阅读说明：本技术 石墨烯改性聚丁烯复合材料及其制备方法 (Graphene modified polybutylene composite material and preparation method thereof ) 是由 徐欢 徐玮彤 刘芳芳 刘婷婷 刘耘成 曲波 马青喜 李金来 于 2019-04-03 设计创作，主要内容包括：本发明公开了一种石墨烯改性聚丁烯复合材料及其制备方法,涉及碳纳米材料改性聚合物复合材料技术领域,可同时提高聚丁烯复合材料导热性能和力学性能,并降低其气体渗透系数。所述石墨烯改性聚丁烯复合材料的制备方法,包括将石墨烯、石墨烯表面处理剂和石墨烯包覆剂进行混合,得到混合物；对混合物进行混炼,得到具有三维导热网络结构的石墨烯填充母粒；将石墨烯填充母粒与聚丁烯进行熔融混合,得到聚丁烯复合材料。上述石墨烯改性聚丁烯复合材料的制备方法用于制备石墨烯改性聚丁烯复合材料。(The invention discloses a graphene modified polybutylene composite material and a preparation method thereof, relates to the technical field of carbon nano material modified polymer composite materials, and can improve the heat conductivity and mechanical property of the polybutylene composite material and reduce the gas permeability coefficient of the polybutylene composite material. The preparation method of the graphene modified polybutylene composite material comprises the steps of mixing graphene, a graphene surface treatment agent and a graphene coating agent to obtain a mixture; mixing the mixture to obtain graphene filling master batches with a three-dimensional heat conduction network structure; and carrying out melt mixing on the graphene filling master batch and the polybutylene to obtain the polybutylene composite material. The preparation method of the graphene modified polybutylene composite material is used for preparing the graphene modified polybutylene composite material.)

1. A preparation method of a graphene modified polybutylene composite material is characterized by comprising the following steps:

mixing graphene, a graphene surface treatment agent and a graphene coating agent to obtain a mixture;

mixing the mixture to obtain graphene filling master batches with a three-dimensional heat conduction network structure;

and melting and mixing the graphene filling master batch and the polybutylene to obtain the graphene modified polybutylene composite material.

2. The preparation method of the graphene-modified polybutylene composite material according to claim 1, wherein the step of mixing the graphene, the graphene surface treatment agent and the graphene coating agent to obtain a mixture specifically comprises: and mixing the graphene, the graphene surface treatment agent, the graphene coating agent, the stabilizer and the antioxidant to obtain a mixture.

3. The method for preparing a graphene-modified polybutylene composite material according to claim 2, wherein the temperature for mixing the mixture is 120 ℃ to 250 ℃; the energy consumed per unit mass of the mixture is between 0.1 and 5 kWh/kg.

4. The preparation method of the graphene-modified polybutylene composite material according to claim 2, wherein the graphene filling masterbatch is melt-mixed with the polybutylene at a temperature of 165-230 ℃; the energy consumed by the unit mass of the total mass of the graphene filling master batch and the polybutylene is 0.5-100 kWh/kg.

5. The method for preparing the graphene-modified polybutylene composite material according to claim 2, wherein the mass ratio of the polybutylene, the graphene surface treatment agent, the graphene coating agent, the stabilizer, and the antioxidant in the graphene-modified polybutylene composite material is (50-90): (5-40): (0.015 to 4): (1-40): (0.5-2): (0.3 to 1.5).

6. The preparation method of the graphene-modified polybutylene composite material according to claim 5, wherein the graphene surface treatment agent comprises a silane coupling agent, and the mass ratio of the graphene surface treatment agent to the graphene is (2-10): 100.

7. the preparation method of the graphene-modified polybutylene composite material according to claim 5, wherein the graphene surface treatment agent comprises octadecylamine, isocyanate or titanate coupling agent, and the mass ratio of the graphene surface treatment agent to the graphene is (0.3-1.5): 100.

8. the method of preparing a graphene-modified polybutylene composite according to claim 2, wherein the stabilizer includes at least one of zinc stearate, calcium stearate, lead stearate, and barium stearate.

9. The method according to claim 2, wherein the antioxidant comprises at least one of tris [2, 4-di-tert-butylphenyl ] phosphite, pentaerythrityl tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and dilauryl thiodipropionate.

