Versatile Approach to Building Dynamic Covalent Polymer Networks by Stimulating the Dormant Groups

Despite many efforts, there is no versatile way to realize reversible cross-linking for most polymers. Inspired by the abstraction of hydrogen and the iniferter polymerization of benzophenone (BP), we report a versatile approach for building dynamic covalent networks for polymers containing C-H bonds. Under ultraviolet irradiation, BP can effectively abstract the hydrogen from polymers to form dormant diarylsemipinacol (DASP) groups on the polymer chains. Then, the dormant DASP-based linkages can be homolytically cleaved upon heating, after which they generate carbon-centered aliphatic radicals and DASP-based radicals. Therefore, the cross-linked polymer network can rearrange its topology through the dissociation and association of DASP-based linkages, which endow polymer networks with remodeling and self-healing abilities. Given that most commercially available polymers contain aliphatic C-H bonds, this provides a general method for forming thermal reversible cross-linked networks.