title: New three-arm amphiphilic and biodegradable block copolymers composed of poly(epsilon-caprolactone) and poly(N-vinyl-2-pyrrolidone). Synthesis, characterization and self-assembly in aqueous solution.
abstract: 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, (1)H NMR and viscosity measurements. The composition and the molecular weights of the block copolymers were established using size exclusion chromatography SEC and (1)H 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 epsilon-caprolactone content of the copolymer.
authors: Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 302, Correo 22, Santiago, Chile. aleivac@puc.cl
authors: Angel
authors: A
authors: Leiva
authors: Frank H
authors: FH
authors: Quina
authors: Emilio
authors: E
authors: Araneda
authors: Ligia
authors: L
authors: Gargallo
authors: Deodato
authors: D
authors: Radić
mesh_terms: D008027:Light; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis*; D011145:Polyvinyls / Q000737:chemistry*; D011759:Pyrrolidines / Q000737:chemistry*; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D008823:Micelles; D011091:Polyesters; D011108:Polymers; D011145:Polyvinyls; D011759:Pyrrolidines; C505150:poly(N-vinylpyrrolidine); C016240:polycaprolactone