Simulations of polymer interpenetration in 2D melts

Polymers in high density 2D melts are believed to segregate into compact disks. This is in contrast to the entanglement and interpenetration characteristic of 3D melts. We investigate this problem using the two-space algorithm, which is both a Cellular Automaton and a Monte Carlo algorithm for polymer structure and dynamics. Our simulations of high density melts in 2D show that contrary to expectations polymers do not completely segregate at high density - there is significant interpenetration. We show that the characteristic size of a polymer in the high density limit is intermediate between the size of a compact disk and a random walk. We then introduce a ''shape factor'' that measures the ratio of the polymer circumference squared to the area. The shape factor increases with increasing melt density, clearly indicating the observed interpenetration.