Liming Tao, Hai-xia Yang, Jingang Liu
Nov 27, 2009
Citations
2
Influential Citations
168
Citations
Quality indicators
Journal
Polymer
Abstract
Abstract Multitrifluoromethyl-substituted aromatic diamines, 1,1-bis[4-(4′- amino-2′-trifluoromethylphenoxy)phenyl]-1-(3″-trifluoromethylphenyl)-2,2,2-trifluoroethane (12FDA) and 1,1-bis[4-(4′-amino-2′-trifluoromethylphenoxy)phenyl]-1-[3″,5″-bis (trifluoromethyl)phenyl]-2,2,2-trifluoroethane (15FDA) were synthesized, which were employed to react with various aromatic dianhydrides to yield a series of highly fluorinated polyimides. The fluorinated polyimides synthesized showed great solubility with inherent viscosities of 0.47–0.69 dL/g. The strong and tough polyimide films exhibited good thermal stability with the glass transition temperature (Tg) of 209–239 °C and outstanding mechanical properties with the tensile strengths of 88–111 MPa and tensile modulus of 2.65–3.17 GPa. Dielectric constants of as low as 2.49 and low moisture absorptions (0.17–0.66%) were measured. The fluorinated polyimide films (7–10 μm in thickness) also showed highly optical transparency with light transmittance at 450 nm of as high as 97.0% and cutoff wavelength of as low as 298 nm. The average refractive indices and birefringence of the fluorinated polyimide films were measured in the range of 1.5060–1.5622 and 0.0036–0.0095, respectively. PI-7 and PI-8 exhibited low light-absorption in the near-infrared region, especially at the optocommunication wavelength of 1310 nm and 1550 nm.