Experimental study and molecular dynamics simulation of dynamic properties and interfacial bonding characteristics of graphene/solution-polymerized styrene-butadiene rubber composites

Abstract

Graphene/solution-polymerized styrene-butadiene rubber (SSBR) composites were prepared by using three types of SSBR matrix with different vinyl contents. The dynamic properties, interfacial bonding characteristics, and fractional free volume (FFV) of the composites were studied through a combined experimental and molecular dynamics (MD) simulation approach. We found that as the vinyl content increases in the SSBR matrix, the grapheme/SSBR interfacial interaction increases, the FFV decreases, and the graphene dispersion is improved. The interfacial interaction, which is derived from the introduction of graphene, can increase the activation energy and limit the mobility of the SSBR chains. Additionally, MD simulations of the pullout of the graphene from SSBR matrix were carried out to explore the interfacial bonding characteristics at the molecular level, which show that the interaction energy, pullout energy, and shear stress between graphene and SSBR increase with the increase of the vinyl content. The modeling results were in good agreement with the experimental results. This present study is expected to deepen the understanding of the basic physics for graphene reinforced rubber nanocomposites, especially the interfacial bonding characteristics at the molecular level.The effect of the vinyl content on microstructure, thermodynamics and dynamics properties of graphene/ SSBR composites was investigated. SSBR with the highest vinyl content has the highest interfacial shear stress by pullout simulation.

A combined molecular dynamics simulation and experimental method to study the compatibility between elastomers and resins

“…The binding energy ( E binding ), which is defined as the negative value of the interaction energy ( E inter ), is a measure of the compatibility between two components mixed with each other. 33 A negative E binding represents poor compatibility between two components. On the contrary, a positive E binding represents good compatibility, and a larger positive value indicates better compatibility.…”

“…33 A negative E binding represents poor compatibility between two components. On the contrary, a positive E binding represents good compatibility, and a larger positive value indicates better compatibility.…”

Molecular Dynamics Simulation Insight Into Two-Component Solubility Parameters of Graphene and Thermodynamic Compatibility of Graphene and Styrene Butadiene Rubber

“…Many studies have shown that the introduction of graphene or graphene oxide as filler into SBR matrix can significantly improve mechanical, electrical conductivity, and gas barrier properties of SBR. , On the basis of previous studies, graphene-rubber interactions and graphene dispersion are two major factors influencing the resulting properties of composites . The above two factors have been attempted to improve through the design of chemical structure of SBR as well as the tailor of graphene surface chemistry. , From the view of thermodynamics, the compatibility of filler and rubber dominates filler dispersion and filler–rubber interactions . As a consequence, it is significant for us to study the compatibility of graphene and SBR.…”

Morphology Evolution, Molecular Simulation, Electrical Properties, and Rheology of Carbon Nanotube/Polypropylene/Polystyrene Blend Nanocomposites: Effect of Molecular Interaction between Styrene-Butadiene Block Copolymer and Carbon Nanotube

“…On the other hand, since the butadiene remained linear, it could easily access more of the CNT surface than the PS, thus, benefiting the interaction. In a work developed by Luo et al [ 50 , 51 ] on styrene-butadiene block copolymer rubber (SBR), the molecular simulation showed that increasing the vinyl content in the SSBR diblock enhanced the binding energy towards a graphene nanosheet surface. They also experimentally demonstrated that as the vinyl content increased, the interaction between SSBR and graphene increased, correlating to (1) an increase of glass transition temperature, (2) a decrease of the fractional free volume of the SSBR chains when mixed with the graphene, and (3) a decrease in mobility as proven by dynamic mechanical analysis and positron annihilation lifetime spectroscopy.…”