Synthesis and properties of polyimides containing 2,2′-bipyridine derivatives

✍ Scribed by Xuehui Sun; Yu-kun Yang; Fengcai Lu

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 387 KB
• Volume: 198
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1997.021980314

✦ Synopsis

Abstract

A series of polyimides containing 2,2′‐bipyridine, 7, were synthesized by reaction of 4,4′‐diamino‐2,2′‐bipyridine (4) with various aromatic dianhydrides, followed by imidization upon heating. These polyimides are fairly thermostable, and 5% weight loss occurs in the range of 484°C‐580°C. The glass transition temperatures are between 276°C and 313°C. Their poly(amic acids) 6 can be partially quaternized using 1,2‐dibromoethane and then easily imidized upon heating. The temperature of quaternized polyimides at which 5% weight loss is observed is around 300°C, the glass transition temperatures range from 202–239°C. These quaternized polyimides can also develop color under UV irradiation in a poly(N‐vinyl‐2‐pyrrolidone) (PVP) matrix with maximum absorption at 800 nm. The bipyridine‐based poly(amic acids) 6 can trap various metal ions from solution and then can be imidized by heating. The XPS data indicate the formation of a 1:1 (bipyridine: metal molar ratio) complex and a 2:1 complex. The temperature at which for the polyimide‐metal complexes 5% weight loss is observed is around 300°C. Both the poly(amic acid)‐metal complex and the polyimide‐metal complex catalyze the condensation of benzaldehyde with acetophenone, with yields of chalcone of ca. 6.7–31.7%. The order of catalytic activity for different metal ions is Zn(II) > Co(II) > Cu(II).