Cement formation by microbial poly(γ-glutamic acid) and fluoroalumino-silicate glass

• Published in: Materials letters Vol. 59; no. 24-25; pp. 3188 - 3191
• Main Authors: Ledezma-Pérez, A.S., Romero-García, J., Vargas-Gutiérrez, G., Arias-Marín, E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2005
• Subjects: Acid-base cements; Composite materials; Glass ionomer cements; Mechanical properties; Poly(γ-glutamic acid); Mechanical properties; Glass ionomer cements; Composite materials; Acid-base cements; Poly(γ-glutamic acid)
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2005.05.048

The feasibility of using microbial poly(γ-glutamic acid) (γ-PGA) in cement formation was analyzed. FT–IR and elemental analyses by energy-dispersive spectroscopy (EDS), indicate that calcium and aluminum carboxylates are formed after the reaction of γ-PGA with fluoroalumino-silicate glass powder. The effect of the formulation variables, i.e., (polymer+glass)/liquid ratio (P/L), glass/polymer ratio (G/P), the average glass particle size and the molecular mass of γ-PGA, on the compressive strength is discussed. A maximum compressive strength value of 130 MPa was obtained when cement samples were aged for 7 days. The compressive strength was achieved with a P/L ratio of 2.5 g/ml, a G/P ratio of 2.5:1, an average glass particle size of 1 μm and a γ-PGA molecular mass (M ¯w) of 115000.