Synthesis and characterization of novel fluorinated aromatic polyimides derived from 1,1‐bis(4‐amino‐3,5‐dimethylphenyl)‐1‐(3,5‐ditrifluoromethylphenyl)‐2,2,2‐trifluoroethane and various aromatic dianhydrides

摘要: A novel fluorinated aromatic diamine, 1,1-bis(4-amino-3,5-dimethyl-phenyl)-1-(3,5-ditrifluoromethylphenyl)-2,2,2-trifluoroethane (9FMA), was synthesized by the coupling reaction of 3',5'-ditrifluoromethyl-2,2,2-trifluoroacetophenone with 2,6-dimethylaniline under catalysis hydrochloride. series polyimides were from 9FMA and various dianhydrides, including pyromellitic dianhydride, 3,3'4,4'-biphenyl tetracarboxylic 4,4'-oxydiphthalic anhydride, 3,3',4,4'-benzophenone dianhydride (BTDA), 4,4'-hexafluoroisopropylidene diphthalic via a high-temperature, one-stage imidization process. The inherent viscosities ranged 0.37 to 0.74 dL/g. All quickly soluble in many low-boiling-point organic solvents such as tetrahydrofuran, chloroform, acetone well some polar N-methyl-2-pyrrolidinone, N,N'-dimethylacetamide, N,N'-dimethylformamide. Freestanding polyimide films could be prepared exhibited good thermal stability glass-transition temperatures 298-334 °C outstanding mechanical properties tensile strengths 69-102 MPa elongations at break 3.3-9.9%. Moreover, possessed low dielectric constants 2.70-3.09 moisture absorption (<0.58%). also optical transparency cutoff wavelength 303-351 nm. One (9FMA/BTDA) an intrinsic negative photosensitivity, fine pattern obtained resolution 5 μm after exposure i-line (365-nm) wavelength.