Glass polyalkenoate cements based on simple CaO-Al<inf>2</inf>O<inf>3</inf>-SiO<inf>2</inf> glasses

Abstract

© 2015 Institute of Materials, Minerals and MiningGlass polyalkenoate/ionomer cements formed from reacting CaO-Al2O3-SiO2 glasses with aqueous poly(acrylic acid) were investigated. Five glasses were investigated based on (1-X)CaO(1-X)Al2O3(2+2X)SiO2 (0≤X≤0.36) with varying Al/Si ratios. The cement properties were found to be highly dependant on the Al/Si ratio of the glass. The setting and working times of the cements decreased, while the compressive strength increased with Al/Si ratio. Fourier transform infrared spectroscopy showed that rate of set defined as change of the ratio of the carboxylate to carboxylic acid absorption bands up to first hour of the setting increased with increasing Al/Si ratio. 27Al magic angle spinning nuclear magnetic resonance (MAS-NMR) showed that the ratio of Al(VI)/Al(IV) in the cements increased with the Al/Si ratio of glass in presence of tartaric acid. The reactivity of these glasses increased with increasing Al/Si ratio consistently with the rate controlling role of acid hydrolysis of Al-O-Si bonds in the setting of the cements.