Abstract: The carboxymethyl cellulose were used to reinforce calcium sulfate hemihydrates ( CSH ) to make it more suitable for bone repair. The compressive strength of the composites was evaluated and an optimistic fiber level was concluded. When 3% cellulosic fiber was added to CSH the resulted composite could stand 42 MPa compressive force. By using X-ray diffraction scans and electric scan microscope, the crystal of CSH and distribution of fibers were analyzed. Excessive fibers resulted in the uneven distribution in CSH matrix and creation of calcium sulfate dihydrate, which would decrease the compressive strength of the composites. The result of soaking samples in phosphate buffer solution proved that the anti-washout of CSH obviously improved when carboxymethyl cellulose were introduced.

Key words: calcium sulfate hemihydrate;carboxymethyl cellulose;composite;bone repair material