Paper Number
SM9 

Session
Polymers Solutions, Melts and Blends

Title
Relating dynamic covalent bond exchange to relaxation modulus in dynamic polymeric networks

Presentation Date and Time
October 10, 2022 (Monday) 2:10

Track / Room
Track 2 / Sheraton 3

Authors (Click on name to view author profile)

1. Tao, Ran (National Institute of Standards and Technology)
2. Dolinski, Neil (University of Chicago)
3. Kotula, Anthony (National Institute of Standards and Technology)
4. Dennis, Joseph (U.S. Army Research Laboratory)
5. Rowan, Stuart J. (The University of Chicago, Pritzker School of Molecular Engineering)
6. Forster, Aaron (National Institute of Standards and Technology)

Author and Affiliation Lines (in printed abstract book)
Ran Tao¹, Neil Dolinski², Anthony Kotula¹, Joseph Dennis³, Stuart J. Rowan² and Aaron Forster^1
1National Institute of Standards and Technology, Gaithersburg, MD; ²University of Chicago, Chicago, IL; ³U.S. Army Research Laboratory, Adelphi, MD

Speaker / Presenter 
Tao, Ran

Keywords
experimental methods; glasses; polymer melts

Text of Abstract
Polymer materials with dynamic covalent bonds exhibit promising self-healing and dissipative capabilities through reversible breaking and reformation of the dynamic bonds. The dynamic chemistry, specifically the association kinetics and dynamic reaction equilibrium for the covalent bond exchange, can be manipulated by utilizing different classes of molecular-scale motifs. This work focuses on two types of dynamic polymer networks based on reversible thia-Michael reactions, through which a wide range of thermomechanical properties are tuned by varying the substituents on the Michael acceptors. By performing linear rheology (oscillatory shear and stress relaxation experiments) and rheo-Raman measurements, the interplay of the polymer chain and network relaxation dynamics, the molecular exchange rate, and the reconfigurable microphase morphologies in the macroscopic materials are unraveled.