چكيده به لاتين
In this study the novel hydroxyapatite/carboxymethyl chitosan/dextrin/polyvinyl pirrolidone composites were printed through binder jetting technique. In binder jetting process, the solid is created by the reaction of a liquid selectively sprayed onto a powder bed. The aim of this research is looking at the link between key powder parameters (particle size, particle size distribution, flowability) and printing accuracy to preparation a printable powder. Ceramic and polymers powder with different weight ratio were mixed in two dry and wet methods. The powder was then characterized to evaluate the printability. Result showed that the combination of 60% hydroxyapatite. 28% carboxymethyl chitosan, 10% dextrin and 2% polyvinyl pirrolidone, having size witdth in the range of 2.28 is the most printable composition. A cylindrical composite sample was printed using this compositon. Then proceesing was carried out using flash dipping in chitosan solution to increase strength. Characterization of these samples was performed by scanning electron microscopy (SEM), infrared Fourier transform (FTIR) spectroscopy, X-ray diffraction (XRD) and compressive strength test. SEM observation showed pores with pore diameters in the range of 40-130 µm. FTIR and X-ray diffraction results demonstrated the composite components. The mechanical properties of components such as compressive strength and modulus of elasticity increased from 3.1 and 10 MPa to 7.4 and 125 MPa, respectively by flash dipping in chitosan solution compared to the printed sample without any processing operations. Also, the porosity percentage of all printed parts was in the range of 40-45%, which decreased to 30-36% after flash dipping in chitosan solution.
Keywords: Binder Jetting, Hydroxyapatite, Carboxymethyl Chitosan, Printability, Optimization powder parameters
