Synthesis and fabrication of lightweight microcellular thermoplastic polyimide foams using supercritical CO2 foaming

Haiming Liu, Xiangdong Wang, Hao-Yang Mi*, Maxwell Fordjour Antwi-Afari, Chuntai Liu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Polyimide foams (PIFs) are usually synthesized by solution polymerization, followed by chemical foaming to prepare thermosetting foam. In this research, lightweight microcellular thermoplastic polyimide foams (TPIFs) were fabricated via a novel two-step foaming approach using supercritical carbon dioxide (scCO2) as a blowing agent. The poly(amic acid) (PAA) and polyester ammonium salt (PEAS) precursor solutions were synthesized with pyromellitic dianhydride (PMDA) as dianhydride reagents and polyether amine Jeffamine D230 as aliphatic diamine reagent via blending and solution polymerization, respectively. The solution polymerization process demonstrated a higher molecular weight and superior formability than the blending process. The optimum thermal imidization temperature of 200 °C was optimized via the thermal and rheological property analysis. The cell morphology and mechanical properties of the TPIFs could be turned by varying the saturation time, foaming pressure, and imidization temperature. At a thermal imidization temperature of 200 °C, the TPIFs exhibited a branched structure with a small mean cell diameter (123.78 μm), and a high compressive strength (0.4 MPa) under 10 % strain at high temperature and pressure, which was more than ten times that of the TPIFs with thermal imidization temperature of 130 °C. This research provides a feasible method for producing high volume expansion ratio TPIFs with adjustable microcellular structures and outstanding mechanical properties.
Original languageEnglish
Article number126548
Early online date4 Dec 2023
Publication statusPublished - 5 Jan 2024

Bibliographical note

Copyright © 2023, Elsevier. This accepted manuscript version is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International


  • Compressive strength
  • Supercritical carbon dioxide
  • Thermal imidization
  • Thermoplastic polyimide foams


Dive into the research topics of 'Synthesis and fabrication of lightweight microcellular thermoplastic polyimide foams using supercritical CO2 foaming'. Together they form a unique fingerprint.

Cite this