LAUSR

Classical Lewis pairs (LPs) between unhindered electron-poor Lewis acids (LAs) and electron-rich Lewis bases (LBs) present an overlooked motif with tremendous potential as dynamic crosslinks in transient polymer networks (TPNs) for self-healing and stimuli-responsive applications. We demonstrate that simple and intuitive matching of weak/strong organoborane LA and amine LB pairs offers access to a large set of binding equilibrium constants, Keq, that span ~6 orders and dissociation rate constants, kdiss, that span ~7 orders of magnitude. The implementation in polystyrene (PS) / polydimethylsiloxane (PDMS) blends results in dynamically cross-linked networks with bulk thermomechanical properties that are directly correlated with the strength and kinetic parameters for the LP interactions. The LP dynamic crosslink design is highly versatile and broadly applicable to different polymer architectures as demonstrated in the formation of reprocessible elastomers from Lewis base-decorated high molecular weight PDMS in combination with Lewis acid-decorated PS, when rein-forced with fumed silica as a filler.