Morphology-Controlled Self-Assembly and Synthesis of Biopolyimide Particles from 4-Amino-l-phenylalanine

Thawinda Hirayama; Amit Kumar; Kenji Takada; Tatsuo Kaneko

doi:10.1021/acsomega.9b03231

Morphology-Controlled Self-Assembly and Synthesis of Biopolyimide Particles from 4-Amino-l-phenylalanine

ACS Omega. 2020 Feb 3;5(5):2187-2195. doi: 10.1021/acsomega.9b03231. eCollection 2020 Feb 11.

Authors

Thawinda Hirayama^{1

2}, Amit Kumar¹, Kenji Takada¹, Tatsuo Kaneko¹

Affiliations

¹ Graduated School of Advanced Science and Technology, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
² Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand.

Abstract

Self-assembling polyimides (PIs) having diketopiperazine (DKP) components were synthesized by polycondensation of a 4-amino-l-phenylalanine (4APhe) dimer, an aromatic diamine newly designed in this study. The amino acid-derived PIs showed high thermal resistance, with a 10% weight loss temperature (T _d10) of 432 °C at the maximum, and did not show any glass transition below the thermal decomposition temperature. The poly(amic acid) (PAA) precursors formed nanospheres upon reprecipitation over dimethylacetamide into water. The nanospheres were then added to solvents with different polarities and sonicated to induce deformation of the spherical forms into spiky balls, flakes, or rods. The PAA particle morphologies were retained in the PIs after the two-step imidization. Finally, the PI particles with self-assembling DKP moieties were formed, and their morphologies were fine-tuned using different mixed solvents.