On the use of continuous relaxation spectra to characterize model polymers

There have been many more papers published on methods for inferring a continuous relaxation spectrum from linear viscoelastic data than have been published on the use of such methods for polymer characterization. But a continuous spectrum can reveal key details of the relaxation process that are not evident from plots of the storage and loss moduli, particularly in the case of model polymers prepared for research. In particular there are sharp peaks in the spectrum where Rouse relaxation is complete and further relaxation is inhibited by entanglements in the plateau zone and at the entry to the terminal zone where molecules have escaped their tubes. Examples of continuous spectra that reveal these relaxation phenomena are presented. (C) 2016 The Society of Rheology.