Glassy Dynamics of an All-Polymer Nanocomposite Based on Polystyrene Single-Chain Nanoparticles

Abstract

We employ broadband dielectric spectroscopy (BDS) and fast scanning calorimetry (FSC) to provide insights on the glassy dynamics of an all-polymer nanocomposite made of linear poly(vinyl methyl ether) (PVME) with dispersed single-chain nanoparticles (SCNPs) based on polystyrene (PS). In doing so we obtain information on both the molecular mobility and the way equilibrium is recovered in the glassy state, the so-called physical aging. Our results show the presence of a PVME matrix with glassy dynamics identical to that of bulk PVME. However, the PVME/SCNPs mixture presents physical aging effects at considerably higher temperatures, as high as 80 K above the glass transition temperature (Tg) of PVME. The connection of these effects with a slow relaxational component detected by BDS, originating from SCNPs enriched by PVME, is highlighted. Accordingly, we conclude that the PVME/SCNPs mixture gives rise to a nanocomposite where the fillers behave similarly to PS-rich blends with PVME. Altogether our results h...