Investigating the Role of Miscibility in Hydrogenated Dicyclopentadiene Resin/Polymer Blends: A Molecular Dynamics...

The behavior and properties of polymer-resin blends are critical for the design of advanced polymeric systems in a wide range of applications. In this work, we present an atomistic molecular dynamics study of the effects of hydrogenated dicyclopentadiene (H-DCPD) resin on the structural, dynamical, and viscoelastic properties of polymer matrices. Two different systems are examined: linear 1,4-cis polyisoprene (PI) and a four-component styrene-butadiene rubber (SBR) copolymer. The results reveal lower miscibility of H-DCPD resin in PI compared to that in SBR, as evidenced by the formation of resin-rich domains, revealed by the magnitude of local peaks in resin-resin radial distribution functions. Temperature-dependent analysis shows that structural and dynamical properties are most sensitive at ambient conditions (T = 300 K, P = 1 atm), with PI exhibiting significantly reduced molecular mobility due to its proximity to the glass transition temperature. This restricted dynamics directly influences the viscoelastic response, leading to increased structural rigidity upon resin addition. Furthermore, the effect of resin concentration is systematically assessed, demonstrating that, while 17 vol% resin has a negligible impact on both systems, increasing the concentration to 34 vol% in PI, results in pronounced changes in its structural and viscoelastic behaviors. Overall, this study highlights atomistic molecular dynamics simulations as powerful predictive tools for the rational design of resin-elastomer blends.