Core-shell macromolecules with rigid dendritic polyphenylene cores and polymer s

2019-09-09 03:48:30

PEO shell oxide ethylene TdG2

责任者: Atanasov, V.;Sinigersky, V.;Klapper, M.;Mullen, K. 单位: Max Planck Institute, Polymer Research, D-55128, Mainz, Germany 来源出处: Macromolecules,2005,38(5):1672-1683 摘要: The synthesis of core-shell nanoparticles consisting of a shape-persistent polyphenylene dendrimer (TdG2) as the core and of different polymers (poly(ethylene oxide), polystyrene and polyisoprene) as mono- or double-shells is presented. Mono-shell systems are obtained either by a grafting- onto (arm first) process attaching poly(ethylene oxide) chains to a TdG2 with an average of 12 chloromethyl functions (TdG 2(CH2Cl) [similar to] 12) or by a grafting-from (core first) method using a TdG2-dendrimer functionalized with exactly 16 hydroxymethyl groups TdG2(CH2OH)16 as multiinitiator for the living anionic polymerization of ethylene oxide (EO). In both cases, well-defined PEO-functionalized polyphenylene dendrimers with molecular weights between 104 and 106 Da were obtained. The hydrodynamic radii of the particles were determined by dynamic light scattering to be in the range 5-20 nm, depending on the length of the PEO-chains. Core-double-shell systems as examples of a more complex onion-type architecture were synthesized by grafting-onto of blockcopolymers, respectively poly(isoprene-block-ethylene oxide) (PI-b-PEO) or poly(styrene-block-ethylene oxide) (PS-b-PEO), on TdG2. Because of the use of blockcopolymers containing PEO, PI and polystyrene shell structures with regions of different polarity and stiffness in the same nanoparticle were made accessible. © 2005 American Chemical Society. 关键词: Organic polymers;Macromolecules;Synthesis (chemical);Dendrimers;Polystyrenes;Polyethylene oxides;Grafting (chemical);Anionic polymerization;Molecular weight;Nanostructured materials;Living polymerization;Core-shell nanoparticles;Polyphenylene dendrimer;Mono-shell systems;Polarity