Molecular Dynamic and Dissipative Particle Dynamic Simulation on the Miscibility of NR/CR Blends

Abstract

Natural rubber (NR) exhibits good elasticity, flexural resistance, wear resistance, and excellent mechanical properties, and it has been widely used in aerospace, transportation, medical, and health fields. For NR, however, the resistance to thermal-oxidation and ozone aging is fairly poor. Although aging properties of NR can be significantly improved with the incorporation of chloroprene rubber (CR) according to some references, the miscibility between NR and CR, the morphologies of the binary blends, and so on are revealed ambiguously. In this work, molecular dynamics simulation (MD) and dissipative particle dynamics (DPD) simulation were carried out to predict the compatibility between natural rubber and chloroprene rubber in view of Flory–Huggins parameters. The morphologies of the blends were obtained with the use of the DPD method. The simulation results were furtherly examined by means of Fourier transform infrared spectroscopy (FT-IR) and dynamic mechanical analysis (DMA). It was found that the miscibility between NR and CR is poor. Nevertheless, the miscibility could be improved when the content of CR is 50% or 90%. In addition, spinodal decomposition with a critical temperature of 390 K would take place according to the phase diagram. Microphase structure such as spherical, lamellar, and bicontinuous phases can be found with different contents of CR in the blends with the results of morphologies analysis.

Compatibility analysis between natural rubber/polybutadiene rubber and protective waxes based on experiments and materials studio simulations

“…The phase diagram is an important method to study and predict the compatibility of polymer blends 13 . It consists of three main sections: critical point, spinodal curve and binodal curve 26 .…”

“…Thus, the minimal size representing the actual size becomes important for calculating thermodynamic parameters 21 . It has been shown that the solubility parameter (δ) and density of polymers stabilize and converge to a constant value with the increasing molecular chain length 13,18,22 . The solubility parameter (δ) and density of NR and BR at different molecular weights need to be calculated to determine the minimum size.…”

“…Molecular simulation has been a cost‐effective research tool to quantitatively analyze the microstructure and properties of molecules thanks to the rapid advances in computer technology 13 . Materials Studio has been applied to calculate physical parameters, such as solubility parameter (δ), solution coefficient (S), diffusion coefficient (D), and mean square displacement (MSD) 14–17 .…”

The effect of hypo‐sulfonamide accelerators on the induction period of rubber vulcanization based on experiments and molecular simulations

“…20,21 In addition, micromechanics have been applied at the macroscopic scale. 22 Through quantum mechanical (QM) simulation and molecular simulation (specifically, kinetic simulation), microscopic information including the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) values, solubility parameter (δ), mean square displacement (MSD), free volume, etc., [23][24][25] can be calculated to probe into the microstructural properties and mechanisms of the materials. When the predicted results are experimentally verified, the explanation of the mechanism is more reasonable.…”