Rheological Modeling of Interaction Existing between Synergistic Combination of Gum Arabic and Khaya senegalensis

Abstract

An Ubbelohde viscometer was used to study the miscibility properties of Khaya senegalensis (KS gum) and Acacia senegal (AS gum) blends in dilute solution when the blends were subjected temperature rise, increase in concentration and as well as on effect of some inorganic salts. The intrinsic viscosity and the elasticity of the gums were evaluated. Molecular conformation of the blend AS-KS was also assessed by the power law and  20% AS–80% KS blend was found to exhibit the strongest attraction between Khaya gum and gum Arabic molecules since the blend had the highest value of intrinsic viscosity value determined, while 60% AS–40% KS blend had the least attraction as evidenced by the polymer miscibility coefficient a, the elastic component and a positive Huggins coefficient Km  found to be less than one, which indicates absence of aggregation in the blend. The power-law model was successfully employed in the predicting the molecular conformation of AS and KS in dilute solution as they were found to have random coil conformation. Their hydrodynamic interaction value bm1 indicates that the blends become more soluble in water when more concentration of gum Arabic is added to the blends. The power-law coefficient b was found to have an indirect relationship with a rising addition of the KS fraction in the blends, suggesting a more flexible AS-KS complex dependent on KS. FTIR and other analysis were carried out, these includes rheological study on the gum with corresponding effects from increased temperature and effects of salts.