Properties Of High Thermal Conductivity Composites Fabricated From Poly(Ether Ether Ketone) Fibers

In the 5G era,electronic devices were known for high frequency?high speed and high density.However,heat dissipation was also becoming one of the main problems of electronic devices.Poly(ether etherketone)(PEEK)was a special engineering plastic with excellent comprehensive properties,which showed great value in many fields.The pure PEEK showed the thermal conductivity(TC)of0.25W/(m·K)at room temperature,which limited severely the application of PEEK in electronic equipment,LED,5G and other fields.The conventional method to enhance the TC of PEEK was to add high content of thermally conductive fillers by melt blending.However,the TC does not satisfy industrial needs.It was necessary to construct a more efficient path of thermal conductivity in the matrix to improve the TC of PEEK greatly.In this paper,PEEK fibers were used as a carrier.The hexagonal boron nitride(h-BN),carbon fiber(CF)and copper(Cu)were selected as thermally conductive fillers.A series of PEEK-based thermally conductive composites with specific thermal conduction paths were prepared by a simple and efficient method successfully.The effects of filler content and distribution on the TC of composites were studied.The composites exhibited excellent thermal management ability.The main research consisted of the following two parts:Firstly,functionalized BNNSs were coated on the surface of PEEK fibers with the assist of poly(vinyl alcohol).The BNNSs/PEEK composites with oriented structures were prepared by hot pressing.The in-plane TC of the composite with the filler loading of 25wt% went up to 1.03 W/(m·K),which was 1.6 times and 4.12 times higher than that of BNNSs/PEEK powder composites and pure PEEK respectively.The interfacial thermal resistance of the material was calculated by the Foygel model.Compared with the randomly dispersed BNNSs/PEEK composite,the BNNSs/PEEK fiber composite exhibited lower interfacial thermal resistance.Secondly,Cu was deposited on the CF surface of PEEK/CF felt by a simple electroplating method.The three-dimensional PEEK/CF-Cu composites were prepared by hot pressing.The relationship between filler loading and TC was studied systematically.The in-plane TC of the composites reached 5.48 W/(m·K)with the Cu content of 27.1vol%,which is 22 times that of pure PEEK and 9.78 times that of PEEK/CF(40wt%)composites.This work provides new ideas and strategies for the design and preparation of PEEK-based three-dimensional thermally conductive composites.