All-conjugated block copolymers

U. Scherf, A. Gutacker, N. Koenen, All-Conjugated Block Copolymers. Acc. Chem. Res. 2008,41,1086-1097. 

R. Verduzco, I. Botiz, D. L. Pickel, S. M. Kilbey, K. Hong, E. Dimasi, S. B. Darling, Polythiophene-BZocfc-Polyfluorene and Polythiophene-B/ocfc-Poly(Fluorene-co-Benzothiadiazole) Insights into the Self-Assembly of All-Conjugated Block Copolymers. Macromolecules 2011,44, 530-539. 

New Polymers Prepared via Chain-Growth Methods 476 End-Functionalized Polymers 476 All-Conjugated Block Copolymers 477 Mechanism 478... 

Recent progress of naphthalimide-based dendrimers 12CJO304. Recent trends in polymer tandem solar cells research 13PPS1909. Rod—coil and all-conjugated block copolymers for photovoltaic applications 13PPS791. 

Until recently, catalyst-transfer polycondensations were limited to the preparation of p-type 7i-conjugated polymers and block copolymers comprising relatively simple electron-rich building blocks (such as thiophene). On the other hand, well-defined conjugated donor-acceptor alternate copolymers and donor-acceptor all-conjugated block copolymers are needed for practical applications. Very recently, controlled polymerizations of a few electron-deficient monomers were also reported." ... 

Scherf, U Gutacker, A., and Koenen, N. (2(X)8) All-conjugated block copolymers. Accounts of Chemical Research, 41,1086. 

Verswyvel M, Verstappen P, De CL, Verbiest T, Koeckelherghs G (2011) Development of a universal chain-growth polymerization protocol of conjugated polymers toward a variety of all-conjugated block-copolymers. J Polym Sci A Polym Chem 49 5339-5349... 

Verduzco, R. Botiz, I. Pickel, D. L. Kilbey II, S. M. Hong, K. Dimasi, E. and Darling, S. B., Polythiophene-block-polyfluorene and polythiophene-block-poly(fluorene-co-benzothiadiazole) Insights into the self-assembly of all-conjugated block copolymers. Macromolecules, 44,530-539 (2011) DOI 10.1021/ mal02728z. 

K. Nakabayashi, H. Mori, All-Polymer Solar Cells Based on Fully Conjugated Block Copolymers Composed of Poly(3-Hexylthiophene) and Poly(Naphthalene Bisimide) Segments. Macromolecules 2012, 45, 9618-9625. 

Chain-growth catalyst-transfer polycondensation (CTP) is a rapidly developing polymerization method, as it allows, in many cases, the above-mentioned limitations of step-growth polymerizations to be overcome. CTP provides a straightforward access to well-defined conjugated homopolymers (e.g., polythiophenes (1), polyfluorenes (2), polyphenylenes (3), etc.), alternate donor-acceptor copolymer e.g., 4) and all-conjugated block polymers (e.g., 5), Chart 20.1. 

It is also possible to incorporate one or several sequences of a conjugated polymer A and of a nonconjugated polymer B in a single chain. This is a block copolymer all chains in the resulting solid are in principle identical, but composite. The simplest such structure is a diblock AB copolymer each chain contains one sequence of each type, A and B. 

Another possibility is to use oligomers [266], as in FETs. Oligomer diodes are, in fact, similar to small molecule LEDs. Block copolymers with short conjugated blocks all of equal lengths provide a means for having the oligomer electronic properties together with the polymer processibility... 

Fig. 4 A second generation of the drug loading micelle with a pH-sensitive drug releasing property, a Formation of pH-sensitive polymeric micelles from PEG-(PAsp-Hyd-Dox) block copolymers. Antitumor drugs (Dox), conjugated through acid-labile hydrazone linkers, are released in lower pH conditions, b Time- and pH-dependent Dox release profile from the micelles. The micelles selectively release Dox under the pH condition of region B, which corresponds to the intracellular environment. The amount of loaded Dox in the micelles was calculated from the released Dox at pH 3.0 where all of the loaded drugs were assumed to be released from the micelle...

In contrast, the order of monomer addition is critical among monomers with different reactivities. As described in Section 5.1, a more-reactive chain-end anion is produced by a less-reactive monomer, and vice versa. Accordingly, less-reactive monomers should first be polymerized, followed by the polymerization of more-reactive monomers. In the block copolymer of styrene and MMA, for instance, it is necessary first to polymerize styrene, after which MM A is polymerized to prepare the second block, as the chain-end enolate anion produced by MMA cannot initiate the polymerization of styrene. Similarly, and for the same reason, the synthesis of P(2)-b-PMMA is possible only by the addition of 2-vinylpyridine first, and then MMA. For the successful design and synthesis of block copolymers, the pJ values of the conjugated acids of chain-end anions, as well as the e- and a-values of monomers (as mentioned above) are valuable guides. The details of almost all block copolymers synthesized to date, using living anionic polymerization, have been summarized by Quirk and Hsieh [190]. With the monomer addition order in mind, ABC triblock terpolymers composed of PS (A), PB (B), and PMMA (C), as well as PS (A), poly(2-vinylpyridine) (P(2VP)) (B), and P BMA (C), could be successfully... 

Nowadays, all the main problems of physics and physic-chemistry of polymers became closely intertwined when studying block-copolymers the nature of ordering in polymers, the features of phase separation in polymers and the infiuence of general molecular parameters on it, the stability of phases at exposing to temperature and power impacts, the features of physical and mechanical properties of microphases and the role of their conjugation. 

Synthesis of all-conjugated donor—acceptor block copolymers and their application in aU-polymer solar cells 13PC5518. 

---