A method for preparing a graphene oxide modified thermoplastic resin masterbatch

Abstract

The application provides a preparation method of graphene oxide modified thermoplastic resin master batch, comprising the following steps: preparing a graphene oxide solution; coating the graphene oxide solution on a thermoplastic resin sheet to form a graphene oxide coating layer, and drying to obtain a graphene oxide / thermoplastic resin sheet; stacking a plurality of graphene oxide / thermoplastic resin sheets, and sequentially performing hot pressing, crushing and blending extrusion to obtain the graphene oxide modified thermoplastic resin master batch. The preparation method provided by the application can make the graphene oxide fully dispersed in the thermoplastic resin by coating the graphene oxide solution on the surface of the thermoplastic resin sheet and combining with the hot pressing, crushing and blending extrusion treatment, effectively improves the compatibility of the graphene oxide and the thermoplastic resin, and has the characteristics of simple operation process, low manufacturing cost, short processing period, less pollution and the like, and has good practical application value.

Description

Technical Field

[0001] This invention relates to a method for preparing graphene oxide-modified thermoplastic resin masterbatch, and relates to the field of composite material technology. Background Technology

[0002] With continuous material innovation, the concepts of energy conservation, environmental protection, and lightweight materials are gaining increasing prominence. Compared with metallic materials such as aluminum alloys, titanium alloys, and structural steel, reinforced polymer composites have the characteristics of high specific strength and high specific stiffness, and have been widely used in technologies such as aircraft, vehicles, and new energy. They can not only reduce energy consumption, but also improve mechanical properties and reduce manufacturing costs.

[0003] Graphene, as a two-dimensional carbon material, has a stable structure, high specific surface area, and excellent electrical, thermal, and mechanical properties, making it an ideal resin modification material. However, graphene has poor dispersibility and is prone to agglomeration, resulting in poor compatibility with resins and hindering the effective utilization of graphene's performance.

[0004] To improve the compatibility between graphene and resin, invention patent CN111087674A provides a lightweight graphene composite material composition, including functionalized graphene, thermoplastic resin, dispersant, coupling agent, and initiator, which effectively solves the problem of poor compatibility between graphene and thermoplastic resin. However, this solution uses a large number of chemical modifiers and the steps are relatively complex. Invention patent CN113045814A discloses a method for preparing graphene-polymer composite materials, which involves adding a compatibilizer and blending... A method for preparing graphene-modified polymer masterbatch, followed by secondary blending and hot pressing to prepare graphene-polymer composites, is proposed. However, this method only uses compatibilizer modification and prepares the masterbatch through twin-screw blending, resulting in limited graphene dispersibility. Patent CN111117041A discloses a graphene-modified oxygen-barrier polyethylene masterbatch, comprising a polyethylene matrix, graphene, a second oxygen barrier, a coating agent, a surface treatment agent, a dispersant, and an antioxidant. This method requires a large amount of coating agent, which can affect the performance of the polymer matrix. The paper "Effect of functionalized graphene on the physical properties of linear low density polyethylene nanocomposites" [J]. Polymer Testing provides a method for mixing graphene and LLDPE in xylene solvent. This method requires a large amount of solvent and is not suitable for industrial applications. Therefore, a simple preparation method is needed to effectively improve the compatibility of graphene and resin while avoiding the impact on resin performance. Summary of the Invention

[0005] This invention provides a method for preparing graphene oxide-modified thermoplastic resin masterbatch, using graphene oxide as raw material, which improves the compatibility of graphene oxide with thermoplastic resin while reducing the impact on resin performance.

[0006] This invention provides a method for preparing graphene oxide-modified thermoplastic resin masterbatch, comprising the following steps:

[0007] Preparation of graphene oxide solution;

[0008] The graphene oxide solution is coated onto a thermoplastic resin sheet to form a graphene oxide coating, and after drying, a graphene oxide / thermoplastic resin sheet is obtained.

[0009] Several graphene oxide / thermoplastic resin sheets are stacked and then subjected to hot pressing, crushing, and co-extrusion in sequence to obtain graphene oxide modified thermoplastic resin masterbatch.

