Hardystonite bioceramics from preceramic polymers

In this work, we demonstrated that the hardystonite (Ca2ZnSi2O7) bioceramics can be produced with high phase purity, starting from different preceramic polymers and suitable fillers (precursors for CaO and ZnO) after heating at 1200 °C in air. Open-celled hardystonite foams were easily prepared from a filler-containing silicone resin using hydrazine as foaming agent. The fabrication of cellular structures using a preceramic polymer and fillers was possible because the polymeric melt allowed for the entrapment of the gases generated by the decomposition of hydrazine, and the simultaneous cross-linking of the preceramic polymer enabled the retention of the foam structure. Samples with a well-developed hierarchical porous structure, with an open porosity ranging from ∼65 to ∼81 vol% and an average cell window size ranging from 150 to 500 μm were produced. The hardystonite components possessed a compressive strength ranging from ∼1.4 to ∼2.1 MPa.