High-heat-conductivity composite material and preparation method thereof

Abstract

The invention discloses a high-heat-conductivity composite material and a preparation method thereof. The preparation method comprises the following steps: evenly mixing fibrous heat-conduction filler and high-heat-conductivity filler graphene in a mass ratio of 1:1-1:200 with thermoplastic polymer, dispersing for 0.5-24 hours, granulating to obtain high-heat-conductivity composite grains, and putting the grains in a die to carry out hot molding at 170-280 DEG C under the pressure of 10-18 MPa. The thermoplastic polymer is any one of polyethylene, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, polyperfluoroalkoxy ester, nylon, polymethyl methacrylate, polycarbonate and polyvinyl chloride. The fibrous heat-conduction filler is carbon fiber or carbon nanotube, and the high-heat-conductivity filler accounts for 5-35 wt% of the high-heat-conductivity composite material. The high-heat-conductivity composite material has the advantages of excellent heat-conduction property, low consumption of heat-conduction filler, favorable mechanical properties, simple preparation technique and low cost.

Description

technical field [0001] The invention relates to a thermally conductive composite material, in particular to a high thermally conductive composite material with excellent thermal conductivity and good mechanical properties and a preparation method thereof. Background technique [0002] With the increasing development of industrial production, the corrosion of equipment is becoming more and more prominent in the fields of chemical industry, petroleum, machinery, textile, metallurgy, aerospace, national defense, etc., especially in heat exchange occasions such as heat exchangers and heat pipes. Corrosion not only brings huge economic losses to the society, causes catastrophic accidents and endangers personal safety, depletes precious resources and energy, pollutes the environment, but also hinders the normal development of high technology. Traditional metal materials can no longer meet the requirements of corrosion resistance and high thermal conductivity. [0003] Polymer has...

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Problems solved by technology

It has been reported in the literature that composite materials with good thermal conductivity have been prepared by blending and modifying polymers with different high thermal conductivity fillers (such as graphite, carbon nanotubes, and carbon fibers) (Polymer Materials Science and Engineering, 2005, 21(6): 170 -173, Mater.Res.Soc.Symp.Proc., 2005, Vol.858E, HH3.31.1-HH3.31.5, Poly.Eng.&Sci., 2008, 2474-2481; J. Chemical Production and Technology, 2001, 8(2):17-19), however, the main problems existing in the existing composite heat-conducting materials: (1) in the case of low filling amount of heat-conducting filler, the thermal conductivity of the composite material is not high; (2) in the case of high filling amount In this case, although the thermal conductivity is significantly improved, the comprehensive mechanical properties of the material are drastically reduced. For example, if 30% graphite is added to PTFE, its tensile strength is only 0.44 times that of PTFE; the mass content of graphite is 40%. At this time, the tensile strength of the thermal conductive material is only 5MPa, which cannot meet the requirements of engineering use at all.

In short, the existing composite heat-conducting materials cannot achieve high thermal conductivity and good comprehensive mechanical properties at the same time, and it is difficult to meet the actual needs of performance, thus limiting the wide application of heat-conducting composite materials

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