Synthesis, characterization and comparison of properties of novel fluorinated polyimides derived from bisphenol - A-di(phthaleic anhydride)

Four new poly(etherimide)s have been synthesized by reaction with commercially available bisphenol-A-(diphthaleic anhydride) (BPADA) with four different kinds of diamines, namely 4,4'-bis(p-aminophenoxy-3,3 ''-trifluoromethyl) terphenyl,4,4'-bis(3 ''-trifluoromethyl-p-aminobiphenyl ether)biphenyl,2,6-bis(3'-trifluoromethyl-p-aminobiphenyl ether)pyridine, 2,5-bis(3'-trifluoromethyl-p-aminobiphenylether)thiopene. The poly(etherimide)s are named as 1a, 1b, 1c and 1d, respectively. The synthesized polyimides show good solubility in various organic solvents. The polyimide films had low water absorption of 0.19-0.30% and low dielectric constant of 2.79-3.1 at 1MHz. These polyimides showed very high thermal stability with decomposition temperature (5% wt loss) up to 522 degrees C in nitrogen. Transparent thin films of these polyimides exhibited tensile strength up to 97MPa, a modulus of elasticity up to 1.56GPa and elongation at break up to 20%.