Ring-opening polymerizations atom transfer radical

He, T, Li, D., Sheng, X., and Zhao, B. (2004) Synthesis of ABC 3-miktoarm star terpolymers from a trifunctional initiator by combining ring-opening polymerization, atom transfer radical polymerization, and nitroxide-medialed radical polymerization. Macromolecules, 37,3128-3135. 

Hedrick, J. L., et al. (1998), Dendrimer-like star block and amphiphilic copolymers by combination of ring-opening and atom transfer radical polymerization, Macromolecules, 31,8691-8705. 

Hedrick, J.L., TroUsas, M., Hawker, C.J. et al. (1998) Dendrimer-like star block and amphiphiUc copolymers by combination of ring opening and atom transfer radical polymerization. Macromolecules, 31,8691-8705. Hedrick, J.L., Magbitang, T., Connor, E.F. et al. (2002) Application of complex macromolecular architectures for advanced microelectronic materials. Chemistry - A European Journal, 8,3308-3319. 

Bielawski, C. W., Morita, T., and Grubbs, R. H. (2000). Synthesis of ABA triblock copolymers via a tandem ring-opening metathesis polymerization atom transfer radical polymerization approach. Macromolecules, 55(3) 678-680. 

Becer CR, Paulus RM, Hoppener S et al. (2008) Synthesis of poly(2-ethyl-2-oxazoline)-h-poly(styrene) copolymers via a dual initiator route combining cationic ring opening polymerization and atom transfer radical polymerization. Macromolecules 41 5210-5215... 

Lenoir S, Riva R, Lou X, Detrembleur C, Jerome R, Lecomte P (2004) Ring-opening polymerization of a-chloro- -caprolactone and chemical modification of poly(a-chloro- -caprolactone) by atom transfer radical processes. Macromolecules 37 4055 061... 

Xie M, Han H, Ding L et al (2009) Promotion of atom transfer radical polymerization and ring-opening metathesis polymerization in ionic liquids. J Macromol Sci R, Part C Polym... 

Heise, Palmans, de Geus, Villarroya and their collaborators (17,41,42) have been working on a chemoenzymatic cascade synthesis to prepare block copolymers. They combine enzymatic ring-opening polymerization (eROP) and atom transfer radical polymerization (ATRP). The synthesis of block copolymers was successful in two consecutive steps, i.e., eROP followed by ATRP. In the one-pot approach, block copolymers could be obtained by sequential addition of the ATRP catalyst, but side reactions were observed when all components were present from at the onset of reactions. A successful one-pot synthesis was achieved by conducting the reaction in supercritical carbon dioxide. 

An approach similar to the previous divergent grafting-from method also served to synthesize dendrigraft poly(L-lysine) by ring-opening polymerization [111], styrene homopolymers and styrene-methacrylate copolymers by a combination of stable free-radical polymerization and atom transfer radical polymerization (ATRP) [112], and copolymers of 2-hydroxyethyl methacrylate with styrene or ferf-butyl methacrylate by ATRP [113]. 

In contrast, here a bifunctional initiator is employed and the polymerization order of the two blocks is inverted In a first step, the styrene block is synthesized by atom transfer radical polymerization (ATRP) followed by the addition of lactide via the recently developed organocatalytic ring-opening polymerization, as depicted in Fig. 3.1 [4, 5]. This synthesis route reduces the involved steps and enables a simplified and time-efficient preparation of copolymers with different block compositions. Importantly, both polymerization techniques offer precise and robust control over the copolymer composition, which is an essential requirement to reliably target the double-gyroid s narrow location in phase space [6]. 

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