Performance modulation and 3D printing parameters optimization of implantable medical tricalcium-silicate/polyetherimide composite

Abstract

Tricalcium silicate (C3S)/polyetherimide (PEI) stents are manufactured through an additive manufacturing process using binder jetting. The key issues of C3S/PEI composite ceramic slurry and additive manufacturing process parameters are discussed in detail. Firstly, the low-temperature auxiliary sintering temperature of the sample was determined, and the influence of PEI content on the compressive strength and bending strength before and after sintering was studied. The sintering temperature and optimal PEI content are 340 °C and 10 wt%. Under this PEI content, the flow rate change during the printing process of the slurry was measured, and a C3S/PEI composite slurry suitable for binder jetting additive manufacturing was obtained, and it had excellent mechanical properties. The effect of the parameters of the binder jetting additive manufacturing process on the molding quality of the C3S/10PEI composite ceramic slurry was studied. The effect of the printed layer height on the deposition line width and height was explored, resulting in a selection rule for the printing layer height using nozzle diameters. The influence of the number of layers of the printed sample on the height and line width of the sample is studied. Under the condition that the height of the printing layer is 80% of the nozzle diameter and the hot air assisted drying, the maximum error of the forming size is only 3.13%. Finally, the biocompatibility and cell adsorption effect of the scaffold were studied, and it was found that the C3S/PEI scaffold, which was additively manufactured by binder jetting and sintered at low temperature, had good biological properties.