10. The method of preparing a graphene-modified polybutylene composite according to claim 1, wherein the graphene coating agent includes at least one of paraffin, a thermoplastic elastomer, a polyolefin elastomer, polyethylene wax, ethylene-propylene-diene monomer, a styrene-based thermoplastic elastomer, an ethylene-vinyl acetate copolymer, styrene-butadiene rubber, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-butyl acrylate copolymer, and a polyester elastomer.

11. The graphene modified polybutylene composite material is characterized by comprising polybutylene and a graphene filling master batch with a three-dimensional heat conduction network structure, wherein the graphene filling master batch comprises graphene, a graphene surface treatment agent and a graphene coating agent, and the graphene forms the three-dimensional heat conduction network structure.

12. The graphene-modified polybutene composite according to claim 11, wherein the polybutene comprises isotactic polybutene-1, the isotactic degree of the isotactic polybutene-1 is more than 90%, the average molecular weight is 200000 to 500000, and the density is 0.85g/cm³～0.94g/cm³The crystallinity is 40-70%, and the melt index is 0.5-20 g/10 min.

13. The graphene-modified polybutylene composite according to claim 11, wherein the graphene has a maximum radial dimension of 0.5 to 40 μm and a thickness of 1 to 20 nm.

Technical Field

The invention relates to the technical field of carbon nano material modified polymer composite materials, in particular to a graphene modified polybutylene composite material and a preparation method thereof.

Background

The polybutylene is nontoxic and harmless, can resist ultraviolet rays, has good performances of flexibility, creep resistance, corrosion resistance and the like, is easy to process, connect and form, and is widely applied to industries such as films, sheets, pipes and the like. However, the low thermal conductivity (0.8W/mK-0.22W/mK) of polybutene limits its wide application in many fields such as floor heating pipes, heat exchangers and radiators.

At present, in the related art, a method of filling and modifying a polybutene material is generally adopted, that is, a metal material (such as copper or aluminum), a metal oxide material (such as aluminum oxide or magnesium oxide), or a non-metal material (such as graphite, boron nitride or carbon fiber) with a high thermal conductivity is added to polybutene as a filler to form a polybutene composite material, so that the composite material has a good thermal conductivity. However, the balance between the thermal conductivity and the mechanical properties of the polybutylene composite material prepared by the method is poor, and good comprehensive properties are difficult to obtain. In addition, the conventional polybutylene composite material has a high gas permeability coefficient, and the application range of the polybutylene composite material is limited.

Disclosure of Invention

The embodiment of the invention aims to provide a graphene modified polybutylene composite material and a preparation method thereof, so that the thermal conductivity of the graphene modified polybutylene composite material is effectively improved, good mechanical properties are obtained, and the gas permeability coefficient of the graphene modified polybutylene composite material is reduced.

In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

the first aspect of the embodiment of the invention provides a preparation method of a graphene modified polybutylene composite material, which comprises the following steps: mixing graphene, a graphene surface treatment agent and a graphene coating agent to obtain a mixture; mixing the mixture to obtain graphene filling master batches with a three-dimensional heat conduction network structure; and melting and mixing the graphene filling master batch and the polybutylene to obtain the graphene modified polybutylene composite material.

The preparation method of the graphene modified polybutylene composite material provided by the embodiment of the invention comprises the steps of mixing a mixture comprising graphene, a graphene surface treatment agent and a graphene coating agent, keeping the graphene in a uniformly dispersed state by using the graphene surface treatment agent and the graphene coating agent, and enabling the graphene in the uniformly dispersed state to be mutually bridged to form a three-dimensional heat conduction network structure, namely enabling the mixture to form a graphene filling master batch with the three-dimensional heat conduction network structure, and then carrying out melt mixing on the graphene filling master batch and polybutylene to enable the graphene filling master batch to be uniformly distributed in the polybutylene, so that the graphene modified polybutylene composite material with isotropic excellent heat conductivity can be formed, and the heat conductivity of the graphene modified polybutylene composite material can be effectively improved.

On the basis, the three-dimensional heat conduction network chain structure uniformly distributed in the graphene modified polybutylene composite material can be used for dispersing and resisting the force applied to the graphene modified polybutylene composite material, so that the graphene modified polybutylene composite material can be ensured to have good mechanical property.

