9,9-Diarylfluorene-based poly(alkyl aryl ether) s: Synthesis and property

Abstract

Polyethers possessing 9,9-diarylfiuorene moieties in the main chain (F-PEs 3) were synthesized in 85-99% yields by the polycondensation of 9,9-bis(hydroxyaryl) fluorenes with alkyl ditosylates in the presence of cesium carbonate. Molecular weight of the F-PEs was dependent on the structure of the ditosylate 1; cyclohexyl-1,4-dimethylene (la), 1,2-ethylene (1b), 1,3-trimethylene (1c), and 1,6-hexamethylene (1d). Higher molecular weight F-PEs (Mn 32000-60000, Mw 74000-160000) was obtained when longer alkyl chain ditosylates (1a and 1d) were used. The F-PEs showed good solubility toward various organic solvents such as toluene and high 5% weight loss temperature (Td5: 424-447 °C). The glass transition temperature of F-PEs (Tg) was ranging from 147 to 220 °C. No melting point (Tm) was observed. F-PEs showed high water-resistance. The transmittance of F-PEs in film state (thickness: 21-32 μm) reached over 90% in the visible region. The F-PEs exhibited high refractive indices in a range of 1.62-1.66 at 590 nm in addition to sufficiently low birefringence values, probably due to the cardo structure of the fluorene moiety placed in the main chain. The structural dependence of dispersing ability to fullerene C 60 was investigated. ©2009 The Society of Polymer Science, Japan.