Polyvinylidene fluoride-based composite material as well as preparation method and application thereof

Abstract

The invention provides a polyvinylidene fluoride-based composite material as well as a preparation method and application thereof, and belongs to the technical field of composite materials. The preparation method comprises the following steps: mixing graphene oxide and dimethyl phthalate, and carrying out a modification reaction to obtain a DMP-GO dispersion liquid; sequentially carrying out solid-liquid separation and drying treatment on the DMP (at) GO dispersion liquid to obtain a DMP (at) GO solid product; and preparing the polyvinylidene fluoride based composite material by taking the DMP (at) GO solid product and polyvinylidene fluoride as raw materials. The gas permeability coefficient of the prepared polyvinylidene fluoride-based composite material is remarkably reduced, and the polyvinylidene fluoride-based composite material has excellent gas barrier property and excellent mechanical property and can be well applied to a lining layer of a marine flexible pipe.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of composite materials, and particularly relates to a polyvinyl fluoride-based composite material and a preparation method and application thereof. BACKGROUND

[0002] With the deep development of oil and gas resources, the environment for offshore oil and gas exploitation is gradually deteriorating. The high-temperature and high-pressure conveying environment poses a challenge to the mechanical and heat resistance performance of the inner liner material of the flexible pipe for offshore use. Since high temperature and high pressure can accelerate the penetration of acidic gases in the oil and gas medium into the inner liner, the acidic gases that have penetrated into the annulus will corrode the metal functional layer, endangering the safety of the pipeline, which puts higher requirements on the barrier performance of the inner liner material of the flexible riser. Therefore, it is very important to develop a new flexible riser inner liner material with high barrier property, heat resistance and excellent mechanical performance.

[0003] Polyvinyl fluoride (PVDF) is a semi-crystalline polymer with good processability. The density is relatively large, and the specific gravity can reach 1.7. The PVDF for pipeline use has good heat resistance and excellent mechanical strength, with a melting point of up to 160℃, a Young's modulus of up to 1000-1300 MPa, and a yield strength of more than 40 MPa. The stable C-F bond makes PVDF have extremely high intramolecular binding force, which makes it have excellent corrosion resistance and thermal stability. The long-term working temperature of PVDF can reach 130℃. Due to the high crystallinity and strong intramolecular force of PVDF, the material has high density, and therefore it has a certain barrier property to acidic gases such as CO2 and H2S. However, when applied to the inner liner material of the flexible pipe for offshore use, the gas permeation coefficient is still relatively large, which cannot meet the application of the inner liner of the flexible pipe for offshore use. SUMMARY

[0004] The present disclosure aims to at least solve one of the technical problems existing in the prior art, and provides a polyvinyl fluoride-based composite material and a preparation method and application thereof.

[0005] In one aspect of the present disclosure, a preparation method of a polyvinyl fluoride-based composite material is provided, and the preparation method comprises: mixing graphene oxide and dimethyl phthalate to perform a modification reaction to obtain a DMP@GO dispersion liquid; sequentially performing solid-liquid separation and drying treatment on the DMP@GO dispersion liquid to obtain a DMP@GO solid product; using the DMP@GO solid product and polyvinyl fluoride as raw materials to prepare a polyvinyl fluoride-based composite material. Optionally, the mass ratio of the graphene oxide and the dimethyl phthalate is 1: (2-10).

[0006] Optionally, the modification reaction is performed under the condition of ultrasonic, at room temperature for 8-12 hours.

[0007] Optionally, the drying treatment is performed at 60-70 DEG C for 12-24 hours.

[0008] Optionally, the polyvinyl fluoride-based composite material is prepared from the DMP@GO solid product and polyvinyl fluoride, comprising: dispersing the DMP@GO solid product in an organic solvent and performing ultrasonic treatment to obtain an ultrasonic treatment solution; mixing the ultrasonic treatment solution and first polyvinyl fluoride to obtain a mixed solution, and sequentially performing alcohol precipitation and drying on the mixed solution to obtain a polyvinyl fluoride composite master batch; melt blending the polyvinyl fluoride composite master batch and second polyvinyl fluoride to obtain a polyvinyl fluoride-based composite material.

[0009] Optionally, the mass ratio of the first polyvinyl fluoride to the second polyvinyl fluoride is 1:(4-9). The amount ratio of the DMP@GO solid product to the organic solvent is (0.2-0.5) g:100 mL.