Moreover, since the graphene has a large specific surface area, after the three-dimensional heat-conducting network structure is formed, the three-dimensional heat-conducting network structure can be used as a nanometer barrier wall, so that the permeation path of gas molecules is greatly reduced, the permeation of the gas molecules is limited, and the gas permeation coefficient of the graphene modified polybutylene composite material is effectively reduced.

From the above, the graphene modified polybutylene composite material prepared by the preparation method provided by the embodiment of the invention can effectively improve the thermal conductivity, obtain good mechanical properties and reduce the gas permeability coefficient.

Optionally, the step of mixing the graphene, the graphene surface treatment agent, and the graphene coating agent to obtain a mixture specifically includes: mixing graphene, a graphene surface treatment agent, a graphene coating agent, a stabilizer and an antioxidant to obtain a mixture

Optionally, when the mixture is mixed, the mixing temperature is 120-250 ℃; the energy consumed per unit mass of the mixture is between 0.1 and 5 kWh/kg.

Optionally, when the graphene filling master batch and the polybutylene are subjected to melt mixing, the temperature of the melt mixing is 165-230 ℃; the energy consumed by the unit mass of the total mass of the graphene filling master batch and the polybutylene is 0.5-100 kWh/kg.

Optionally, in the graphene modified polybutylene composite material, the mass ratio of polybutylene to graphene to the graphene surface treatment agent to the graphene coating agent to the stabilizer to the antioxidant is (50-90): (5-40): (0.015 to 4): (1-40): (0.5-2): (0.3 to 1.5).

Optionally, the graphene surface treatment agent comprises a silane coupling agent, and the mass ratio of the graphene surface treatment agent to graphene is (2-10): 100.

optionally, the graphene surface treatment agent comprises octadecylamine, isocyanate or a titanate coupling agent, and the mass ratio of the graphene surface treatment agent to graphene is (0.3-1.5): 100.

optionally, the stabilizer includes at least one of zinc stearate, calcium stearate, lead stearate, and barium stearate.

Alternatively, the antioxidant includes at least one of tris [2, 4-di-tert-butylphenyl ] phosphite, pentaerythrityl tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and dilauryl thiodipropionate.

Optionally, the graphene coating agent includes at least one of paraffin, a thermoplastic elastomer, a polyolefin elastomer, polyethylene wax, ethylene propylene diene monomer, a styrene-based thermoplastic elastomer, an ethylene-vinyl acetate copolymer, styrene-butadiene rubber, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-butyl acrylate copolymer, and a polyester elastomer.

The second aspect of the embodiment of the invention provides a graphene modified polybutylene composite material, which comprises polybutylene and a graphene filling master batch with a three-dimensional heat conduction network structure, wherein the graphene filling master batch comprises graphene, a graphene surface treatment agent and a graphene coating agent, and the three-dimensional heat conduction network structure is formed by the graphene.

The beneficial effects that can be achieved by the graphene modified polybutylene composite material provided by the embodiment of the invention are the same as the technical effects that can be achieved by the preparation method of the graphene modified polybutylene composite material provided by the technical scheme, and are not described herein again.

Optionally, the polybutene comprises isotactic polybutene-1, wherein the isotactic polybutene-1 is more than 90%, the average molecular weight is 200000-500000, and the density is 0.85g/cm³～0.94g/cm³The crystallinity is 40-70%, and the melt index is 0.5-20 g/10 min.

Optionally, the graphene has a maximum radial dimension of 0.5 to 40 μm and a thickness of 1 to 20 nm.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention and not to limit the embodiments of the invention unduly. In the drawings:

fig. 1 is a schematic flow chart of a preparation method of a graphene-modified polybutylene composite provided by an embodiment of the invention;

fig. 2 is a schematic flow chart of another preparation method of a graphene-modified polybutylene composite according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a graphene-modified polybutylene composite provided in an embodiment of the present invention;

fig. 4 is a TEM (transmission electron Microscope) image of the graphene modified polybutylene composite provided in the embodiment of the present invention;

fig. 5a is a Scanning Electron Microscope (SEM) image of a tensile section of a graphene-modified polybutylene composite according to an embodiment of the present invention;

fig. 5b is a high-magnification SEM image of a tensile section of a graphene modified polybutylene composite according to an embodiment of the present invention;

fig. 6 is an SEM image of a tensile section of a graphene-modified polybutylene composite in a comparative example.

