adsorbent is 80-480 m². 2 / g; In one embodiment, the specific surface area of ​​the silica gel adsorbent is 80m². 2 / g, 100m 2 / g, 150m 2 / g、200m 2 / g、250m 2 / g、300m 2 / g、380m 2 / g、480m 2 The range of one or both of the values ​​in / g.

[0012] This application provides a polypropylene composite material that, through the synergistic effect of silica gel adsorbent and carbon nanotubes, addresses the issue of material odor emission by forming a physically cross-linked structure within the system, achieving a low coefficient of linear expansion (CLE) and excellent scratch resistance. The compatibility between the D50 outer diameter of the carbon nanotubes and the pore size of the silica gel adsorbent allows the carbon nanotubes to migrate into the porous adsorbent during melt shearing, forming a physical overlap that connects the adsorbents into a cross-linked network. Firstly, the silica gel adsorbent rapidly captures and adsorbs low-emission odor molecules generated during the melt shearing of the material. Simultaneously, the cross-linked network confines these pre-adsorbed odor molecules within the porous adsorbent, further reducing odor interference and enhancing the adsorption effect. Secondly, the cross-linked network restricts molecular chain slippage, reducing the degree of internal molecular chain movement caused by temperature changes, minimizing macroscopic dimensional changes, and imparting a low CLE characteristic to the material. Thirdly, the cross-linked network improves the material's rigidity, and the addition of carbon nanotubes induces increased crystallinity in the polypropylene, increasing surface hardness and giving the material excellent scratch resistance.

[0013] As an embodiment of this application, the polypropylene composite material comprises the following components in parts by weight: 50-70 parts of PP resin, 2-4 parts of silica gel adsorbent, 2-4 parts of carbon nanotubes, and 5-15 parts of filler.

[0014] As an embodiment of this application, the weight percentage of PP resin in the polypropylene composite material is not less than 60%.

[0015] As an embodiment of this application, the weight ratio of the silica gel adsorbent to the carbon nanotubes is (0.2-2):1; in one embodiment, the weight ratio of the silica gel adsorbent to the carbon nanotubes is (0.5-1):1.

[0016] In one embodiment, the silica gel adsorbent has a weight percentage of 1.0-5.8 wt% in the polypropylene composite material; in another embodiment, the silica gel adsorbent has a weight percentage in the polypropylene composite material within the range of one or any two of the following: 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt%, 2 wt%, 2.3 wt%, 2.5 wt%, 2.9 wt%, 3 wt%, 3.3 wt%, 3.5 wt%, 3.9 wt%, 4 wt%, 4.3 wt%, 4.5 wt%, 5 wt%, 5.3 wt%, 5.6 wt%, and 5.8 wt%.

[0017] In one embodiment, the carbon nanotubes in the polypropylene composite material have a weight percentage of 2.0-6.2 wt%; in another embodiment, the carbon nanotubes in the polypropylene composite material have a weight percentage of one or any two of the following: 2.0 wt%, 2.3 wt%, 2.5 wt%, 2.9 wt%, 3 wt%, 3.3 wt%, 3.5 wt%, 3.9 wt%, 4 wt%, 4.3 wt%, 4.5 wt%, 5 wt%, 5.3 wt%, 5.5 wt%, 5.9 wt%, and 6.2 wt%.

[0018] In one embodiment, the PP resin is in the range of 40 parts, 50 parts, 55 parts, 60 parts, 65 parts, 68 parts, 70 parts, 80 parts, 85 parts, 90 parts, and 95 parts by weight, or any two of these values; the silica gel adsorbent is in the range of 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, and 5 parts by weight, or any two of these values; and the carbon nanotubes are in the range of 1 part, 1 part, and 1 part by weight. The range of 5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, or any two of these values; the weight of the filler is 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, or any two of these values.

[0019] As an implementation scheme of this application, the following conditions must be met: 3nm≤D1≤35nm.

[0020] In one embodiment, D1 is a range of one or any two of the following: 3nm, 5nm, 5.5nm, 6nm, 5.5nm, 7nm, 7.5nm, 8nm, 9nm, 9.5nm, 10nm, 13nm, 15nm, 20nm, 23nm, 25nm, 28nm, 30nm, 32nm, and 35nm.

