Determination of the relaxation time spectrum from dynamic moduli using anedge preserving regularization method

For the numerical determination of a continuous relaxation time spectrum fr om rheological data so-called regularization methods are necessary. The reg ularization method based on Tikhonov regularization and commonly used in rh eology assumes the relaxation time spectrum to be smooth. Accordingly, this method is not able to properly resolve spectra containing edges or at leas t large curvatures as proposed in the literature. In order to reconstruct s uch spectra a novel edge preserving regularization (EPR) method was develop ed which extends the properties of the commonly used method. In order to de monstrate the efficiency of EPR it is compared with the commonly used regul arization method by means of simulated and experimental data. This reveals that EPR is able to prove whether or not the theoretically predicted edge c ontaining spectra for high-molecular-weight, monodisperse polymers are comp atible with experimental data.