C. Carrot et V. Verney, DETERMINATION OF A DISCRETE RELAXATION SPECTRUM FROM DYNAMIC EXPERIMENTAL-DATA USING THE PADE-LAPLACE METHOD, European Polymer Journal, 32(1), 1996, pp. 69-77
The Pade-Laplace method using the Laplace transform and the Pade appro
ximants has been used to recover a discrete relaxation spectrum from d
ynamic oscillatory data in the molten state for polymers. The method d
etects by its own stability the number of modes of the spectrum and ha
s been shown to be able to provide spectra with a low number of modes.
These spectra are found to be sufficient to obtain an accurate descri
ption of the linear viscoelastic behavior in a large frequency range f
rom the terminal zone to the plateau zone. Some intrinsic parameters o
f the numerical technique have been extensively studied in order to re
fine it. Its applicability is shown in the case of polystyrene having
monomolecular, bimodal or broad molecular weight distributions. It can
easily be implemented on a personal computer and the computing time i
s of the order of a few seconds.