Additive manufacturing of high-performance polycyanurates photo-induced catalytic poly-trimerization

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2023-05, Vol.11 (2), p.1545-155
• Main Authors: Wolff, Raffael, Knaack, Patrick, Seidler, Konstanze, Gorsche, Christian, Koch, Thomas, Stampfl, Jürgen, Liska, Robert
• Format: Article
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d3ta01264f

Polycyanurates offer outstanding thermomechanical properties due to their unique triazine structure in combination with phenolic chains. Generally, these resistant thermosets are formed into the desired shape via lengthy molding processes. With the aid of photo-induced catalytic poly-trimerization, not only the photochemical curing of cyanate esters can be described here, but also the production of pure polycyanurates by employing an additive manufacturing variant, the Hot Lithography. Other methods in the field of additive manufacturing of this class of thermosets relied on matrix polymers or fillers for less precise printing variants. The presented reaction process could be monitored via photo-DSC and IR, and the thermomechanical properties could be analyzed by simultaneous thermal analysis and dynamic mechanical analysis. The presented formulation is stable under the selected conditions for 3D printing at elevated temperatures, showing sufficient reactivity. The thermomechanical values obtained for the 3D printed structures are in regions that have rarely been attainable for additive manufacturing using laser-induced curing. Together with the commonly used high chemical resistance, this proof-of-concept process offers an extraordinary opportunity for the production of high-performance polymers for additive manufacturing. Investigation of a cyanate ester based formulation and stereolithography-based additive manufacturing via Hot Lithography to produce polycyanurates with a glass transition temperature of 336 °C without any additives.