Síntese, caracterização e estudo de nanômeros de silício como reforço mecânico em resinas acrílicas a base de PMMA
Resumen
The search for improvements in material properties has been studied
extensively and fabrication of polymeric nanocomposites stands out for having
excellent mechanical properties. In this work, silicon nanomers were prepared by solgel
process and grafted in a poly(methyl methacrylate) (PMMA) matrix by powderliquid
polymerization, a very common process in prosthodontic procedures to
polymerize acrylic resins.
Two different types of nanomers were prepared: nanoparticles of silicon
dioxide (NPs SiO2) from the tetraethylorthosilicate (TEOS) as precursor and
molecules of polyhedral oligomeric silsesquioxane (POSS) from the methyl
trimethoxysilane (MTMS), both using the silane coupling agent 3-(trimetoxisilil) propyl
methacrylate (TMSPM) also as precursor. The nanomers were produced at different
concentrations and embedded in the polymeric matrix after 1 and 7 days to form the
PMMA/SiO2 and PMMA/POSS nancomposites. They showed different mechanical
behavior with respect to present concentration in the matrix, for PMMA/SiO2
nanocomposites best results were obtained for flexural strength, flexural modulus,
yield strength and surface microhardness at low concentrations (less than 1%), while
PMMA/POSS with about 1,5% presented better results for flexural strength, flexural
modulus and microhardness. In addition, there was a decline to almost all the
observed results for the nanocomposites prepared after 7 days compared to those
prepared after 1 day, regardless of nanomer and concentration.