[0010] In one specific embodiment, the graphene oxide solution is in water as the solvent, and ethanol or acrylic resin is added to adjust the graphene oxide solution to a viscous state.

[0011] In one specific embodiment, the mass ratio of graphene oxide to ethanol is 1:(0.25-25); the mass ratio of graphene oxide to acrylic resin is 1:(0.25-25).

[0012] In one specific embodiment, a long-chain alkylamine is added to the graphene oxide solution, the long-chain alkylamine having the general structural formula C0. n H 2n+1 NH2, n = 10-18.

[0013] In one specific embodiment, the mass ratio of the long-chain alkylamine to the graphene oxide is (0.05-5):1.

[0014] In one specific embodiment, the thermoplastic resin sheet includes one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polycarbonate, and polyphenylene ether.

[0015] In one specific embodiment, the thickness of the thermoplastic resin sheet is 0.1-1 mm.

[0016] In one specific embodiment, the thickness of the graphene coating is no greater than 0.5 mm.

[0017] In one specific embodiment, the hot pressing temperature is 150-350°C.

[0018] In one specific embodiment, the blending extrusion is carried out in a twin-screw extruder, wherein the processing section temperature of the twin-screw extruder is 150-350°C.

[0019] The preparation method provided by this invention involves coating a graphene oxide solution onto the surface of a thermoplastic resin sheet, combined with hot pressing, pulverizing, and co-extrusion processes. This allows the graphene oxide to be fully dispersed in the thermoplastic resin, effectively improving the compatibility between the graphene oxide and the thermoplastic resin. Furthermore, this method features simple operation, low manufacturing cost, short processing cycle, and low pollution, making it highly valuable for practical applications. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic flowchart of a preparation method provided in an embodiment of the present invention;

[0022] Figure 2 The thermogravimetric (TG) curve of the graphene oxide modified polyethylene masterbatch provided in Example 1 of the present invention;

[0023] Figure 3 The tensile strength variation curves of polyethylene provided in Examples 3-6 and Comparative Example 1;

[0024] Figure 4 The flexural strength variation curves of polyethylene provided in Examples 3-6 and Comparative Example 1;

[0025] Figure 5 Impact strength variation curves of polyethylene provided in Examples 3-6 and Comparative Example 1;

[0026] Figure 6 The images are scanning electron microscope (SEM) images of graphene oxide-modified polyethylene provided in Examples 3-4.

[0027] Figure 7 The images are scanning electron microscope (SEM) images of graphene oxide modified polyethylene provided in Examples 5-6.

[0028] Figure 8 The curves showing the change in the nitrogen permeability coefficient of polyethylene provided in Examples 3-6 and Comparative Example 1. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] Figure 1 A method for preparing graphene oxide-modified thermoplastic resin masterbatch according to an embodiment of the present invention includes the following steps:

[0031] Step 1: Prepare graphene oxide solution;

[0032] Step 2: Apply the graphene oxide solution onto a thermoplastic resin sheet to form a graphene oxide coating, and after drying, obtain a graphene oxide / thermoplastic resin sheet.

[0033] Step 3: Stack several graphene oxide / thermoplastic resin sheets together, and then sequentially hot-press, crush, and co-extrude to obtain graphene oxide modified thermoplastic resin masterbatch.

[0034] The preparation method provided by this invention involves coating a graphene oxide solution onto the surface of a thermoplastic resin sheet, combined with hot pressing, pulverizing, and co-extrusion processes. This allows the graphene oxide to be fully dispersed in the thermoplastic resin, effectively improving the compatibility between graphene oxide and the thermoplastic resin. Furthermore, this method features simple operation, low manufacturing cost, short processing cycle, and low pollution, making it highly valuable for practical applications. The preparation method is described in detail below:

[0035] Step 1: Prepare graphene oxide solution:

[0036] A graphene oxide solution was prepared using the Hummers method or a modified Hummers method, specifically an aqueous solution of graphene oxide, wherein the mass fraction of graphene oxide was 1-5 wt%.

