Fabrication and Properties of Novel Polyetheretherketone/Barium Titanate Composites with Low Dielectric Loss

Dielectric, thermal, and microhardness properties of high-performance barium titanate (BaTiO3)-filled polyetheretherketone (PEEK) composites were studied. BaTiO3 was varied from 0 vol.% to 67 vol.% in the PEEK matrix. The dielectric constant of the composites measured at 1 MHz increased approximately 14-fold. There was no dispersion in the dielectric constant with frequency between 10 kHz and 15 MHz. The Lichtenecker equation and modified Lichtenecker equation agreed well with the experimental data. The dissipation factor of the composites varied from 0.0056 to 0.0096. Scanning electron microscopy showed uniform dispersion of BaTiO3 in the matrix. The microhardness of the composites increased by more than 2.5-fold compared with pure PEEK. The coefficient of thermal expansion measured below and above the glass-transition temperature was reduced by up to 56%. These results make these composites promising candidate high-temperature organic substrates.