Detailed Description

For the convenience of understanding, the technical solutions provided by the embodiments of the present invention are described in detail below with reference to the drawings of the specification. It is obvious that the described embodiments are only some, not all embodiments of the proposed solution. All other embodiments obtained by a person skilled in the art based on the embodiments of the present invention without any creative work belong to the protection scope of the embodiments of the present invention.

As mentioned in the background art, the polybutene composite material obtained by adding the filler to the polybutene by the conventional filling modification method has poor balance between the heat-conducting property and the mechanical property, and is difficult to form good barrier to gas molecules.

Illustratively, when expanded graphite or a mixture of graphite powder and carbon fiber is used as a filler, when the content of the added filler is low, the filler is difficult to be sufficiently and uniformly mixed in polybutene, so that the heat-conducting property of the polybutene composite material is not obviously improved, and when the content of the added filler is high, the filler can be uniformly distributed in the polybutene, so that the polybutene composite material has good heat-conducting property, but the toughness of the polybutene composite material is damaged by high content of graphite, so that the application range of the polybutene composite material is limited.

When graphene is used as a filler, due to the fact that the surface energy of the graphene is high, the interaction force between graphene lamellar structures is large, the aggregation phenomenon is easy to generate, the graphene is easy to gather in a certain area of polybutene, and uniform dispersion is difficult to obtain, and further the heat conduction performance and the mechanical performance of the polymer composite material are affected.

In view of the above disadvantages, referring to fig. 1, an embodiment of the present invention provides a method for preparing a graphene-modified polybutylene composite, including:

step S1: and mixing the graphene, the graphene surface treatment agent and the graphene coating agent to obtain a mixture.

Step S2: and mixing the mixture to obtain the graphene filling master batch with the three-dimensional heat conduction network structure.

Step S3: and melting and mixing the graphene filling master batch and the polybutylene to obtain the graphene modified polybutylene composite material.

The maximum radial dimension of the graphene may be 0.5 to 40 μm, and the thickness may be 1 to 20 nm. Therefore, the graphene has enough surface area and smaller thickness, and a three-dimensional network structure with relatively larger specific surface area can be formed after the subsequent graphene is uniformly dispersed. Graphene is a two-dimensional structure with good thermal conductivity along its plane, so graphene can be considered as a thermally conductive mesh with good thermal conductivity.

According to the embodiment of the invention, the mixture comprising the graphene, the graphene surface treatment agent and the graphene coating agent is mixed, so that the graphene can be kept in a uniformly dispersed state under the combined action of the graphene coating agent and the graphene surface treatment agent, namely, the graphene has various different orientations in a three-dimensional space. The graphene in the uniformly dispersed state can be bridged with each other by van der waals force to form a three-dimensional network structure, and the bridged end points can conduct good heat conduction through the tunnel effect. After the graphene is uniformly dispersed to form the isotropic three-dimensional heat conduction network structure, the heat conduction performance of the graphene modified polybutylene composite material is effectively improved.

After the mixing is finished, the graphene filling master batch with the three-dimensional heat conduction network structure can be obtained in a cooling and grain-cutting or direct granulation mode. Meanwhile, in the mixing process, the graphene and the graphene coating agent can be combined together, so that the graphene with smaller particles can be uniformly mixed in the polybutene with larger particles when the graphene is subsequently mixed with the polybutene, and the good dispersibility of the graphene in the polybutene is ensured, thereby avoiding the conditions of difficult blanking, uneven discharging or poor dispersibility and the like in the process of processing the graphene modified polybutene composite material.

After the graphene filling master batch is obtained, the graphene filling master batch and the polybutene are subjected to melt mixing, so that the graphene filling master batch is uniformly distributed in the polybutene, and then the graphene filling master batch and the polybutene subjected to melt mixing are granulated, so that a three-dimensional heat conduction network structure is formed in the graphene modified polybutene composite material, and the heat conduction performance of the graphene modified polybutene composite material is effectively improved.

Because the surface of the graphene has more folds, the interface interaction between the three-dimensional heat conduction network structure and the graphene surface treating agent, the graphene coating agent and the polybutylene can be enhanced, and the components can be combined more strongly. In the process of deformation or fracture of the graphene modified polybutylene composite material, the graphene modified polybutylene composite material can uniformly absorb, disperse and resist external energy, and further has good mechanical properties.

