The paper reports the development of a Monte Carlo lattice model (cubic F) of polymer chains which was able to access times where the diffusion of the centre-of-mass of the chains was the dominant process, even though the chain lengths were well above that for entanglement. The volume of the model was large when compared with the volume of gyration of the individual molecules. The model incorporates an algorithm, which allowed for the possibility of co-operative motions over sections of the chains and increased the time efficiency of the simulation. Both the model and the modifying algorithm were tested against the known scaling laws. The model, for shorter chains, was 'reverse mapped' into full atomic detail as polyethylene and the shorter time processes simulated using molecular dynamics. The molecular dynamics model was tested against experimental diffusion data for polyethylene, of the same molecular weight and at the same temperature, and then used to time-calibrate the lattice model. Both the fine grained molecular dynamics model and the coarse grained Monte Carlo model were thus interlocked to cover a time range from the individual atomic motions of molecular dynamics up to the order of a microsecond, a range of six orders of magnitude.

A Monte Carlo Lattice Model for Chain Diffusion in Dense Polymer Systems and Its Interlocking with Molecular Dynamics Simulation. Haire, K.R., Carver, T.J., Windle, A.H.: Computational and Theoretical Polymer Science, 2000, 11[1], 17-28