Dielectric Properties of Composites Based on Ethylene Vinyl Acetate Filled with a Hollandite-Like Ceramic Material K1.5Co0.75Ti7.25O16

• Published in: Russian journal of physical chemistry. B Vol. 17; no. 6; pp. 1311 - 1315
• Main Authors: Vikulova, M. A., Tsyganov, A. R., Artyukhov, D. I., Gorokhovsky, A. V., Gorshkov, N. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2023; Springer Nature B.V
• Subjects: Chemical Physics of Polymer Materials; Chemistry; Chemistry and Materials Science; Dielectric loss; Dielectric properties; Ethylene vinyl acetates; Fillers; Frequency ranges; Heat treatment; Physical Chemistry; Polymer matrix composites; Polymers; Solid solutions; Synthesis; cobalt doping; potassium titanate; polymer composites; dielectric properties; hollandite-like structure
• ISSN: 1990-7931; 1990-7923
• DOI: 10.1134/S199079312306009X

Polymer-matrix composites based on ethylene vinyl acetate (EVA) and K x Co y Ti 8 –  y O 16 solid solution with a hollandite-like structure (KCoTO(H)) are obtained and studied as promising materials for components of electronic devices. The filler is synthesized by modifying X-ray amorphous potassium polytitanate (PPT) K 2 O· n TiO 2 ( n = 4.3) in a CoSO 4 ·7H 2 O solution under alkaline conditions, followed by thermal treatment at 900°C. The structure of the synthesized material and the morphology of particles are studied by X‑ray phase analysis (XPA) and scanning electron microscopy (SEM), respectively. KCoTO(H) is introduced in the EVA polymer matrix by mixing a preliminarily prepared polymer solution and a dispersion of filler powder in an appropriate solvent in amounts of 10, 20, 30, 40, and 50 vol %. The frequency behavior of the permittivity, dielectric loss tangent, and conductivity of the obtained composites is studied by impedance spectroscopy. It is established that an increase in the KCoTO(H) content in the composite contributes to the growth of all the studied dielectric characteristics of a relatively pure EVA polymer matrix in the entire frequency range of 0.1 kHz–1 MHz (the maximum values are noted at a 50 vol % of the filler and f = 10 2 Hz: ε = 518, tanδ = 4, and σ = 1.35 S/cm).