Synthesis and Characterization of Fluorene-Imidazole Copolymers

Abstract

New PAF derivatives [poly(fluorene-co-1,3diphenylimidazolium chloride) 7 and poly(fluorene-co-1,3-diphenylimidazol-2-thione) 9] with high thermal stability were synthesized and their physical and optical properties were investigated. The obtained polymers were characterized by 1 H NMR, 13 C NMR, DSC, TGA, GPC, and SEM-EDX. Thermogravimetric analysis (TGA) showed excellent thermal stability of the resulting polymers. Initial weight loss (5 %) was observed around 700 K, with the main decomposition occurring around 760 K (50 %). The glass transition temperature of 9 was higher than that of the host copolymer 7. The copolymers in this study emitted in the blue region with a maximum around 440 nm. The emission spectra of copolymer 9 showed a red shift compared to that of the host copolymer 7. The optical band gaps deduced from the onset of the absorption of copolymers were about 3.06 and 2.91 eV for copolymers 7 and 9, respectively.