Characterization of sintered TCP sheets with various contents of binder prepared by tape-casting technique

Objectives The purpose of this study was to investigate the effect of binder content on the characterization of sintered tricalcium phosphate (TCP) sheets prepared by the tape-casting technique. Methods Poly(acrylic acid)-based binder was added at four contents: 5, 10, 15, or 30 mass%, to a β-TCP aqueous slurry. The TCP green sheets were fabricated with the prepared TCP slurry by the tape-casting technique, and were sintered at 1200 °C for 2 h. The sintered TCP sheets were characterized by field-emission scanning electron microscope (FE-SEM) observation, X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectrometry. Apatite precipitation on the sintered TCP sheet surface in Hanks’ balanced salt (HBS) solution at pH 7.4 was monitored over 14 days at 37 °C. Results A TCP green sheet with 5 mass% binder content had insufficient flexibility before sintering, and that with 30 mass% binder content had a problem in controlling the viscosity of slurry. FE-SEM observation showed that no differences in grain size existed in the various sintered TCP sheets. Measurement of XRD and FT-IR showed the presence of α-TCP phase in the various sintered TCP sheets, and same crystallographic structure was observed among various sintered TCP sheets. After 14 days immersion in HBS solution, the surfaces of sintered TCP sheets were completely covered with precipitated apatite crystals. Significance The binder content of 10 or 15 mass% is suitable for sintering TCP sheets. The sintered TCP sheet prepared by the tape-casting technique is a promising material as bone substitute.