Electroinitiated polymerization of carbazole was achieved in acetonitrile by direct electron transfer via constant potential electrolysis based on anodic peak potentials. The anodic peak potential of carbazole was determined by cyclic voltammetry to be ϩ 1.4V. It has been observed that polymer yield increased with some factors, such as time, monomer concentration, and polymerization potential. Conducting polycarbazole material obtained on a platinum anode electrode was characterized by FT-IR, TGA, and conductance measurements. The conductivities of samples were measured to be about 10 Ϫ3 -10 Ϫ4 S/cm by the four-probe method. Temperature-dependence of electrical resistance values of polycarbazole between 30°-125°C suggest that it can be used as a thermal sensor.

Combination of cationic, redox free radical, and thermal free radical polymerizations was performed to obtain linear and star polytetramethylene oxide (poly-THF)-polymethyl methacrylate (PMMA)/polystyrene (PSt) multiblock copolymers. Cationic polymerization of THF was initiated by the mixture of AgSbF 6 and bis(4,4Ј bromomethyl benzoyl) peroxide (BBP) or bis (3,5,3Ј,5Ј dibromomethyl benzoyl) peroxide (BDBP) at 20°C to obtain linear and star poly-THF initiators with M w varying from 7,500 to 59,000 Da. Poly-THF samples with hydroxyl ends were used in the methyl methacrylate (MMA) polymerization in the presence of Ce(IV) salt at 40°C to obtain poly(THF-b-MMA) block copolymers containing the peroxide group in the middle. Poly(MMA-b-THF) linear and star block copolymers having the peroxide group in the chain were used in the polymerization of methyl methacrylate (MMA) and styrene (St) at 80°C to obtain PMMA-b-PTHF-b-PMMA and PMMAb-PTHF-b-PSt linear and star multiblock copolymers. Polymers obtained were characterizated by GPC, FT-IR, DSC, TGA, 1 H-NMR, and 13 C-NMR techniques and the fractional precipitation method.

A new and promising method for the diversification of microbial polyesters based on chemical modifications is introduced. Poly(3‐hydroxy alkanoate)‐g‐(poly(tetrahydrofuran)‐b‐poly(methyl methacrylate)) (PHA‐g‐(PTHF‐b‐PMMA)) multigraft copolymers were synthesized by the combination of cationic and free radical polymerization. PHA‐g‐PTHF graft copolymer was obtained by the cationic polymerization of THF initiated by the carbonium cations generated from the chlorinated PHAs, poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV), and poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBHx) in the presence of AgSbF6. Therefore, PHA‐g‐PTHF graft copolymers with hydroxyl ends were produced. In the presence of Ce+4 salt, these hydroxyl ends of the graft copolymer can initiate the redox polymerization of MMA to obtain PHA‐g‐(PTHF‐b‐PMMA) multigraft copolymer. Polymers obtained were purified by fractional precipitation. In this manner, their γ‐values (volume ratio of nonsolvent to the solvent) were also determined. Their molecular weights were determined by GPC technique. The structures were elucidated using 1H‐NMR and FTIR spectroscopy. Thermal analyses of the products were carried out using differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

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