Influence of Cross-linkers on the Cohesive and Adhesive Self-Healing Ability of Polysulfide-Based Thermosets

Synthetic systems with intrinsic self-repairing or self-healing abilities have emerged during the past decade. In this work, the influence of the cross-linker and chain rigidity on the healing ability of thermoset rubbers containing disulfide bonds have been investigated. The produced materials exhibit adhesive and cohesive self-healing properties. The recovery of these two functionalities upon the thermally triggered healing events has shown to be highly dependent on the network cross-link density and chain rigidity. As a result, depending on the rubber thermoset intrinsic physical properties, the thermal mending leading to full cohesive recovery can be achieved in 20-300 min at a modest healing temperature of 65 degrees C. The adhesive strength ranges from 0.2 to 0.5 MPa and is fully recovered even after multiple failure events.