Copolymers from thiophene/benzene

The electrical conductivity of a thiophene/benzene copolymer increases from 9.5 x 10 Scm"Mn the neutral state to 10 Scm" on iodine doping, in contrast to poly-p-phenylene which has no significant evolution of conductivity on doping. The crystalline structure of poly-p-phenylene and of a thiophene/ benzene copolymer is similar, but the copolymer has a lower degree of crystallinity which allows for easier penetration of iodine into the bulk material [281]. A blend of PAT (n = 8,12,22) and polystyrene doped with iodine vapor has an electrical conductivity of up to 10 Scm [282],... 

Copolymerization, Composites. The electrochemical copolymerization of 3-do-decylthiophene and 3-methylthiophene is carried out galvanostatically. A molar ratio of 1 1 gives a copolymer with an electrical conductivity of 260Scm [701]. A polymer containing a thiophene-benzene-thiophene unit is chemically or electrochemically prepared from the monomer l,4-di(2-thienyl)benzene with H, Me or OMe groups in 2,5 position of the phenylene ring [607],... 

Thiophene-Benzene. l,4-bis(2-thienyl)phenylene has been elec-tropolymerized [806, 807]. Electrochemical polymerization of l,3-bis(2-thienyl)phenylene and l,4-bis(2-thienyl)biphenylene has also been reported [784,808] (Fig. 55). Random copolymers have been obtained from the Ni(II) coupling of different molar ratios of 2,5-dibromothiophene and 1,4-dibromobenzene [809, 810]. A series of substituted l,4-bis(2-thienyl)phenylenes have been polymerized on the basis of a procediue similar to the Rieke method [811, 812]. In addition, the group of Reynolds prepared an exten-... 

In an analogous way, soluble substituted poly(p-phenylene)s were prepared from substituted benzene rings functionalized with MgCl and Br in para position (see Formula 16.10). It proved to be necessary to add LiCl in addition to the Ni-catalyst to achieve low DPs (1.17-1.27) and Mns up to 36 kDa [130]. Furthermore, it was feasible to synthesize diblock copolymers, when the poly(p-phenylene) was prepared first and used as a macroinitiator for thiophene monomers. The same approach also allowed to perform CCPs of 2,5-dihalo N-hexylpyrrol, but again... 

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