CPOS Seminar: "Efficient Cross-Linking of Unfunctionalized Commodity Materials Using Diazirine-Containing Polymers"

Speaker: Mizhi Xu, PhD, Materials Research Laboratory - Craig Hawker Group, UC Santa Barbara

Cross-linking plays a crucial role in enhancing the mechanical properties and stability of polymeric materials. For unfunctionalized commodity polymers, diazirine-derived carbene insertion into the abundant C–H bonds of polymer backbones is an attractive and universal cross-linking strategy. In this work, multifunctional diazirine-containing polymers were developed for on-demand cross-linking of unfunctionalized polymers under mild photochemical or thermal conditions. These polymeric cross-linkers were readily prepared via controlled radical copolymerization of diazirine-based (meth)acrylate monomers with conventional (meth)acrylate comonomers, yielding copolymers with precisely controlled diazirine content and molecular weight. Compared to small-molecule bis-diazirine cross-linkers, these polymer-based diazirine cross-linkers showed enhanced compatibility for polymer blending and significantly improved cross-linking efficiency, achieving high gel fractions with low diazirine loading. This work highlights the potential of diazirine-containing polymers as efficient and versatile cross-linkers for the design and fabrication of advanced materials.