Nonlinear mechanics of thermoreversibly associating dendrimer glasses

TL;DR

This paper models the nonlinear mechanics of thermoreversibly associating dendrimer glasses, revealing how different bond strengths and kinetics influence toughness, strength, and ductility, guiding design of customizable polymer glasses.

Contribution

It introduces a model for associating dendrimer glasses that links bond parameters to mechanical properties, highlighting the impact of bond kinetics on toughness and ductility.

Findings

Strong, slow bonds optimize strength.

Weak, fast bonds enhance ductility.

Bond dynamics influence energy dissipation.

Abstract

We model the mechanics of associating trivalent dendrimer network glasses with a focus on their energy dissipation properties. Various combinations of sticky bond (SB) strength and kinetics are employed. The toughness (work-to-fracture) of these systems displays a surprising deformation-protocol dependence; different association parameters optimize different properties. In particular, "strong, slow" SBs optimize strength, while "weak, fast" SBs optimize ductility via self-healing during deformation. We relate these observations to breaking, reformation, and partner-switching of SBs during deformation. These studies point the way to creating associating-polymer network glasses with tailorable mechanical properties.