Preparation and characterization of hydrogels based on homopolymeric fractions of sodium alginate and PNIPAAm

► Copolymerization of poly-l-guluronic acid with semi-telechelic PNIPAAm was achieved. ► Association of poly-d-mannuronic acid and PNIAAm afforded porous semi-IPN hydrogels. ► Surface morphology of hydrogels was studied by SEM. ► Graft copolymers hydrogels showed better water retention than semi-IPN hydrogels.