[0037] To facilitate the uniform coating of the graphene oxide aqueous solution onto the surface of the thermoplastic resin sheet, the viscosity of the graphene oxide solution needs to be adjusted to a viscous state. This can be achieved by adding ethanol or acrylic resin to the graphene oxide solution. Ethanol can better dissolve graphene oxide, while acrylic resin, as a thickener, can increase the viscosity of the solution. The mass ratio of graphene oxide to ethanol is 1:(0.25-25), and the mass ratio of graphene oxide to acrylic resin is 1:(0.25-25), thus preparing a viscous graphene oxide solution.

[0038] In addition, long-chain alkylamines can be added to the graphene oxide solution. As a surfactant, the hydrophilic amine groups of long-chain alkylamines can be grafted onto graphene oxide, further improving the compatibility of graphene oxide with thermoplastic resins. Long-chain alkylamines refer to long-chain alkanes with amine end groups, and their general structural formula is CnH. 2n+1 NH2, n = 10-18.

[0039] In one specific embodiment, the mass ratio of the long-chain alkylamine to the graphene oxide is (0.05-5):1. If the amount of long-chain alkylamine added is too low, the modification of graphene oxide cannot be fully achieved, while if it is too high, it will easily affect the specific gravity of graphene oxide, resulting in an excessively high interfacial component between graphene oxide and the matrix in the composite material, which cannot effectively transfer stress and affect the mechanical properties of the composite material.

[0040] After adding long-chain alkylamines, the graphene oxide solution needs to be stirred thoroughly to ensure that the long-chain alkylamines are fully grafted onto the graphene oxide. Specifically, stirring can be carried out at room temperature for at least 24 hours.

[0041] Step 2: Apply the graphene oxide solution onto a thermoplastic resin sheet to form a graphene oxide coating, and after drying, obtain a graphene oxide / thermoplastic resin sheet.

[0042] Step 1 prepares a graphene oxide solution with a suitable viscosity, which can then be coated onto the surface of a thermoplastic resin sheet. The coating method is chosen because graphene oxide has a low density and a large density difference with the polymer matrix, making it difficult to achieve high-concentration filling during the blending and granulation process. However, by coating, laminating, and hot pressing, graphene oxide can be effectively filled into the thermoplastic resin matrix. It is understood that in order to improve the compatibility between graphene oxide and thermoplastic resin, the thermoplastic resin sheet should be thin and have a thickness of 0.1-1 mm.

[0043] Thermoplastic resin sheets can be prepared from thermoplastic resins through processing methods such as casting, compression molding, blow molding, and cutting. Thermoplastic resins specifically include one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polycarbonate, and polyphenylene ether. In addition, the thermoplastic resins can be modified to make them more compatible with graphene oxide. The modification treatment can be a conventional modification method in the field, and the present invention does not impose further limitations on it.

[0044] In addition, the thickness of the graphene oxide coating should not be too high, and it should be coated as evenly as possible to prevent local areas from not drying sufficiently during subsequent drying, which would cause the graphene oxide coating to not adhere well to the thermoplastic resin sheet. Specifically, the thickness of the graphene oxide coating should not be greater than 0.5 mm.

[0045] Drying can be performed using methods conventional in the art, such as vacuum drying.

[0046] Step 3: Stack several graphene oxide / thermoplastic resin sheets and sequentially pass them through hot pressing, crushing, and co-extrusion to obtain graphene oxide modified thermoplastic resin masterbatch.

