3D Printing All-Aromatic Polyimides Using Stereolithographic 3D Printing of Polyamic Acid Salts

Area of Science:

• Polymer Chemistry
• Materials Science
• Additive Manufacturing

Background:

• All-aromatic polyimides offer exceptional thermal and chemical stability.
• Conventional processing of imidized polyimides is challenging.
• Photocuring additive manufacturing offers a route to complex polymer structures.

Purpose of the Study:

• To develop a facile method for photocuring polyamic acid (PAA) salts into all-aromatic polyimides.
• To enable three-dimensional printing of high-performance polyimides.
• To explore applications in aerospace and automotive industries.

Main Methods:

• Addition of 2-(dimethylamino)ethyl methacrylate (DMAEMA) to poly(4,4'-oxydiphenylene pyromellitamic acid) (PMDA-ODA PAA).
• Preparation of ultraviolet (UV) curable PAA salt solutions.
• Vat photopolymerization 3D printing of organogels.
• Thermal treatment to convert cross-linked PAA to polyimide.

Main Results:

• Readily prepared UV curable PAA salt solutions were achieved without multistep synthesis.
• Fast gel times (<5 s) and high gel-state moduli (G') were observed.
• Self-supporting organogels were produced via vat photopolymerization.
• Thermal treatment successfully converted the PAA precursor to all-aromatic PMDA-ODA polyimide.

Conclusions:

• A fast and facile strategy for 3D printing all-aromatic PMDA-ODA polyimides was established.
• This method overcomes conventional processing limitations for high-performance polymers.
• The developed technique has significant potential for aerospace and automotive applications.