Document Type
Article
Publication Date
12-24-2023
Abstract
Controlling the extensional rheological properties of solutions is of great interest for a number of applications, such as printing and coatings, as polymeric additives can modify a fluid's droplet size, formation, and breakup. We have measured the extensional flows of polyacrylamide graft poly(ethylene glycol) amine (PAM-g-PEGa) solutions as a function of grafting density. PAM-g-PEGa is synthesized with grafting densities of 2.5%, 5.5%, 8%, and 30% and extensional flow was analyzed with drop-on-substrate rheology. Flow time scales and profiles are then compared to understand the effects of backbone extension from the addition of side chains. At low grafting densities, the viscous friction from the added side chains is comparable to, and in some cases, counteracts the losses in extensibility to the graft polymer's backbone, leading to increases in the relaxation time of the polymer. At higher grafting densities, the extension of the backbone reduces the relaxation time. By characterizing the effects of the graft density architecture on extensional flows, we are able to fine-tune and control the breakup dynamics of elastic solutions.
Keywords
drop-on-substrate rheology, extensional rheology, fluid dynamics, graft density, graft polymers, solution flows
Language
English
Publication Title
Journal of Polymer Science
Rights
© 2023 The Authors. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/), which permits non-commercial copying and redistribution of the material in any medium or format, provided the original work is not changed in any way and is properly cited.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
A. Linscott, R. Zhu, L. Hong, M. Castellanos, S. Morozova, J. Polym. Sci. 2024, 62(16), 3848. https://doi.org/10.1002/pol.20230449
Manuscript Version
Final Publisher Version