Prereration Of CF/ASA Electricmagnetic Shielding Composites And Its Performance Study

With the rapid progress of science and technology and the rapid development of the electronics industry,a variety of intelligent,digital electronic equipment is increasing,and with it,the phenomenon of electromagnetic radiation pollution is gradually increasing.Therefore,filled composite materials with electromagnetic shielding ability have become a hot spot for research,and now people have started to conduct in-depth research on composite materials with electromagnetic shielding performance.At present,the research progress of electromagnetic shielding materials in China still lags behind that of developed countries,so the development of new electromagnetic shielding composites has a greater application demand and important practical significance.Conventional electromagnetic wave shielding materials,such as ferrite,metal,and intrinsically conductive polymers,cannot meet the shielding requirements due to their high density and narrow band width.In this paper,CF/ASA carbon fiber polymeric resin composites were prepared by using CF carbon fiber as conductive filler and ASA polymeric resin as polymer matrix by mixing through filler dispersion conforming method and then molded after mixing using twin-screw hot extruder.The factors affecting the performance of the composite such as the length and content of carbon fibers were compared by the controlled variable method,and the influence of the length and content of carbon fibers on the conductive properties and electromagnetic shielding performance in the frequency band 1?18 GHz of the composite was studied in depth,and the changes of its mechanical properties were also analyzed.According to the experimental results,other conditions are the same,the conductivity of the composite material within a certain range of carbon fiber content increases with the increase of carbon fiber content;within a certain range of fiber length,the longer the carbon fiber length the better the conductivity of the composite material.The smallest square resistance is 25.4?/sq for the sample with 26% fiber content of carbon fiber length3 mm,and the smallest square resistance is 23.4?/sq for the sample with 29% fiber content of carbon fiber length 6mm.the composite material shows better electromagnetic shielding performance in the frequency band 10?15GHz,and the sample with 26% carbon fiber content of carbon fiber length 6mm reaches the highest electromagnetic shielding performance at The maximum tensile strength of CF/ASA carbon fiber polymer resin composite is 20.85 MPa at 20% carbon fiber content for 3mm carbon fiber length,and21.78 MPa at 13% carbon fiber content for 6mm carbon fiber length.The longer the length of carbon fiber,the higher the tensile strength of the composite samples.The maximum compressive strength of the samples with 3 mm carbon fiber length was 42.28 MPa at 26%carbon fiber content,and the maximum compressive strength of the samples with 6 mm carbon fiber length was 45.38 MPa at 26% carbon fiber content,and the longer the carbon fiber length was,the higher the compressive strength of the samples with the same carbon fiber content.The bending strength of the samples with 3 mm carbon fiber length reached a maximum of 30.81 MPa at 20% carbon fiber content,and the bending strength of the samples with 6 mm carbon fiber length reached a maximum of 32.77 MPa at 26% carbon fiber content.the longer the carbon fiber length,the higher the bending strength of the composites at the same carbon fiber content.