Nnabuk Okon Eddy^{1, 2,}, Inemesit Udofia¹, Adamu Uzairu¹, Anduang O. Odiongenyi², Clement Obadimu²

Analysis of physicochemical properties of Eucalyptus citriodora gum revealed that the gum is mildly acidic, brownish in colour, ionic and has the potentials to swell four times its original volume. GCMS analysis of the gum indicated the presence of some carboxylic acids, pyran-4-one, 1,3-dioxolane, benzofuran and 1,2-ethanediyl acetate while analysis of its FTIR spectrum revealed functional groups that are common to polysaccharides. Scanning electron micrograph of the gum also revealed the existence of particle aggregations with some internal bridges within the system. Rheological properties of the gum were found to be affected by pH, concentration, temperature and by the presence of some electrolytes (KCl, CaCl₂, AlCl₃ and urea). Average value of intrinsic viscosity deduced from Huggins and Kraemer plots was 3.51 dL/g while the sum of their constants was 0.36 (i,e< 0.5 and suggested the absence of molecular association). Calculated value of the Power law constant was (b= 0.812) less than unity and pointed to a rod like conformation. From the Master’s curve, the existence of dilute and concentrated regimes, (corresponding to η_sp0α C^1.04 (at C> C*) and η_sp0 α C^0.95 (at C < C*) respectively) was established. Eucalyptus citriodora gum is a shear thinning, non-Newtonian polymer that is characterized by pseudoplastic behavior. The gum has some potentials for use as food additives and for other industrial applications.

Eucalyptus citriodora gum, physicochemical parameters, GCMS, FTIR, SEM, rheology