Thermally conductive and insulating composite material and preparation method thereof

Abstract

The invention discloses a thermally conductive and insulating composite material and a preparation method thereof. By using polypropylene powder as a matrix and irregular morphology ZnO and flaky Al2O3 as thermally conductive fillers, through reasonable combination of the thermally conductive fillers with different morphologies and different particle diameters, a contact and interaction function is formed between the fillers to form a thermally conductive network chain. The thermally conductive and insulating composite material disclosed by the invention has the advantages of excellent processing property, good heat resistance, lower production cost, thermally conductive coefficient of 1.6-2.2W / (m.k)(ASTMD5470, HotDisk method) and volume resistivity of above 1015 Omega.cm, and is capable of meeting the requirements of heat radiation and insulation of some high-power electronic devices and heat exchange devices.

Description

technical field [0001] The invention relates to a thermally conductive and insulating composite material and a preparation method, which are mainly used for heat dissipation of electronic devices and some heat exchange equipment. Background technique [0002] At present, there are two main ways to improve the thermal conductivity of polymer materials: one is to synthesize intrinsic polymers with high thermal conductivity; the other is to prepare thermally conductive composite materials by adding high thermal conductivity fillers. Although intrinsic polymers have high thermal conductivity, the production cost is high, the production process is complicated, and it is difficult to achieve large-scale. Filling with thermally conductive fillers to improve the thermal conductivity of polymers is an effective method. [0003] When the filling amount of thermally conductive filler is small, the fillers cannot form contact and interaction with each other in the matrix, and the therma...

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Problems solved by technology

[0004] Metal powders such as Au, Ag, Cu, Al, etc. have high thermal conductivity and can be used as thermally conductive fillers, but metal powders are good conductors, so the composite materials prepared by filling with metal powders have poor insulation; inorganic fillers such as carbon black, Al 2 o 3 , ZnO, AlN, etc. have large thermal conductivity, and the properties of composite materials prepared by filling different thermally conductive fillers vary greatly. Graphite is a conductor, and the insulation of composite materials prepared by filling graphite is also poor, and AlN is better in insulation. Thermally conductive filler, but its price is more expensive, which increases the production cost