Potentiometric Titration of Poly (acrylic acid) s with Various Mean molecular Weights in the Presence of Calcium Ion

概要

論文の詳細を見る
The binding of free calcium ions in aqueous solutions of poly (acrylic acid) s (PAAs) with various mean molecular weights (MMWs) were studied by potentiometric titration of their PAAs and a free calcium ion in the solution was measured by the calcium ion electrode. The binding molar ratio between the carboxy group and Ca^<2+> was about 2 : 1 for the PAAs (35×10^4 MMW, 4×10^<-3>M), and about 3 : 1 for the concentration of 8×10^<-3>M. The reaction of the PAAs with Ca^<2+> was affected by the molecular weight and concentration of the PAAs. For example, the precipitation reaction occured, when the concentration of the PAAs with 100×10^4 MMW was 4×10^<-3> M and the concentration of Ca^<2+> in the solution was 8mM and when that of the PAA with 35×10^4 MMW was 8×10^<-3> M and Ca^<2+> was 16mM. Their precipitates contained the unreacted carboxy groups with calcium. The molecular weight and concentration of PAA and the unreacted carboxy groups affected the tensile bond strength of the polycarboxyate cements using poly (acrylic acid), e.g., the bond strength to stainless steel became maximum at about 15×10^4 MMW.
神奈川歯科大学の論文
1998-03-31