Morphology control of various aromatic polyimides by using phase separation during polymerization

Kanji Wakabayashi, Shin ichiro Kohama, Shinichi Yamazaki, Kunio Kimura

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


Morphology control of various aromatic polyimides representative as poly(4,4′-oxydiphenylene pyromelliteimide) was examined by using the phase separation during solution polymerization. Polymerizations of aromatic dianhydrides and aromatic diamines to the polyimides were carried out in poor solvents at 240-330 °C for 6 h with no stirring. Polymerization concentrations were from 0.25% to 3.0%. The polyimides were obtained as yellow precipitates. Two categorized morphologies were created, which were particles and crystals exhibiting lath-like and plate-like habits. These morphologies of polyimides could be selectively controlled by the polymerization conditions. The higher concentrations, less miscible solvents and lower temperatures were preferable to yield the particles via liquid-liquid phase separation. On the contrary, the lower concentration, miscible solvents and higher temperature were desirable to yield the crystals. The polyimide precipitates showed high crystallinity and possessed excellent thermal stability at which the 10 wt% loss temperatures in N2 were in the range of 590-694 °C.

Original languageEnglish
Pages (from-to)458-466
Number of pages9
Issue number2
Publication statusPublished - Jan 12 2007


  • Morphology
  • Phase separation
  • Polyimide

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry


Dive into the research topics of 'Morphology control of various aromatic polyimides by using phase separation during polymerization'. Together they form a unique fingerprint.

Cite this