The Mechanical Properties and Microstructures of Cement Formed from Pyrophosphoric and Orthophosphoric Acids
In this study the setting times, compressive strengths and microstructures of cements formed using pyrophosphoric acid solution and b-tricalcium phosphate (β-TCP; Ca3(PO4)2) were compared with those of cement formed using orthophosphoric acid solution and b-TCP. It was found that cement formed using pyrophosphoric acid solution set more slowly than that formed using orthophosphoric acid and could be mixed to a higher powder to liquid ratio, facilitating the production of cement exhibiting compressive strengths, without pre-compaction, as high as 25 MPa. The use of pyrophosphoric acid as opposed to orthophosphoric acid resulted in a marked change in the microstructure of the cement.
Panjian Li, Kai Zhang and Clifford W. Colwell, Jr.
L. M. Grover et al., "The Mechanical Properties and Microstructures of Cement Formed from Pyrophosphoric and Orthophosphoric Acids ", Key Engineering Materials, Vols. 284-286, pp. 125-128, 2005