Artículo
Synthesis of silsesquioxanes based in (3-methacryloxypropyl)- trimethoxysilane using methacrylate monomers as reactive solvents
Fecha de publicación:
09/2010
Editorial:
Pergamon-Elsevier Science Ltd
Revista:
European Polymer Journal
ISSN:
0014-3057
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The polycondensation of (3-methacryloxypropyl)-trimethoxysilane in acidic conditions using different methacrylate monomers as reactive solvents resulted in incompletely condensed methacrylate-functionalized silsesquioxanes with a very large fraction of intramolecular cycles. UV-MALDI-TOF-MS analysis demonstrated that the species present after 2 weeks of reaction at 60 °C were: T6(OH)2, T7(OH), T8(OH) 2, T9(OH), T10(OH)2 and T 11(OH). Analysis of samples after 30 months of storage at room temperature revealed the presence of T12(OH)2 and T 13(OH) species. The absence of higher molar mass oligomers after prolonged storage periods is attributed to dilution of the reacting medium, which discourages bimolecular reactions that lead to polymer growth. 29Si NMR spectroscopy showed that the conversion in the polycondensation reaction was in the range 0.91-0.96. The methacrylate monomers are not involved in the hydrolysis-condensation reactions with MPTMS and therefore can be polymerized by thermal or photochemical means, thereby cross-linking the preformed nanosized cagelike silsesquioxanes. The formulations containing silsesquioxanes showed a markedly reduced content of extractable monomer after photopolymerization, which makes these resins very attractive for dental filling materials.
Palabras clave:
DENTAL RESINS
,
NANOCOMPOSITES
,
PHOTOPOLYMERIZATION
,
SILSESQUIOXANES
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Licencia
Identificadores
Colecciones
Articulos(CIHIDECAR)
Articulos de CENTRO DE INVESTIGACIONES EN HIDRATOS DE CARBONO
Articulos de CENTRO DE INVESTIGACIONES EN HIDRATOS DE CARBONO
Citación
Asmussen, Silvana Valeria; Giudicessi, Silvana Laura; Erra Balsells, Rosa; Vallo, Claudia Ines; Synthesis of silsesquioxanes based in (3-methacryloxypropyl)- trimethoxysilane using methacrylate monomers as reactive solvents; Pergamon-Elsevier Science Ltd; European Polymer Journal; 46; 9; 9-2010; 1815-1823
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