Atom transfer radical polymerization copolymers

Polystyrene-Woc -polysulfone-/ /oc -polystyrene and poly(butyl acrylate)-Woc -polysulfone-/ /oc -poly(butyl acrylate) triblock copolymers were prepared using a macroinitiator.214 The hydroxyl-terminated polysulfone was allowed to react with 2-bromopropionyl bromide, an atomic transfer radical polymerization (ATRP) initiator, in the presence of pyridine. The modified macroinitiator could initiate die styrene polymerization under controlled conditions. 

Brzezinska KR, Deming TJ (2004) Synthesis of AB diblock copolymers by atom-transfer radical polymerization (ATRP) and living polymerization of alpha-amino acid-N-carboxyan-hydrides. Macromol Biosci 4 566—569... 

Block copolymers were synthesized by a combination of fipase-catalyzed polymerization and atom transfer radical polymerization (ATRE). " " At first, the polymerization of 10-hydroxydecanoic acid was carried out by using lipase CA as catalyst. The terminal hydroxy group was modified by the reaction with a-bromopropionyl bromide, followed by ATRP of styrene using CuCE2,2 -bipyridine as catalyst system to give the polyester-polystyrene block copolymer. Trichloromethyl-terminated poly(e-CL), which was synthesized by lipase CA-catalyzed polymerization with 2,2,2-trichloroethanol initiator, was used as initiator for ATRP of styrene. 

Synthesis of Block Copolymers by Atom Transfer Radical Polymerization, ATRP... 

In this review, synthesis of block copolymer brushes will be Hmited to the grafting-from method. Hussemann and coworkers [35] were one of the first groups to report copolymer brushes. They prepared the brushes on siUcate substrates using surface-initiated TEMPO-mediated radical polymerization. However, the copolymer brushes were not diblock copolymer brushes in a strict definition. The first block was PS, while the second block was a 1 1 random copolymer of styrene/MMA. Another early report was that of Maty-jaszewski and coworkers [36] who reported the synthesis of poly(styrene-h-ferf-butyl acrylate) brushes by atom transfer radical polymerization (ATRP). 

Scheme 2 Synthesis of surface-immobilized diblock copolymer brush (Si/Si02//PS-fc-PMMA) using reverse atom transfer radical polymerization and ATRP...

Dynamic formation of graft polymers was synthesized by means of the radical crossover reaction of alkoxyamines by using the complementarity between nitroxide radical and styryl radical (Fig. 8.13) [40]. Copolymer 48 having alkoxyamine units on its side chain was synthesized via atom transfer radical polymerization (ATRP) of TEMPO-based alkoxyamine monomer 47 and MMA at 50°C (Scheme 8.9). The TEMPO-based alkoxyamine-terminated polystyrene 49 was prepared through the conventional nitroxide-mediated free radical polymerization (NMP) procedure [5,41], The mixture of copolymers 48 and 49 was heated in anisole... 

Scheme 8.9 Preparation of copolymer of 47 and MMA by atom transfer radical polymerization at 50°C [40],...

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... 

Matyjaszewski K, Miller PJ, ShuklaN, Immarapom B, Gelman A, LuokalaBB, Siclovan TM, Kickelbick G, Valiant T, Hoffmann H, Pakula T (1999) Polymers at interfaces using atom transfer radical polymerization in the controlled growth of homopolymers and block copolymers from silicon surfaces in the absence of untethered sacrificial initiator Macromolecules 32 8716-8724... 

Mecerreyes D, Atthoff B, Boduch KA, Trollsas M, Hedrick JL (1999) Unimolecular combination of an atom transfer radical polymerization initiator and a lactone monomer as a route to new graft copolymers. Macromolecules 16 5175-5182... 

Controlled free-radical polymerization methods, like atom-transfer radical polymerization (ATRP), can yield polymer chains that have a very narrow molecular-weight distribution and allow the synthesis of block copolymers. In a collaboration between Matyjaszewski and DeSimone (Xia et al., 1999), ATRP was performed in C02 for the first time. PFOMA-/)-PMMA, PFOMA-fr-PDMAEMA [DMAEMA = 2-(dimethylamino)ethyl methacrylate], and PMMA-/)-PFOA-/)-PM M A copolymers were synthesized in C02 using Cu(0), CuCl, a functionalized bipyridine ligand, and an alkyl halide initiator. The ATRP method was also conducted as a dispersion polymerization of MMA in C02 with PFOA as the stabilizer, generating a kine-... 

