title: Original stimuli-sensitive polysaccharide derivatives/N-isopropylacrylamide hydrogels. Role of polysaccharide backbone.
abstract: This article compares the properties of a novel class of unsaturated Xanthan and Gellan derivatives/N-isopropylacrylamide stimuli-responsive hydrogels synthesized by free radical polymerization. Xanthan and Gellan Gum were partially functionalized by esterification with maleic anhydride under various conditions. By copolymerization of these maleate polysaccharides with a N-isopropylacrylamide known temperature sensitive precursor, water-swollen hydrogels with interpenetrating polymer networks (IPN) were obtained. The hydrogels were characterized for their temperature and pH-responsive behaviour by equilibrium swelling experiments and differential scanning calorimetry. The investigation of these materials also includes solid-state (13)CP/MAS NMR and elemental analysis of the nitrogen content. Morphology was visualized by scanning electron microscopy. Depending upon composition and the nature of the base-polysaccharide, the hydrogels showed different response rates to the external changes of temperature as well as pH. By changing the feed composition ratio of precursors and crosslinking agent (β-cyclodextrin acrylate or N,N'-methylenebisacrylamide respectively) the phase transition temperature (lower critical solution temperature) could also be adjusted near to the body temperature for biomedical and biotechnological applications. The role of the rigidity and the charge density of the polysaccharide chain, its ability to form hydrogen bonding on these properties are more particularly considered.
authors.affiliation: "Gheorghe Asachi" Technical University, Faculty of Chemical Engineering and Environment Protection, Department of Natural and Synthetic Polymers, Bd. Prof. dr. docent Dimitrie Mangeron, nr. 73, 700050 Iasi, Romania; Université de Pau et des Pays de l'Adour, Hélioparc Pau Pyrénées - IPREM - 2, av. Président Angot, 64053 Pau Cedex 09, France; Université de Haute Alsace, Laboratoire de Photochimie et Ingénierie Macromoléculaires - Ecole Nationale Supérieure de Chimie de Mulhouse, 3 rue Alfred Werner, 68093 Mulhouse Cedex, France.
authors.forename: Mihaela
authors.initials: M
authors.lastname: Hamcerencu
authors.affiliation: Université de Pau et des Pays de l'Adour, Hélioparc Pau Pyrénées - IPREM - 2, av. Président Angot, 64053 Pau Cedex 09, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Desbrieres
authors.affiliation: "Gheorghe Asachi" Technical University, Faculty of Chemical Engineering and Environment Protection, Department of Natural and Synthetic Polymers, Bd. Prof. dr. docent Dimitrie Mangeron, nr. 73, 700050 Iasi, Romania.
authors.forename: Marcel
authors.initials: M
authors.lastname: Popa
authors.affiliation: Université de Haute Alsace, Laboratoire de Photochimie et Ingénierie Macromoléculaires - Ecole Nationale Supérieure de Chimie de Mulhouse, 3 rue Alfred Werner, 68093 Mulhouse Cedex, France.
authors.forename: Gérard
authors.initials: G
authors.lastname: Riess
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D000179:Acrylates / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008299:Maleic Anhydrides / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D013696:Temperature
chemical_list: D000178:Acrylamides; D000179:Acrylates; D003432:Cross-Linking Reagents; D020100:Hydrogels; D008299:Maleic Anhydrides; D011135:Polysaccharides, Bacterial; C048288:gellan gum; C067295:N-isopropylacrylamide; C021221:N,N'-methylenebisacrylamide; C002563:xanthan gum