To prepare polymers with pendant functionality capable of participating in highly efficient CuI- catalyzed 1, 3-dipolar cycloaddition of azide and alkynes, monomers with acetylene or azido groups were polymerized via controlled radical polymerization. Atom transfer radical polymerization (ATRP) of propargyl methacrylate (PgMA) resulted in high polydispersities (M w/M n> 3), multimodal molecular weight distributions, and cross-linked networks at ...