| 초록 |
In this study, we emphasized the synthesis and characterization of polyimides from new unsymmetric diamine monomers. The new diamines containing trifluoromethyl group, 4-(4-amino-3-(trifluoromethyl)phenoxy)-2,6-dimethylaniline (ARFPA) and 4-(4-amino-2-(trifluoromethyl)phenoxy)-2,6-dimethylaniline (ALFPA) was synthesized by nucleophilic aromatic substitution reaction (SNAr) and then reduction nitro to amino groups. The new polyimides were synthesized with commercial aromatic dianhydrides, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA). The PI films exhibit good thermal stability (the 5% weight loss at temperatures range of 523-562 oC) and high glass transition temperature (Tg ＞ 307 oC). They show good solubility in several solvent such as chloroform, dimethyl sulfoxide, ethyl acetate and acetone. Additionally, the PI has low refractive indices in the range of 1.5470-1.5735 at a wavelength of 637 nm and low dielectric constant. |
