High-thermal-conductivity polypropylene composite material and preparation method thereof

Abstract

The invention discloses a high-thermal-conductivity polypropylene composite material and a preparation method thereof, and belongs to the technical field of high polymer material modification. The high-thermal-conductivity polypropylene composite material comprises the following components in parts by mass: 70-80 parts of polypropylene resin; 20 to 30 parts of graphene oxide; 0.1 to 0.5 part of a double-walled carbon nanotube; 5 parts of maleic anhydride grafted polypropylene; and 1 part of an auxiliary agent. Wherein the adopted graphene oxide has a two-position structure, the double-walled carbon nanotube has a one-dimensional structure, and both the graphene oxide and the double-walled carbon nanotube have very high heat conductivity coefficients; when the two materials are added into polypropylene at the same time, the micro-content of the double-walled carbon nanotube with the one-dimensional structure plays a role in lapping in the melt blending process, and forms a network structure together with the graphene oxide with the two-dimensional structure, so that the heat-conducting property of the polypropylene composite material is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material modification, and particularly relates to a high thermal conductivity polypropylene composite material and a preparation method thereof. Background Art

[0002] As an indispensable functional material in military and civilian applications, thermal conductive materials are widely used in various fields such as electronic and electrical packaging, heat exchangers, aerospace, etc. At present, electronic technology is advancing rapidly, and electronic devices have formed a development trend towards intelligence and integration. The heat generated per unit volume has increased sharply. If this heat cannot be dissipated in time, it will seriously affect the stability, safety and life of the equipment. This puts forward higher and newer requirements for the performance of the material. It is hoped that the thermal conductivity of the material can better meet the requirements of industrial use on the basis of excellent mechanical properties.

[0003] Polypropylene has the advantages of light weight, corrosion resistance, good insulation performance and easy processing, and has been widely used in the automotive, home appliance and other industries. However, its poor thermal conductivity seriously affects the application of polypropylene in high-end industrial fields. Therefore, a high thermal conductivity polypropylene composite material is proposed. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a high thermal conductivity polypropylene composite material and a preparation method thereof, which solves the problems in the prior art.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A polypropylene composite material comprises the following raw materials in parts by weight:

[0007]

[0008]

[0009] Furthermore, the auxiliary agent includes an antioxidant, an auxiliary antioxidant, a light absorber and a light stabilizer, and the mass ratio thereof is 1:1:1:1.

[0010] Furthermore, the antioxidant is a hindered phenol antioxidant.

[0011] Furthermore, the auxiliary antioxidant is a phosphite antioxidant.

[0012] Furthermore, the light absorber is a benzotriazole light absorber.

[0013] Furthermore, the light stabilizer is a hindered amine light stabilizer.

[0014] The method for preparing the above-mentioned polypropylene composite material comprises the following steps:

[0015] S1, mixing polypropylene resin, graphene oxide, double-walled carbon nanotubes, maleic anhydride grafted polypropylene and an additive, and stirring to obtain a mixture;

[0016] S2, feeding the mixture into the main feeding port of a parallel twin-screw extruder, and then melting and extruding to obtain granules.

[0017] Furthermore, in S1, the stirring speed is 500 r / min and the stirring time is 10 min.

[0018] Furthermore, in S2, the barrel temperature of the twin-screw extruder is: 160°C in zone 1, 180°C in zone 2, 190°C in zone 3, 200°C in zone 4, 210°C in zone 5, and 220°C in zone 6; the head temperature is 210°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0019] The above-mentioned polypropylene composite material is used in the preparation of electronic device packaging shells.

[0020] Beneficial effects of the present invention:

[0021] 1. The high thermal conductivity polypropylene composite material prepared by the present invention can be recycled and reused to meet the development needs of green and recycled materials.

[0022] 2. The graphene oxide used in the present invention has a very high thermal conductivity, and the increased oxygen-containing functional groups make its properties more active than graphene, and its dispersion performance is better than graphene. When added to polypropylene, it is well dispersed under the dual effects of PP-MA compatibilizer and twin screw, which can significantly improve the thermal conductivity of polypropylene.

[0023] 3. The high thermal conductivity polypropylene composite material prepared by the present invention has a two-dimensional graphene oxide and a one-dimensional double-arm carbon nanotube, both of which have very high thermal conductivity. When both are added to polypropylene at the same time, the trace amount of double-walled carbon nanotubes with a one-dimensional structure plays a role of overlapping during the melt blending process, so that the heat conduction path formed by the two-dimensional graphene oxide is further improved, and the two together form a more complex network structure, which greatly improves the thermal conductivity of the polypropylene composite material.

[0024] 4. The preparation process of the present invention is simple and can be mass-produced. The injection-molded high thermal conductivity polypropylene composite material product has the characteristics of high strength, high modulus, high toughness and high thermal conductivity, and has very high commercial properties. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] A high thermal conductivity polypropylene composite material comprises the following raw materials in parts by weight:

[0027]

[0028] The polypropylene resin is industrial conventional polypropylene; the graphene oxide is industrial conventional graphene oxide; the double-walled carbon nanotube is industrial conventional double-arm carbon nanotube; and the maleic anhydride grafted polypropylene is industrial conventional maleic anhydride grafted polypropylene.