[0010] Optionally, the melt blending temperature of the polyvinyl fluoride composite master batch and second polyvinyl fluoride is 180-200 DEG C, the screw rotation speed is 50-100 r / min, and the time is 6-10 min.

[0011] Optionally, the mass percentage content of the DMP@GO solid product in the polyvinyl fluoride-based composite material is 0.2-0.9%.

[0012] In another aspect of the present disclosure, a polyvinyl fluoride-based composite material is provided, which is prepared by the preparation method described above.

[0013] In another aspect of the present disclosure, the application of a polyvinyl fluoride-based composite material is provided, which is applied to the inner lining layer of a flexible pipe for marine use.

[0014] The present disclosure provides a polyvinyl fluoride-based composite material and a preparation method and application thereof. The preparation method comprises: mixing graphene oxide and dimethyl phthalate to perform a modification reaction to obtain a DMP@GO dispersion liquid; performing solid-liquid separation and drying treatment on the DMP@GO dispersion liquid in sequence to obtain a DMP@GO solid product; and using the DMP@GO solid product and polyvinyl fluoride as raw materials to prepare a polyvinyl fluoride-based composite material. The polyvinyl fluoride-based composite material prepared by the present disclosure has a significantly reduced gas permeation coefficient, excellent gas barrier performance, and excellent mechanical properties (including tensile strength and elongation at break), and can be well applied to the inner lining layer of a flexible pipe for marine use. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A flowchart of the preparation method of the polyvinyl fluoride-based composite material of the specific embodiment of the present disclosure; Figure 2 A comparison diagram of the yield strength of the GO / PVDF material prepared in Comparative Example 1 of the present disclosure and the KH550@GO / PVDF material prepared in Comparative Example 3; Figure 3 A comparison diagram of the elongation at break of the GO / PVDF material prepared in Comparative Example 1 of the present disclosure and the KH550@GO / PVDF material prepared in Comparative Example 3; Figure 4 A comparison diagram of the gas permeation coefficient of the GO / PVDF material prepared in Comparative Example 1 of the present disclosure and the KH550@GO / PVDF material prepared in Comparative Example 3; Figure 5 A comparison result of the yield strength of the material prepared in Comparative Example 4 of the present disclosure. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and are part of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present disclosure.

[0017] As shown in FIG. 1, in one aspect of the present disclosure, a preparation method S100 of a polyvinyl fluoride-based composite material is provided, which specifically comprises the following steps S110-S130: S110, mixing graphene oxide (GO) and dimethyl phthalate (DMP) to perform a modification reaction to obtain a DMP@GO dispersion liquid.

[0018] In some preferred embodiments, the mass ratio of graphene oxide and dimethyl phthalate is 1: (2-10), for example, 1:2, 1:4, 1:5, 1:6, 1:8, 1:10, etc. can be preferred, and 1:5 is further preferred.

[0019] In other preferred embodiments, the modification reaction is carried out under ultrasonic conditions, and the temperature of the modification reaction is room temperature, and the time is 8-12h, for example, 8h, 10h, 12h can be preferred.

[0020] S120, sequentially performing solid-liquid separation and drying treatment on the DMP@GO dispersion to obtain a DMP@GO solid product.

[0021] It should be noted that the solid-liquid separation of step S120 can be preferably centrifugal separation, and the solid-phase product after centrifugal separation is washed, and then the washed solid product is dried. The washing can be preferably carried out with anhydrous ethanol, and the number of washing can be preferably 3 times.

[0022] In some preferred embodiments, the drying can be preferably carried out in a drying box, and the temperature of the drying is 60-70℃, for example, 60℃, 65℃, 70℃, etc. can be preferred, and the time is 12-24h, for example, 12h, 15h, 20h, 24h, etc. can be preferred.

[0023] S130, preparing a polyvinylidene fluoride-based composite material using the DMP@GO solid product and polyvinylidene fluoride as raw materials. Specifically, step S130 specifically includes the following processes: The DMP@GO solid product is dispersed in an organic solvent for ultrasonic treatment to obtain an ultrasonic treatment solution. The ultrasonic treatment solution and the first polyvinylidene fluoride are mixed to obtain a mixed solution, and the mixed solution is sequentially subjected to alcohol precipitation and drying to obtain a polyvinylidene fluoride composite master batch; the polyvinylidene fluoride composite master batch and the second polyvinylidene fluoride are melt blended to obtain the polyvinylidene fluoride-based composite material.

