CHAPTER 5: Tailoring Mechanochemical Reactivity of Covalent Bonds in Polymers by Non-covalent Interactions

The last decade has witnessed a growing interest in the field of polymer mechanochemistry, where exogenous forces are utilized to trigger the chemical transformation of covalent and non-covalent bonds embedded in polymer chains. This chapter summarizes the effects of non-covalent interactions on the mechanochemical reactivity of covalent bonds, including the degradation of polymer chains, the unfolding of biomacromolecules, and the activation of mechanophores (mechanical sensitive groups). After a brief overview of contemporary polymer mechanochemistry, we will discuss in detail the effects of non-covalent interactions (i.e. hydrogen bonding, van der Waals and metal–ligand interactions) on polymer mechanochemistry, specifically the physical aspects of these interactions at different length scales, followed by discussions of stress-responsive materials. It is shown how the mechanochemical reactivity of covalent bonds is tuned by the incorporation of supramolecular motifs in both isolated polymer chains and bulk materials, and how the non-covalent interactions of oligomers – and hence the microscopic structures of polymers – are altered by mechanical force. We expect that this chapter will aid in the future development of polymer mechanochemistry, especially the design of advanced mechanophores and stress-responsive materials that utilize non-covalent interactions.