[0021] As an implementation of this application, 0.5nm≤D2≤35nm is satisfied; in one embodiment, 12nm≤D2≤15nm is satisfied.

[0022] In one embodiment, D2 is a range of one or any two of the following: 0.5nm, 2nm, 3nm, 4nm, 5nm, 5.5nm, 6nm, 5.5nm, 7nm, 7.5nm, 8nm, 9nm, 9.5nm, 10nm, 13nm, 15nm, 20nm, 23nm, 25nm, 28nm, 30nm, 32nm, and 35nm.

[0023] As an embodiment of this application, the PP resin has a melt flow rate of 28-65 g / 10 min at 230°C / 2.16 kg load according to ISO 1133-2011; in one embodiment, the PP resin has a melt flow rate of 28 g / 10 min, 30 g / 10 min, 35 g / 10 min, 40 g / 10 min, 45 g / 10 min, 48 g / 10 min, 50 g / 10 min, 65 g / 10 min, or any two of these values ​​at 230°C / 2.16 kg load according to ISO 1133-2011.

[0024] As an embodiment of this application, the filler is at least one of talc, mica, wollastonite, and calcium carbonate.

[0025] In one embodiment, the particle size D90 of the filler is 5-15 μm; in another embodiment, the particle size D90 of the filler is a range of one or any two of 5 μm, 6 μm, 7 μm, 8 μm, 10 μm, 12 μm, 13 μm, and 15 μm.

[0026] The particle size D90 of the filler was tested using a laser method, as follows: 3g of filler was added to 500mL of water and shaken in an ultrasonic instrument for 1min. The well-dispersed sample was then added and placed in a Malvern laser particle size analyzer for testing. The laser wavelength was 630nm, the scattering angle was 90°, the test time was 300s, the correlator was set to low speed, the medium temperature was 21°C, the light intensity distribution type was selected, and the CONTIN2 analysis mode was used.

[0027] As an embodiment of this application, the polypropylene composite material further includes 0-5 parts of processing aids, wherein the aids are at least one of antioxidants, lubricants, and light stabilizers; for example, 0.2-2 parts of antioxidants, 0.3-3 parts of lubricants, and 0.2-1 parts of light stabilizers.

[0028] In one embodiment, the antioxidant is at least one of hindered phenolic antioxidants, hindered amine antioxidants, and phosphite antioxidants. Specifically, the antioxidant includes, but is not limited to, at least one of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine (antioxidant 1098), tris[2,4-di-tert-butylphenyl]phosphite (antioxidant 168), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), and phosphite antioxidants.

[0029] In one embodiment, the lubricant is at least one of stearic acid, stearate, and organosilicon compounds, such as pentaerythritol stearate, zinc stearate, etc.

[0030] In one embodiment, the light stabilizer is a hindered amine light stabilizer, such as UV-3808, LA-402XP, LA-402AF, etc.

[0031] In addition, this application also provides a method for preparing the aforementioned polypropylene composite material, comprising the following steps: (1) Weigh each component according to its weight parts; (2) The above components are mixed and added to an extruder for melt dispersion, melt mixing, extrusion granulation, and the polypropylene composite material is obtained.

[0032] In one embodiment, the conditions for melt extrusion of the extruder are: extrusion temperature 200-240℃, screw length-to-diameter ratio 40-50:1, and screw speed 350-450 rpm.

[0033] Furthermore, this application provides the application of the aforementioned polypropylene composite material in the automotive field; specifically, it includes at least one of automotive interior and exterior trim, such as door panels, dashboards, pillars, tailgate interior panels, and other components that are relatively large in size and require high dimensional stability, as well as low emission and scratch resistance.

[0034] Furthermore, this application provides a component formed from the aforementioned polypropylene composite material, wherein the forming method includes, but is not limited to, injection molding, blow molding, vacuum forming, and extrusion.

