Browsing by Author "Araneda, Emilio"

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    Crystallization behavior of PEO in blends of poly(ethylene oxide)/poly(2-vinyl pyridine)-b-(ethylene oxide) block copolymer
    (2012) Araneda, Emilio; Leiva Campusano, Ángel; Gargallo Gómez, Ligia Teresita; Hadjichristidis, Nikos; Mondragon, Inaki; Radić Foschino, Deodato D.
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    New three-arm amphiphilic and biodegradable block copolymers composed of poly(6-caprolactone) and poly(N-vinyl-2-pyrrolidone). Synthesis, characterization and self-assembly in aqueous solution
    (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2007) Leiva, Angel; Quina, Frank H.; Araneda, Emilio; Gargallo, Ligia; Radic, Deodato
    The synthesis, characterization and the self-assembly process of a novel biodegradable block copolymer containing a poly (epsilon-caprolactone), PCL, central block and three poly(N-vinyl-2-pyrrolidone), PVP, arms are reported. Three samples with different amounts of PVP were investigated. The copolymers were characterized by FTIR spectroscopy, H-1 NMR and viscosity measurements. The composition and the molecular weights of the block copolymers were established using size exclusion chromatography SEC and H-1 NMR. Micelle formation by these copolymers was monitored by using the vibrational fine structure of pyrene monomer fluorescence and the critical aggregation concentrations, cac, of the copolymers in aqueous solution were determined using sigmoid Boltzmann-type fitting of the fluorescence data. Dynamic light scattering measurements showed a bimodal size distribution for the copolymers in solution, indicating that the micellization is an intermolecular process. Partitioning coefficients of pyrene between copolymer micelles and water were also determined and increase in magnitude with increasing 8-caprolactone content of the copolymer. (c) 2007 Elsevier Inc. All rights reserved.