Dielectric bionanocomposites with organoclay and silane-treated conductive fillers for reduced dielectric relaxation times

Abstract

The effect of 3-Glycidyloxypropyl-trimethoxysilane (GPTMS) on aluminum nanoparticles incorporated into polylactic acid/polyhydroxyalkanoate/intercalated montmorillonite composite was investigated for its dielectric properties. The dielectric constant, losses and a. c conductivity of these composites were measured and a dielectric spectroscopy for studying the relaxation times (τ) was conducted. Scoped to address the reduction in dielectric relaxation times and charge dissipation, it was found that GPTMS treatment shifted the relaxation frequencies to much higher limits and stabilized the dielectric permittivity of the fabricated composite. At high frequencies of 1.75 MHz, two distinct relaxation times were calculated for varying loading of 5 wt%, 10 wt % and 15 wt % of silane-treated aluminum nanoparticles incorporated PLA/PHA/iMMT composites. The increase in a. c conductivity reveals the increased conduction in the insulative polymer matrix notably between 2.33 × 10⁻⁴ and 4.24 × 10⁻⁵ S/m. The argand plot for identifying dielectric relaxation phenomena, provided insights on polarization phenomena, regions of conduction, and most importantly a non-Debye type dielectric relaxation was observed with a reduction in τ values. This improvement would possibly affect the surface functionalization and coating techniques applied in polymer composite fabrication in the microelectronic applications.