[0035] Compared to existing technologies, the beneficial effects of this application are as follows: This application provides a polypropylene composite material that, through the synergistic effect of silica gel adsorbent and carbon nanotubes, solves the material emission problem and forms a physical cross-linked structure in the system to achieve a low linear expansion coefficient and excellent scratch resistance. The compatibility between the D50 outer diameter of the carbon nanotubes and the pore size of the silica gel adsorbent allows the carbon nanotubes to migrate into the porous adsorbent during melt shearing, forming a physical overlap that connects the adsorbents to form an interconnected cross-linked network. Firstly, the silica gel adsorbent rapidly captures and adsorbs low-emission odor molecules generated during the melt shearing of the material. Simultaneously, the interconnected cross-linked network confines the odor molecules pre-adsorbed into the porous adsorbent within the porous adsorbent, further reducing odor interference and enhancing the adsorption effect. Secondly, the interconnected cross-linked network restricts the slippage of molecular chains, reduces the degree of internal molecular chain movement caused by temperature changes, reduces macroscopic size changes, and endows the material with low CLTE characteristics. Thirdly, the interconnected cross-linked network improves the rigidity of the material, and the addition of carbon nanotubes induces increased crystallinity in polypropylene, increasing surface hardness and giving the material good scratch resistance. Detailed Implementation

[0036] To better illustrate the purpose, technical solution, and advantages of this application, the following detailed description, in conjunction with specific embodiments, will further illustrate the application. The purpose is to provide a detailed understanding of the content of this application, not to limit it. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application. Unless otherwise specified, the experimental reagents and instruments designed in the embodiments and comparative examples of this application are commonly used and commercially available. Unless otherwise specified, the experimental methods used in the embodiments and comparative examples are conventional methods; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch.

[0037] The raw materials used in the embodiments and comparative examples are described below, but are not limited to these materials: PP-1: Melt flow rate 30g / 10min (230℃ / 2.16kg), PP KF-Z30S, Ningbo Kingfa New Materials Co., Ltd.; PP-2: Melt flow rate 60g / 10min (230℃ / 2.16kg), PP M60RHC, Zhenhai Refining & Chemical Branch of China Petroleum & Chemical Corporation; Silica gel adsorbent-1: pore size 6nm, particle size D50 3μm, SP-60-3-P, Beijing Yinglaike Technology Development Co., Ltd.; Silica gel adsorbent-2: pore size 12nm, particle size D50 3μm, SP-120-3-P, Beijing Yinglaike Technology Development Co., Ltd.; Silica gel adsorbent-3: pore size 20nm, particle size D50 3μm, SP-200-3-P, Beijing Yinglaike Technology Development Co., Ltd.; Silica gel adsorbent-4: pore size 30nm, particle size D50 3μm, SP-300-3-P, Beijing Yinglaike Technology Development Co., Ltd.; Silica gel adsorbent-5: pore size 12nm, particle size D50 20μm, SP-120-20-P, Beijing Yinglaike Technology Development Co., Ltd.; Silica gel adsorbent-6: pore size 12nm, particle size D50 50μm, SP-120-40 / 60, Beijing Yinglaike Technology Development Co., Ltd.; Carbon nanotube-1: Single-walled carbon nanotube, HQNANO-CNTs-002, D50 outer diameter 1.5nm, Suzhou Carbon-rich Graphene Technology Co., Ltd. Carbon nanotube-2: Multi-walled carbon nanotube, HQNANO-CNTs-006, D50 outer diameter 5nm, Suzhou Carbon-rich Graphene Technology Co., Ltd. Carbon nanotube-3: Multi-walled carbon nanotube HQNANO-CNTs-006-1, D50 outer diameter 12nm, Suzhou Carbon-rich Graphene Technology Co., Ltd. Carbon nanotube-4: Multi-walled carbon nanotube, HQNANO-CNTs-006-2, D50 outer diameter 15nm, Suzhou Carbon-rich Graphene Technology Co., Ltd. Carbon Nanotube-5: Multi-walled carbon nanotube, HQNANO-CNTs-006-3, D50 outer diameter 20nm, Suzhou Carbon-rich Graphene Technology Co., Ltd. Talc powder: TYT-777A, commercially available; The antioxidant is a compound of commercially available hindered phenolic antioxidant 1010 and commercially available phosphite antioxidant 168 in a mass ratio of 1:1.

