MXene@bn heterostructure heat-conducting filler and epoxy composite material thereof and preparation method thereof

Abstract

The application provides a MXene@BN heterostructure heat-conducting filler and a preparation method of an epoxy composite material thereof, boron nitride and MXene nanosheets are modified by cation and anion modifiers respectively, and a heterostructure filler is constructed by using electrostatic self-assembly. The filler is applied to an epoxy resin, and the prepared MXene@BN / epoxy composite material exhibits excellent thermal conductivity and electrical insulation. The method is simple and efficient in preparation process, is suitable for large-scale industrial production, can balance high thermal conductivity and excellent electrical insulation performance under low filler loading, and provides an innovative and efficient heat dissipation solution for the electronic packaging field.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of epoxy resin composites, and relates to a preparation method of an MXene@BN heterostructure heat-conducting filler using synergistic action of two fillers and an epoxy composite material thereof BACKGROUND

[0002] With the rapid development of electronic technology, the integration of electronic devices is continuously improved, and the power density is also increased. If the large amount of heat generated during the working process cannot be effectively dissipated, the performance of the device will be affected. Epoxy resin is widely used as an electronic packaging material due to its good mechanical properties, electrical insulation and chemical corrosion resistance. Electrical insulation and thermal conductivity are important indicators of electronic packaging materials. The volume resistivity of epoxy resin is greater than 10 15 Ω·m, which meets the electronic packaging requirements (greater than 10 12 Ω·m). However, the intrinsic thermal conductivity is usually only 0.18-0.22 W / m·K, which cannot meet the high-efficiency heat dissipation requirements of electronic devices. Adding heat-conducting fillers is the most common method to improve the thermal conductivity of epoxy resin. However, in order to obtain high thermal conductivity, a relatively high amount of fillers is often required, which inevitably leads to problems such as filler agglomeration, poor material processing performance, and decreased mechanical properties.

[0003] Heterostructure fillers are more likely to form heat-conducting paths due to their unique structure and morphological characteristics, thereby achieving higher thermal conductivity improvement effect than single or simply blended fillers.

[0004] Chinese invention patent CN202110371409.4 discloses a preparation method of an Al2O3@BN / epoxy composite material. When the amount of heat-conducting fillers is 30wt%, the thermal conductivity of the composite material reaches 0.84 W / m·K. Chinese invention patent CN202211629533.7 discloses a preparation method of an MXene@silver / polyvinyl alcohol composite material. When the amount of heat-conducting fillers MXene@silver is 60wt%, the thermal conductivity of the composite material reaches 3.72 W / m·K. However, the electrical conductivity is as high as 156 S / m, which cannot meet the electrical insulation requirements of electronic packaging materials. SUMMARY

[0005] To solve the above technical problems, the application provides a preparation method of an MXene@BN heterostructure heat-conducting filler and an epoxy composite material thereof, which can obtain an epoxy composite material with high thermal conductivity and excellent electrical insulation at a relatively low filler loading. To achieve the above purpose, the application adopts the following technical solutions:

[0006] A preparation method of an MXene@BN heterostructure heat-conducting filler, characterized in that the method comprises the following steps:

[0007] 1) The surface of the boron nitride nanosheet is modified by a cationic modifier, the boron nitride nanosheet is added to an aqueous solution of the cationic modifier at a mass ratio of (1-10):1, the modification temperature is 15-50 DEG C, and the modification time is 6-36 h, to obtain modified boron nitride nanosheets with positive charges on the surface;

[0008] 2) The surface of the MXene nanosheet is modified by an anionic modifier, the MXene nanosheet is added to an aqueous solution of the anionic modifier at a mass ratio of (1-10):1, the modification temperature is 15-50 DEG C, and the modification time is 6-36 h, to obtain modified MXene nanosheets with negative charges on the surface;

[0009] 3) The modified boron nitride nanosheet and the modified MXene nanosheet are electrostatically self-assembled at a mass ratio of (10-100):1, and the electrostatic self-assembly temperature is 10-50 DEG C, to obtain a MXene@BN heterostructure heat-conducting filler;

[0010] The MXene nanosheet is prepared as follows:

[0011] Concentrated hydrochloric acid and distilled water are mixed at a volume ratio of (2-4):1, and then lithium fluoride is added after stirring and mixing, wherein the mass ratio of lithium fluoride to concentrated hydrochloric acid is 1:(10-20), and Ti3AlC2 is slowly added to the above solution, stirring at a temperature of 30-50 DEG C for 1-2 days, wherein the mass ratio of Ti3AlC2 to lithium fluoride is 1:(1-2); after the reaction is completed, pour into a centrifuge tube and shake well, centrifuge for 5-8 minutes and pour out the supernatant, add 1M hydrochloric acid to the centrifuge tube and repeat the above centrifugation steps 3-5 times, then pour out the supernatant, add an appropriate amount of distilled water to the centrifuge tube and repeat the above centrifugation steps 5-7 times, then pour out the upper liquid, collect the bottom precipitate, add an appropriate amount of distilled water, and ultrasonic under nitrogen atmosphere at room temperature for 40-70 minutes, centrifuge for 10-15 minutes, take the upper liquid, freeze-dry to obtain MXene nanosheets.

