Soluble, transparent and heat-resistant fluorinated copoly(ether imide)s containing pyridyl and biphenyl units in the main chain

Abstract

A series of new fluorinated copoly(ether imide)s containing pyridyl and biphenyl moieties were prepared by thermal imidization of poly(amic acid)s derived from 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (BATB), 4-(4-trifluoromethylphenyl)-2,6-bis(4-aminophenyl)pyridine (TFMPBPP) and 3,3’,4,4’-biphenyltetracarboxylic dianhydride with various mole ratios of BATB and TFMPBPP ranging from 80/20 to 20/80. All copoly(ether imide)s were amorphous and soluble in polar solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone at room temperature or upon heating at 70 °C, and displayed good thermal properties with gradually increasing of a glass transition temperature ranged from 282 to 347 °C as an increase of the TFMPBPP component, the temperature at 5% weight loss of 574–586 °C, and the residue of 57–62% at 750 °C in nitrogen. Tough and flexible polymer films also exhibited outstanding mechanical properties with tensile strengths of 109.1–111.9 MPa, tensile moduli of 1.3–1.5 GPa, and elongations at break of 27.9–48.7%, low dielectric constants of 2.98–3.15 (1 MHz) and water uptake 0.36–0.55%, as well as high optical transparency with the UV-vis cutoff wavelength in the 370–382 nm range and the wavelength of 80% transparency in the range 518–550 nm.

Graphical Abstract

Keywords:

• Fluorinated copoly(ether imide)s
• 4-(4-trifluoromethylphenyl)-2,6-diphenylpyridyl
• biphenyl
• solubility
• thermal stability
• transparency

Additional information

Funding

The authors acknowledge the financial support of this work from the National Natural Science Foundation of China (No. 51763013, 21907043), the Research Program of Jiangxi Province Department of Education (No. GJJ211707), the Open Project Program of Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Jiangxi Normal University (No. KLFS-KF-201912, KLFS-KF-201928), and the Graduate Student Innovation Foundation of Jiangxi Normal University (YC2021-S235).