[0029] The auxiliary agents include antioxidants, auxiliary antioxidants, light absorbers and light stabilizers, and the mass ratio thereof is 1:1:1:1.

[0030] The antioxidant is a hindered phenol antioxidant, such as Irganox 1 and RIANOX 330; the auxiliary antioxidant is a phosphite antioxidant, such as AN 168 and PEP-36; the light absorber is a benzotriazole light absorber, such as Chiguard 5050 and UV-P; the light stabilizer is a hindered amine light stabilizer, such as LA-52 and RIASORB UV-944.

[0031] The above-mentioned method for preparing a high thermal conductivity polypropylene composite material comprises the following steps:

[0032] S1, mixing polypropylene resin, graphene oxide, double-walled carbon nanotubes, maleic anhydride grafted polypropylene, and an auxiliary agent, and stirring at a speed of 500 r / min for 10 minutes to obtain a mixture.

[0033] S2, feeding the mixture into the main feeding port of a parallel twin-screw extruder, and obtaining a high thermal conductivity polypropylene composite material through melting, extrusion and granulation;

[0034] Among them, the barrel temperature of the parallel twin-screw extruder is: 160°C in zone 1, 180°C in zone 2, 190°C in zone 3, 200°C in zone 4, 210 in zone 5, and 220°C in zone 6, the head temperature is 210°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0035] The preparation process of the polypropylene composite material is described below by the following examples (the parts in Examples 1-5 and Comparative Examples 1-3 are all parts by mass), wherein the raw materials used in Examples 1-5 and Comparative Examples 1-3 are specifically as follows:

[0036] Polypropylene homopolymer (PP-H), grade 012, density 0.9g / cm 3 , melt index 1.2g / 10min (temperature 230℃, load 2.16Kg), Shandong Wusheng Natural Gas Chemical Co., Ltd.

[0037] Graphene oxide, thickness: 0.55-1.2 nm, diameter: 0.5-3 μm, number of layers: 1-5 layers, Zhongke Leiming (Beijing) Technology Co., Ltd.

[0038] Double-walled carbon nanotubes, diameter 10-20nm, length 10-30μm, manufacturer: Beijing Dekedaojin Technology Co., Ltd.

[0039] Maleic anhydride grafted polypropylene, brand: Saudi Basel 350K, grafting rate 0.7-0.9%, manufacturer: Dongguan Shenghao Plastic Raw Materials Co., Ltd.

[0040] The additives include a primary antioxidant, a secondary antioxidant, a light absorber and a light stabilizer, which are mixed in a mass ratio of 1:1:1:1. The primary antioxidant is Irganox 565, manufactured by BASF, Germany. The secondary antioxidant is AN 168, manufactured by Qingdao Deda Special Chemical Group. The light absorber is Chiguard 5050, manufactured by Qitai Co., Ltd. The light stabilizer is LA-52, manufactured by Aidico (China) Investment Co., Ltd.

[0041] Example 1

[0042] S1, weigh 80 parts of polypropylene resin, 20 parts of graphene oxide, 0.1 parts of double-walled carbon nanotubes, 5 parts of maleic anhydride grafted polypropylene, and 1 part of an auxiliary agent, and stir them at a speed of 500 r / min for 10 minutes using a high-speed mixer to obtain a uniformly mixed material.

[0043] S2, putting the uniformly mixed materials into a parallel twin-screw extruder for melting, extrusion and granulation to obtain a polypropylene composite material; wherein the barrel temperature of the parallel twin-screw extruder is: 160°C in zone 1, 180°C in zone 2, 190°C in zone 3, 200°C in zone 4, 210°C in zone 5, and 220°C in zone 6, the machine temperature is 210°C at the head, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0044] Example 2

[0045] S1, weigh 80 parts of polypropylene resin, 20 parts of graphene oxide, 0.3 parts of double-walled carbon nanotubes, 5 parts of maleic anhydride grafted polypropylene, and 1 part of an auxiliary agent, and stir them at a speed of 500 r / min for 10 minutes using a high-speed mixer to obtain a uniformly mixed material.

[0046] S2 is the same as S2 in Example 1.

[0047] Example 3

[0048] S1, weigh 80 parts of polypropylene resin, 20 parts of graphene oxide, 0.5 parts of double-walled carbon nanotubes, 5 parts of maleic anhydride grafted polypropylene, and 1 part of an auxiliary agent, and stir them at a speed of 500 r / min for 10 minutes using a high-speed mixer to obtain a uniformly mixed material.

[0049] S2 is the same as S2 in Example 1.

[0050] Example 4

[0051] S1, weigh 75 parts of polypropylene resin, 25 parts of graphene oxide, 0.5 parts of double-walled carbon nanotubes, 5 parts of maleic anhydride grafted polypropylene, and 1 part of an auxiliary agent, and stir them at a speed of 500 r / min for 10 minutes using a high-speed mixer to obtain a uniformly mixed material.

[0052] S2 is the same as S2 in Example 1.