Moreover, since the graphene has a large specific surface area, after the three-dimensional heat-conducting network structure is formed, the three-dimensional heat-conducting network structure can be used as a nanometer barrier wall to well block gas molecules, so that permeation paths of the gas molecules are reduced, and the gas permeation coefficient of the graphene modified polybutylene composite material is effectively reduced.

As can be seen from the above, the preparation method of the graphene modified polybutylene composite material provided by the embodiment of the invention has simple and convenient steps, and the graphene modified polybutylene composite material prepared by the preparation method provided by the embodiment of the invention can effectively improve the thermal conductivity, has good mechanical properties, and reduces the gas permeability coefficient.

Referring to fig. 2, in order to prolong the service life of the graphene-modified polybutylene composite and ensure the structural integrity of each component during the preparation process, in some embodiments, the step S1 specifically includes a step S1', in which graphene, a graphene surface treatment agent, a graphene coating agent, a stabilizer, and an antioxidant are mixed to obtain a mixture. By adding the stabilizer into the mixture, the processing stability of the mixture and the graphene filling master batch obtained through the mixture can be enhanced, the structural damage of the mixture and the graphene filling master batch under the action of high temperature or shearing can be shielded, and the good performance of the graphene modified polybutylene composite material can be ensured, wherein the good performance can comprise good heat conductivity, mechanical property, lower gas permeability coefficient and the like. By adding the antioxidant into the mixture, the oxidation process of the graphene modified polybutylene composite material can be delayed or inhibited, the thermal oxidation aging of the graphene modified polybutylene composite material is avoided, and the service life of the graphene modified polybutylene composite material can be prolonged.

Illustratively, the stabilizer may be at least one of zinc stearate, calcium stearate, lead stearate, and barium stearate. The antioxidant may be at least one of tris [2, 4-di-tert-butylphenyl ] phosphite, pentaerythrityl tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and dilauryl thiodipropionate, wherein tris [2, 4-di-tert-butylphenyl ] phosphite may be referred to as antioxidant 168, and pentaerythrityl tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] 1010.

In the step S2, in order to improve the efficiency of preparing the graphene filling master batch, when the mixture is mixed, the mixing temperature may be in the range of 120 ℃ to 250 ℃, in this temperature range, the components in the mixture are conveniently and sufficiently mixed quickly, the graphene is promoted to form a three-dimensional heat conducting network structure, meanwhile, the condition that the components are thermally aged due to the excessively high mixing temperature is avoided, and the graphene filling master batch is ensured to have good processability and use value.

It is worth mentioning that when the mixture is mixed, the mixture can be mixed by at least one mixing device of a high-speed mixer, an open mill, a turnover type internal mixer, a continuous internal mixer, a Z-type kneader, a screw kneader, a vacuum kneader and a horizontal double-screw mixer, and the energy consumed by the mixture per unit mass is 0.1 kWh/kg-5 kWh/kg, wherein the mixture per unit mass refers to the unit mass of the total mass of the graphene, the graphene surface treatment agent, the graphene coating agent, the stabilizer and the antioxidant. The energy consumed by mixing is determined according to the quality of the mixture, so that the phenomena that the components in the mixture are difficult to be fully mixed due to insufficient energy and the graphene is difficult to form a good three-dimensional heat conduction network structure can be avoided, and the conditions that the mixture is over-treated, the structure of each component in the mixture is damaged, and the performance and the use value of the graphene filling master batch are influenced can be avoided.

In step S3, in order to sufficiently and uniformly melt and mix the graphene filling master batch and the polybutene, the temperature for melt mixing may be in the range of 165 ℃ to 230 ℃, so that both the graphene filling master batch and the polybutene can be in a molten state and uniformly mixed in the molten state, thereby not only preventing the graphene filling master batch and the polybutene from being difficult to be sufficiently melt and mixed at too low melt mixing temperature, but also preventing the graphene filling master batch and the polybutene from being thermally degraded at too high melt mixing temperature.

