Currently, some of the most desirable materials for polymer 3D printing are PAEK family polymers such as PEEK, PEKK or PEI (ULTEM), which have a thermal resistance of around 400° and can be 3D printed by laser sintering and/or filament extrusion. Researchers at Virginia Tech’s Macromolecules Innovation Institute have devised a method for using a mask projection stereolithography process for 3D printing with PMDA-ODA (Kapton) which are polyimides thermally stable up to 600° C.
High-performance, all-aromatic, insoluble, engineering thermoplastic polyimides, such as pyromellitic dianhydride and 4,4′-oxydianiline (PMDA–ODA) (Kapton), exhibit exceptional thermal stability (up to ≈600 °C) as well as excellent mechanical properties such as Young’s modulus exceeding 2 GPa.
However, their thermal resistance, which is a consequence of the all-aromatic molecular structure, prohibits processing using conventional techniques. Previous reports describe an energy-intensive sintering technique as an alternative technique for processing polyimides with limited resolution and part fidelity.
This study demonstrated the unprecedented 3D printing of PMDA–ODA using mask-projection stereolithography, and the preparation of high-resolution 3D structures without sacrificing bulk material properties. Synthesis of a soluble precursor polymer containing photo-crosslinkable acrylate groups enables light-induced, chemical crosslinking for spatial control in the gel state.
Postprinting thermal treatment transforms the crosslinked precursor polymer to PMDA–ODA. The dimensional shrinkage is isotropic, and postprocessing preserves geometric integrity. Furthermore, large-area mask-projection scanning stereolithography demonstrates the scalability of 3D structures. These unique high-performance 3D structures offer potential in fields ranging from water filtration and gas separation to automotive and aerospace technologies.
Macromolecules Innovation Institute at Virginia Tech (MII) is an interdisciplinary group committed to continuing the growth and advancing the stature of the existing, highly-ranked macromolecular science and engineering program at Virginia Tech. We are committed to fostering a dynamic environment that enthusiastically promotes the recruitment and education of high-quality students; actively initiates and conducts timely research at both the basic and applied levels; and vigorously pursues continuing education and economic growth through outreach activities with industry and government agencies.