Development of Entanglements in a Fully Disentangled Polymer Melt

A long-lived metastable "new melt" state of polymers has been recently reported, where monomers exhibit different mobilities due to an unusual distribution of entanglements. We study the relaxation of (fully disentangled) globules to the entangled state by means of computer simulations, and compare our data to the scenario of de Gennes' explosion upon melting. The entanglement length N-e is measured using the primitive path analysis method. The results show that in the case of relatively short chains (N approximate to 20N(e)), the relaxation of the entanglement length is very fast compared to that of the chains' size which slows down as the chain length N exceeds the equilibrium value of N-e.