Influence of α-calcium sulfate hemihydrate particle characteristics on the performance of calcium sulfate-based medical materials

This paper presents a systemic study on the effect of α-calcium sulfate hemihydrate (α-hemihydrate) particle characteristics on the performance of calcium sulfate-based materials (CSBM) that widely used in the medical field. The hydration performance and water requirement for normal consistency of α-hemihydrate were investigated. The mechanical strength, microstructure, and pore structure of the hardened CSBM were also examined. The performance of CSBM was greatly affected by the α-hemihydrate crystal properties. α-Hemihydrate crystals with good gradation and a length/diameter ratio of 1–3:1 tended to have perfect fluidity, lower water requirement for normal consistency, and low crystallization velocity. Moreover, in the hardened CSBM hydrated from such α-hemihydrate crystals, the crystal size of the dehydrate was large, and the crystals were interconnected. The strength of the hardened CSBM was sufficient because of low porosity, small pore diameter, and dihydrate crystals firmly in contact. This study serves as a foundation for preparing high performance for CSBM medical applications.