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N. Klikovits, L. Sinawehl, P. Knaack, T. Koch, J. Stampfl, C. Gorsche, R. Liska:
"UV-Induced Cationic Ring-Opening Polymerization of 2-Oxazolines for Hot Lithograph";
ACS Macro Letters, 9 (2020), 4; 546 - 551.

The cationic ring-opening polymerization (CROP) of 2-oxazolines gives polymers with unique characteristics arising from its polyamide backbones and structural versatility. Up to now, poly(2-oxazoline)s were obtained by classical thermal polymer-ization methods not aiming for application in bulk curing of structural polymers. We introduce the cationic photopolymeriza-tion of 2-oxazolines at elevated temperatures for the direct UV-induced curing of materials with exclusive chemical and structural particularities. After efficient photoinitiation via onium salt photoacid generators (PAGs), the immanent low-rate propagation is crucially promoted by thermal energy input to the ring-opening reaction. In simultaneous thermal analysis (STA), photo-DSC, and (thermo)mechanical analyses we investigated the UV-induced CROP of 2-oxazolines in a temperature range of 100−140 °C and show the exceptional potential of the introduced photopolymers. Furthermore, we applied the photopolymerizable system in Hot Lithography, a stereolithography-based 3D printing technology at elevated temperatures.

The cationic ring-opening polymerization of 2-oxazolines, classical thermal polymerization methods, photo-DSC, Hot Lithography, a stereolithography-based 3D printing technology

http://dx.doi.org/10.1021/acsmacrolett.0c00055

https://pubs.acs.org/doi/10.1021/acsmacrolett.0c00055