Structure-function integrated poly (aryl ether ketone)-grafted MWCNTs/poly (ether ether ketone) composites with low percolation threshold of both conductivity and electromagnetic shielding

In this work, a soluble poly (aryl ether ketone) with an azide-group (az-PAEK) was designed and synthesized, and poly (aryl ether ketone) was successfully grafted onto the surface of multi-walled carbon nanotubes (PAEK-g-MWCNTs) by [2 + 1] cycloaddition reaction between azide-group of az-PAEK and similar carbon-carbon double bond (C C) on MWCNTs. In addition, PAEK-g-MWCNTs were dispersed into semi-crystalline poly (ether ether ketone) (PEEK) matrix as fillers, the electrical conductivity, electromagnetic shielding performance, mechanical properties and thermal stability of PAEK-g-MWCNTs/PEEK composites with different filler contents were discussed. The results show that the excellent dispersion effect of PAEK-g-MWCNTs filler in PEEK matrix leads to the percolation threshold of conductivity and electromagnetic shielding of PAEK-g-MWCNTs/PEEK composites are only 0.372 vol% and 0.496 vol% respectively, which endows PAEK-g-MWCNTs/PEEK composites with extraordinary conductivity (1.123 S/cm) and electromagnetic shielding performance (36 GHz, 53.56 dB). At the same time, the mechanical properties (tensile strength of 118.2 MPa) and thermal stability (561 °C) of PAEK-g-MWCNTs/PEEK composite are enhanced, which is a kind of structure-function integrated composite with low percolation threshold of both conductivity and electromagnetic shielding. The good dispersion of PAEK-g-MWCNTs filler in PEEK matrix leads to the low percolation threshold of both conductivity (0.372 vol%) and electromagnetic shielding (0.496 vol%), which endows extraordinary conductivity (1.123 S/cm), electromagnetic shielding performance (36 GHz, 53.56 dB), the mechanical properties (tensile strength of 118.2 MPa) and thermal stability (561 °C) of structure-function integrated PAEK-g-MWCNTs/PEEK composite.