[0047] Several graphene oxide / thermoplastic resin sheets are stacked. Specifically, several graphene oxide / thermoplastic resin sheets can be prepared separately and stacked sequentially from bottom to top. Alternatively, thermoplastic resin sheets can be placed on the surface of one graphene oxide / thermoplastic resin sheet, then coated with a graphene oxide solution, dried to obtain a graphene oxide coating, and then thermoplastic resin sheets can be placed on top of each other, and so on, to obtain a layered structure of graphene oxide coating and thermoplastic resin sheets. Subsequently, the stacked whole is subjected to hot pressing, crushing, and blending extrusion treatment in sequence. Among them, hot pressing can be carried out in a hot press. During the hot pressing process, the thermoplastic resin softens due to heat, which is beneficial to the dispersion of graphene oxide and does not affect the performance of thermoplastic resin. The hot pressing temperature can be determined according to the processing temperature of different thermoplastic resins. Generally, the hot pressing temperature is 150-350℃.

[0048] Subsequently, the hot-pressed product is pulverized, which can be carried out in a crusher, to break it into powder or fragments. Finally, the pulverized product is subjected to co-extrusion processing in a twin-screw extruder. The extruder's process conditions need to be determined according to the processing conditions of different thermoplastic resins. Generally, the processing section temperature of the twin-screw extruder can be set to 150-350℃. The prepared graphene oxide-modified thermoplastic resin masterbatch can then be blended with the matrix resin to prepare a graphene oxide-modified composite material. Specifically, the ratio of masterbatch to matrix resin can be adjusted according to the graphene oxide content in the masterbatch and the amount required in the actual composite material.

[0049] In summary, the preparation method provided by this invention, by coating a graphene oxide solution onto the surface of a thermoplastic resin sheet and combining it with hot pressing, crushing, and co-extrusion processes, allows the graphene oxide to be fully dispersed in the thermoplastic resin, effectively improving the compatibility between graphene oxide and the thermoplastic resin. Furthermore, this method features simple operation, low manufacturing cost, short processing cycle, and low pollution, and has significant practical application value.

[0050] The following detailed description is provided in conjunction with specific embodiments:

[0051] Example 1

[0052] The method for preparing graphene oxide-modified polyethylene resin masterbatch provided in this embodiment includes the following steps:

[0053] Step 1: Weigh 4 kg of graphene oxide aqueous solution (GO content is 1 wt%) and pour it into a container. Then weigh 50 g of acrylic resin thickener and add it to the graphene oxide aqueous solution. Stir thoroughly for more than 24 hours until it becomes viscous.

[0054] Step 2: Weigh 468g of polyethylene resin (HMCRP100N) sheet with a thickness of 0.3mm. Apply a viscous graphene oxide solution to the polyethylene sheet to form a graphene oxide coating. Dry the coating under vacuum at 60℃ to obtain graphene oxide / polyethylene sheet.

[0055] Step 3: Stack the obtained graphene oxide / polyethylene sheets layer by layer, and use a hot press at 180°C to press the stacked graphene oxide / polyethylene sheets into a whole. Then crush them with a crusher and feed the crushed material into a twin-screw extruder. The temperature zones of the twin-screw extruder are set to 170, 190, 190, 190 and 180°C respectively. The extruded strip is water-cooled and granulated to obtain graphene oxide modified polyethylene masterbatch.

[0056] The graphene oxide-modified polyethylene masterbatch obtained in this embodiment was tested using the thermogravimetric method under a nitrogen atmosphere, and the thermogravimetric curve was obtained. Figure 2 The thermogravimetric (TG) curve of the graphene oxide-modified polyethylene masterbatch provided in Example 1 of this invention is shown below. Figure 2 It can be seen that the graphene content in the graphene oxide modified polyethylene masterbatch obtained in this embodiment is 7.16 wt%.

[0057] Example 2

[0058] The method for preparing graphene oxide-modified polyethylene resin masterbatch provided in this embodiment includes the following steps:

[0059] Step 1: Weigh 1 kg of graphene oxide aqueous solution (GO content is 1 wt%) and pour it into a container. Then weigh 10 g of octadecylamine and dissolve it in 250 ml of ethanol to obtain octadecylamine ethanol solution. Mix the above graphene oxide aqueous solution and octadecylamine ethanol solution and stir at room temperature for 24 h until it becomes viscous.