[0024] In the present embodiment, by further ultrasonic treatment of the DMP@GO solid product in an organic solvent, the peeling of the DMP@GO solid product is realized, so that the DMP@GO solid product can exist in the form of uniform dispersion in the PVDF matrix; the gas barrier property of the composite material is improved; at the same time, the masterbatch method is adopted, which can further improve the dispersibility of GO in the PVDF matrix, and further improve the gas barrier property and mechanical property of the composite material.

[0025] It should be noted that the conditions for mixing the ultrasonic treatment solution and the first polyvinylidene fluoride are not specifically limited in the present embodiment, as long as the two are mixed uniformly, for example, mixing under stirring conditions can be preferred, and the mixing temperature is preferably room temperature, and the mixing time is preferably 8-12h.

[0026] Further, the solvent used in the alcohol precipitation is not specifically limited in the embodiment, for example, anhydrous ethanol and the like, and the solid product obtained by the alcohol precipitation should be dried, wherein the drying temperature is preferably 60-70℃, and the time is preferably 24-48h.

[0027] In some preferred embodiments, the mass ratio of the first polyvinylidene fluoride and the second polyvinylidene fluoride is 1:(4-9), for example, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, and further preferably 1:4.

[0028] In other preferred embodiments, the ratio of the amount of the DMP@GO solid product to the amount of the organic solvent is (0.2-0.5) g:100 mL, for example, 0.2:100 mL, 0.3:100 mL, 0.4:100 mL, 0.5:100 mL.

[0029] In other preferred embodiments, the organic solvent comprises N,N-dimethylformamide.

[0030] In other preferred embodiments, the DMP@GO solid product is dispersed in the organic solvent for ultrasonic treatment for 1-2h.

[0031] In other preferred embodiments, the temperature for melt blending of the polyvinylidene fluoride composite master batch and the second polyvinylidene fluoride is 180-200℃, the screw rotation speed is 50-100r / min, and the time is 6-10min.

[0032] It should be noted that the equipment for melt blending of the polyvinylidene fluoride composite master batch and the second polyvinylidene fluoride is not specifically limited in the embodiment, for example, melt blending is performed in a Brabender torque rheometer.

[0033] Further, the mass percentage content of the DMP@GO solid product in the polyvinylidene fluoride-based composite material obtained by the embodiment is 0.2-0.9%, for example, 0.2%, 0.3%, 0.4%, 0.6%, or 0.9%.

[0034] The present disclosure utilizes the esterification reaction between the carboxyl group (-COOH) produced by the hydrolysis of dimethyl phthalate (DMP) in the modification reaction and the hydroxyl group (-OH) or epoxy group on the surface of graphene oxide, to realize the surface modification of graphene oxide, the benzene ring and ester group structure of DMP can improve the processability of PVDF, increase the compatibility of graphene oxide and PVDF, improve the agglomeration problem of graphene oxide, and improve the dispersibility of graphene oxide in the polyvinylidene fluoride (PVDF) matrix; thereby improving the gas barrier property and mechanical property of the polyvinylidene fluoride-based composite material.

[0035] In another aspect of the present disclosure, a polyvinylidene fluoride-based composite material is provided, which is prepared by the method described above.

[0036] The gas permeation coefficient of the polyvinylidene fluoride-based composite material prepared in the present embodiment is significantly reduced, and the material has excellent gas barrier properties and excellent mechanical properties (including tensile strength and elongation at break), and can be well applied to the inner liner of a flexible pipe for marine use.

[0037] In another aspect of the present disclosure, the polyvinylidene fluoride-based composite material is applied to the inner liner of a flexible pipe for marine use.

[0038] The polyvinylidene fluoride-based composite material and the method for preparing the same will be further described below with reference to specific examples: Example 1 (1) Preparation of DMP@GO 1.0 g of graphene oxide (GO) was added to 5.0 g of dimethyl phthalate (DMP), and ultrasonic treatment was performed for 12 hours to obtain a uniform DMP@GO dispersion. Subsequently, the dispersion was centrifuged and washed with anhydrous ethanol three times, and finally dried in a 70°C oven for 24 hours to obtain DMP@GO solid particles.

[0039] (2) Preparation of DMP@GO / PVDF composite material by master batch method First, the DMP@GO solid particles were dispersed in 100 mL of N,N-dimethylformamide (DMF) solvent and ultrasonically dispersed for 1 hour. Then, 10.0 g of first polyvinylidene fluoride (PVDF) was added and continuously stirred at room temperature for 12 hours to fully dissolve. Anhydrous ethanol was added to precipitate the solute, and the obtained precipitate was dried at 70°C for 48 hours to prepare a PVDF composite master batch.

