Monte Carlo simulation of the glass transition in three-dimensional dense polymer melts

Abstract

We determine the incoherent intermediate scattering function φ s q ( t) for a three-dimensional dense polymer melt. This function shows the signature of a two-step process which was quantitatively compared to the idealized mode coupling theory (MCT) within the β-relaxation regime. A major result of this analysis is that the studied temperature interval splits in a high temperature part, where the idealized theory describes φ s q ( t) over about three decades in time, and a low temperature part, where it strongly overestimates the freezing tendency of the melt. Since one can qualitatively attribute this discrepancy between the idealized MCT and the simulation data to hopping processes, the critical temperature T c was estimated from the fits with the idealized MCT, yielding T c ≈ 0.150 (the temperatures is measured in units of the energy parameter of the model).