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Journal of Chemistry
Volume 2013, Article ID 254347, 10 pages
http://dx.doi.org/10.1155/2013/254347
Research Article

Rheological Modeling and Characterization of Ficus platyphylla Gum Exudates

1Department of Chemistry, Ahmadu Bello University, Samaru Campus, Zaria, Kaduna State, Nigeria
2Department of Chemistry, School of Mathematical and Physical Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa

Received 5 April 2012; Revised 9 June 2012; Accepted 18 June 2012

Academic Editor: Peter R. Chang

Copyright © 2013 Nnabuk O. Eddy et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Ficus platyphylla gum exudates (FP gum) have been analyzed for their physicochemical parameters and found to be ionic, mildly acidic, odourless, and yellowish brown in colour. The gum is soluble in water, sparingly soluble in ethanol, and insoluble in acetone and chloroform. The nitrogen (0.39%) and protein (2.44%) contents of the gum are relatively low. The concentrations of the cations were found to increase according to the following trend, Mn>Fe>Zn>Pb>Cu>Mg>Cd>Ca. Analysis of the FTIR spectrum of the gum revealed vibrations similar to those found in polysaccharides while the scanning electron micrograph indicated that the gum has irregular molecular shapes, arranged randomly. The intrinsic viscosity of FP gum estimated by extrapolating to zero concentrations in Huggins, Kraemer, Schulz-Blaschke, and Martin plots has an average value of 7 dL/g. From the plots of viscosity versus shear rate/speed of rotation and also that of shear stress versus shear rate, FP gum can be classified as a non-Newtonian gum with characteristics-plastic properties. Development of the Master_s curve for FP gum also indicated that the gum prefers to remain in a dilute domain ( C < C ∗ ), such that 𝜂 s p 𝛼 C 1 . 2 . The apparent activation energy of flow for FP gum (calculated from Arrhenius-Frenkel-Eyring plot) was relatively low and indicated the presence of fewer inter- and intramolecular interactions.