  We consider the rupture dynamics of a homopolymer chain pulled at one end at
a constant loading rate r. Compared to single bond breaking, the existence of
the chain introduces two new aspects into rupture dynamics: the non-Markovian
aspect in the barrier crossing and the slow-down of the force propagation to
the breakable bond. The relative impact of both these processes is
investigated, and the second one was found to be the most important at moderate
loading rates. The most probable rupture force is found to decrease with the
number of bonds as f_{max} const-(ln(N/r))^(2/3) and finally to approach a
saturation value independent on N. All our analytical findings are confirmed by
extensive numerical simulations.
