  While polymer solutions lack the mechanical stability only transiently
cross-linked networks can fulfill the competing requirements of structural
stability and maximal energy dissipation. Here, we show that transient
cross-links entail local stress relaxation and energy dissipation in an
intermediate elasticity dominated frequency regime. We quantify the mechanical
response of a semi-flexible polymer network by experimentally tuning the
off-rate of the transient cross-linker molecule and theoretically reproduce the
measured frequency response by a model that is predicated on microscopic
unbinding events.