[0012] The cationic modifier is at least one selected from hexadecyl trimethyl ammonium chloride, polydimethyl diallyl ammonium chloride, and polydimethyl siloxane; and the anionic modifier is at least one selected from polyvinyl alcohol sulfonate, sodium dodecyl sulfate, and sodium polyacrylate.

[0013] The application also provides an epoxy composite material containing the MXene@BN heterostructure heat-conducting filler prepared by the above method, wherein the components and mass fractions of the epoxy composite material are as follows:

[0014]

[0015] The epoxy resin is one selected from bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic aldehyde polyepoxy resin, alicyclic epoxy resin, and aliphatic epoxy resin, the curing agent is an amine curing agent or an acid anhydride curing agent, and the accelerator is one of a phenolic accelerator, a tertiary amine accelerator, and a substituted urea accelerator.

[0016] Preferably, the bisphenol A epoxy resin is epoxy resin E-51 or epoxy resin E-44, the bisphenol F type epoxy resin is epoxy resin EP-862, the acid anhydride curing agent is selected from methylhexahydrophthalic anhydride or maleic anhydride, the amine curing agent is 4,4'-diaminodiphenyl methane or 4,4'-diaminodiphenyl sulfone, and the tertiary amine accelerator is 2,4,6-tris(dimethylaminomethyl)phenol or benzyl dimethylamine.

[0017] Preferably, the components and mass fractions of the epoxy composite material are as follows:

[0018]

[0019] The application further provides a preparation method of the epoxy composite material, characterized by uniformly mixing the epoxy resin, the curing agent, and the accelerator according to the proportions, adding MXene@BN heterostructure heat-conducting fillers, stirring or ultrasonically oscillating to uniformly disperse the heat-conducting fillers, and naturally cooling after curing to obtain the epoxy composite material.

[0020] The application has the following advantages:

[0021] On the one hand, the heat-conducting fillers with a heterostructure are obtained by electrostatic self-assembly, and the preparation method is simple, efficient, and low in cost, which is conducive to large-scale industrial production.

[0022] On the other hand, compared with zero-dimensional fillers, two-dimensional sheet structure fillers have a larger diameter-thickness ratio, and are more likely to contact each other to form an effective heat-conducting network in the matrix. The introduction of MXene with a higher heat-conducting coefficient into the boron nitride sheet layer through electrostatic action can significantly increase the heat-conducting coefficient of the composite fillers. At the same time, since the MXene is sandwiched in the insulating boron nitride sheet layer, the conductivity of the composite fillers does not increase significantly, and the electronic packaging material can meet the requirement of electrical insulation. DETAILED DESCRIPTION

[0023] The application is further described below through examples.

[0024] In the application, if not specifically stated, the required raw materials for preparation are all commercially available goods well known to those skilled in the art.

[0025] Example 1:

[0026] In 1 g of an aqueous solution of polydimethyldiallylammonium chloride, 10 g of modified boron nitride nanosheets were added, stirred at room temperature for 12 hours to obtain modified boron nitride nanosheets.

[0027] In 1 g of an aqueous solution of sodium polyacrylate, 10 g of MXene nanosheets were added, stirred at room temperature for 12 hours to obtain modified MXene nanosheets.

[0028] The above 10 g of modified boron nitride, 0.1 g of modified MXene was added to deionized water, stirred at room temperature for 2 hours to obtain MXene@BN heterostructure thermal conductive filler.

[0029] The above 3.45 g of MXene@BN was added to a mixture of 8 g of E51 type epoxy resin, 5.84 g of methylhexahydrophthalic anhydride curing agent and 0.12 g of 2,4,6-tris(dimethylaminomethyl) phenol, and the mixture was uniformly mixed, degassed, and then poured into a mold. After curing, the epoxy composite was naturally cooled.

