Exact relaxation times and eigenfunctions for a simple mechanical model of
polymer dynamics are obtained using supersymmetry methods of quantum mechan
ics. The model includes the finite extensibility of the molecule and does n
ot make use of the selfconsistently averaging approximation. The finite ext
ensibility reduces the relaxation times when compared to a linear force. Th
e linear viscoelastic behaviour is obtained in the form of the "generalized
Maxwell model". Using these results, a numerical integration scheme is pro
posed in the presence of a given flow kinematics.