Abstract:

A polyimide containing fluorene group was prepared by 9,9-bis(3-fluoro-4-aminophenyl) fluorene and 4,4′(hexafluoroisopropylidene) diphthalic anhydride as a monomer. The structure of polyimide was characterized by Fourier transform infrared spectoscopy (FTIR) and nuclear magnetic resonance hydrogen spectrum (¹H NMR). Experimental results show that the structure of FFDA-6FDA is the same as the expected results, and the imidization reaction between monomers is conducted completely. FFDA-6FDA has good solubility in most common organic solvents at room temperature. FFDA6FDA has high thermal performance: its glass transition temperature is 370 ℃, the temperature at 10% weight loss is 582 ℃ and the weight maintenance rate in 800 ℃ is beyond 61% in nitrogen atmospheres. Furthermore, the thin film of FFDA6FDA has good optical transparency with 294 nm UV cutoff wavelength.

Key words: polyimide, optical transparency, thermal stability, solubility