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• Double-stranded, stiff structure
• May dissociate into more flexible single strands at high T
(depends on I (ionic strength))
• Very high M
w
(typically > 10
6
g/mol)
• q (persistence length) = ca. 120 nm
• Important industrial polysaccharide (E415): Viscosifyer
1,000 10,000 100,000 1,000,00010,000,000
M
w
1
10
100
1,000
10,000
Intrinsic viscosity (ml/g)
I = 0.1 M
Xanthan
(double stranded)
Alginate
(mannuronan)
Lignosulfonate
Xanthan: Macromolecular properties
Xanthan: Shear thinning
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Milas et al. Polymer Bulletin 14, 157 (1985)