Syntheses of Soluble Biopolyimides Using 4-Aminophenylalanine

Kenji Takada, Hiromasa Shinagawa, Yuki Morita, Manjit S. Grewal, Kazuya Taya, Amit Kumar, Tatsuo Kaneko

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


4-Aminophenylalanine (4APhe), an exotic amino acid which is obtained as a microorganism metabolite of glucose, is polycondensed with various tetracarboxylic dianhydrides as a diamine monomer to obtain poly(amic acid)s. Subsequent thermal imidization of poly(amic acid)s is made at 220 °C with stepwise heating from 100 °C. Some of the obtained polyimides (PIs) exhibited good solubility in organic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and more. The progress of imidization was observed by proton nuclear magnetic resonance and infrared spectroscopy to confirm that the imidization ratio was up to 98%. Carboxylate group of the side-chains of PIs affected their solubilities despite the high imidization ratio, and the solubility was lost for any organic solvents by decarboxylation at 280 °C, confirmed from mass-loss of thermogravimetric analysis. Thus, a new series of PIs were obtained with abilities of solvent-molding in PI state and thermal resistivity enhancement by further heating after molding.

Original languageEnglish
Pages (from-to)1117-1123
Number of pages7
JournalChinese Journal of Polymer Science (English Edition)
Issue number10
Publication statusPublished - 2020 Oct 1
Externally publishedYes


  • 4-Aminophenylalanine
  • Amino acids
  • Bio-based polymers
  • Polyimides
  • Soluble polyimides

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Polymers and Plastics
  • Organic Chemistry


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