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Hydrophilic and morphological aspects of films based on quaternary salts of chitosan for edible applications
Author(s) -
de Britto Douglas,
Assis Odilio B.G.
Publication year - 2010
Publication title -
packaging technology and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.365
H-Index - 50
eISSN - 1099-1522
pISSN - 0894-3214
DOI - 10.1002/pts.884
Subject(s) - wetting , swelling , contact angle , chitosan , homogeneity (statistics) , polymer , alkyl , chemical engineering , materials science , polymer chemistry , coating , moiety , solubility , alkylation , surface finish , chemistry , composite material , organic chemistry , statistics , mathematics , engineering , catalysis
Aiming to improve the homogeneity of films based on chitosan to be applied as edible coating, we carried out some chemical modifications in the polymeric structure by reductive alkylation and quaternization reactions. The resulting derivatives had different hydrophilic behaviours and cast films were characterized by wetting, swelling and topographic measurements. Concerning wetting, all samples presented similar time dependence with receding water contact angles. The quaternized chitosans were the most hydrophilic derivatives, with lower values of contact angles when compared with the parent sample. These derivatives also exhibited a higher swelling tendency. The analysis shows that the relative amount of absorbed water increases according to the length of moiety added. In general, the cast films of chitosan showed good homogeneity, displaying low roughness and regular distribution over a polar surface. On the other hand, alkyl quaternary salts showed an irregular topography with undulation and mountain‐like formation due probably to agglomeration of polymeric chains. The final film morphology was dependent on the polymer solubility, as observed by microscopic techniques. Copyright © 2010 John Wiley & Sons, Ltd.