Synthesis of Crosslinkable Polyetherimide and Application as an Additive in 3D Printing of Photopolymers

Three-dimensional printing of photopolymers is now technically mature and economical, but its widespread use is hampered by the limited availability of resins tailored for specific industrial applications. In this study, crosslinkable glycidyl methacrylate-grafted polyetherimide (PEI-GMA) is obtained by synthesizing polyamic acid, subsequent imidization and grafting with glycidyl methacrylate. The good solubility in N-vinylpyrrolidone (NVP) as the reactive diluent allows blending PEI-GMA with a photopolymerizable resin. The resins are additively processed on an LCD shadow masking printer operating at 405 nm wavelength to form a series of custom-designed components with a range of different geometries. After adding 20 wt% of PEI-GMA to a resin made of NVP and polyethylene glycol diacrylate, both the strength and the elasticity of the cured structures benefit significantly with improved thermal stability at the same time. This opens up new possibilities for the individual or small series production of complex components with high resolution and a polyetherimide-like finish, which can be particularly helpful in the design of aircraft, vehicles, portable devices or tools.