GCMS, FTIR, SEM, Physiochemical and Rheological Studies on Albizia zygia Gum

Abstract

GCMS (Gas Chromatography Mass Spectrometry), FTIR (Fourier Transformed Infra-Red Spectroscopy), SEM (Scanning Electron Microscopy), physiochemical and rheological analysis of Albizia zygia gum have been carried out. Albizia zygia exudate is a brownish in colour, acidic and ionic gum. GCMS spectra of the gum indicated the presence of ( E )-methyl octadec-7-enoate (41.18 %), methyl palmitate (18.64 %), methyl stearate (19.13 %), (9 E ,12 E )-methyl octadeca-9,12-dienoate (11.88 %), methyl icosanoate (1.85 %), 2,3-dihydroxypropyl oleate (2.05 %), ( Z )-octadec-13-enal (1.63 %), 2-hydroxy-3-(palmitoyloxy)propyl stearate (1.55 %), 2,3-dihydroxypropyl stearate (0.82 %), dimethyl phthalate (0.58 %) and 3-((aminomethoxy) (hydroxy)phosphoryloxy)propane-1,2-diyl dipalmitate (0.70 %). The FTIR spectrum of the gum indicated several functional groups, including –OH, C-O and C=O. From the scanning electron micrograph, the morphology of the gum shows irregular shapes embedded on the surface. Rheological studies indicated that the viscosity of the gum increased with increasing pH but decreased with an increase in temperature. Application of Huggins, Kraemer and Tanglertpaibul and Rao models indicated that the intrinsic viscosity of the gum is in the range of 0.5 - 0.8. Plots obtained for the variation of viscosity with shear rate and shear rate with shear stress confirmed that Albizia zygia gum is a non Newtonian dilatant polymer with a characteristic shear thickening property.