[0060] Step 2: Weigh 80g of polyethylene sheet with a thickness of 0.9mm, apply viscous graphene oxide solution onto the polyethylene sheet to form a graphene oxide coating, and vacuum dry at 70℃ to obtain graphene oxide / polyethylene sheet.

[0061] Step 3: Stack the obtained graphene oxide / polyethylene sheets layer by layer, and use a hot press to press the stacked graphene oxide / polyethylene sheets into a whole at 185°C. Crush the material with a crusher, and feed the crushed material into a twin-screw extruder. The temperature zones of the twin-screw extruder are 170, 195, 195, 195 and 185°C. The extruded strip is water-cooled and granulated to obtain graphene oxide modified polyethylene masterbatch.

[0062] Example 3

[0063] 30g of graphene oxide modified polyethylene masterbatch obtained in Example 1 was mixed with 970g of high-density polyethylene (HMCRP100N) and fed into a twin-screw extruder for extrusion. The temperature zones of the twin-screw extruder were 170, 185, 190, 190 and 180°C. The extruded strip was water-cooled and granulated to obtain modified polyethylene.

[0064] Example 4

[0065] Using the same method as in Example 3, 60g of graphene oxide modified polyethylene masterbatch obtained in Example 1 was mixed with 940g of high-density polyethylene (HMCRP100N) and then fed into a twin-screw extruder for extrusion to obtain modified polyethylene.

[0066] Example 5

[0067] Using the same method as in Example 3, 180g of graphene oxide modified polyethylene masterbatch obtained in Example 1 was mixed with 820g of high-density polyethylene (HMCRP100N) and then fed into a twin-screw extruder for extrusion to obtain modified polyethylene.

[0068] Example 6

[0069] Using the same method as in Example 3, 300g of graphene oxide modified polyethylene masterbatch obtained in Example 1 was mixed with 700g of high-density polyethylene (HMCRP100N) and then fed into a twin-screw extruder for extrusion to obtain modified polyethylene.

[0070] Comparative Example 1

[0071] This comparative example uses 1000g of pure high-density polyethylene (HMCRP100N).

[0072] The parameters involved in Examples 3-6 and Comparative Example 1 are listed below. The graphene oxide content (%) is calculated as: (mass of graphene oxide-modified polyethylene masterbatch / (mass of graphene oxide-modified polyethylene masterbatch + mass of high-density polyethylene)) * 100% * 7.16%.

[0073] Table 1 shows the modified polyethylene formulation parameters provided in Examples 3-6.

[0074]

[0075] The tensile strength, flexural strength, and impact strength of the modified polyethylene with different graphene oxide contents provided in Examples 3-6 and the high-density polyethylene without graphene oxide provided in Comparative Example 1 were tested. The tensile strength was tested according to the method specified in GB / T 1040.1-2018, the flexural strength was tested according to the method specified in GB / T 9341-2008, and the impact strength was tested according to the method specified in GB / T 1043.1-2008.

[0076] Figure 3 The tensile strength variation curves of polyethylene provided in Examples 3-6 and Comparative Example 1 are shown. Figure 4 The flexural strength variation curves of polyethylene provided in Examples 3-6 and Comparative Example 1 are shown. Figure 5 The impact strength variation curves of polyethylene provided in Examples 3-6 and Comparative Example 1 are shown below. Figure 3-5 As shown, with the increase of graphene oxide content, the tensile strength of graphene oxide-modified polyethylene material first decreases and then increases. When the graphene oxide content is low, it not only fails to enhance the tensile strength of polyethylene but also reduces its tensile properties. This may be because the graphene oxide content is too low to form a continuous phase in the polyethylene matrix, but instead acts as a defect in the polyethylene. With the increase of graphene oxide content, the flexural strength of graphene oxide-modified polyethylene material gradually increases, indicating that graphene oxide has a good enhancing effect on the flexural properties of polyethylene. With the increase of graphene oxide content, the impact strength of graphene oxide-modified polyethylene material gradually decreases, indicating that the addition of graphene oxide enhances the rigidity of polyethylene but reduces its toughness.

