Tensile performance and viscoelastic properties of rubber nanocomposites filled with silica nanoparticles: A molecular dynamics simulation study

Understanding the relationship between the macro-properties and microstructure of rubber and rubber nanocomposites (RNCs) is crucial for the design and optimization of relevant rubber composite products. Herein, we explore the mechanical and viscoelastic properties of rubber and RNCs filled with silica nanoparticles by using atomistic molecular dynamics simulation. It is found that increasing cross-linking density can greatly enhance the tensile performance of pure rubber, and reduce the permanent deformation and hysteresis loss. The addition of silica nanoparticles causes significant changes in the sta -tic distribution, movement, and bond orientation, and the Tg of RNCs increases by more than 6% when the volume fraction of NPs reaches 10%. At fixed volume fraction of NPs, decreasing the NP size can further enhance the mechanical properties of RNCs, and the maximum tensile stress can increase by 50%. In addi-tion, cross-linking in the RNCs can improve the viscoelastic properties, and more highly crosslinked RNCs present larger storage modulus and loss modulus, and smaller loss angle. This work gives an in-depth understanding of the effect of microstructure on the mechanical properties of RNCs.(c) 2022 Elsevier Ltd. All rights reserved.