Predicting the glass transition temperature and solubility parameter between rubber/silica and rubber/resins via all-atom molecular dynamics simulation

Resin is a widely used additive in rubber composites, which not only improves the processing properties of the composites but also enhances their mechanical properties, rolling resistance and wear resistance. However, there are specific differences in compatibility among resin, rubber and silica, which directly affect the performance of the composite materials. In this work, we first computed the glass transition temperature ($T_g$) of five resins in styrene−butadiene rubber (SBR) composites to prove the reliability of the computational method. Then, we explored the effects of different components and resin types on $T_g$ of SBR and found that the addition of silica can increase $T_g$ due to weak attractive interactions between silica and rubber molecular chains, which restrict the movement of the molecular chains. Furthermore, using solubility parameters, we analyzed the compatibility of rubber and five different resins and found that all five resins had good compatibility with rubber, especially C5/C9 copolymerized petroleum resin and hydrogenated resin. Finally, we revealed that there is a mutually attractive force between resin and silica. In summary, understanding the interactions among resins, silica and rubber is crucial for optimizing the performance of composite materials. © 2024 Society of Chemical Industry.