[0038] Comparative raw materials: Zeolite molecular sieve; MCM-41, Aladdin, pore size 3.5 nm; Diatomaceous earth; Celite@ R566, Sigma-Aldrich, pore size 12nm; Examples and Comparative Examples The polypropylene composite material of the present invention has the following composition as shown in Tables 1-2. The preparation method of the polypropylene composite material includes the following steps: (1) Weigh each component according to its weight parts; (2) The above components are mixed and added to an extruder for melt dispersion, melt mixing, extrusion granulation, and the polypropylene composite material is obtained.

[0039] The conditions for melt extrusion of the extruder are as follows: extrusion temperature 200-240℃, zone 1: 200℃, zone 2: 200℃, zone 3: 205℃, zone 4: 210℃, zone 5: 220℃, zone 6: 220℃, zone 7: 230℃, zone 8: 240℃, screw length-to-diameter ratio 40, and screw speed 450 rpm.

[0040] Performance testing (1) Odor test: Tested according to Volkswagen's PV 3900-2019 standard, 50g particles, dried at 80℃ for 2 hours, and evaluated at 65℃; (2) Scratch resistance: Tested according to Volkswagen PV 3952-2002 standard. The specific test conditions are as follows: test load: F=10N, cutting speed: V=1000mm / min, scraper diameter: 1mm, number of scratches: 20*20, scratch spacing: 2mm, colorimeter-light source: D65 / 10 ° test ΔL.

[0041] (3) CLTE test: The polypropylene composition was injection molded into a sample of 80×10×4mm, and the CLTE was tested using the sample according to the standard ISO11359-2:2021. Example 1 A polypropylene composite material comprises the following components in parts by weight: PP resin - 165 parts, silica gel adsorbent - 13 parts, carbon nanotubes - 13 parts, talc powder - 12 parts and antioxidant - 0.4 parts.

[0042] Example 2 A polypropylene composite material, compared with Example 1, differs only in the selection of silica gel adsorbent and carbon nanotubes; specifically, silica gel adsorbent-2 and carbon nanotube-2 are selected.

[0043] Example 3 A polypropylene composite material, compared with Example 1, differs only in the selection of silica gel adsorbent and carbon nanotubes; specifically, silica gel adsorbent-3 and carbon nanotubes-2 are selected.

[0044] Example 4 A polypropylene composite material, compared with Example 1, differs only in the selection of silica gel adsorbent and carbon nanotubes; specifically, silica gel adsorbent-3 and carbon nanotube-3 are selected.

[0045] Example 5 A polypropylene composite material, compared with Example 1, differs only in the selection of silica gel adsorbent and carbon nanotubes; specifically, silica gel adsorbent-3 and carbon nanotubes-4 are selected.

[0046] Example 6 A polypropylene composite material, compared with Example 1, differs only in the selection of silica gel adsorbent and carbon nanotubes; specifically, silica gel adsorbent-3 and carbon nanotubes-5 are selected.

[0047] Example 7 A polypropylene composite material, compared with Example 1, differs only in the selection of silica gel adsorbent and carbon nanotubes; specifically, silica gel adsorbent-4 and carbon nanotubes-5 are selected.

[0048] Example 8 A polypropylene composite material, compared with Example 2, differs only in the choice of silica gel adsorbent; specifically, silica gel adsorbent-5 is selected.

[0049] Example 9 A polypropylene composite material, compared with Example 2, differs only in the choice of silica gel adsorbent; specifically, silica gel adsorbent-6 is selected.

[0050] Table 1 Table 2 Table 3 As shown in the table above, the polypropylene composite material prepared in the embodiments of the present invention has an odor of ≤4.0, ΔL ≤1.0, and CLTE ≤50. The polypropylene composite material prepared in the embodiments of the present invention has low CLTE value, low odor, and good scratch resistance.