[0077] Figure 6 The images shown are scanning electron microscope (SEM) images of graphene oxide-modified polyethylene provided in Examples 3-4, wherein (a) is a scanning electron microscope (SEM) image of graphene oxide-modified polyethylene provided in Example 3 at 50 μm, (b) is a scanning electron microscope (SEM) image of graphene oxide-modified polyethylene provided in Example 3 at 5 μm, (c) is a scanning electron microscope (SEM) image of graphene oxide-modified polyethylene provided in Example 4 at 50 μm, and (d) is a scanning electron microscope (SEM) image of graphene oxide-modified polyethylene provided in Example 4 at 5 μm. Figure 7The images shown are scanning electron microscope (SEM) images of graphene oxide-modified polyethylene provided in Examples 5-6. Specifically, (a) is a scanning electron microscope (SEM) image of the graphene oxide-modified polyethylene provided in Example 5 at 50 μm, (b) is a scanning electron microscope (SEM) image of the graphene oxide-modified polyethylene provided in Example 5 at 5 μm, (c) is a scanning electron microscope (SEM) image of the graphene oxide-modified polyethylene provided in Example 6 at 50 μm, and (d) is a scanning electron microscope (SEM) image of the graphene oxide-modified polyethylene provided in Example 6 at 5 μm. Figure 6-7 As shown, graphene oxide is dispersed in the polyethylene matrix in the form of tiny sheets and distributed in different directions; in addition, the higher the graphene oxide content, the denser its distribution in the polyethylene matrix, and the larger the graphene oxide sheets.

[0078] The polyethylene provided in Examples 3-6 and Comparative Example 1 was evaluated for gas permeability according to the method specified in GB / T 1038-2000. Figure 8 The permeability coefficient variation curves of polyethylene to nitrogen provided in Examples 3-6 and Comparative Example 1 are shown below. Figure 8 As shown, the higher the graphene oxide content in the composite material, the lower its nitrogen permeability coefficient, indicating that the addition of graphene oxide can improve the nitrogen barrier performance of polyethylene materials.

[0079] Example 7

[0080] The method for preparing graphene oxide-modified polypropylene resin masterbatch provided in this embodiment includes the following steps:

[0081] Step 1: First, weigh 2 kg of graphene oxide aqueous solution (GO content is 2 wt%) and pour it into a container. Then, weigh 30 g of acrylic resin thickener and add it to the graphene oxide aqueous solution. Stir thoroughly until the mixed solution becomes viscous.

[0082] Step 2: Weigh 400g of polypropylene (PPH-T03) sheet with a thickness of 0.5mm, and apply a viscous graphene oxide solution onto the polypropylene sheet to form a graphene oxide coating. Dry the coating under vacuum at 80℃ to obtain graphene oxide / polypropylene sheet.

[0083] Step 3: After drying, the obtained graphene oxide / polypropylene sheets are stacked layer by layer and pressed into a whole at 200°C using a hot press. Then, they are crushed by a crusher and fed into a twin-screw extruder with temperature zones of 190, 210, 210, 210, and 200°C. After water cooling and granulation, graphene oxide modified polypropylene masterbatch is obtained.

[0084] Following the methods in Examples 3-6, graphene oxide / polypropylene composite materials with a graphene oxide content of 0.2wt%-2.1wt% were prepared using masterbatch. After testing, compared with polypropylene materials without added graphene oxide, the tensile strength was increased by more than 10%, and the nitrogen barrier performance was improved by more than 15%.

[0085] Example 8

[0086] The method for preparing graphene oxide-modified nylon resin masterbatch provided in this embodiment includes the following steps:

[0087] Step 1: Weigh 4 kg of graphene oxide aqueous solution (GO content is 1 wt%) and pour it into a container. Then weigh 50 g of acrylic resin thickener and add it to the graphene oxide aqueous solution. Stir thoroughly until the mixed solution becomes viscous.

[0088] Step 2: Weigh 400g of nylon (nylon 66) sheet with a thickness of 0.1mm, coat the nylon sheet with graphene oxide mixed solution to form a graphene oxide coating, and vacuum dry at 100℃ to obtain graphene oxide / nylon sheet.

