Self-healing behavior and tribological performance of dynamic crosslinked polymers
by Zhijiang Ye
& B. Ballal, D. Konkolewicz, M. Zanjani, Miami University, Oxford, Ohio, UNITED STATES
Dynamically crosslinked polymers and their composites have tremendous potential in the development of the next round of advanced materials for aerospace, sensing and tribological applications. These materials contain dynamic or exchangeable crosslinkers of two main types: non-covalently bound crosslinkers, and dynamic covalently bound crosslinkers. These two categories provide significantly different self-healing behaviors. Here, we use a combined computational and experimental approach to study the self-healing behavior, mechanical performance and tribological properties of various crosslinked polymer systems. Atomistic and coarse-grained models are used to study their mechanical response and to understand the mechanism with which both non-covalent and dynamic covalent linkages respond to different types of external stimuli (cutting, shearing and loading). The results of the simulations are then compared and validated against experimental measurements. Furthermore, we use the computational models to investigate the design of dual dynamic crosslinkers where one linkage exchanges rapidly and provides autonomic dynamic character, while the other is a stimulus responsive dynamic covalent linkage that provides stability with dynamic exchange on-demand.