Abstract
Summary: A series of organosoluble and colorless fluorinated poly(ether imide)s (IV~aโg~) were prepared from 3,6โbis(3,4โdicarboxyphenoxy)benzonorbornane dianhydride (I) and various trifluoromethyl (CF~3~)โsubstituted aromatic bis(ether amine)s II~aโg~ by a standard twoโstep process with thermal and chemical imidization of poly(amic acid) precursors. These poly(ether imide)s had inherent viscosities of 1.02โ1.28 dLโยทโg^โ1^ and showed excellent solubility in many organic solvents. They could be solutionโcast into transparent, flexible, and tough films with good mechanical properties. These films were virtually colorless, with an ultravioletโvisible absorption edge of 372โ381 nm and a very low b* value (a yellowness index) of 10.8 to 18.2. The glassโtransition temperatures (T~g~) and softening temperatures (T~s~) were recorded between 216โ292โยฐC and 209โ285โยฐC, respectively. The decomposition temperature for 10% weight loss all occurred above 472โยฐC in nitrogen and 481โยฐC in air, and the char yields at 800โยฐC in nitrogen were more than 51%. They also showed low dielectric constants of 2.84โ3.58 (1 MHz) and moisture absorptions in the range of 0.05โ0.19%. In comparison with analogous V series poly(ether imide)s without the CF~3~ substituents, the IV series ones showed better solubility, lower color intensity, and lower dielectric constants.
A novel series of fluorinated poly(ether imide)s.
magnified imageA novel series of fluorinated poly(ether imide)s.