Heat conduction composite material with aluminum-like linear expansion coefficient and preparation method thereof

Abstract

The invention relates to a heat conduction composite material with aluminum-like linear expansion coefficient and a preparation method thereof. The composite material comprises the following components in parts by weight: 20-45 parts of PA6, 1-3 parts of polypropylene, 0.5-3 parts of branching agent, 35-55 parts of heat conduction filler and 10-30 parts of glass fiber; wherein the melting point ofPA6 is 215-220 DEG C, the melting point of polypropylene is 139-145 DEG C, and the branching agent is an alternating copolymerization product of ethylene and maleic anhydride. The preparation methodcomprises the following steps of: mixing components other than glass fibers according to the formula ratio to obtain a mixture, feeding the mixture into a twin-screw extruder from a main feeding port,simultaneously feeding the glass fibers into the twin-screw extruder from a side feeding port, and melt extruding to prepare the heat conduction composite material with aluminum-like linear expansioncoefficient. The preparation method of the invention is simple, efficient and low in cost; the prepared thermal conductivity composite material has good mechanical strength and excellent thermal conductivity, and has broad application prospects.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and relates to a heat-conducting composite material with an aluminum-like linear expansion coefficient and a preparation method thereof. Background technique [0002] Aluminum is a metal material with excellent thermal conductivity. However, due to its own electrical conductivity, aluminum is expensive to process and form, and its use in some complex parts and applications requiring high insulation is limited. At present, in the field of polymer materials, the application of replacing metal with plastic continues to expand, but the excellent thermal conductivity of metal is not available in ordinary plastics. At present, in many fields such as civil electronic appliances, toys, communications, cables, military industry, etc., parts that need to have certain heat conduction or heat dissipation functions are involved, and at the same time, they need to have high mechanical strength and ce...

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Problems solved by technology

[0003] In the prior art, the thermal conductivity of the material is generally improved by adding fillers with high thermal conductivity to the resin matrix, but its strength and thermal conductivity are still far behind those of metal aluminum. Combining thermal conductivity fillers with metal aluminum At present, metal insert injection molding to improve its performance is a relatively efficient general practice. However, in the actual operation process, due to the large difference in thermal expansion coefficient between metal aluminum and thermoplastic resin, and the large amount of thermal conductive filler, the plastic has poor ductility. In the high and low temperature cycle environment, problems such as metal and plastic separation and stress cracking are prone to occur, which greatly affects the yield rate of the product, and the actual use is greatly affected

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