When the graphene filler masterbatch and the polybutene are melt-mixed, the melt-mixing may be performed by at least one melt-mixing device selected from a twin-screw extruder, a single-screw extruder, a planetary screw extruder, and a continuous internal mixer, and the energy consumed by the unit mass of the total mass of the graphene filler masterbatch and the polybutene may be 0.5kWh/kg to 100kWh/kg, that is, the energy consumed by each 1kg of the composition including the graphene filler masterbatch and the polybutene may be 0.5kWh to 100 kWh. The energy required to be provided by melt mixing is determined according to the total mass of the actually processed graphene filling master batch and the actually processed polybutene, so that the phenomenon that the graphene filling master batch and the polybutene are difficult to uniformly mix due to insufficient energy can be avoided, the phenomenon that the structure of the graphene filling master batch or the polybutene is damaged due to excessive processing of the graphene filling master batch and the polybutene can be avoided, and adverse effects on the heat conductivity, the mechanical property and the gas barrier property of the graphene modified polybutene composite material are caused.

In some embodiments, in the prepared graphene modified polybutylene composite material, the mass ratio of polybutylene to graphene to the graphene surface treatment agent to the graphene coating agent to the stabilizer to the antioxidant may be (50-90): (5-40): (0.015 to 4): (1-40): (0.5-2): (0.3-1.5), namely, in the process of preparing the graphene modified polybutylene composite material, the mass ratio of the added components can be the mass ratio. By adopting the mass ratio, the performances of the components can be optimized and balanced, so that the graphene modified polybutylene composite material not only has good heat conductivity, but also has good mechanical properties, and the mechanical properties of the graphene modified polybutylene composite material are prevented from being deteriorated due to the addition of multiple components.

In order to ensure that the prepared graphene modified polybutylene composite material has good mechanical properties, the polybutylene can be selected to be isotactic polybutene-1, the isotacticity of the isotactic polybutene-1 is more than 90 percent, namely the isotactic polybutene-1 is high isotactic polybutene-1, meanwhile, the average molecular weight of the isotactic polybutene-1 can be 200000-500000, and the density is 0.85g/cm³～0.94g/cm³The crystallinity is 40-70 percent, and the melt index is 0.5g/10minAbout 20g/10 min. By adopting the high-grade isotactic polybutene-1 with higher strength and toughness as the matrix, the graphene modified polybutene composite material can be ensured to have better mechanical property and higher application value.

It is understood that the graphene surface treatment agent may include various surface treatment agents, and exemplarily, may include a silane coupling agent, octadecylamine, isocyanate, or titanate coupling agent. When the graphene surface treatment agent comprises a silane coupling agent, the mass ratio of the graphene surface treatment agent to graphene can be (2-10): 100, when the graphene surface treatment agent comprises octadecylamine, isocyanate or a titanate coupling agent, the mass ratio of the graphene surface treatment agent to graphene can be (0.3-1.5): 100. because the processing capacity of the graphene surface treating agents is high, the graphene surface treating agents with low quality can be used to achieve similar processing effects.

In still other embodiments, the graphene capping agent may have various options, and may illustratively include at least one of paraffin wax, thermoplastic elastomer, polyolefin elastomer, polyethylene wax, ethylene-propylene-diene monomer, styrene-based thermoplastic elastomer, ethylene-vinyl acetate copolymer, styrene-butadiene rubber, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, and polyester elastomer. By adopting the graphene coating agent, good adhesion between the graphene coating agent and graphene can be ensured.

The embodiment of the present invention further provides a graphene modified polybutylene composite material, please refer to fig. 3 to 4, including: the graphene-based heat conduction master batch comprises polybutene and a graphene filling master batch with a three-dimensional heat conduction network structure, wherein the graphene filling master batch comprises graphene, a graphene surface treatment agent and a graphene coating agent, and the graphene forms the three-dimensional heat conduction network structure.

The graphene, the graphene surface treatment agent and the graphene coating agent in the graphene filling master batch are the graphene, the graphene surface treatment agent and the graphene coating agent which are mutually combined together after being mixed. The graphene is in a uniformly dispersed state, namely, has multiple different orientations in a three-dimensional space, and simultaneously, the lamellar structures of the graphene are mutually bridged to form a three-dimensional network structure, and the bridging end points of the three-dimensional network structure can conduct good heat conduction through a tunnel effect, namely, the three-dimensional network structure can be regarded as a structure with good heat conduction performance.

