Artículos de revistas
Thermoresponsive hydrogels based on alginate-g-poly(N-isopropylacrylamide) copolymers obtained by low dosis of gamma radiation
Fecha
2015-04-17Registro en:
Lencina, María Malvina Soledad; Ciolino, Andrés Eduardo; Andreucetti, Noemi Amalia; Villar, Marcelo Armando; Thermoresponsive hydrogels based on alginate-g-poly(N-isopropylacrylamide) copolymers obtained by low dosis of gamma radiation; Elsevier; European Polymer Journal; 68; 17-4-2015; 641-649
0014-3057
CONICET Digital
CONICET
Autor
Lencina, María Malvina Soledad
Ciolino, Andrés Eduardo
Andreucetti, Noemi Amalia
Villar, Marcelo Armando
Resumen
Low doses of gamma radiation from 60Co have been used in the synthesis of water soluble alginate-g-poly(N-isopropylacrylamide) (PNIPAAm) copolymers. Irradiation was carried out using glass vials containing aqueous solutions of alginate and NIPAAm monomers. The resulting copolymers have been characterized by different characterization techniques such as Fourier transform infrared spectra, 1H Nuclear Magnetic Resonance, elemental analysis and thermogravimetric analysis. NIPAAm concentration in the initial reaction mixture and irradiation dose evidenced a direct effect on the grafting percentage; an increasing in NIPAAm concentration in the initial reaction mixture always led to a higher content of grafted PNIPAAm in the copolymers. On the other hand, for a fixed NIPAAm concentration in the reaction mixture, the amount of PNIPAAm in the copolymer increased with the dose. Copolymers were used in hydrogels formation by cross-linking alginate carboxylic groups with Ca2+and swelling properties of the new materials were studied at 24 °C and 37 °C. Hydrogels presented thermo-sensitivity, showing lower swelling ratios at 37 °C. Hydrogel water uptake was hindered as a consequence of the collapsed state of PNIPAAm moieties in the copolymers.