title: Relation between solution properties and degree of acetylation of chitosan: role of aging.
abstract: Aging of solutions of chitosan varying in degree of acetylation (DA) and degree of dissociation (alpha) was studied using two techniques. The first concerned potentiometric experiments performed during 3 days on solutions having the same concentration of amino groups (5.2% < DA < 70.6% and 0 < alpha < 1.1). The presence of aggregates at low alpha certainly depends on electrostatic interactions for low DA values and on hydrophobic interactions and H-bondings for high values. When alpha increases, the role of the cationicity of the amine groups, which depends on DA, seems to play a more important role on the behavior of the polymer chains. The second regarded capillary viscometric experiments performed during 5 days on solutions of the same polymer concentration (5.2% < DA < 70.6% and 0 < alpha < 0.30). The observations mentioned above and the results obtained in a previous paper (Biomacromolecules 2001, 2 (3), 765) are confirmed, and the influence of the electroviscous effects is discussed.
authors.affiliation: Laboratoire des Matériaux Polymères et des Biomatériaux, UMR CNRS 5627, ISTIL, Domaine Scientifique de la Doua, 15 Bd. Latarjet, 69 622 Villeurbanne Cedex, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Sorlier
authors.forename: Christophe
authors.initials: C
authors.lastname: Viton
authors.forename: Alain
authors.initials: A
authors.lastname: Domard
mesh_terms: D000107:Acetylation; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry*; D048271:Chitosan; D004563:Electrochemistry; D012996:Solutions; D013696:Temperature; D014783:Viscosity
chemical_list: D012996:Solutions; D002686:Chitin; D048271:Chitosan