Wave hierarchies in viscoelasticity

An evolution operator L_n with n arbitrary, typical of several models, is analyzed. When n= 1, the operator characterizes the standard linear solid of viscoelasticity, whose properties are already established in previous papers. The fundamental solution {\epsilon}n of L_n is explicitly obtained and it's estimated in terms of the fundamental solution {\epsilon}1 of L_1. So, whatever n may be, asymptotic properties and maximum theorems are achieved. These results are applied to the Rouse model and reptation model, which describe different aspects of polymer chains.