fulltext.study @t Gmail

Influence of setting liquid composition and liquid-to-powder ratio on properties of a Mg-substituted calcium phosphate cement

Paper ID Volume ID Publish Year Pages File Format Full-Text
1525 85 2009 8 PDF Available
Title
Influence of setting liquid composition and liquid-to-powder ratio on properties of a Mg-substituted calcium phosphate cement
Abstract

The influence of four variables on various properties of a Mg-substituted calcium phosphate cement (CPC) was investigated. The variables were the heat treatment temperature of the precipitated powders, the composition of the setting liquid, the liquid-to-powder ratio (LPR), and the time over which hardened specimens were cured in air. The properties analysed were the phase composition of the starting powder, the initial setting time, the evolution of the storage shear modulus (G′) and the loss shear modulus (G″) with the cement paste curing time (t), and the compressive strength. The presence of α-TCP in CPC facilitated the setting and hardening properties due to its progressive dissolution and the formation of brushite crystals. As far as the liquid composition is concerned, in cases where citric acid was used, adding a rheology modifier (10 wt.% polyethylene glycol or 0.5 wt.% hydroxyl propylmethylcellulose) to the acid led to an increase in the initial setting time, while an increase in the acid concentration led to a decrease in the initial setting time. The initial setting time showed to be very sensitive towards the LPR. The evolution of G′ and G″ with curing time reflected the internal structural changes of cement pastes during the setting process. The compressive strength of the wet-hardened cement specimens with and without Mg increased with curing time increasing, being slightly higher in the case of Mg-substituted CPC. The results suggest that Mg-substituted CPC holds a promise for uses in orthopaedic and trauma surgery such as for filling bone defects.

Keywords
Magnesium; Calcium phosphate; Cement; Rheology; Setting time
First Page Preview
Influence of setting liquid composition and liquid-to-powder ratio on properties of a Mg-substituted calcium phosphate cement
Publisher
Database: Elsevier - ScienceDirect
Journal: Acta Biomaterialia - Volume 5, Issue 4, May 2009, Pages 1233–1240
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering