Thermosensitive Copolymers Based on Alginate and Poly(N-isopropylacrylamide) Obtained by gamma-Radiation

M.M.S. LENCINA; N.A. ANDREUCETTI; M.A. VILLAR

Granada

Congreso; European Polymer Congress (EPF 2011); 2011

European Polymer federation

Irradiation is a valuable technique for the modification of physical and chemical properties of polymeric materials. The use of gamma-irradiation methods has advantages, such as relatively simple manipulation and the absence of any extra agents for polymerization and/or crosslinking. Alginate is a linear biopolymer of 1,4-linked â-D-mannuronate (M) and á-L-guluronate (G) residues. N-isopropylacrylamide (NIPAAm) could be polymerized in order to obtain poly(NIPAAm), a thermo-responsive polymer, which shows coil-globule transformation at a lower critical solution temperature (LCST) around 32 °C. The aim of this work is to obtain alginate-PNIPAAm copolymers via irradiation with gamma rays from 60Co with the final goal of synthesized thermoresposive hydrogels.Alginate-PNIPAAm copolymers were obtained by solution irradiation of alginate and NIPAAm monomer. % G is a function of NIPAAm content and % GE is a function of both NIPAAm content and irradiation dose. At higher irradiation dose a gel is produced as consequence of PNIPAAm crosslinking. For this reason, low doses with a low dose rate must be used in order to obtain soluble copolymers.