Mechanism of enhancement of conductivity for pyrolyzed polypyrrolone film at high temperature

✍ Scribed by Mingjun Piao; Meixiang Wan; Fengcai Lu

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 535 KB
• Volume: 34
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199606)34:8<1567::aid-pola21>3.0.co;2-5

✦ Synopsis

The effects of the pyrolytic temperature on the structure of the pyrolyzed polypyrrolone (PMDA-DAB) films were investigated. The structure of pyrolyzed PMDA-DAB film was characterized by elemental analysis, X P S spectra, x-ray diffraction, and SEM images. It suggests that the pyrolysis process of PMDA-DAB films consists of carbonization and graphitization processes, and the transitional temperature is at ca. 800°C. During carbonization process (T, < 80OoC), most oxygen is removed and the enhancement of conductivity with the pyrolytic temperature may be due to an extended conjugation of *-electron orbitals resulting in an increase of the number of charge carriers. During graphitization (37, > 800"C), both oxygen and hydrogen are removed completely, and an increase in the mobility of charge carriers may increase conductivity with pyrolytic temperature. A graphite-like structure with heterocyclic rings containing nitrogen atoms is proposed for the PMDA-DAB film pyrolyzed at 1200°C.