title: Effect of the lignin type on the morphology and thermal properties of the xanthan/lignin hydrogels.
abstract: This paper reports the morphological and thermal characterization of xanthan/lignin hydrogels. It has been emphasized the effect of the lignin type on the hydrogel properties. The hydrogels described here were obtained by chemical crosslinking, in the presence of epichlorohydrine as a cross-linker agent. The obtained materials were analyzed by AFM, TG/DTG, DSC, and FT-IR spectroscopy. It has been established that hydrogels have a porous morphology. The lignin type influences the hydrogel morphology which is either fibrilar as in case of hydrogel containing aspen wood lignin (which has the highest content of COOH groups and lowest content of phenolic OH groups) or smooth surface for other hydrogels. The specific intermolecular interactions are stronger in the case of 70 xanthan (X)/30 aspen wood lignin (AWL) hydrogel. The thermal properties of the hydrogels also depend on lignin type, the lowest thermal stability being found for the hydrogel containing lignin with the highest content of functional groups (AWL).
authors.affiliation: Petru Poni Institute of Macromolecular Chemistry of Romanian Academy, Department of Physical Chemistry of Polymers, 41A Gr. Ghica Voda Alley, Iasi-700487, Romania. iecoj@icmpp.ro
authors.forename: Irina Elena
authors.initials: IE
authors.lastname: Raschip
authors.forename: Gabriela Elena
authors.initials: GE
authors.lastname: Hitruc
authors.forename: Cornelia
authors.initials: C
authors.lastname: Vasile
authors.forename: Maria-Cristina
authors.initials: MC
authors.lastname: Popescu
mesh_terms: D002152:Calorimetry, Differential Scanning; D020100:Hydrogels / Q000737:chemistry*; D008031:Lignin / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature; D013818:Thermogravimetry; D014934:Wood / Q000737:chemistry
chemical_list: D020100:Hydrogels; D011135:Polysaccharides, Bacterial; D008031:Lignin; C002563:xanthan gum