Soluble copoly(pyridine ether imide)s derived from 6FDA, 1,4-bis(4-amino-2-trifluromethylphenoxy)benzene, and 4-(4-trifluoromethylphenyl)-2,6-bis(4-aminophenyl)pyridine

摘要

A series of new fluorinated copoly(pyridine ether imide)s were prepared by thermal imidization of polyamide acid derived from 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (BATB), 4-(4-trifluoromethylphenyl)-2,6-bis(4-aminophenyl)pyridine (TFMPBPP), and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) with various mole ratios of BATB and TFMPBPP ranged from 80/20 to 20/80. All copolyimides were amorphous and had excellent solubility in organic solvents such as N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and N,N-dimethylformamide (DMF) at room temperature and displayed good thermal properties with glass transition temperature (T-g) of 272 degrees C-338 degrees C, 5% weight loss temperature of 520 degrees C-540 degrees C, and the residue of 44-56% at 750 degrees C in nitrogen. Meanwhile, the T-g of the copolymers increased with an increase in the TFMPBPP component. Tough and flexible copolyimide films also exhibited outstanding mechanical properties with tensile strengths of 107.2-153.2 MPa, tensile moduli of 1.4-1.8 GPa, and elongations at break of 13.2-19.6%, low dielectric constants of 2.76-2.92 (1 MHz), and water uptake 0.32-0.62% as well as high optical transparency with the UV cutoff wavelength in the 371-386 nm range and the wavelength of 80% transparency in the range 459-498 nm.