Influence of Specific Structure on the Dielectric and Thermal Performance of Bulk Polymers: Atomistic Molecular Dynamics Simulations of XNBR

Abstract

In this work, we investigate the influence of the molecular structure of carboxylated acrylonitrile-butadiene rubber (XNBR) on the dielectric properties through non-equilibrium molecular dynamics (NEMD) simulations. The NEMD simulations are performed for calculating the permittivity (ε) of XNBR under different alternating electric field strength (Ei), alternating electric field frequency (Ef), and temperature. The simulation results show a similar change trend with the reported experimental consequence of dielectric elastomer. Interestingly, a critical alternating Ei at which the dielectric properties of XNBR with different acrylonitrile contents change seriously is found. Moreover, a deep insight into the mechanisms of the dielectric and thermal performance of XNBR is explored through the analysis from the atomistic level, including intermolecular interaction, fractional free volume, molecular chain migration ability, hydrogen bonds breaking and re-formation, dipole autocorrelation function, phonon vibration power spectrum, and kinetic energy. The research results will inspire the design of polymer structures to obtain high-performance polymer materials. This article is protected by copyright. All rights reserved