Room temperature self healing crosslinked elastomer
Designing a crosslinked polymer with autonomous self-healing at room temperature (RT) remains an arduous challenge because the topological network reconstructions are governed by crosslinking. In a recent study, a flexible strategy is described to develop intrinsically dynamic crosslinked elastomers with RT self-healing via a photo-initiated copolymerisation to address these issues. The key is to incorporate a urea–urethane structure with dynamic urea bond into the polymer network as a flexible crosslinking unit.
This strategy endows the crosslinked elastomer with superior properties, including autonomously rapid self-healing at RT, extreme stretchability of up to 1726%, high toughness (∼24.45 MJ m–3), extended stability, and recyclability.
Self-healing within 10 min
Upon damaged, the resultant elastomers instantly self-heal at RT and completely self-heal within 10 min without the assistance of external triggers. These amazing properties of the dynamic elastomer are attributed to the synergistic effect of the robustly dynamic urea bonds and inter- and intrachain hydrogen bond interactions. Notably, the self-healing and mechanical properties of the network can be optimised by tuning the dynamic crosslinker content. Dynamic reversibility occurs at RT evidenced by rheological tests. According to the researchers, the facile fabrication method and multifunctional properties of the self-healable and stretchable crosslinked elastomer demonstrate that it shows great potential in smart protective coating and wearable electronics industry.
The study has been published in Progress in Organic Coatings, Volume 154, May 2021.