Tuning Mechanical and Self-Healing Properties Using Multivalent Crosslinking

Dynamic crosslinking in polymer networks has played a major role in contributing to various material properties, including toughness, tensile resistance, and self-healing. Dynamic covalent crosslinking, which connects two points on the polymer backbone using divalent crosslinkers, has been studied to date. Here, we systematically investigate the impact of using multivalent crosslinkers on the mechanical and self-healing properties of polymer materials. We used the thiol-Michael "click" chemistry to crosslink thiol-maleimide functional groups, which are well known for their thermoresponsive dynamic properties. Di-, tri-, tetra-, and hexathiols were used as crosslinkers to increase the complexity of the crosslinked polymer network. The results indicated that the mechanical and self-healing properties can be tuned by using multivalent networks, potentially paving the way for the development of better self-healing elastomers and opening opportunities for new chemistries to be explored.