Effects of TiO2 nanoparticle size and concentration on dielectric properties of polypropylene nanocomposites

• Published in: Journal of materials science Vol. 53; no. 12; pp. 9149 - 9159
• Main Authors: Womble, Michael D., Herbsommer, Juan, Lee, Yun-Ju, Hsu, Julia W. P.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2018; Springer Nature B.V
• Subjects: Anhydrides; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Complex permittivity; Crystallography and Scattering Methods; Dielectric loss; Dielectric properties; Dielectric waveguides; Electronic Materials; Frequency ranges; Maleic anhydride; Materials Science; Millimeter waves; Nanocomposites; Nanoparticles; Permittivity; Polymer Sciences; Polypropylene; Solid Mechanics; Titanium dioxide; Effective Permittivity; Loss Contribution; TiO2 Nanoparticles; Nano-sized TiO2 Particles; Dielectric Waveguide
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-018-2223-6

Polymer nanocomposites are promising materials for dielectric waveguides in high-data-rate communications, where extremely low loss is required. In this paper, we study the effect of titania (TiO 2 ) nanoparticle size (30–300 nm) and concentration on the effective permittivity ( ε eff ) and dielectric loss (tan  δ ) of polypropylene (PP) nanocomposites in two different frequency ranges: 100 Hz–300 kHz and 140 GHz–220 GHz. To aid the dispersion of TiO 2 in the PP matrix, polypropylene-graft-maleic anhydride (PP-g-MA) is added. Using this approach, an ε eff of 6.84 with tan  δ of 0.0049 at 220 GHz is achieved in a 21.5 vol% 100 nm TiO 2 /PP nanocomposite. We find that ε eff is insensitive to nanoparticle size in both frequency ranges while tan  δ appears to depend on the filler size at the low frequency range. By using complex permittivity in Lichtenecker’s model, we are able to separate the loss contribution of the polymer matrix from that of the TiO 2 nanoparticles. Our results provide insight into the choice of nanoparticle size and the effects of compatibilizer on millimeter-wave dielectric properties.