Viscoelasticandtransportpropertiesofpolymersintheliquid(solution, melt)or liquid-like (rubber) state determine their processing and application to a large extent and are of basic physical interest 1 3]. An understanding of these dynamic properties at a molecular level, therefore, is of great importance. However, thisunderstandingiscomplicatedbythefactsthatdi?erentmotional processes may occur on di?erent length scales and that the dynamics are governed by universal chain properties as well as by the special chemical structure of the monomer units 4,5]. The earliest and simplest approach in...