Preparation And Properties Of Fe₃O₄/MWCNTs/PEEK Electromagnetic Shielding Composite

With the development of modern science,various electronic and electrical equipment provide high efficiency for social production and confidential life for daily life.At the same time,electromagnetic radiation produced by electrical devices has great influence in production and life which lead electromagnetic pollution to be a new source pollution.The electromagnetic pollution affects normal communication,but also threats human health.Therefore,how to prevent electromagnetic pollution has become a focal point of research.A ideal efficient electromagnetic shielding material can be constituted by two parts,wave-transparent material and wave-absorbing material.In recent years,though many electromagnetic shielding material have been studied,they cannot achieve the integration of structure and function.Therefore,it’s meaningful for researchers to find a material that has good EMI shielding properties,mechanical properties,thermal stability and resistance to corrosion.PEEK,which has been widely applied in aerospace technology as well as the energy and chemical industries,is a semi-crystalline engineering thermoplastic with outstanding properties such as superior mechanical properties,thermal stability,and solvent resistance.Numerous efforts have been devoted to further improving the properties of PEEK by incorporation with fillers such as carbon fibers,glass fibers,and nanoparticles.Carbon nanotubes（CNTs）are excellent candidates for the improvement of composites owing to their unique mechanical,electrical,and hermal properties combined with their small diameters and very low densities.Compared to single-walled CNTs（SWCNTs）,multi-walled CNTs（MWCNTs）cost less and are more suitable for large-scale industrialization.Due to its small size effect and optical properties,Fe₃O₄ nanoparticles can increase their energy loss during light absorption and light reflection,and they have good magnetic properties and high magnetic loss tangent angle.Hence,it can be used for the absorption and attenuation of electromagnetic waves.At present,Fe₃O₄ nanoparticles as magnetic loss absorbing materials has been widely studied.Therefore,studies on PEEK are gradually changing from those with a focus on its use as a structural material to those that emphasize its potential as an integrative material of structure and function to meet the needs of certain harsh environments.Though PEEK can be an ideal matrix resin because of its mechanical properties,thermal stability,and solvent resistance,it’s difficult that MWCNTs and Fe₃O₄ have a good dispersity in PEEK resin due to its high viscosity.If filler cannot be evenly dispersed in the resin,electrical breakdown and stress concentration point will be generated which is not favorable for electrical and mechanical properties of composites.To obtained an integrative material of structure and function,PEEK is chosen as matrix resin,MWCNTs as dielectric loss filler,Fe₃O₄ nanosphere as magnetic loss filler,ternary composites are prepared by melt blending method.Polyether sulfone（PES）or polyetherimide（PEI）are used as modifier of MWCNTs to improve the dispersion of MWCNTs in polymer matrix.As a result,PEI was found to be a more efficient modifier that make MWCNTs have better dispersity in PEEK matrix.Two ways had be used to solve the aggregation of Fe₃O₄ nanoparitcles.in PEEK matrix.The results showed that the Fe₃O₄ nanoparticles deposited on the MWCNTs coated by PEI can better achieve its dispersion in the PEEK matrix.Uniform dispersion of MWCNTs and Fe₃O₄ nanoparticles in the PEEK matrix facilitates the construction of high-performance PEEK-based electromagnetic shielding composites.