3D Printing of Polyimide

Polyimide (PI) is an important engineering polymer with excellent thermomechanical, electrical and chemical resistant properties at high temperatures. However, melt processing of polyimide is difficult. At present, it is limited to filmic structure or compression molding. This proposal posits two concepts to improve melt processibility of PI. From prior research, we demonstrated 1) imidization temperature can be reduced by up to 200?C via block copolymerization with polysiloxane, and 2) CNT acts as microwave heat absorbers. The project is to separately and uniformly disperse polyamic acid (precursor of PI), polysiloxane and CNT in solvent. Via in-situ polymerization, we produced PI-b-polysiloxane + CNT. These material matrices will be melt- extruded in a 3D printing process and evaluated on structure property, interlayer adhesion and print fidelity.    Additive manufacturing is a well-accepted manufacturing technique in the USAF. Developing a 3D PI structure would be a first step to metal replacement, on-demand part design or part replacement in aerospace applications. In the private sector, Groundstar will deploy 3D PI in the consumer electronics, automotive and aerospace verticals with a focus on lightweighting structures. We estimate this nascent market could grow to $10B on a 24% CAGR.