Rheology of a reversible supramolecular polymer studied by comparison of the effects of temperature and chain stoppers.
The rheology of a reversible supramolecular polymer is studied by comparing the effects of an increase in temperature and the addition of chain stoppers. The dependence of the zero-shear viscosity and the terminal relaxation time on temperature is exponential, and the activation energy for viscous flow can be calculated. Above a critical stopper fraction, power laws describe the stopper dependence of the viscosity and relaxation time. A simple model for the effect of the addition of chain stoppers on the average degree of polymerization adequately describes the results. A comparison of flow curves at several temperatures and stopper fractions reveals considerable differences between solutions with the same zero-shear viscosity. These are mainly associated with differences in the terminal relaxation time. A mechanism of shear-induced alignment and subsequent elongation of chains is proposed, with which the experimental results are consistent.
Knoben
W
W
Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands.
Besseling
N A M
NA
Cohen Stuart
M A
MA
D001704:Biopolymers / Q000737:chemistry*; D003198:Computer Simulation; D046911:Macromolecular Substances / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D044367:Phase Transition; D012212:Rheology / Q000379:methods*; D013696:Temperature; D014783:Viscosity
D001704:Biopolymers; D046911:Macromolecular Substances