Photoinduced Atom Transfer Radical Polymerization Research Articles

Synthesis of polymer particles possessing radical initiating sites on the surface by emulsion copolymerization and construction of core–shell structures by a photoinduced atom transfer radical polymerization approach

AbstractThe crosslinked polystyrene particles possessing photofunctional N,N‐diethyldithiocarbamate groups on their surface were prepared by free‐radical emulsion copolymerization of a mixture of styrene, divinylbenzene and 4‐vinylbenzyl N,N‐diethyldithiocarbamate with redox system as an initiator under UV irradiation. In this copolymerization, the inimer 4‐vinylbenzyl N,N‐diethyldithiocarbamate acted the formation of hyperbranched structures by living radical photopolymerization. The particle sizes (number‐average particle diameter = 214–523 nm) were controlled by varying the feed amount of surfactant and size distributions were relatively narrow. Subsequently, core–shell particles were synthesized by photoinduced atom transfer radical polymerization approach of methyl methacrylate initiated by photofunctional polystyrene particles as a macroinitiator. Such core–shell particles were stabilized sterically by grafted chains in organic solvents. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1771–1777, 2007

Architecture of Star−Block Copolymers Consisting of Triblock Arms via aN,N-Diethyldithiocarbamate-Mediated Living Radical Photo-Polymerization and Application for Nanocomposites by Using as Fillers

Highly branched poly(methyl methacrylate) (PMMA) stars were prepared by one-pot approach based on N,N-diethyldithiocarbamate- (DC-) mediated living radical photopolymerization. Soluble alternating hyperbranched microgel formation was initiated fast with preferential consumption of inimer 4-vinylbenzyl N,N-diethyldithiocarbamate (VBDC) and 4,4‘-bismaleimidediphenylmethane (BMIM) in the presence of an excess of methyl methacrylate (MMA). PMMA arms could then grow from DC groups of microgel as macroinitiator. Next, star−block copolymers consisting of diblock arms [(AB)f-DC; arm: PMMA-block-poly(n-butyl methacrylate) (PBMM)] were synthesized by photoinduced atom transfer radical polymerization (ATRP) of n-butyl methacrylate (BMM) initiated by the functionalized PMMA star (A)f-DC in the presence of CuCl/bipyridine (bpy) catalyst. Subsequently, star−block copolymers consisting of triblock arms [(ABA)f-DC; arm = PMMA-block-PBMM-block-PMMA] were synthesized by similar method initiated by (AB)f-DC macroinitiator....