Investigation on the Preparation of New Sulfonated Polyimide Fuel Cell Membranes in Organic and Ionic Liquid Media

Abstract

A new sulfonated and an unsulfonated diamine were prepared. These diamines together with 4,4′-oxydianiline and 1,8-diamino-3,6-dioxaoctane were used for preparation of new sulfonated copolyimides (SPIs). Different ratios of sulfonated and unsulfonated diamines were reacted with 1,4,5,8-naphthalene tetracarboxylic dianhydride to prepare SPIs with controlled degrees of sulfonation. These copolyimides were prepared via two different routes: high-temperature polycondensation reaction in m-cresol in the presence of catalyst, and in ionic liquid medium without any catalyst. Copolyimides prepared in ionic liquid medium showed superior properties in comparison to preparation in common solvent method. Polymers revealed promising properties for application in fuel cell.

Keywords:

• Fuel cell
• ionic liquid
• membrane
• polyimides
• thermal properties

Acknowledgment

The authors would like to appreciate Renewable Energy Organization of Iran for collaboration and partial support of this research.

Notes

^a Inherent viscosity of copolyimide synthesized in organic solvent.

^b Inherent viscosity of copolyimide synthesized in ionic liquid.