These methods are based on the idea of establishing equilibrium between the active and dormant species in solution phase. In particular, the methods include three major techniques called stable free-radical polymerization (SFRP), atom transfer radical polymerization (ATRP), and the degenerative chain transfer technique (DCTT) [17]. Although such syntheses pose significant technical problems, these difficulties have all been successively overcome in the last few years. Nevertheless, the procedure of preparation of the resulting copolymers remains somewhat complicated. 

Frechet and coworkers recently described how living free radical polymerization can be used to make dendrigrafts. Either 2,2,6,6-tetramethylpiperidine oxide (TEMPO) modified polymerization or atom transfer radical polymerization (ATRP) can be used [96] (see Scheme 10). The method requires two alternating steps. In each polymerization step a copolymer is formed that contains some benzyl chloride functionality introduced by copolymerization with a small amount of p-(4-chloromethylbenzyloxymethyl) styrene. This unit is transformed into a TEMPO derivative. The TEMPO derivative initiates the polymerization of the next generation monomer or comonomer mixture. Alternatively, the chloromethyl groups on the polymer initiate an ATRP polymerization in the presence of CulCl or CuICl-4,4T dipyridyl complex. This was shown to be the case for styrene and n-butylmethacrylate. SEC shows clearly the increase in molecu-... 

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. 

In this paper, we first present a model study on blending a a,co-3,5-dinitrobenzoate PDMS and free 9H-carbazole-9-ethanol, in order to check whether the recently proposed 1 1 stoechiometry between carbazole and dinitrobenzoate molecules indeed applies (Scheme 1). [26] Then, we describe the preparation of triblock copolymers, poly[2-(N-carbazolyl)ethyl methacrylate]-fc-PDMS-fc-poly[2-(N-carbazolyl)ethyl methacrylate] (P(CzEMA)-fe-PDMS-fc-P(CzEMA)), using Atom Transfer Radical Polymerization (ATRP), and their blending with the acceptor-functionalized PDMS. In both studies, the physical association and thermal reversibility of these were followed by different techniques, including UV-Vis spectroscopy, DSC or Rheology. 

A block copolymer consisting of a SCLCP-block of monomer XXVII with a laterally-attached mesogenic unit, and butyl-acrylate, was synthesized using a combination of ROMP and atom transfer radical polymerization (ATRP) (Fig. 16) [81]. 

Recently diblock copolymers of PEG and ionic segments were prepared by atom-transfer radical polymerization of methacrylic aminoester using a monofunctionalized PEG macroinitiator and then subsequent quaternization. Like others [60] these polymers form so called polyion complex micelles by electrostatic interaction with oppositely charged molecules (e.g. drugs, oligonucleotides), where the PEG block acts as a steric stabilizer [67]. 

Controlled free-radical polymerization (CFRP) has been used successfully to produce block, graft, and other controlled architecture copolymers within the last decade for a variety of free radically polymerizable monomers. The main techniques include reversible addition fragmentation and transfer (RAFT) polymerization, stable free-radical polymerization (SFRP) mediated by nitroxide/alkoxyamine based radicals, atom transfer radical polymerization (ATRP), diphenyl ethylene (DPE) mediated polymerization, and novel precipitation/emulsion polymerization based methods like free-radical retrograde precipitation polymerization (FRRPP). ... 

The PDEA-PEG block copolymer was synthesized by a typical atom-transfer radical polymerization (ATRP) using PEG as the macroinitiator (Scheme 10.4). This block copolymer formed micelles with diameters less than lOOnm, which is ideal for endocytosis. The dissolution of the micelles at low pH was monitored using A-phenyl-2-naphthylamine (PNA) as a florescent probe which has a low fluorescent activity in hydrophilic environments. The PDEA-PEG micelle was loaded with PNA. Its flnorescence was monitored as a fnnction of the solution pH. Eigure 10.18 suggests that the micelles dissolved at a pH about 6.0, which implies that the nanoparticles can... 

Cai, Y Armes, S. P. Synthesis of well-defined Y-shaped zwitterionic block copolymers via atom-transfer radical polymerization. Macromolecules 2005, 38, 271-279. 

Fig. 15 Solid phase strategy towards peptide-containing block copolymers by polymerization from the supported peptide via atom transfer radical polymerization [66]...

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