Properties in Solution of Bototo Gum Exudate (Cochlospermum vitifolium). Salt Effects.

The properties in solution of bototo gum exudate ( Cochlospermum vitifolium ) were studied. There were measured the intrinsic viscosities of the polymer under study in water, in NaCl (at different concentrations) and in NaCl, CaCl 2 and AlCl 3 , at the same ionic strength (I = 1) using an Ubbelohde viscometer at 25 ° C. The Huggins intersection model (R 2 ) is better fitted to the intrinsic viscosity calculation than the Kraemer's equation. This parameter tends to decrease as a result of the increase of the concentration of a cosolute and the ion charge. The molecules of C. vitifolium gum exudate in water (solvent Φ) tend to adopt a “random coil” conformation, of great volume and radius, that prefer to exist in two regimes: diluted and semi-diluted (in which the overlap it is probably not enough to form a lattice or network); in the presence of salts, the coils exist only in a diluted regime where they are separate each other. These macromolecules in water have probably an ellipsoid shape, more extended, but in presence of salts, change their shape to another more compact, probably spherical, with radii and smaller volumes. The knowledge of the behavior of C. vitifolium gum molecules in solution is an important criterion for their rational use in various industries