Paper Number
SR9 

Session
Sustainable and Recyclable Polymers

Title
Viscoelastic properties of vitrimers with fast exchange reaction

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

Track / Room
Track 4 / Michigan AB

Authors (Click on name to view author profile)

1. Khabaz, Fardin (The University of Akron, School of Polymer Science and Polymer Engineering)
2. Perego, Alessandro (The University of Akron)
3. Cloitre, Michel (ESPCI Paris - PSL, Molecular, Macromolecular Chemistry and Materials)

Author and Affiliation Lines (in printed abstract book)
Fardin Khabaz¹, Alessandro Perego¹ and Michel Cloitre^2
1School of Polymer Science and Polymer Engineering, The University of Akron, Akron, OH; ²Molecular, Macromolecular Chemistry and Materials, ESPCI Paris - PSL, Paris, France

Speaker / Presenter 
Khabaz, Fardin

Keywords
computational methods; polymer sustainability; recyclable polymers

Text of Abstract
Vitrimers are a class of polymers that bring together desirable mechanical properties of thermosets with the reprocessing of thermoplastics. This ability arises from the rearrangement of the vitrimer network via a bond shuffling mechanism while its cross-link density remains preserved. As the properties of the material are directly affected by the dynamics of the polymer chains, it is critical to understand the link between the macroscopic behavior and the microscopic dynamic of the molecules. Molecular dynamics simulations can provide detailed molecular mechanisms of the system under macroscopic stress-induced deformations. We present a simulation methodology that utilizes coarse-grained molecular dynamics in conjunction with a Monte Carlo method to capture the bond exchange in vitrimers. Constant stress is applied to the system below its glass transition temperature while monitoring the strain (e.g., creep). Vitrimer shows accelerated dynamics under applied shear stress compared to that of thermoset. This different behavior between the two networks is reflected in the mean squared displacement of the crosslinker. In addition, the motion of the crosslinker shows non-affine displacement, resulting in regions of enhanced mobility (i.e., dynamics heterogeneities).