CHAPTER 4: Materials Design Principles for Mechanochemical Transduction

Mechanochemically responsive polymers and composites can be realized through the covalent incorporation of mechanophores – chemical units that undergo a specific chemical transformation in response to applied force. The transmission of macroscale mechanical load to the mechanophores and the subsequent mechanophore population response depends heavily on the matrix architecture. For this chapter, proven mechanophore function is taken implicitly; the focus is on the material, loading mode and loading history. First, preliminaries for informed research in mechanochemically responsive polymers are presented including mechanics background, mechanophore kinetics and experimental methods. Second, existing experimental results and theories on mechanophore triggering and recovery within materials are presented. The unique phenomenology associated with elastomers, glassy polymers and composites are each discussed. Finally, the design of materials whose mechanical properties are substantively modified by the mechanochemical reaction is discussed along with future prospects.