Songklanakarin Journal of Science and Technology (SJST) (Aug 2013)
Improving flexural strength of resin modified glass-ionomer cement by poly(alkenoic acid) modifications
Abstract
Poly(alkenoic acid)s based on copolymers of acrylic acid and itaconic acid were synthesized and further modifiedwith glutamic acid (Glu) and glycidyl methacrylate (GMA). The resultant polymers were characterized by means of protonnuclear magnetic resonance, gel permeation chromatography, and elemental analysis. Specimens of resin modified glassionomer cement (RMGIC) prepared from the cement-forming reactions between the synthesized polymers and a commerciallyreactive glass were fabricated and investigated for flexural strength using three-point bending test. The effects of differentamounts of Glu and GMA on the flexural strength were evaluated. The results showed significantly improved cement strengthdue to the incorporation of Glu into the copolymer with an optimal feed of Glu and GMA at 0.1-0.2 and 0.4 per mole ofcopolymer, respectively. The addition of 2-hydroxyethyl methacrylate (HEMA) to the RMGIC formulations tremendouslyincreased the cement strength. In this study, a formulation containing 20%-wt. of HEMA and 45%-wt. of polymer concentration gave the highest flexural strength with 62.7±3.4 MPa.