[0089] Step 3: After drying, the obtained graphene oxide / nylon sheets are stacked layer by layer and pressed into a whole using a hot press at 270°C. Then, they are crushed by a crusher and fed into a twin-screw extruder with temperature zones of 260, 270, 270, 270, and 265°C. After water cooling and granulation, graphene oxide modified nylon masterbatch is obtained.

[0090] Following the methods in Examples 3-6, graphene oxide / nylon composite materials with a graphene oxide content of 0.2wt%-2.1wt% were prepared using masterbatch. After testing, compared with nylon materials without added graphene oxide, the tensile strength was increased by more than 8%, and the nitrogen barrier performance was improved by more than 10%.

[0091] Comparative Example 2

[0092] Graphene oxide powder was directly mixed with the aforementioned grades of polyethylene, polypropylene, and nylon, and then granulated by twin-screw extrusion to obtain a graphene oxide / polymer composite material.

[0093] Thermogravimetric analysis revealed that the graphene oxide content ranged from 0.2 wt% to 2.1 wt%. Tests were conducted on its mechanical properties and gas permeability. Compared with polymer materials without added graphene oxide, its tensile strength increased by less than 5%. However, due to poor compatibility, its barrier properties against nitrogen decreased.

[0094] Comparative Example 3

[0095] An aqueous solution of octadecylamine-modified graphene oxide was dried into powder, and then directly mixed with the above-mentioned grades of polyethylene, polypropylene and nylon. The mixture was then granulated by twin-screw extrusion to obtain a graphene oxide composite material.

[0096] Thermogravimetric analysis revealed that the graphene oxide content ranged from 0.2 wt% to 2.1 wt%. Mechanical properties and gas permeability were tested. Compared to polymer materials without graphene oxide, the tensile strength increased by less than 7%. However, due to poor compatibility, its nitrogen barrier properties decreased.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing graphene oxide-modified thermoplastic resin masterbatch, characterized in that, Includes the following steps: Preparation of graphene oxide solution; The graphene oxide solution is coated onto a thermoplastic resin sheet to form a graphene oxide coating, and after drying, a graphene oxide / thermoplastic resin sheet is obtained; the thickness of the thermoplastic resin sheet is 0.1-1 mm; the thickness of the graphene oxide coating is no more than 0.5 mm. Several graphene oxide / thermoplastic resin sheets are stacked and then subjected to hot pressing, crushing, and co-extrusion in sequence to obtain graphene oxide modified thermoplastic resin masterbatch. The hot pressing is used to press the stacked graphene oxide / thermoplastic resin sheets into a whole. The hot pressing temperature is determined according to the processing temperature of the thermoplastic resin. During the hot pressing process, the thermoplastic resin softens due to heat. In the graphene oxide solution, the solvent is water, and ethanol or acrylic resin is added to adjust the graphene oxide solution to a viscous state; If ethanol is added to adjust the graphene oxide solution to a viscous state, the mass ratio of graphene oxide to ethanol is 1:(0.25-25). If acrylic resin is added to adjust the graphene oxide solution to a viscous state, the mass ratio of graphene oxide to acrylic resin is 1:(0.25-25).

2. The preparation method according to claim 1, characterized in that, A long-chain alkylamine, having the general structural formula C0, is added to the graphene oxide solution. n H 2n+1 NH2, n=10-18.

3. The preparation method according to claim 2, characterized in that, The mass ratio of the long-chain alkylamine to the graphene oxide is (0.05-5):

1.

4. The preparation method according to claim 1, characterized in that, The thermoplastic resin sheet includes one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polycarbonate, and polyphenylene ether.

5. The preparation method according to claim 1, characterized in that, The hot pressing temperature is 150-350℃.

6. The preparation method according to claim 1, characterized in that, The blending extrusion is carried out in a twin-screw extruder, and the processing section temperature of the twin-screw extruder is 150-350℃.

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