Determination of the Mark-Houwink equation for chitosans with different degrees of deacetylation.
The values of k and alpha in the Mark-Houwink equation have been determined for chitosans with different degrees of deacetylation (DD) (69, 84, 91 and 100% respectively), in 0.2 M CH3COOH/0.1 M CH3COONa aqueous solution at 30 degrees C by the light scattering method. It was shown that the values of alpha decreased from 1.12 to 0.81 and the values of k increased from 0.104 x 10(-3) to 16.80 x 10(-3) ml/g, when the DD varied from 69 to 100%. This is due to a reduction of rigidity of the molecular chain and an increase of the electrostatic repulsion force of the ionic groups along the polyelectrolyte chain in chitosan solution, when the DD of chitosan increases gradually.
Wang
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Polymer Physics Laboratory, Changchun Institute of Applied Chemistry, Academia Sinica, People's Republic of China.
Bo
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SQ
Li
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Qin
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W
D000107:Acetylation; D000818:Animals; D003386:Brachyura; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry; D048271:Chitosan; D006860:Hydrogen Bonding; D008970:Molecular Weight; D009391:Nephelometry and Turbidimetry; D014783:Viscosity
D002686:Chitin; D048271:Chitosan