[0040] Finally, the obtained master batch and 40.0 g of second PVDF were melt blended by a Brabender torque rheometer at 200°C, with a screw rotation speed of 50 r / min, a mixing temperature of 200°C, and a time of 6 min, to finally prepare a DMP@GO / PVDF composite material.

[0041] In this embodiment, by adjusting the content of DMP@GO solid particles, DMP@GO / PVDF composite materials with different solid particle contents are prepared, for example, the mass percentage content of DMP@GO solid particles in the DMP@GO / PVDF composite material is 0.3%, 0.6% or 0.9% respectively, and the corresponding composite materials are respectively denoted as (0.3% DMP@GO / PVDF)-m, (0.6% DMP@GO / PVDF)-m, (0.9% DMP@GO / PVDF)-m.

[0042] The (0.6% DMP@GO / PVDF)-m compression molding sheet material prepared in this embodiment 1 is not transparent, which indicates that the DMP@GO solid particles are uniformly dispersed in the matrix.

[0043] Comparative Example 1 The graphene oxide (GO) and PVDF are melt blended by a Brabender torque rheometer at 200℃, the screw rotation speed is 50 r / min, the mixing temperature is 200℃, and the time is 6 min, and finally the PVDF / GO composite material is prepared.

[0044] In this comparative example, by adjusting the content of graphene oxide (GO), composite materials with different GO contents are prepared, for example, in the PVDF / GO composite material, the mass content of GO is 0%, 0.2%, 0.3%, 0.4%, 0.6% or 0.9% respectively, and the corresponding composite materials are respectively denoted as PVDF, 0.2%GO / PVDF, 0.3%GO / PVDF, 0.4%GO / PVDF, 0.6%GO / PVDF or 0.9%GO / PVDF.

[0045] The 0.6%GO / PVDF compression molding sheet material prepared in this comparative example 1 is transparent, but the focused black particles in the material can be clearly observed, which indicates that the GO solid particles are not uniformly dispersed in the matrix.

[0046] Comparative Example 2 The GO is dispersed in 100 mL N,N-dimethylformamide (DMF) solvent for 1 hour of ultrasonic dispersion. Then 10.0 g of polyvinylidene fluoride (PVDF) is added, and stirred at room temperature for 12 hours to make it fully dissolved. Anhydrous ethanol is added to precipitate the solute, and the obtained precipitate is dried at 70℃ for 48 hours to prepare PVDF / GO masterbatch. The obtained PVDF / GO masterbatch and 40 g of PVDF are melt blended by a Brabender torque rheometer at 200℃, the screw rotation speed is 50 r / min, the mixing temperature is 200℃, and the time is 6 min, and finally the composite material is prepared.

[0047] In the present comparative example, composite materials with different contents of graphene oxide (GO) are prepared by adjusting the content of GO, for example, the mass content of GO in the composite material is 0.3%, 0.6% and 0.9%, and the corresponding composite materials are denoted as (0.3%GO / PVDF)-m, (0.6%GO / PVDF)-m or (0.9%GO / PVDF)-m, respectively.

[0048] Further, the products prepared in Example 1, Comparative Example 1 and Comparative Example 2 are subjected to gas permeation performance test, and the test results are shown in Table 1. The composite material of Example 1 has a lower permeation coefficient and a lower diffusion coefficient, and has excellent gas barrier performance.

[0049] Table 1 Permeation and diffusion coefficients of the materials prepared in Example 1, Comparative Examples 1-2

[0050] Further, the products prepared in Example 1, Comparative Example 1 and Comparative Example 2 are subjected to tensile strength and elongation at break performance test, and the test results are shown in Table 2. The composite material of Example 1 still has relatively high mechanical properties, which are basically consistent with those of PVDF. This indicates that the composite material of the present example 1 still has good mechanical properties while having a lower gas permeation coefficient and diffusion coefficient and good gas barrier performance.

[0051] Table 2 Tensile strength and elongation at break of the materials prepared in Example 1, Comparative Examples 1-2

[0052] Comparative Example 3 5 mL of KH550, 100 mL of deionized water and 150 mL of anhydrous ethanol were mixed, then 1.0 g of GO was added, and the modification reaction was carried out at room temperature for 24 h. Subsequently, the dispersion liquid was centrifuged and washed with anhydrous ethanol for three times, and finally dried in a 70°C oven for 24 hours to obtain KH550 modified GO solid particles (KH550@GO).

