Block copolymers by atom transfer radical

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

Bednarek, M., Biedron, T., and Kubisa, R, Synthesis of Block Copolymers by Atom Transfer Radical Rolymerization of fert-Butyl Acrylate with Roly(oxyeth-ylene) Macroinitiators, Macromol. Rapid Commun., 20, 59, 1999. 

Tsolakis, RK., and J.K. Kallitsis. 2003. Synthesis and characterization ofluminescent rod-coil block copolymers by atom transfer radical polymerization Utilization of novel end-fimctionalized terfluorenes as macroinitiators. Chem Eur J 9 (4) 936-943. 

Miihlebach, A., S.G. Gaynor, and K. Matyjaszewski. 1998. Synthesis of amphiphilic block copolymers by atom transfer radical polymerization (ATRP). Macromolecules 31(18) 6046-6052. 

Ma, Q., and Wooley, K. L. (2000). The preparation of t-butyl acrylate, methyl acrylate, and styrene block copolymers by atom transfer radical polymerization precursors to amphiphilic and hydrophilic block copolymers and conversion to complex nanostructured materials. /. Polym. Sci., Part A Polym. Chem., 3 (Suppl.) 4805-4820. 

Radhakrishnan, K., Switek, K.A., and Hihmyer, M.A. (2004) Synthesis of semifluorinated block copolymers by atom transfer radical polymerization. Journal of Polymer Science Part A-Polymer Chemistry, 42,853-861. 

Licciardi M, Tang Y, BiUingham NC, Armes SP. Synthesis of novel folic acid-functionalized biocompatible block copolymers by atom transfer radical polymerization for gene delivery and encapsulation of hydrophobic drugs. Biomacromolecules 2005 6 1085-96. 

Wever, D.A.Z., Raffa, P, Picchioni, E, Broekhuis, A.A. Acrylamide homopolymers and acrylamide-n-isopropylacrylamide block copolymers by atomic transfer radical polymerization in water. Macromolecules 45(10), 4040-4045 (2012)... 

Okubo, M., Minami, H., Zhou, J. Preparation of block copolymer by atom transfer radical seeded emulsion polymerization. CoUoid Polym. Sci. 282(7), 747-752 (2004)... 

Luo et al. [6] used a polydimethylsiloxane macro-initiator to initiate polymerization of methacrylate monomers with fluorinated side groups to prepare fluorosilicone polymers. To obtain diblock copolymers with a low surface energy, they designed poly(dimethylsiloxane)-block-poly(2,2,3,3,4,4,4-heptafluorobutyl methacrylate) (PDMS-1 -PHFBMA) diblock copolymers by atom transfer radical polymerization (ATRP) technique. To initiate 2,2,3,3,4,4, 4-heptafluorobutyl methacrylate polymerization, bromine end-capped polydimethylsiloxane (PDMS-Br) was used as the macro-initiator. Scheme 6.5 shows a schematic representation of the PDMS-fc-PHFBMA diblock copolymers. The system was strictly deoxygenated... 

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). 

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]. 

Numerous examples of block copolymers formed in supercritical C02 via the bifunctional initiator approach have been reported [54], Perhaps the most common approach is to incorporate eROP with free-radical polymerization-the general scheme for this methodology is shown in Figure 13.3. Howdle et al. [55] was the first to report the synthesis of a block copolymer by the bifunctional initiator approach in supercritical C02 and showed the simultaneous eROP of e-caprolactone with controlled free radical polymerization of methyl methacrylate by atom transfer radical polymerization (ATRP)-at this time simultaneous eROP and ATRP had not been reported in any media. The bifunctional initiator incorporated both a primary hydroxyl group (as an initiation site for eROP of e-caprolactone) and a bromine moiety (for initiation of ATRP). Howdle showed that... 

Thermoresponsive polymers based on oligo(ethylene glycol) acrylates or methacrylates can be easily prepared by atom transfer radical polymerization under straightforward experimental conditions (i.e. in bulk or in ethanol solution and in the presence of commercially available catalysts). Thus, these stimuli-responsive macromolecules can be exploited for preparing a wide range of smart advanced materials such as thermoreversible hydrogels, thermoresponsive block-copolymer micelles and switchable surfaces. Hence, some of the results... 

KOT Kotsuchinashi, Y., Kuboshima, Y., Yamamoto, K., and Aoyagi, T., Synthesis and characterization of donble thenno-responsive block copolymer consisting N-isopropylaciylamide by atom transfer radical polymerization, J. Polym. Sci. Part A Polym. Chem., 46, 6142, 2008. 

Figure 6.2. Examples of amphiphilic block copolymers synthesized by atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization (end groups and block-linking groups are omitted).

