3D Printing of Strong and Room-Temperature Reprocessable Silicone Vitrimers.

Silicones find use in a myriad of applications from sealants and adhesives to cooking utensils and medical implants. However, state-of-the-art silicone parts fall short in terms of shape complexity and reprocessability. Advances in three-dimensional printing and the discovery of vitrimers have recently opened opportunities for shaping and recycling of silicone objects. Here, we report the 3D printing via direct ink writing of silicone vitrimers into complex-shaped parts with high strength and room-temperature reprocessability. The reprocessing properties of the printed objects result from the adaptive nature of the silicone vitrimer, which can deform under stress without losing its network connectivity. Rheological and mechanical experiments reveal that printable inks can be tuned to generate strong parts with high creep resistance and room-temperature reprocessability, two properties that are usually challenging to reconcile in vitrimers. By combining printability, high strength, and room-temperature reprocessability, the reported silicone vitrimers represent an attractive sustainable alternative to currently available elastomers in a broad range of established and prospective applications.