Paper Number
SM36 

Session
Polymers Solutions, Melts and Blends

Title
Stress relaxation in ring-linear polymer blends

Presentation Date and Time
October 23, 2019 (Wednesday) 2:20

Track / Room
Track 3 / Room 201

Authors (Click on name to view author profile)

1. Parisi, Daniele (Foundation for Research and Technology Hellas, Institute of Electronic Structure & Laser)
2. Rubinstein, Michael (Duke University)
3. Vlassopoulos, Dimitris (FORTH, Institute of Electronic Structure & Laser)

Author and Affiliation Lines (in printed abstract book)
Daniele Parisi¹, Michael Rubinstein², and Dimitris Vlassopoulos^1
1Institute of Electronic Structure & Laser, Foundation for Research and Technology Hellas, Heraklion 70013, Greece; ²Duke University, Durham, NC 27708

Speaker / Presenter 
Parisi, Daniele

Text of Abstract
An essential feature associated with the mechanism of motion of linear polymers is the presence of free-ends1. Ring polymers without chain ends exhibit a very different behavior characterized by a power-law stress relaxation2,3, no entanglement plateau and lower viscosity compared to their linear counterparts. A natural question is what happens when linear and ring polymers are blended. We show, by means of rheological experiments, that the addition of rings to an entangled linear polymer melt gives rise to a nonmonotonic variation of the viscosity as a function of the ring polymer fraction. As it was also shown by McKenna and Plazek.4 Interestingly, the viscosity of the blend can even reach values up to two times higher than the pure linear polymer chains because of threading effects of the latter on rings. By adopting the self-consistent model of constraint release of polymer chains5 and accounting for the coherent constraint release of ring polymers mediated by the reptation of linear chains, we show how to describe the linear viscoelasticity of the linear-ring polymer blends in the region of small fraction of rings. In the limit of very large fractions of rings the rheology is extremely sensitive to the presence of linear chains, as also confirmed by simulations6. These results contribute toward the development of a generic picture of polymer blend dynamics. (1) Rubinstein, M.; Colby, R. H. Polymer Physics; Oxford University Press New York, 2003; Vol. 23. (2) Kapnistos, M.et al., Nature materials 2008, 7 (12), 997. (3) Pasquino, R.et al., ACS macro letters 2013, 2 (10), 874–878. (4) McKenna, G. B.; Plazek, D. J., Polym. Commun. 1986, 27 (10), 304–306. (5) Rubinstein, M.; Colby, R. H., The Journal of chemical physics 1988, 89 (8), 5291–5306. (6) Halverson, J. D. et al., Physical review letters 2012, 108 (3), 038301.