A Comparison of the Dynamical Relaxations in a Model for Glass Transition in Polymer Nanocomposites and Polymer Thin Films

We present the results of a facilitated kinetic Ising model based investigation of the confinement and filler-induced changes in the glass transition, fragility, and aging dynamics of a model system. This work is motivated by the issue of relationships, if any, in the glass transition phenomena of polymer nanocomposites and polymer thin films Our results suggest that addition of plasticizing fillers lower the T-g and increase the fragility of the system, while antiplasticizing fillets have an opposite effect Confinement arising in freely suspended films of both filled and unfilled systems were seen to reduce the overall T, oldie system Confinement and filler-induced shifts in the T, were not found to be quantitatively equivalent when comp:tied at the appropriate film thicknesses and interparticle spacings However, the fragilities exhibited a trend that suggests a closer quantitative equivalence between the PNCs and thin films In all the cases we examined, the aging dynamics and nonequilibrium relaxations were seen to be quan natively correlated to the filler or confinement induced changes in the relaxation times, but not at the same impel attire relative to their T, due to the differences in the fragility and relaxation spectrum of the different systems