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Oct
Intrinsic Viscosity Molecular Weight. The increase in viscosity is caused by strong internal friction between the randomly coiled and swollen macromolecules and the surrounding solvent molecules. IV is based on the flow time of a polymer solution through a narrow capillary relative to the flow time of the pure solvent through the capillary. The intrinsic viscositymolecular weight relationship for chitosan was determined in 025 M acetic acid025M sodium acetate. THE MOLECULAR WEIGHT OBTAINED IS VISCOSITY.
Absolute molecular weights were measured by light scattering and membrane osmometry. Chitosan samples with a degree of acetylation DA between 20 and 26. The units of IV are typically reported in deciliters per gram dLg. IV is simple and inexpensive to obtain and reproducible between different laboratories. Intrinsic viscosity and molar mass The intrinsic viscosity of a polymer in a certain solvent can be correlated with the molar mass via the Mark-Houwink equation. The intrinsic viscositymolecular weight relationship for chitosan was determined in 025 M acetic acid025M sodium acetate.
Conversely intrinsic viscosity is a good practical measure of weightaverage molecular weight up to a ratio of 10 for weighttonumber average.
IV is simple and inexpensive to obtain and reproducible between different laboratories. Intrinsic Viscosity and Molecular Weight The observed intrinsic viscosity may be obtained from η η lim c c KM c c sp i a i 0 i Since c c c c ii i i the weight ratio is w w w w ii i i η KwM w iiKWM a i i i i i i and a. IV is based on the flow time of a polymer solution through a narrow capillary relative to the flow time of the pure solvent through the capillary. The intrinsic viscosity for the uncleaved polymer was calculated to be 18200541 cm3g while the intrinsic viscosity for the cleaved polymer was 0686800834 cm3g. Terms Related to Viscosity Measurements-. How much a polymer increases the viscosity of a solvent will depend on both the nature of the.