Characterizing the Mechanical Strengths of Chemical Bonds via Sonochemical Polymer Mechanochemistry

Mechanically induced chemical bond scission underlies the fracture and macroscopic failure of polymeric materials. Thus, the mechanical strength of scissile chemical bonds plays a role in material failure and in the mechanical initiation of cascade reactions, but quantitative measurements of mechanical strength are rare. This dissertation describes research that quantifies relative mechanical strengths of polymers that possess a variety of chemical and topological functionalities along their backbones, including: 1) relative mechanical strengths of ¿weak¿ bonds in the context of chain scission triggered by pulsed sonication of polymer solutions, by using the competing non-scissile mechanochemical reaction of gem dichlorocyclopropane mechanophores; 2) relative mechanical strengths of three bonding topologies formed from the same set of chemical functionalities: a catenane, a symmetrical macrocycle, and a linear construct; 3) relative mechanical strengths of triazoles; 4) sonochemistry of a zinc-templated polymeric trefoil knot by pulsed ultrasound.