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The preparation of a new form of ionomer is described. This class of material is based on the polymerization of a neutral monomer with a small amount of a cationic–anionic monomer pair. The resulting ionomers are ampholytic in character and contain no inorganic ions. In this investigation, the polymerization of styrene with 3‐methacrylamidopropyldimethylammonium and trimethylammonium 2‐acrylamido‐2‐methylpropanesulfonate in a variety of solvents is described.

Aromatic triazole chromophores were incorporated into polyfluorene in an attempt to increase electron affinity, to promote emission efficiency, and to diminish excimer formation. Poly(9,9-dihexylfluorene) (P1) and new copolymers with aromatic triazoles (P2-P4) were prepared by Suzuki coupling polymerization. In P2, the aromatic triazole (3.8 mol %) was attached exclusively as terminal groups, whereas P3 and P4 were main-chain copolymers containing 3.9 and 10.3 mol % aromatic triazole chromophores, respectively. The copolymers were soluble in common organic solvents and showed high decomposition temperatures (437-458 8C). The twisted structure between the triazole and fluorene increased the emission efficiency and effectively prevented excimer formation in P2-P4. After the introduction of the triazole units, the absorption spectra showed a blueshift (from 388 to 381 nm in chloroform) due to confined conjugation, but the photoluminescence spectra remained almost the same (417-418 nm); this was attributed to oligofluorene segments. No emission of triazole fluorophores was observed because of efficient energy transfer from the triazole to oligofluorene segments. However, incomplete energy transfer was observed in CH 3 COOH. The optical stability upon thermal annealing was also improved by the incorporation of aromatic triazole segments. From cyclic voltammetry results, P2-P4, containing triazole groups, showed greater electron affinity (lowest unoccupied molecular orbital level ¼ À2.67 to À2.71 eV) than P1 (À2.52 eV). Electroluminescence devices of P1-P4 all exhibited excimer emissions (483-521 nm), which could also be diminished by the introduction of aromatic triazole chromophores. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: [136][137][138][139][140][141][142][143][144][145][146] 2007

The mechanism of the spontaneous polymerization of vinylpyridinium salts in aqueous and acidic solution has been actively investigated in recent years. Recent reports have suggested that these reactions are free radical in nature. In order to investigate the involvement of free radical initiation in the spontaneous polymerization reactions, an investigation of ion pair copolymers between the cationic 4‐vinylpyridinium moiety and the anionic vinylsulfonate, 2‐acrylamido‐2‐methylpro‐panesulfonate, and p‐styrenesulfonate has been undertaken. The results of spontaneous polymerization suggest that for 4‐vinylpyridinium vinylsulfonate, only the cationic moiety is polymerized, whereas for 4‐vinylpyridinium 2‐acrylamido‐2‐methylpropanesulfonate, two homopolymers or a block copolymer apparently result, and for 4‐vinylpyridinium p‐styrenesulfonate, an alternating copolymer appears to be obtained.