LAUSR

Abstract The classical tube-reptation (TR) model is based on the assumption, that in entangled polymer melts diffusion takes place inside the effective tubes having a conformation of ideal chains and being stable on the time scale of the terminal relaxation time τ t , the latter being strongly molar mass (M) dependent. We argue, that this assumption leads for high M to a characteristic, strongly non-exponential time dependence of the deuteron Free Induction Decay, or likewise of the Hahn Echo amplitude. This holds for times t satisfying the condition τ e ≪ T 2 t ≪ τ t , where T 2 is an effective spin-spin relaxation time and τ e is the entanglement time.