Production method of high thermal conductivity and insulation graphene for high polymer material and graphene

Abstract

The invention discloses a preparation method of high-thermal-conductivity insulating graphene for a high polymer material and graphene. The method comprises the following steps: taking graphene oxide as a raw material to obtain uniformly dispersed graphene oxide slurry; the preparation method comprises the following steps: dissolving soluble aluminum salt, magnesium salt and alkali in deionized water to obtain an acid-base solution, and stirring and mixing a silane coupling agent, deionized water, acetic acid and ethanol to obtain a silane coupling agent reaction solution; pumping the graphene oxide slurry into an acid and alkali resistant reaction kettle, wherein the reaction kettle has stirring and jacket temperature control functions; an alkali solution is pumped in until the pH value is 6-9, and the temperature in the reaction kettle is 20-40 DEG C; the preparation method comprises the following steps: grinding and crushing sintered aluminum oxide / magnesium aluminate spinel / magnesium oxide coated graphene powder by adopting a heatable vertical stirring mill until the particle size is equal to the flake diameter of graphene, spraying a silane coupling agent reaction solution into the stirring mill, and continuously carrying out ball milling until the silane coupling agent reaction solution uniformly coats the surface of the powder, so as to obtain the silane coupling agent coated graphene powder. The product aluminum magnesium oxide and coupling agent modified graphene is obtained.

Description

technical field [0001] The invention belongs to a high thermal conductivity insulating inorganic additive and is used for the modification of polymer materials, in particular to a production method of high thermal conductivity insulating graphene used for polymer materials and graphene. Background technique [0002] With the increase in the integration density of electronic components, the requirements for heat dissipation of insulating materials are also getting higher and higher. The substrates of high-density wafers have adopted high thermal conductivity ceramics, ranging from alumina, silicon carbide, to aluminum nitride and other high thermal conductivity. Ceramics, whose thermal conductivity ranges from tens of W / mK to hundreds of W / mK, also use ceramic materials for high-power circuit boards. The hardness, brittleness and high-temperature forming process of ceramic materials make them very expensive. Polymer materials are the most cost-effective insulating materials, ...

AI Technical Summary

Problems solved by technology

The price of diamonds is relatively high, more than 1,000 yuan per kilogram, and the application scenarios are limited

Due to the very large anisotropy of graphene and carbon nanotubes, a higher thermal conductivity can be achieved at a lower addition amount, but the electrical conductivity also increases rapidly

[0003] The surface coating of graphene insulating material can reduce the electrical conductivity of polymer composites. In order not to affect the thermal conductivity of graphene, the coating material must be of high thermal conductivity and insulation. Partially crystalline ceramic materials meet this requirement, such as alumina, For silicon carbide, aluminum nitride, boron nitride, magnesium oxide, magnesium aluminum spinel, etc., the formation of crystals requires sintering above 1400°C. After high temperature sintering, most ceramics lose active hydroxyl groups, such as alumina, and will lose chemical bonds. It cannot be linked with the chemical bond of the polymer material, reducing the strength of the polymer composite material. After high-temperature treatment, magnesium oxide also has the activity of reacting with water to form magnesium hydroxide, and magnesium hydroxide will partially remain at high temperature, and will not be completely converted into Magnesium oxide, the hydroxyl group of magnesium hydroxide can be used as an active functional group to be compatible with polymers, but magnesium oxide is reduced when it reacts with carbon at high temperature, and the coated graphene is lost

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