The graphene filling master batch and the polybutylene are fully and uniformly mixed, so that the three-dimensional heat conduction network structure of the graphene filling master batch can be uniformly and dispersedly filled in the polybutylene, and all areas of the formed graphene modified polybutylene composite material can have uniform heat conduction performance. Due to the fact that the thermal conductivity of the graphene is extremely high, the three-dimensional heat conduction network structure formed by the graphene has extremely high heat conduction performance, and the heat conduction performance of the graphene modified polybutylene composite material can be effectively improved by the aid of the three-dimensional heat conduction network structure.

Because the graphene surface has more folds, the interface interaction between the three-dimensional heat conduction network structure and the graphene surface treating agent, the graphene coating agent and the polybutylene can be enhanced by the more folds, so that the components can be better compounded together, and in the process that the graphene modified polybutylene composite material deforms or breaks, the energy can be uniformly absorbed, dispersed and resisted, and the graphene modified polybutylene composite material is ensured to have good mechanical property.

Moreover, since the graphene has a large specific surface area, after the three-dimensional heat-conducting network structure is formed, the three-dimensional heat-conducting network structure can be used as a nanometer barrier wall to well block gas molecules, so that the permeation of the gas molecules is reduced, and the gas permeation coefficient of the graphene modified polybutylene composite material is effectively reduced.

From the above, the graphene modified polybutylene composite material provided by the embodiment of the invention can effectively improve the thermal conductivity, has good mechanical properties, and reduces the gas permeability coefficient.

In some embodiments, the graphene filling masterbatch further includes a stabilizer and an antioxidant, which are mixed together with the graphene, the graphene surface treatment agent, and the graphene coating agent. By adding the stabilizer into the mixture, the stability of each component in the graphene modified polybutylene composite material can be enhanced, the structural damage caused by the heat or shearing action of each component in the process of forming the graphene modified polybutylene composite material is avoided, and the graphene modified polybutylene composite material can be ensured to have good heat-conducting property, mechanical property and gas barrier property. By adding the antioxidant into the mixture, the thermal/oxidation reaction of the graphene modified polybutylene composite material can be delayed or inhibited, the graphene modified polybutylene composite material is prevented from aging, and the service life of the graphene modified polybutylene composite material is further prolonged. It is understood that the stabilizers and antioxidants used in this example may be the same as those used in the previous examples.

In some embodiments, the maximum radial dimension of the graphene may be 0.5 μm to 40 μm, and the thickness may be 1nm to 20nm, and the graphene in a uniformly dispersed state may be formed into a three-dimensional network structure having a relatively large specific surface area by using the graphene having a large radial dimension and a small thickness.

The polybutene includes isotactic polybutene-1, the isotactic degree of isotactic polybutene-1 is more than 90%, the average molecular weight is 200000-500000, and the density is 0.85g/cm³～0.94g/cm³The crystallinity is 40-70%, and the melt index is 0.5-20 g/10 min. The isotactic polybutene-1 has high strength and high toughness, and relatively high mechanical property balance and application value can be obtained by adopting the isotactic polybutene-1.

In the graphene modified polybutylene composite material, the mass ratio of polybutylene to graphene surface treatment agent to graphene coating agent to stabilizer to antioxidant is (50-90): (5-40): (0.015 to 4): (1-40): (0.5-2): (0.3 to 1.5). By adopting a proper mass ratio, the performances of the components can be optimized and balanced, and the performances of the graphene modified polybutylene composite material are balanced, namely the graphene modified polybutylene composite material has good heat conductivity and good mechanical properties, and the mechanical properties of the graphene modified polybutylene composite material can be prevented from being deteriorated.

In still other embodiments, the graphene surface treatment agent may include a plurality of surface treatment agents, and for example, the graphene surface treatment agent may include a silane coupling agent, and at this time, the mass ratio of the graphene surface treatment agent to the graphene may be (2 to 10): 100, respectively; the graphene surface treatment agent can also comprise octadecylamine, isocyanate or titanate coupling agent, and the mass ratio of the graphene surface treatment agent to graphene can be (0.3-1.5): 100. because the processing capacity of the graphene surface treating agents is high, the same processing effect can be achieved by using the graphene surface treating agent with low quality.

Hereinafter, the embodiments of the present invention will describe, by way of example and comparative example, technical effects achieved by the preparation method of the graphene-modified polymer composite provided in the embodiments of the present invention. These examples are merely examples provided to specifically illustrate the present invention, and it will be understood by those skilled in the art that the scope of the present invention is not limited to these examples and comparative examples.