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SYNTHESIS, THERMAL BEHAVIOR, AND AGGREGATION IN AQUEOUS SOLUTION OF POLY(METHYL METHACRYLATE)-B-POLY(2-HYDROXYETHYL METHACRYLATE)
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Archivos
Fecha
2013-12
Autores
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
Sociedad Chilena de Química
Nombre de Curso
Licencia CC
Licencia CC
Resumen
Amphiphilic block copolymers of poly(methyl methacrylate) PMMA and poly(2-hidroxyethyl methacrylate) PHEMA were synthesized by a two-step atom transfer radical polymerization (ATRP). Copolymers with various degrees of polymerization and different relative block sizes were obtained. The structure of the resulting polymers have been characterized and verified by FT-IR and 1H-NMR, molecular weight were determined by size exclusion chromatography analyses. The thermal properties of these polymers were investigated by differential scanning calorimetry DSC and thermogravimetric analysis TGA. The glass transition temperature of mono halogenated PMMA increases from 116 °C to 123 °C with increasing molecular weight, whereas the glass transition temperature of block copolymers depends slightly on polymer structure. The derivatives of TGA curves indicate that thermal degradation occurs in one stage. The self-assembly of PMMA-b-PHEMA in aqueous solution have been investigated by fluorescence probing methods. The critical micelle concentrations are in the range 10-6 - 10-7 M. The micropolarity sensed by pyrene is higher than in aggregates formed by block copolymers based on polystyrene.
Notas
Indexación: Web of Science; Scielo.
Palabras clave
Block copolymers, Glass transition temperature, Thermogravimetric analysis, Critical micelle concentration, Fluorescence probing methods
Citación
J. Chil. Chem. Soc. vol.58 no.4 Concepción Dec. 2013