High-molecular-weight (HMw) sulfonated polyimide thin films with a semialiphatic main chain exhibited an oriented lamellar structure and high proton conductivity (1.5 × 10-1 S cm-1) under humidified conditions. Low-molecular-weight (LMw) sulfonated polyimide thin films with the same semialiphatic backbone exhibited a nonoriented lamellar structure and low proton conductivity (3.0 × 10-2 S cm-1) under humidified conditions. The results indicate that, in sulfonated polyimide thin films with semialiphatic main chain, the lamellar orientation greatly contributes to the high proton conductivity.
- Kensaku Takakura
- Yutaro Ono
- Yuki Nagao