Dresden 2017 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Poster: Polymer Networks and Dynamics

CPP 17.9: Poster

Montag, 20. März 2017, 18:30–21:00, P1C

Non-monotonic effect of small molecules on the glass transition temperature of entangled polymers — •Elias Mahmoudinezhad and Fathollah Varnik — Interdisciplinary Centre for Advanced Materials Simulation (ICAMS), IC 02-753, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany

Using molecular dynamics simulations, we aim to study how the presence of small particles within a polymer melt affects its glass transition temperature, T_g. In this study, T_g is determined via standard cooling simulations from the liquid state to the glassy phase. We use a variant of a well-established fully flexible polymer model, first proposed by Kremer and Grest [1], extended by the attractive part of the Lennard-Jones interactions. The chain length, N_p is chosen larger than the entanglement length of the model (N_p=64 > N_e~=32, see Refs. [1, 2]). The size of small particles is smaller than the monomer diameter and is varied in a wide range. It is found that the size of small particles plays a crucial role for the T_g of the investigated polymer-particle mixture. Importantly, the glass transition temperature of the system changes in a non-monotonic way with the size of small particles. Our results are in qualitative agreement with experiments on polymers. The present observations can also be rationalized in terms of a recent mode coupling theory for binary mixtures [3], thus highlighting the generic character of the observed non-monotonic behavior [4].