Time−Temperature and Time−Concentration Superposition of Nanofilled Elastomers: A Molecular Dynamics Study

We systematically investigated the structural and dynamic properties of nanofilled elastomer on the basis of the idealized model of elastomer and nanoparticle. The simulated results indicate that the introduced nanoparticles induce more efficient chain packing. Meanwhile, a mobility gradient of polymer chains is found to exist approaching the nanoparticles. For the dynamic properties, we find for the first time that both the time−concentration and time−temperature superposition principles (TCSP and TTSP) are applicable at the chain length scale, while both break down at the segmental length scale for the filled system. However, the TTSP still holds at the segmental length scale for the pure system. Furthermore, the time−temperature−concentration superposition principle (TTCSP) applies well for the terminal relaxation of polymer nanocomposites. This scaling behavior has the underlying implication that the rheological properties (i.e., steady-state shear viscosity) of polymer nanocomposites possess thermorh...