[0030] Example 2

[0031] In 1 g of an aqueous solution of hexadecyltrimethylammonium chloride, 10 g of boron nitride nanosheets with hydroxyl groups were added and uniformly mixed, and stirred at room temperature for 16 hours to obtain modified boron nitride nanosheets.

[0032] In 1 g of an aqueous solution of sodium polyacrylate, 10 g of MXene nanosheets were added and uniformly mixed, and stirred at room temperature for 16 hours to obtain modified MXene nanosheets.

[0033] The above 10 g of modified boron nitride, 0.2 g of modified MXene was added to deionized water, stirred at room temperature for 4 hours to obtain MXene@BN heterostructure thermal conductive filler.

[0034] The above 3.45 g of MXene@BN was added to a mixture of 6.95 g of EP 862 type epoxy resin, 6.95 g of methylhexahydrophthalic anhydride curing agent and 0.06 g of 2,4,6-tris(dimethylaminomethyl) phenol, and the mixture was uniformly mixed, degassed, and then poured into a mold. After curing, the epoxy composite was naturally cooled.

[0035] Example 3

[0036] In 1 g of an aqueous solution of polydimethyldiallylammonium chloride, 10 g of boron nitride nanosheets with hydroxyl groups were added and uniformly mixed, and stirred at room temperature for 24 hours to obtain modified boron nitride nanosheets.

[0037] In 1 g of an aqueous solution of polyvinyl alcohol sulfonate, 10 g of MXene nanosheets were added and uniformly mixed, and stirred at room temperature for 24 hours to obtain modified MXene nanosheets.

[0038] 10 g modified boron nitride, 0.5 g modified MXene were added into deionized water, stirred at room temperature for 6 hours to obtain MXene@BN heterostructure thermal conductive filler.

[0039] 4.64 g MXene@BN above was added into a mixture of 10.47 g E51 type epoxy resin, 3.49 g 4,4'-diamino diphenyl sulfone, mixed uniformly, after degassing, pouring, natural cooling after curing to obtain epoxy composite material.

[0040] Example 4

[0041] 10 g boron nitride nanosheets with hydroxyl groups were added into 1 g aqueous solution of polydimethylsiloxane and mixed uniformly, stirred at room temperature for 30 hours to obtain modified boron nitride nanosheets.

[0042] 10 g MXene nanosheets were added into 1 g aqueous solution of sodium dodecyl sulfate and mixed uniformly, stirred at room temperature for 30 hours to obtain modified MXene nanosheets.

[0043] 10 g modified boron nitride, 0.5 g modified MXene were added into deionized water, stirred at room temperature for 8 hours to obtain MXene@BN heterostructure thermal conductive filler.

[0044] 4.64 g MXene@BN above was added into a mixture of 8 g E51 type epoxy resin, 5.84 g methyl hexahydrophthalic anhydride curing agent and 0.12 g 2,4,6-tris(dimethylaminomethyl) phenol, mixed uniformly, after degassing, pouring, natural cooling after curing to obtain epoxy composite material.

[0045] Comparative Example 1

[0046] A mixture of 9 g E51 type epoxy resin, 3 g 4,4'-diamino diphenyl sulfone was mixed uniformly, after degassing, pouring, natural cooling after curing to obtain epoxy composite material.

[0047] Comparative Example 2

[0048] 4.64 g boron nitride nanosheets were added into a mixture of 6.95 g EP 862 type epoxy resin, 6.95 g methyl hexahydrophthalic anhydride curing agent and 0.06 g 2,4,6-tris(dimethylaminomethyl) phenol, mixed uniformly, after degassing, pouring, natural cooling after curing to obtain epoxy composite material.

[0049] Comparative Example 3

[0050] 2.32g boron nitride nanosheets and 2.32g Al2O3 were blended and added to a mixture of 8g E51 type epoxy resin, 5.84g methyl hexahydrophthalic anhydride curing agent and 0.12g 2,4,6-tris(dimethylaminomethyl) phenol, and mixed uniformly, then cast after degassing, and the epoxy composite was obtained after natural cooling after curing.

[0051] A TC3000 type thermal conductivity measuring instrument produced by Xi'an Xiaxi Science and Technology Company was used to test the thermal conductivity of the sample, and the average of three measurements was taken as the final result, the test temperature was 30 DEG C, and the sample size was 30mm x 40mm x 3mm. A broadband dielectric impedance spectrometer produced by Germany NOVOCONTROL Company was used to measure the resistivity of the sample, and the sample was a round piece with a diameter of 30mm and a thickness of 1mm.

[0052] The performance data of each sample are listed in Table 1.

