Nonmonotonic Composition Dependence of Viscosity upon Adding Single-Chain Nanoparticles to Entangled Polymers

Author(s)
Christina Pyromali, Nikolaos Patelis, Marta Cutrano, Mounika Gosika, Emmanouil Glynos, Angel J. Moreno, Georgios Sakellariou, Jan Smrek, Dimitris Vlassopoulos
Abstract

Well-characterized single-chain nanoparticles (SCNPs), synthesized from a linear polystyrene precursor through an intramolecular [4 + 4] thermal cycloaddition cross-linking reaction in dilute conditions, were added to entangled polystyrene melts at different concentrations. Starting from the pure linear melt, which is much more viscous than the melt of SCNPs, the zero-shear viscosity increased upon the addition of nanoparticles and reached a maximum before eventually dropping to the value of the SCNP melt. Molecular simulations reveal the origin of this unexpected behavior, which is the interplay of the very different compositional dependences of the dynamics of the two components. The SCNPs become much slower than the linear chains as their concentration decreases because they are threaded by the linear chains, reaching a maximum viscosity which is higher than that of the linear chains at a fraction of about 20%. This behavior is akin to that of single-loop ring polymers when added to linear matrices. This finding provides insights into the design and use of SCNPs as effective entropic viscosity modifiers of polymers and contributes to the discussion of the physics of loopy structures.

Organisation(s)
Computational and Soft Matter Physics
External organisation(s)
Foundation for Research and Technology—Hellas (FORTH), University of Crete, National & Kapodistrian University of Athens, Università degli Studi di Cagliari, Centro de Física de Materiales (CSIC-UPV/EHU), Vellore Institute of Technology, Donostia International Physics Center
Journal
Macromolecules
Volume
57
Pages
4826-4832
No. of pages
7
ISSN
0024-9297
DOI
https://doi.org/10.1021/acs.macromol.4c00206
Publication date
05-2024
Peer reviewed
Yes
Austrian Fields of Science 2012
103023 Polymer physics, 210004 Nanomaterials, 104003 Inorganic chemistry
ASJC Scopus subject areas
Organic Chemistry, Polymers and Plastics, Inorganic Chemistry, Materials Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/e891039e-113a-4802-b4d0-ea88ec200066