[0051] A comparison of Examples 1-9 shows that when the pore size of the silica gel adsorbent is D1 and the outer diameter (D50) of the carbon nanotubes is D2, the prepared polypropylene composite material exhibits low CLTE value, low odor, and good scratch resistance when 0 ≤ D1 - D2 ≤ 17 nm. A comparison of Examples 3-6 shows that the overall performance is better when the outer diameter (D50) of the carbon nanotubes is 12 nm ≤ D2 ≤ 15 nm. A comparison of Examples 2 and Examples 8-9 shows that the larger the particle size (D50) of the silica gel adsorbent, the worse the scratch resistance.

[0052] As can be seen from the comparison between Example 1 and Example 10, the melt flow rate of PP resin has little effect on the final performance. The prepared polypropylene composite material has low CLTE value, low odor, and good scratch resistance.

[0053] A comparison of Examples 1 and 11-13 shows that the overall performance is better when the weight ratio of silica gel adsorbent to carbon nanotubes is (0.5-1):1. A comparison of Examples 1 and 14-16 shows that the overall performance is better when the mixture consists of 50-70 parts PP resin, 2-4 parts silica gel adsorbent, 2-4 parts carbon nanotubes, and 5-15 parts filler.

[0054] As can be seen from the comparison of Example 1 and Comparative Examples 1-2, when the pore size of the silica gel adsorbent is D1 and the outer diameter of the carbon nanotube is D2, which does not satisfy 0≤D1-D2≤17nm, the carbon nanotube cannot migrate into the interior of the porous adsorbent, and the odor deteriorates significantly.

[0055] As can be seen from the comparison of Example 1 and Comparative Examples 3-4, zeolite molecular sieves or diatomaceous earth were chosen to replace silica gel adsorbents because zeolite molecular sieves and diatomaceous earth are both rigid materials. The migration of carbon nanotubes into the adsorbent will cause breakage, reduce the ability to induce crystallization, increase the CLTE value, and reduce scratch resistance.

[0056] As can be seen from the comparison of Example 1 and Comparative Examples 5-6, Comparative Example 5 does not contain silica gel adsorbent, has poor adsorption capacity, and has an extremely unpleasant odor. Comparative Example 6 does not contain carbon nanotubes, resulting in a poorer ability to induce crystallization, leading to an increase in the CLTE value and a decrease in scratch resistance.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit the scope of protection of this application. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A polypropylene composite, characterized in that, It includes the following components in parts by weight: 40-95 parts PP resin, 1-5 parts silica gel adsorbent, 1-5 parts carbon nanotubes, and 1-20 parts filler. Wherein, the pore size of the silica gel adsorbent is D1, the outer diameter of the carbon nanotube is D2 (D50), and 0 ≤ D1 - D2 ≤ 17 nm.

2. The polypropylene composite of claim 1, wherein, It includes the following components in parts by weight: 50-70 parts PP resin, 2-4 parts silica gel adsorbent, 2-4 parts carbon nanotubes, and 5-15 parts filler.

3. The polypropylene composite of claim 1, wherein the polypropylene is a homopolymer of propylene. The weight ratio of the silica gel adsorbent to the carbon nanotubes is (0.2-2):1; preferably, the weight ratio of the silica gel adsorbent to the carbon nanotubes is (0.5-1):

1.

4. The polypropylene composite material as described in claim 1, characterized in that, The 3nm≤D1≤35nm; and / or the 0.5nm≤D2≤35nm.

5. The polypropylene composite material as described in claim 1, characterized in that, Includes at least one of the following (1)-(2): (1) The melt flow rate of the PP resin at 230℃ / 2.16kg load is 28-65g / 10min according to ISO 1133-2011; (2) The filler is at least one of talc, mica, wollastonite and calcium carbonate.

6. The polypropylene composite material as described in claim 1, characterized in that, It also includes 0-5 parts of processing aids, wherein the aids are at least one of antioxidants, lubricants, and light stabilizers.

7. A method for preparing a polypropylene composite material according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Weigh each component according to its weight parts; (2) The above components are mixed and added to an extruder for melt dispersion, melt mixing, extrusion granulation, and the polypropylene composite material is obtained.

8. The application of a polypropylene composite material as described in any one of claims 1-6 in the automotive field.

9. The application as described in claim 8, characterized in that, The automotive field includes at least one of automotive interiors and automotive exteriors.

10. An article formed from a polypropylene composite material comprising any one of claims 1-6.

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