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Effects of starch gelatinization and oxidation on the rheological behavior of chitosan/starch blends
Author(s) -
Horn Marilia M,
Martins Virginia CA,
Plepis Ana MG
Publication year - 2011
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.3021
Subject(s) - starch , chitosan , rheology , dynamic mechanical analysis , materials science , modified starch , dynamic modulus , chemical engineering , modulus , viscosity , rheometry , composite material , polymer chemistry , chemistry , polymer , organic chemistry , engineering
Chitosan/starch blends represent an interesting alternative for the preparation of biocompatible drug delivery systems, packing materials and edible films. This paper reports on the effects of starch gelatinization and oxidation on the rheological behavior of chitosan/starch blends. The results show that the modifications in the starch structure cause changes in G ′ (storage modulus) and G ″ (loss modulus) as a function of frequency. For chitosan/starch, G ″ is higher than G ′, showing a viscous behavior. However, for chitosan/gelatinized starch and chitosan/oxidized starch, an increase in the angular frequency promotes a modulus crossover at ω = 0.02 and 0.04 rad s −1 , respectively. The viscosity curves as a function of shear rate show that both modifications cause an increase in viscosity, and all blends show a non‐Newtonian behavior. Copyright © 2011 Society of Chemical Industry