CPOS Seminar: Polymeric Diazirines as Efficient Cross-linking Agents

Speaker:  Mizhi Xu, Postdoctoral Researcher, Materials Research Laboratory, University of California, Santa Barbara; Banruo Huang & Craig J. Hawker Groups

Abstract: The formation of polymer networks through cross-linking of linear polymers is an important process for enhancing the mechanical properties and stability of the resulting materials. Among the various strategies for introduction of cross-links, carbene insertion into the abundant C-H bonds in polymer backbones is potentially an attractive and universal cross-linking strategy. Recently, diazirine, as a stable carbene precursor, has garnered significant attention for functionalization of different polymer backbones due to its mild activation under either thermal or photochemical conditions, rapid C–H insertion capabilities, and commercial accessibility. While diazirine small molecules have been designed for cross-linking and functionalizing commodity polymers, the synthesis and utilization of polymeric diazirines remains unexplored. In this study, we demonstrate the synthesis and polymerization of diazirine-based monomers under different controlled radical conditions. Gelation of the resulting polymers is achieved upon activation of the diazirine moieties through either thermal or photochemical means.