[0053] The KH550@GO and PVDF were melt blended by Brabender torque rheometer at 200°C, the screw rotation speed was 50 r / min, the mixing temperature was 200°C, and the time was 6 min, and finally the PVDF / KH550@GO composite material was prepared.

[0054] In the present comparative example, by adjusting the content of GO solid particles modified by KH550 (KH550@GO), composite materials with different contents of KH550@GO were prepared, for example, in PVDF / KH550@GO composite materials, the mass content of KH550@GO was 0.2%, 0.4% or 0.6% respectively, and the corresponding composite materials were recorded as 0.2% KH550@GO / PVDF, 0.4% KH550@GO / PVDF, 0.6% KH550@GO / PVDF respectively.

[0055] Figure 2 A comparison chart of yield strength of GO / PVDF material prepared in Comparative Example 1 and KH550@GO / PVDF material prepared in Comparative Example 3, Figure 3 A comparison chart of elongation at break of GO / PVDF material prepared in Comparative Example 1 and KH550@GO / PVDF material prepared in Comparative Example 3, Figure 4 A comparison chart of gas permeability coefficient of GO / PVDF material prepared in Comparative Example 1 and KH550@GO / PVDF material prepared in Comparative Example 3, Figure 4 The test temperature of the permeability coefficient in the above table is 90°C.

[0056] From the above table, Figure 2 , Figure 3 and Figure 4 It can be seen that in Comparative Example 3, GO is modified by KH550, and the performance of the composite materials obtained before and after modification has no obvious change, which indicates that the modification of KH550 does not enhance the direct interaction between GO and PVDF.

[0057] Comparative Example 4 DMP and PVDF were melt blended by Brabender torque rheometer at 200°C, the screw rotation speed was 50 r / min, the mixing temperature was 200°C, and the time was 6 min, finally PVDF / DMP blend was prepared. The mass content of DMP was 1% (recorded as PVDF / 1%DMP) and 2% (recorded as PVDF / 2%DMP) respectively.

[0058] Graphene oxide (GO) was added to dimethyl phthalate (DMP), and after ultrasonic treatment for 12 hours, a uniform DMP / GO dispersion was obtained. The dispersion was melt blended with PVDF by Brabender torque rheometer at 200°C, the screw rotation speed was 50 r / min, the mixing temperature was 200°C, and the time was 6 min, finally PVDF / DMP / GO composite material was prepared.

[0059] In this comparative example, composite materials with different GO and DMP contents were prepared by adjusting the contents of dimethyl phthalate (DMP) and graphene oxide (GO). For example, in the PVDF / DMP / GO composite material, when the mass content of DMP is 1% and the mass content of GO is 0.2%, the corresponding composite material is denoted as PVDF / 1%DMP / 0.2%GO; in the PVDF / DMP / GO composite material, when the mass content of DMP is 2% and the mass content of GO is 0.2%, the corresponding composite material is denoted as PVDF / 2%DMP / 0.2%GO; and in the PVDF / DMP / GO composite material, when the mass content of DMP is 2% and the mass content of GO is 0.4%, the corresponding composite material is denoted as PVDF / 2%DM / 0.4%GO.

[0060] The gas permeability of the PVDF prepared in Comparative Example 1 and the product prepared in Comparative Example 4 was tested, and the test results are shown in Table 3.

[0061] Table 3 Gas permeability coefficients of materials prepared in Comparative Example 4

[0062] The mechanical properties of PVDF, 0.2%GO / PVDF, and 0.4%GO / PVDF prepared in Comparative Example 1, and PVDF / 1%DMP, PVDF / 1%DMP / 0.2%GO, PVDF / 2%DMP, PVDF / 2%DMP / 0.2%GO, and PVDF / 2%DMP / 0.4%GO prepared in Comparative Example 4 were tested. The test results are as follows: Figure 5 As shown.

[0063] From Table 3 and Figure 5 It can be seen that the composite material prepared in Comparative Example 4 has decreased mechanical properties and worse gas barrier properties compared to the material prepared in Comparative Example 1. This is because DMP is a small molecule liquid, and its direct incorporation into PVDF disrupts the crystalline structure of PVDF, leading to a decrease in material performance. However, comparing the mechanical properties (Table 2) and gas permeation data (Table 1) of the composite material prepared in Example 1 with those of PVDF and the material prepared in Comparative Example 1, the material prepared in Example 1 shows improved barrier properties while maintaining essentially unchanged mechanical properties. This indicates that removing excess DMP and employing a masterbatch method in Example 1 is more effective in improving the barrier properties and maintaining excellent mechanical properties of the composite material.

