Multiarm Star Triblock Terpolymers via Sequential Double Click Reactions

Multiarm star triblock terpolymers were obtained by using two different click reactions sequentially: Cu(I) catalyzed azide-alkyne and Diels-Alder. The synthetic strategy is described as follows: (poly(methyl methacrylate))(n)-(polystyrene)(m)-poly(divinyl benzene)) ((PMMA)(n)-(PS)(m)-polyDVB) multiarm star diblock copolymer was first obtained from an azide-alkyne click reaction of (alkyne-PS)(m)-polyDVB multiarm star polymer with alpha-anthracene-omega-azide PMMA (anth-PMMA-N-3), followed by a Diels-Alder click reaction of the anthracene groups at the star periphery with alpha-maleimide poly (tert-butyl acrylate) (PtBA-MI) or alpha-maleimide poly(ethylene glycol) (PEG-MI) leading to target (PtBA)(k)-(PMMA)(n)-(PS)(m)-polyDVB and (PEG)(p)-(PMMA)(n)-(PS)(m)-polyDVB multiarm star triblock terpolymers. The hydrodynamic diameter of individual multiarm star triblock terpolymers were measured by dynamic light scattering (DLS) to be similar to 24-27 nm in consistent with the atomic force microscopy (AFM) images on silicon substrates. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1557-1564, 2010