Block copolymers consisting of PPV and poly(methyl methacrylate) (PMMA) blocks, can be obtained by atom transfer radical polymerization. The thermal stability is slightly improved in comparison to neat PPV derivates by the introduction of PMMA blocks. The onset of thermal degradation starts around 200°C. 

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]. 

Block copolymers consisting of PPV and poly(methyl methacrylate) (PMMA) blocks can be obtained by atom transfer radical polymerization. 

Boyes, S.G. Akgun, B. Brittain, W.J. Foster, M.D. Synthesis, characterization, and properties of polyelectro-1)46 block copol3fmer brushes prepared by atom transfer radical pol3fmerization and their use in the synthesis of metal nanoparticles. Macromolecules 2003, 36, 9539. Neugebauer, D. Zhang, Y. Pakula, T. Matyjaszewski, K. Heterografted PEO-Pn BA brush copolymers. Polymer 2003, 44, 6863. 

Z.H. Luo, T.Y. He, Synthesis and characterization of poly (dimethylsiloxane)-block-poly (2,2,3,3,4,4,4-heptafluorobutyl methacrylate) diblock copolymers with low surface energy prepared by atom transfer radical polymerization, React. Funct. Pol. 68 (5) (2008) 931-942. 

Figure 1.21 Nanocomposites based on block copolymer generated by atom transfer radical polymerization. Reproduced from Ref [45] by permission from Elsevier.

Similar to the pH-responsive micelles, the pH responsive vesicles are also made from amphiphilic polymers consisting of pH-responsive blocks. The pH-responsive blocks usually form the wall of the vesicle. For example, Du et al reported a vesicle prepared from a zwitterionic diblock copolymer from monomers 2-(methacryloyloxy) ethylphosphorylcholine (MFC) and 2-(diisopropylamino) ethylmethacrylate (DPA) by atomic transfer radical polymerization. The structure of the block polymer and the formed vesicle is shown in Figure 17. The PDPA block dissolves in water below pH 6 as a weak cationic polyelectrolyte, but becomes insoluble above approximately pH 6 due to deprotonation of its tertiary amine groups (its p (a is around 6.3). Therefore, the PDPA blocks form the... 

Davis, K. A., Charleux, B., and Mat aszewski, K. (2000). Preparation of block copolymers of polystyrene and poly(t-butyl acrylate) of various molecular weights and architectures by atom transfer radical pol5merization. J. Polym. ScL, Part A Polym. Chem., 55(12) 2274-2283. 

Li, Z.-C., et al. (2000). S5mthesis of amphiphilic block copolymers with well-defined glycopolymer segment by atom transfer radical polymerization. Macromol. Rapid Common., 21(1) 375-380. 

Liquid crystalline amphiphilic diblock copolymers poly(ethylene oxide)-h/oc -ll-[4-(4-butylphenyl-azo)phenoxy]-undecyl methacrylate, PEOn,-h-PMA(Az) , as shown in Fig. 16, prepared by atom transfer radical polymerization [61], were composed of hydrophilic PEOn, sequences and hydrophobic PMA(Az) , with azobenzene moieties such as mesogen connected by a flexible spacer. The synthesis of such amphiphilic liquid crystal block copolymers has been recently reported [62]. In diblock copolymers PEO ,-h-PMA(Az)n, m and n indicate the degree of polymerization of PEO and PMA(Az) components, respectively. Differential scanning calorimetry (DSC) of PEO ,-f>-PMA(Az)n gives a clear picture of the thermal properties of these liquid crystaUine polymers, as shown in Fig. 17, for PEOn4-h-PMA(Az)2o [58, 61]. 

Hikita, M., Tanaka, K., Nakamura, T. et al. (2004) Aggregation states and surface wettability in films of poly(styrene-block-perfluorooctyl ethyl acrylate) diblock copolymers synthesized by atom transfer radical polymerization. 

Jankova, K. and Hvilsted, S. (2005) Novel fluorinated block copolymer architectures fuelled by atom transfer radical polymerization. Journal of Fluorine Chemistry, 126,241-250. 

By this chemistry, polymers with one amine end group as well as a,co-diamine-functionalized polymers can be used to prepare AB or ABA copolymers, respectively. The method gives copolymers with well-controlled polypeptide segments. Furthermore, no unreacted homopolymers or homopolypeptides could be detected. Several examples of the polymer B block have been reported poly(octenamer) prepared by acylic diene metathesis polymerization [67], poly(methyl acrylate) prepared by atom transfer radical polymerization (ATRP) [70], poly(ethylene glykol) PEG, and PDMS [68]. The method was expanded for the synthesis of... 

---