Relaxation of disordered polymer networks: Regular lattice made up of small-world Rouse networks

As models for inhomogeneous polymer networks, we investigate the Rouse dyna mics of regular lattices built from subunits with arbitrary internal struct ure. We analyze as an example a two-dimensional lattice, consisting of smal l-world networks (SWNs). Using analytical and numerical calculations we stu dy the stretching of such a structure under an external force. We find that the network shows interesting relaxation features and an unusual behavior in the intermediate time (frequency) domain, which lies in the region betwe en the modes of the SWN subunits and those of the lattice. This behavior is related to the SWN-density of states, which leads to the appearance of a " pseudogap" between the highest lattice eigenvalue and the lowest SWN eigenv alue. (C) 2001 American Institute of Physics.