Prepolymerized organic-inorganic hybrid nanoparticles as fillers for light-cured methacrylate monomers

VERONICA MUCCI; GUSTAVO F. ARENAS; CLAUDIO J. PÉREZ; CLAUDIA I. VALLO

JOURNAL OF MATERIALS SCIENCE

SPRINGER

Lugar: Berlín; Año: 2012 vol. 47 p. 2951 - 2959

0022-2461

Poly (hydroxyethyl methacrylate)/silica (PHEMA/SiO2) hybrid organic-inorganic nanocomposites were prepared through the simultaneous polymerization of 2-hydroxyethyl methacrylate and tetraethoxysilane. PHEMA/SiO2 materials were obtained as monolithic and transparent films consisting of silica nanoparticles (diameter below 100 nm) surrounded by the PHEMA matrix. The films were crushed into fine powder and the PHEMA/SiO2 particles were used as filler of methacrylate monomers. The polymeric methacrylate present in the PHEMA-SiO2 hybrid particles improves the compatibility of the filler with the methacrylate monomer to be photopolymerized, resulting in enhanced wetting capabilities. The composites prepared from PHEMA/SiO2 prepolymerized particles offer the possibility of reduced polymerization shrinkage without severe reductions in flow characteristics of the precured polymers. The monomer conversions of composites prepared with either 30 wt% or 60 wt% PHEMA/SiO2 particles were similar. This indicates that the penetration of visible radiation into the sample is not reduced significantly by the presence of the filler.