Polyfluorene derivatives with non-conjugated alkoxy segment (-O-CH2-CH2-CH2-CH2-O-) in backbone, poly(9,9-dioctyl-2,7-fluorene-co-4,4’-butoxydiphenyl) (PFP) and poly(9,9-dioctyl-2,7-fluorene- co-4,4’-butoxydiphenyl-co-N-phenyl-4,4’-diphenylamine) (PFTP11), were synthesized by Suzuki coupling reaction and the control polymer with alternating fluorene and triphenylamine groups as main chain, poly(9,9-dioctyl-2,7-fluorene-co-N-phenyl-4,4’-diphenylamine) (PFTPA), was prepared under the same polymerization condition. The chemical structures of above-mentioned polymers were verified by 1H NMR and FT-IR analyses. These polymers showed good solubility in common organic solvents, and the solid films of them can be facilely obtained by solution processing. All of these polymers possess high thermal stability, with thermal decomposition temperature above 400 ℃. PFP possesses relatively high Tg temperature (at around 130 ℃), but for PFTP11 and PFTPA there was no obvious glass transition process observed. UV-Vis investigation of these polymers indicates the wide bandgaps of them (2.89～3.29 eV). The films of PFP, PFTP11 and PFTPA emitted blue light, with the maximum PL emission at 425, 437 and 440 nm, respectively. The investigation of the electrochemical properties of these polymers reveals that the HOMO levels of PFTP11 and PFTPA were significantly higher than that of PFP due to the introduction of triphenylamine group, suggesting the improvement of hole-transport capability of them.

Key words: non-conjugated, polyfluorene, triphenylamine, blue-light emitting