%0 Journal Article
%A Gold, Barbara
%A Hövelmann, C. H.
%A Lühmann, N.
%A Szekely, Noemi
%A Pyckhout-Hintzen, W.
%A Wischnewski, A.
%A Richter, D.
%T Importance of Compact Random Walks for the Rheology of Transient Networks
%J ACS Macro Letters
%V 6
%N 2
%@ 2161-1653
%C Washington, DC
%I ACS
%M FZJ-2017-07506
%P 73 - 77
%D 2017
%X Controlling the mechanical behavior of novel supramolecular materials is of the utmost importance and requires a fundamental understanding of the underlying physical processes. We present a multimethods approach to the dynamics of entangled transient polyisoprene networks. Small-angle neutron scattering (SANS) on randomly functionalized chains shows homogeneous supramolecular melts with Gaussian chain conformations. The H-bond lifetimes (dielectric α*-process) and the rheological response in terms of the loss modulus G″ differ by 2 orders of magnitude in time. Within the concept of a compact random walk (RW), where the random walker (urazole group acting as a sticker) undergoes multiple returns to its starting point and following the concept of theoretical proposed renormalized sticky bond lifetimes, we quantitatively solve this longstanding and unexplained large discrepancy: While the bond opening gives rise to the dielectric response, for rheological relaxation the association with a new partner is relevant. This takes place only after multiple returns to the original binding partner.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000394732000002
%R 10.1021/acsmacrolett.6b00880
%U https://juser.fz-juelich.de/record/839928