Orthogonal Click Postfunctionalization of Alternating Copolymers Prepared by Nitroxide-Mediated Polymerization.

Nitroxide-mediated polymerization (NMP) was applied to prepare alternating copolymers using 1,1,1,3,3,3-hexafluoroisopropyl acrylate (HFIPA) 1 and ((6-trimethylsilyl)-hex-5-yn-1-yl)vinyl ether (THVE) 2 as monomers. The alternating sequence of the resulting poly(HFIPA-alt-THVE) 3 was proved by using tandem mass spectrometry (MS/MS) and further supported by H NMR spectroscopy. Alternating alkyne and activated ester moieties of copolymer 3 were further functionalized with organic azides and amines using sequential Cu-catalyzed azide-alkyne click (CuAAC) and amidation reactions, providing dually functionalized poly(acrylamide-alt-triazole) polymers 5. Water-soluble alternating poly(acrylic acid-alt-triazole) copolymers 9 were obtained by saponification of HFIP esters. H and F NMR spectroscopy, IR spectroscopy as well as gel permeation chromatography (GPC) were used to characterize the polymers before and after functionalization.