1. Transparent and organosoluble cardo polyimides with different trans/cis ratios of 1,4‐diaminocyclohexane via aromatic nucleophilic substitution polymerization.
- Author
-
Tang, Yongmei, Li, Lan, Ma, Kai, Chen, Guofei, Wang, Wei, and Fang, Xingzhong
- Subjects
POLYIMIDES ,GLASS transition temperature ,CYCLOHEXANE ,THERMAL stability ,POLYMERIZATION - Abstract
Abstract: Two series of cardo polyimides were prepared from 1,4‐bis(4‐fluorophthalimide)cyclohexane with different trans/cis ratios and phenolphthalein/o‐cresolphthalein via aromatic nucleophilic substitution reaction. The inherent viscosities of the synthesized polymers were found to be 0.55–0.66 dL g
−1 in N,N′‐dimethylacetamide. The cardo polyimides showed excellent solubility in organic solvents, high glass transition temperatures (Tg ) of 275–312 °C and moderate thermal stability with 5% weight loss temperatures (Td5% ) of 415–441 °C in nitrogen and 370–436 °C in air. The polyimide films exhibited high optical transparency with cut‐off wavelengths of 350–355 nm and moderate mechanical properties. The different properties of the polymers caused by trans and cis configurations of 1,4‐diaminocyclohexane were also investigated. It was found that with an increasing content of trans configuration of 1,4‐diaminocyclohexane in the polyimide backbone, Tg of the polyimides increased as well as Td5% , while the solubility gradually decreased. The polyimide films had good optical transparency regardless of trans/cis configuration. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF