Cationic photopolymerization of cyclic esters at elevated temperatures and their application in hot lithography

The 3D printing of polyesters is most commonly performed using polylactide filaments for material extrusion (formerly known as fused-deposition modelling) or by introducing methacrylate end-groups to polyesters, which can be polymerized a radical mechanism. However, cyclic esters also via cationic ring-opening photopolymerization, opens up the possibility high-resolution stereolithography method choice form polyester networks in situ during process. Hereby, we present first approach print starting directly from ?-caprolactone at elevated temperatures, low amounts crosslinks into provide stability structure but maintain its degradable character and especially semicrystallinity. Photorheology tests showed that high temperatures introduction crosslinkers led increased reactivity fast gelation. By performing tensile tests, dynamic mechanical thermal analysis simultaneous properties were evaluated depending on amount type crosslinker. It was shown decreasing crosslinker significantly crystallinity influenced well shape memory properties. Finally, successful 10 mol% with oxetane moieties 90 120 °C. © 2022 Authors. Polymer International published John Wiley & Sons Ltd behalf Society Industrial Chemistry.