title: An arm-first approach to cleavable mikto-arm star polymers by RAFT polymerization.
abstract: Redox-cleavable mikto-arm star polymers are prepared by an "arm-first" approach involving copolymerization of a dimethacrylate mediated by a mixture of macroRAFT agents. Thus, RAFT copolymerization of the monomers BMA, DMAEMA, and OEGMA, with the disulfide dimethacrylate cross-linker (DSDMA), bis(2-methacryloyl)oxyethyl disulfide, mediated by a 1:1:1 mixture of three macroRAFT agents with markedly different properties [hydrophilic, poly[oligo(ethylene glycol) methacrylate]-P(OEGMA)8-9 ; cationizable, poly[2-(dimethylamino)ethyl methacrylate]-P(DMAEMA); hydrophobic, poly(n-butyl methacrylate)-P(BMA)] provides low dispersity mikto-arm star polymers. Good control (Đ < 1.3) is observed for the target P(DMAEMA)/P(OEGMA)/P(BMA) (3:3:1) mikto-arm star, a double hydrophilic P(DMAEMA)/P(OEGMA) (3:3) mikto-arm star and a hydrophobic P(BMA) homo-arm star. However, Đ for the target mikto-arm stars increases with an increase in either the ratio [DSDMA]:[total macroRAFT] or the fraction of hydrophobic P(BMA) macroRAFT agent. The quaternized mikto-arm star in dilute aqueous solution shows a monomodal particle size distribution and an average size of ≈145 nm.
authors: State Key Laboratory of Chemical Resource Engineering, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China; CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria, 3168, Australia.
authors: Xiaohu
authors: X
authors: Wei
authors: Graeme
authors: G
authors: Moad
authors: Benjamin W
authors: BW
authors: Muir
authors: Ezio
authors: E
authors: Rizzardo
authors: Julien
authors: J
authors: Rosselgong
authors: Wantai
authors: W
authors: Yang
authors: San H
authors: SH
authors: Thang
mesh_terms: D057927:Hydrophobic and Hydrophilic Interactions; D008689:Methacrylates / Q000737:chemistry; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D015394:Molecular Structure; D010421:Pentanoic Acids / Q000737:chemistry; D010720:Phosphines / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy
chemical_list: D008689:Methacrylates; D010421:Pentanoic Acids; D010720:Phosphines; D011108:Polymers; C524499:polyethylene glycol methacrylate; C043255:tri-n-butylphosphine; D011092:Polyethylene Glycols; C004919:ethylene dimethacrylate; C049840:2-(dimethylamino)ethyl methacrylate; C016284:butyl methacrylate
keywords: arm first; cross-linking polymerization; mikto-arm star; raft polymerization