1997 Fiscal Year Final Research Report Summary
Component Design and Property Analysis/Control of Bioactive Cement
| Project/Area Number |
07455268
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | Kogakuin University |
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Principal Investigator |
MONMA Hideki Kogakuin University, Faculty of Engineering, Profesor, 工学部, 教授 (00265951)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Hideo Kogakuin University, Faculty of Engineering, Lecturer, 工学部, 講師 (50100300)
TAKAHASHI Satoshi Kogakuin University, Faculty of Engineering, Lecturer, 工学部, 講師 (10100322)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Calcium phosphate / Apatite / Cement / Biocement / Bioactive Cement / Gypsum / Hydraulicity |
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| Research Abstract |
Water-suspension hydration reactions of high-temperature synthesized (nonequilibrium synthesized) alpha-tricalcium phosphate (alpha-TCP) were a successivereaction above pH 4 and dissolution*precipitation below pH 4. In the case of alpha-TCP+CaHPO_4・2H_2O(DCPD) cement, hydration behavior resembled that of alpha-TCP or typical "dissolution-precipitation" depending on the mixing ratio of the two cement components. The solidification of the cement in wet atmosphere could be prevented under conditions below 30ﾟC and 30% in relative humidity. Using a high free energy of amorphous calcium phosphate (ACP), conditions for the preparation of high-temperature phase alpha-TCP were clarified and discussed about the alpha-TCP's low hydraulicity.
A new process for the preparation of apatite porous hardened body was proposed by using superior hydraulic properties of gypsum hemigydrate (CaSO_4・1/2H_2O). The conversion into apatite in (NH_4)_2HPO_4 solution proceeded from the surface into the inside of hardened gypsum bodies (CaSO_4・2H_2O). Although the separation or cracks between the interface of apatite layr and unreacted gypsum core tended to occur, crack-free conditions were clarified. The convertion reaction was a topo-chemical reaction. Thus obtained apatite hardened bodies had about 60% in porosity and compresive strengsths compared to conventional data.
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