Materials often fail as a result of the mechanical loads they experience during use. On the molecular level, forces within polymers are distributed unevenly throughout the material, and some polymer subchains experience greater stress than others. In some cases, the forces experienced by these overstressed subchains can trigger chain scission events. Chain scission in turn might nucleate the formation of a microcrack that subsequently propagates, ultimately leading to material failure. In recent years, force reactive functional groups, or mechanophores, have emerged as the basis of a potential strategy for not only signaling, but also combatting this destructive cascade. The strategy comprises embedding mechanophores along the polymer backbone or within cross-links, so that otherwise destructive force within an overstressed subchain trigger a constructive, rather than a destructive, response. Examples of potentially constructive responses include mechanically activated catalysis, mechanochromism, self-healing / self-strengthening, and small molecule release. In this work, we examine the mechanical reactivity of cyclobutene-based mechanophores and their utility towards developing stress-reporting and stress-responding materials.

Examining the mechanical reactivity of substituted cyclobutene mechanophores

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.