The Impact Of The Curing Liquid On The Physical And Chemical Properties Of (TTCP + MCPM + β-TCP) Bone Cement

Experimental purposes:(1) Calcium phosphate (TTCP)used as raw material of calcium phosphate cement, but laboratory staff has always been troubled by the problem that prepared high-purity TTCP due to high energy consumption and the process unstable, study a process that easily operate and can get high purity powder TTCP. (2) The traditional recipe TTCP + MCPM +β-TCP system bone cement was used in phosphoric acid as a chemical liquid, while the use of other liquid has not been reported, we tried to introduce a variety of chemical liquid, and with different chemical liquid bone cement research to explore the impact of physical and chemical properties of other chemical liquid bone cement to such a system, it is to provide the fundamental basis for the system of this bone cement's further biological experiments.Experimental methods:(1) The TTCP powder was synthesised by solid-solid reaction and the characteristics of the powders were determined by self-infrared spectroscopy (FTIR) and XRD; (2) The physical and chemical properties of bone cement with different curing liquid were determined:The solidification time of complex was determined by the Gill Morocco (Gilmore) Determination of needle; The compressive strength of composites was determined by material universal test machine; The degradation rate and compressive strength changes was detemined in simulating physiological environment; The micro-morphology of the bone cement was observated by using scanning electron microscopy (SEM) and its hydration reaction mechanism was descripted.The experimental results:(1) The relatively pure TTCP powder was achieved under the condition of 1 500℃,6h; (2) When the bone cement used Human simulated body fluid (SBF) as a curing liquid, the calcium and phosphorus ratio was 1.67 was higher than 1.5 in compressive strength and setting time; when the volume of the chemical liquid to join was 0.90mL, its maximum compressive strength 12.4Mpa was achieved and setting time was 6min; The compressive strength shows a gradual decreasing trend with the soaking time increases, the hydroxyapatite (HA) is generated ratio is 1.67, the resulting cured product is HA + dicalcium phosphate dihydrate (DCPD) when calcium and phosphorus ratio is 1.5; the degradation rate of 14 days to reach 15.88% when the calcium and phosphorus ratio was 1.67. (3) When the molar concentration is 1.5mol·L-1, the adding volume is 0.70 mL the curing time is 24h, the compressive strength of bone cement witch used citric acid as a chemical liquid and the calcium and phosphorus ratio was 1.67 reaches its maximum 25.4Mpa and the setting time was 3 min; The bigger volume of citric acid added,the more easily generate HA; the degradation rate of 14 days to reach 14.78%. (4) When the joining volume was 2.00 mL, the compressive strength of bone cement witch used PMA as the curing liquid and the calcium and phosphorus ratio was 1.67 reaches its maximum 20.86Mpa, setting time is 7mins, the degradation rate of 14 days to reach 16.21%. The two-phase of generate products are HA and DCPD.Experiment Conclusion: Because of different Ca /P ratio, ratio of powder and liquid curing has great influence on physical and chemical properties of TTCP + MCPM +β-TCP system bone cement, the different bone cement can be modulated according to the actual needs. The Gel properties of TTCP + MCPM +β-TCP system bone cement is fast curing.