[0064] In summary, according to the above examples, the acid group or hydroxyl group generated by hydrolysis of dimethyl phthalate (DMP) is reacted with graphene oxide to realize the activation modification of graphene oxide, and the dispersibility of graphene oxide in a polyvinylidene fluoride (PVDF) matrix is improved; the benzene ring and ester group of DMP are used to increase the compatibility with PVDF, and the compatibility of the DMP@GO solid product with the PVDF matrix and the flowability in the PVDF matrix are further improved, so as to realize the good dispersibility of graphene oxide in the PVDF matrix, and the barrier property and mechanical property of the polyvinylidene fluoride-based composite material are significantly improved. That is, the gas permeation coefficient of the polyvinylidene fluoride-based composite material prepared by the present disclosure is significantly reduced, and the composite material has excellent gas barrier property and excellent mechanical property (including tensile strength and elongation at break).

[0065] The present disclosure provides a polyvinylidene fluoride-based composite material and a preparation method and application thereof, and has the following beneficial effects compared with the prior art: the gas permeation coefficient of the polyvinylidene fluoride-based composite material prepared by the present disclosure is significantly reduced, and the composite material has excellent gas barrier property and excellent mechanical property (including tensile strength and elongation at break), and can be well applied to the inner lining layer of a flexible pipe for ocean use.

[0066] It can be understood that the above embodiments are only exemplary embodiments adopted for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Various modifications and improvements can be made by those skilled in the art without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also considered to be within the protection scope of the present disclosure.

Claims

1. A method for producing a polyvinylidene fluoride-based composite material, characterized by, The preparation method comprises: mixing graphene oxide and dimethyl phthalate to perform a modification reaction to obtain a DMP@GO dispersion liquid; performing solid-liquid separation and drying treatment on the DMP@GO dispersion liquid in sequence to obtain a DMP@GO solid product; using the DMP@GO solid product and polyvinylidene fluoride as raw materials to prepare a polyvinylidene fluoride-based composite material.

2. The production method according to claim 1, characterized by, The mass ratio of the graphene oxide to the dimethyl phthalate is 1: (2-10).

3. The production method according to claim 1, characterized by, The modification reaction is performed under ultrasonic conditions, at room temperature, for 8-12 hours.

4. The method of claim 1, wherein, The drying treatment is performed at a temperature of 60-70 DEG C for 12-24 hours.

5. The preparation method according to claim 1, characterized in that, The DMP@GO solid product and polyvinylidene fluoride are used as raw materials to prepare a polyvinylidene fluoride-based composite material, which comprises: dispersing the DMP@GO solid product in an organic solvent to perform ultrasonic treatment to obtain an ultrasonic treatment solution; mixing the ultrasonic treatment solution and first polyvinylidene fluoride to obtain a mixed solution, and performing alcohol precipitation and drying on the mixed solution in sequence to obtain a polyvinylidene fluoride composite master batch; melting and blending the polyvinylidene fluoride composite master batch and second polyvinylidene fluoride to obtain a polyvinylidene fluoride-based composite material.

6. The production method according to claim 5, wherein The mass ratio of the first polyvinylidene fluoride to the second polyvinylidene fluoride is 1: (4-9). The use amount ratio of the DMP@GO solid product to the organic solvent is (0.2-0.5) g: 100 mL.

7. The preparation method according to claim 5, characterized in that, The melting and blending temperature of the polyvinylidene fluoride composite master batch and second polyvinylidene fluoride is 180-200 DEG C, the screw rotation speed is 50-100 r / min, and the time is 6-10 minutes.

8. The method of claim 1, wherein, The mass percentage content of the DMP@GO solid product in the polyvinylidene fluoride-based composite material is 0.2-0.9%.

9. A polyvinylidene fluoride-based composite material, characterized by, The polyvinylidene fluoride-based composite material is prepared by the preparation method in any one of claims 1-8.

10. Use of a polyvinylidene fluoride-based composite material, characterized in that, The polyvinylidene fluoride-based composite material in claim 9 is applied to a flexible pipe inner lining layer for marine use.

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