Revealing the intrinsic dielectric properties of mediterranean green fiber composites for sustainable functional products

The ability of biodegradable materials to be miniaturized and degrade at specific rates when subjected to certain bacterium types and/or a given range of temperatures has led to a newly emerging technology: organic transient bioelectronics. In this work, the electrical characteristics of new natural composite materials are presented. Four types of natural lignocellulosic fibers were used with polypropylene: black pepper, sumac, pomegranate, and lemon. The composites were prepared as flat smooth sheets with thicknesses ∼1 mm. The dielectric constant and the ac conductivity of the prepared samples were determined for the frequency range of 1 KHz to 4 MH. All measurements were performed at room temperature and humidity utilizing parallel plate capacitor technique associated with high precision Hioki IM3536 LCR meter. The frequency response of the composites under study shows similar behavior to that of the pure sample but with various percentage increments. The dielectric constant shows that the consistent dispersion was highly affected by filler content specially at the low frequency side of the spectrum. The maximum recorded increment was around 55% for 30wt.% sumac samples at 1 KHz. The effect of larger filler loading concentration on the incremental change of the ac conductivity was more obvious at higher frequencies.