Dielectric Permittivity, AC Electrical Conductivity and Conduction Mechanism of High Crosslinked-Vinyl Polymers and Their Pd(OAc)2 Composites

Abstract

Semiconductor materials based on metal high crosslinked-vinyl polymer composites were prepared through loading of Pd(OAc)2 on both Poly(ethylene-1,2-diyl dimethacrylate) (poly(EDMA)) and poly(ethylene-1,2-diyl dimethacrylate-co-methyl methacrylate) (Poly(EDMA-co-MMA)). The thermochemical properties for both poly(EDMA) and poly(EDMA-co-MMA) were investigated by thermal gravimetric analysis TGA technique. The dielectric permittivity, AC electrical conductivity and conduction mechanism for all the prepared polymers and their Pd(OAc)2 composites were studied. The results showed that the loading of polymers with Pd(OAc)2 led to an increase in the magnitudes of both the dielectric permittivity and AC electrical conductivity (σac). The value of σac increased from 1.38 × 10−5 to 5.84 × 10−5 S m−1 and from 6.40 × 10−6 to 2.48 × 10−5 S m−1 for poly(EDMA) and poly(EDMA-co-MMA), respectively, at 1 MHz and 340 K after loading with Pd(OAc)2. Additionally, all the prepared polymers and composites were considered as semiconductors at all the test frequencies and in the temperature range of 300–340 K. Furthermore, it seems that a conduction mechanism for all the samples could be Quantum Mechanical Tunneling (QMT).

Impact of Charge Transfer Complex on the Dielectric Relaxation Processes in Poly(methyl methacrylate) Polymer

“…In the second region, and independent of temperature may be attributed to the quantum mechanical tunneling mechanism of charge carriers over the potential barrier separating two energetically favorable centers in a random distribution. The QMT mechanism has been reported to be the dominant operating conduction mechanism in many synthesized polymeric materials [ 48 , 49 , 50 , 51 ].…”

Enhanced dielectric properties of freestanding, flexible, hydrophobic cellulose/poly(vinylidene fluoride) composite films

“…These can be measured using the capacitance () measured in parallel plate configuration and the tangent loss () of the material, respectively. The values of and of representative films was calculated using Equations () and (), respectively 50,51 where is the thickness of the film, is the permittivity of free space (8.85 × 10 −12 F/m), is the contact area. The dielectric constant of the films under study, were found to increase with the increase in the filler concentrations across the entire frequency range, as shown in Figure 6A, with the pristine film showing the lowest values.…”

“…The ac conductivity of the samples was calculated from the angular frequency () and the imaginary dielectric permittivity by using the following equation: 50 A plot of the measured ac conductivity versus frequency is shown in Figure 7A. The ac conductivity for all the samples was found to increase with frequency.…”

“…These can be measured using the capacitance (C) measured in parallel plate configuration and the tangent loss ( tan δ ð Þ) of the material, respectively. The values of ε r and ε i of representative films was calculated using Equations ( 3) and ( 4), respectively 50,51 F I G U R E 5 (A) Fourier transformed infrared spectra for the representative pure and composite films of cellulose/ poly(vinylidene fluoride) films between 400 and 1500 cm À1 and (B) fraction of electroactive phase versus filler concentration…”

A Sequenced Study of Improved Dielectric Properties of Carbon Nanotubes and Metal Oxide-Reinforced Polymer Composites

“…This problem has created the need for materials that have greater stability against environmental stresses. To resolve this issue, the fabrication of polymeric nanocomposites is under consideration, and especially the usage of inorganic nanofillers, which not only provide greater stability against the environment, but also enhance their electrical and dielectric properties [3][4][5]. Different morphologies of nanofiller are being explored to achieve a greater interface area.…”