The ``jammed state'' of a simulated transient polymeric network

Novel hybrid Molecular Dynamics/Monte Carlo simulations are employed to study transient polymeric networks -- e.g. hydrophilic polymers with hydrophobic endgroups -- computationally. Endgroups of short polymeric chains form junctions that continuously form and break over time. When the temperature is lowered, the probability that a junction breaks decreases. Below a critical temperature the system jams: it stops flowing and exhibits a yield stress under an applied shear. We will report on the underlying topological changes that occur in the polymeric network at this transition point. We will also discuss the behavior of the system under the influence of external stress. Results will be compared with observations in other jammed systems.