[0053] Example 5

[0054] S1, weigh 70 parts of polypropylene resin, 30 parts of graphene oxide, 0.5 parts of double-walled carbon nanotubes, 5 parts of maleic anhydride grafted polypropylene, and 1 part of an auxiliary agent, and stir them at a speed of 500 r / min for 10 minutes using a high-speed mixer to obtain a uniformly mixed material.

[0055] S2 is the same as S2 in Example 1.

[0056] Comparative Example 1

[0057] S1, weigh 100 parts of polypropylene resin and 1 part of auxiliary agent, and stir them at a speed of 500r / min for 10 minutes using a high-speed mixer to obtain a uniformly mixed material.

[0058] S2 is the same as S2 in Example 1.

[0059] Comparative Example 2

[0060] S1, weigh 80 parts of polypropylene resin, 20 parts of graphene oxide, and 1 part of an auxiliary agent, and stir them at a speed of 500 r / min for 10 minutes using a high-speed mixer to obtain a uniformly mixed material.

[0061] S2 is the same as S2 in Example 1.

[0062] Comparative Example 3

[0063] S1, weigh 80 parts of polypropylene resin, 20 parts of graphene oxide, 5 parts of maleic anhydride grafted polypropylene, and 1 part of an auxiliary agent, and stir them at a speed of 500 r / min for 10 minutes using a high-speed mixer to obtain a uniformly mixed material.

[0064] S2 is the same as S2 in Example 1.

[0065] The raw material ratios of Examples 1-5 and Comparative Examples 1-3 are shown in Table 1 below:

[0066] Table 1 A formula of a high thermal conductivity polypropylene composite material

[0067]

[0068]

[0069] Experimental test:

[0070] The polypropylene composite materials prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were respectively put into an injection molding machine for melting to obtain standard samples; the barrel temperature of the injection molding machine was 220°C and the mold temperature was 60°C.

[0071] Experimental tests were conducted on the injection-molded standard samples of the polypropylene composite materials prepared in Examples 1 to 5 and Comparative Examples 1 to 3, and the tensile properties, bending properties and impact properties were tested according to ISO standards. The test results are shown in Table 2 below:

[0072] Table 2 Test table of injection molding of polypropylene composite materials of Examples 1 to 5 and Comparative Examples 1 to 3

[0073]

[0074] It can be seen from Table 2 that the thermal conductivity of pure polypropylene itself in Comparative Example 1 is relatively low. After adding 20 parts of graphene oxide in Comparative Example 2, the thermal conductivity coefficient is significantly improved, but due to the lack of the dispersing effect of the compatibilizer, the graphene oxide is agglomerated, resulting in a decrease in the tensile strength and impact strength of the material. In Comparative Example 3, after adding the maleic anhydride grafted polypropylene compatibilizer, it is helpful to disperse the graphene oxide, the network structure is further improved, a partial thermal conduction path is formed, the thermal conductivity is improved, and the tensile strength and impact strength of the material are improved. In Examples 1 to 5, the addition of trace amounts of double-arm carbon nanotubes makes the network structure of the material more perfect, forms a complete thermal conduction path, and greatly improves the thermal conductivity. And because the double-arm carbon nanotubes have a one-dimensional structure, they form a bridge between different components, which plays a role in stress transfer, so that the tensile strength, bending strength and impact strength of the material are further improved.

[0075] In summary, under the combined effect of trace double-arm carbon nanotubes and graphene oxide, the thermal conductivity of polypropylene is significantly improved. At the same time, it has high tensile strength, bending strength and impact strength.

[0076] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0077] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A polypropylene composite material, characterized in that: Including the following raw materials by weight:

2. A polypropylene composite material according to claim 1, characterized in that: The auxiliary agents include antioxidants, auxiliary antioxidants, light absorbers and light stabilizers, and the mass ratio thereof is 1:1:1:

1.

3. A polypropylene composite material according to claim 2, characterized in that: The antioxidant is a hindered phenol antioxidant.

4. A polypropylene composite material according to claim 2, characterized in that: The auxiliary antioxidant is a phosphite antioxidant.

5. A polypropylene composite material according to claim 2, characterized in that: The light absorber is a benzotriazole light absorber.

6. A polypropylene composite material according to claim 2, characterized in that: The light stabilizer is a hindered amine light stabilizer.

7. The method for preparing a polypropylene composite material according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, mixing polypropylene resin, graphene oxide, double-walled carbon nanotubes, maleic anhydride grafted polypropylene and an additive, and stirring to obtain a mixture; S2, feeding the mixture into the main feeding port of a parallel twin-screw extruder, and then melting and extruding to obtain granules.

8. The method for preparing a polypropylene composite material according to claim 7, characterized in that: In S1, the stirring speed is 500 r / min and the stirring time is 10 min.

9. The method for preparing a polypropylene composite material according to claim 7, characterized in that: In S2, the barrel temperature of the twin-screw extruder is: 160°C in zone 1, 180°C in zone 2, 190°C in zone 3, 200°C in zone 4, 210°C in zone 5, and 220°C in zone 6; the head temperature is 210°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

10. Use of a polypropylene composite material according to any one of claims 1 to 6 in preparing packaging shells for electronic devices.

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