Vitrimer materials have gained increasing attention since their introduction in 2011, due to their recyclable and dynamic nature. In addition to a traditional glass transition temperature (Tg), vitrimers have a second topology freezing temperature (Tv) above which dynamic covalent bonds allow for rapid stress relaxation, self-healing, and shape reprogramming. However, in order to take advantage of these unique properties it is crucial to correctly identify the Tv and understand the impact of various experimental parameters upon its identification. Herein, we present a unique data interpretation method to identify the Tv via multiple thermomechanical testing methodologies with excellent agreement. In addition, we demonstrate that the Tv is shifted to higher temperatures by decreasing the catalyst concentration, increasing the applied heating rate, or decreasing the applied force on the sample. Furthermore, vitrimer nanocomposites are explored with a variety of nanofillers (e.g., graphene and gold-coated graphene nanoplatelets) demonstrating an increase in composite Tv with nanofiller addition; the resulting mechanical properties and photothermal response is also explored for both neat vitrimers and vitrimer nanocomposites. These photothermally activated composites allow for shape memory and shape reconfigurable applications such as actuators and self-healing components.

Topology Freezing Temperature: Implications for Vitrimers and Vitrimer Nanocomposites

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.