[0053] Table 1 Comparison of properties of several composite materials

[0054]

[0055] As can be seen from the data in the table, the thermal conductivity of the MXene@BN epoxy composite prepared in the application is much higher than that of other samples, and the insulation performance is excellent.

[0056] It should be noted that the above-described embodiments are only used to explain the present application and do not constitute any limitation on the present application. The present application is described by referring to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than limiting words. The present application can be modified as specified within the scope of the claims of the present application, and the present application can be revised within the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and embodiments, it does not mean that the present application is limited to the specific examples disclosed therein, on the contrary, the present application can be extended to all other methods and applications with the same function.

Claims

1. A method for preparing MXene@BN heterostructure heat-conducting filler, characterized in that, The method comprises the following steps: 1) modifying the boron nitride nanosheet with a cationic modifier, adding the boron nitride nanosheet to an aqueous solution of the cationic modifier at a mass ratio of (1-10):1, modifying at a temperature of 15-50℃ for 6-36h to obtain modified boron nitride nanosheets with positive charges on the surface; 2) modifying the MXene nanosheet with an anionic modifier, adding the MXene nanosheet to an aqueous solution of the anionic modifier at a mass ratio of (1-10):1, modifying at a temperature of 15-50℃ for 6-36h to obtain modified MXene nanosheets with negative charges on the surface; 3) electrostatic self-assembly of the modified boron nitride nanosheet and the modified MXene nanosheet at a mass ratio of (10-100):1 to obtain MXene@BN heterostructure heat-conducting filler, and the temperature of the electrostatic self-assembly is 10-50℃; The MXene nanosheet is prepared as follows: A concentrated hydrochloric acid and distilled water solution is prepared at a volume ratio of (2-4):1, and after stirring and mixing uniformly, lithium fluoride is added, wherein the mass ratio of lithium fluoride to concentrated hydrochloric acid is 1:(10-20), and Ti3AlC2 is slowly added to the above solution, stirring at a temperature of 30-50℃ for 1-2 days, wherein the mass ratio of Ti3AlC2 to lithium fluoride is 1:(1-2); after the reaction is completed, pour into a centrifuge tube, shake well, centrifuge for 5-8 minutes, pour out the supernatant, add 1M hydrochloric acid to the centrifuge tube, repeat the above centrifugation steps 3-5 times, pour out the supernatant, add an appropriate amount of distilled water to the centrifuge tube, repeat the above centrifugation steps 5-7 times, pour out the upper liquid, collect the bottom precipitate, add an appropriate amount of distilled water, and ultrasonic under nitrogen atmosphere at room temperature for 40-70 minutes, centrifuge the above mixture for 10-15 minutes, take the supernatant, freeze-dry to obtain MXene nanosheets.

2. The method of claim 1, wherein the heterostructure thermally conductive filler is prepared by the steps of: The cationic modifier is at least one selected from cetyltrimethylammonium chloride, polydimethyl diallyl ammonium chloride, and polydimethylsiloxane; and the anionic modifier is at least one selected from polyvinyl alcohol sulfonate, sodium dodecyl sulfate, and sodium polyacrylate.

3. An epoxy composite material of MXene@BN heterostructure thermally conductive filler prepared by the method of claim 1, characterized in that, The components and mass fractions of the epoxy composite are as follows: The epoxy resin is selected from one of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic polyepoxy resin, alicyclic epoxy resin, and aliphatic epoxy resin, the curing agent is amine curing agent or acid anhydride curing agent, and the accelerator is one of phenolic accelerator, tertiary amine accelerator, and substituted urea accelerator.

4. The epoxy composite of claim 3, wherein, The bisphenol A epoxy resin is epoxy resin E-51 or epoxy resin E-44, the bisphenol F type epoxy resin is epoxy resin EP-862, the acid anhydride curing agent is selected from methyl hexahydrophthalic anhydride or maleic anhydride, the amine curing agent is 4,4'-diaminodiphenyl methane or 4,4'-diaminodiphenyl sulfone, and the tertiary amine accelerator is 2,4,6-tris(dimethylaminomethyl)phenol or benzyl dimethylamine.

5. The epoxy composite of claim 3 or 4, wherein the epoxy resin is a diglycidyl ether of bisphenol A. The components and mass fractions of the epoxy composite are as follows:

6. A method of making the epoxy composite of claim 3, wherein, The epoxy resin, the curing agent and the accelerator are mixed uniformly according to the proportions, then the MXene@BN heterostructure heat-conducting filler is added, stirring or ultrasonic oscillation is conducted to uniformly disperse the heat-conducting filler, after degassing and curing, natural cooling is conducted to obtain the epoxy composite.

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