Polythiophenes graft copolymers

OKnga, T., and B. Franfois. 1991. Synthesis of soluble polystyrene-graft-polythiophene comblike copolymers A new precursor for polythiophene film preparation. Makromol Chem Rapid Commun 12 575-582. 

This chapter is divided into two main parts polythiophene copolymers and polypyrrole copolymers. Each part reviews the random copolymerization of the heterocyclic monomer and important derivatives, principally those with substituents at the 3-position of thiophene and at the 1- and 3-positions of pyrrole. Alternating, block and graft copolymers are covered in both segments. Because applications of conducting polymers are reviewed in Volume 4, only applications unique to specify copolymers are covered here. In addition, a few theoretical studies dealing with conducting copolymers are reviewed. 

This section reviews the synthesis and characterization of random, alternating, block and graft copolymers of thiophenes. A review [2] of processable electronically conducting polymers published in 1991 contains only two references on polythiophene random copolymers and another article [3] describes the synthetic methods used to prepare block and graft copolymers of thiophene. 

Francois and coworkers reported on the synthesis of polystyrene-polythiophene block and graft copolymers [142-144]. These materials incorporate the unique properties of polythiophenes with ease of solubilization and processing. The reported block copolymers showed nearly the same spectral characteristics as pure polythiophene and the authors proved that their block... 

Poly (thiophene)s are of particular interest as electfochromic materials owing to their chemical stability, ease of synthesis and processability. For the most part, current research has been focused on composites, blends and copolymer formations of several conjugated polyheterocyclics, polythiophene and its derivatives, especially PEIX)T. In one example, poly(3,4-ethylenedioxythiophene) (PEDOT)/poly(2-acrylamido-2-methyl-l-propanesulfonate) (PAMPS) composite films were prepared by Sonmez et al. for alternative electrochromic applications [50]. Thin composite films comprised of PEDOT/PAMPS were reported to switch rapidly between oxidized and neufial states, in less than 0.4 s, with an initial optical contrast of 76% at A.max. 615 nm. Nanostructured blends of electrochromic polymers such as polypyrrole and poly(3,4-ethylenedioxythiophene) were developed via self-assembly by Inganas etal. for application as an electrochromic window [26]. Uniir etal. developed a graft-type electrochromic copolymer of polythiophene and polytetrahydrofuran for use in elecfiochromic devices [51]. Two EDOT-based copolymers, poly[(3,4-ethylenedioxythiophene)-aZ/-(2,5-dioctyloxyphenylene)] and poly[(3,4-ethylenedioxythiophene)-aft-(9,9 -dioctylfluorene)] were developed by Aubert et al. as other candidates for electrochromic device development [52],... 

RAFT polymerization or nitroxide-mediated polymerization (NMP) was used instead of ATRP for the synthesis of the block copolymer of polythiophene and polyisoprene or polystyrene, because ATRP generates materials containing traces of metals from the catalyst [146]. A block copolymer of P3HT and poly (perylene bisimide acrylate) was also synthesized by NMP from a polythiophene macroinitiator (Scheme 51) [147, 148]. This block copolymer is a crystalline-crystalline donor-acceptor block copolymer and shows microphase separation, implying efficient photovoltaic applications. A similar polythiophene macroinitiator for NMP was used for the synthesis of fullerene-grafted rod-coil block copolymers [149]. 

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