Figure 8.

(a) Monomers used for the boronic-exchange xLCE: diacrylate, dithiols, and the 4-functional thiol cross-linker. Isotropic and LCE networks are formulated with various boronic ester concentrations through Michael addition. (b) Boronic ester exchange reaction through transesterification. (c) Iso-strain stress relaxation (a signature of vitrimer exchange) depends on the fraction of bond-exchange spacers in the network (labeled on the plot): at lower concentrations of BDB, there is an increasing fraction of permanent covalent network in the material. Adapted with permission from ref (95). Copyright 2020 John Wiley and Sons.