Effect of interface on the mechanical behavior of polybutadiene–silica composites: An experimental and simulation study

The effect of interface property on the mechanical behavior of silica–polybutadiene composites is systematically investigated via combined experimental and dynamics simulation. In experiment, the interface property is controlled by SiO₂ particle size, silane coupling agents, and silane grafting density. The effects of these control parameters on the vulcanization kinetics, tensile strength, and dynamic mechanic properties are investigated and discussed. Both the experimental and simulation studies reveal the pivot role of filler–polymer interface on the mechanical reinforcement. Simulation study reveals that the constrained polymer layer (∼12 nm) surrounding the silica particles shows increased stress from 30 to 230 MPa, which is identified as the major reason for the overall enhancement of 100% modulus from 0.8 to 1.6 MPa. The molecular mechanics of interface from simulation is well correlated to the experimental results in this study, which provides a molecular level understanding of the relationship between interfacial interaction and mechanical reinforcement.