A Computational Study of Physical Properties of Nitrile‐Butadiene Rubber via Molecular Dynamics Simulations

As a widely used elastomer, the properties of nitrile butadiene rubber (NBR) are strongly influenced by its monomer composition and molecular structure. In this work, we employ all‐atom molecular dynamics simulations to systematically investigate the effects of chain length, acrylonitrile (ACN) content, and trans‐butadiene (T‐B) ratio on the properties of NBR. Key properties examined include density ( ρ ), unit free volume (UFV), root‐mean‐square radius of gyration (), and glass transition temperature (). We also analyze two dynamic parameters: mean square displacement (MSD) and diffusion coefficient (DC). Our results indicate that increasing the chain length leads to higher density and larger , while reducing UFV, which consequently decreases molecular mobility. With increasing ACN content, density, and rise, whereas all other structural and dynamic parameters decline. In contrast, variations in T‐B content ratio have a minor effect on density; however, , UFV, and all increase with a higher T‐B ratio. Notably, the dynamic parameters (MSD and DC) reach a maximum at 60 mol% T‐B ratio. This study provides molecular‐level insights into the role of monomer composition and chain architecture in determining NBR properties, offering theoretical guidance for the rational design of NBR materials with tailored performance.