Thermomechanically stable dielectric composites based on poly(ether ketone) and BaTiO3 with improved electromagnetic shielding properties in X-band

High-performance barium titanate (BaTiO3) filled poly(ether ketone) (PEK) composites were prepared by melt compounding with an aim to investigate the effect of BaTiO3 on thermal, thermomechanical, dielectric, and electromagnetic interference shielding behavior of PEK. The content of BaTiO3 in the PEK matrix was varied from 0 to 18 vol %. Scanning electron microscopy studies shows that BaTiO3 particles were uniformly distributed in the PEK matrix up to 13 vol % loading followed by the formation of agglomerates at higher loading (18 vol %). Rockwell hardness increased up to 13 vol % loading followed by a decrease at 18 vol % loading. Dynamic mechanical analysis revealed that storage modulus increases with increase in BaTiO3 loading with a maximum value of 3192 MPa at 13 vol % compared to 2099 MPa for neat PEK. Dielectric constant of composites measured in the frequency range of 8.2-12.4 GHz increased approximately three times upon incorporation of 18 vol % of BaTiO3. This increment in dielectric constant is reflected in improved electromagnetic shielding properties as loading of dielectric filler (BaTiO3) increases. Total shielding effectiveness of -11 dB (approximate to 92% attenuation) at loading of 18 vol % BaTiO3 justifies the use of these composites for suppression of EM radiations. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46413.