IJSRP, Volume 5, Issue 5, May 2015 Edition [ISSN 2250-3153]
Sani I. Alhassan, Paul A. P. Mamza, Aliyu M. Ja’o and Udofia I. Asukwo
Gum Arabic exudate was collected from Acacia Senegal trees around Zaria metropolis. The gum was hydrated in double strength chloroform water, purified in 95% ethanol and then washed with diethyl ether. Modification of the gum was performed with ethanol and Acetic anhydride. Densities of the samples were compared with that of the unmodified gum and it was found that both samples were less dense than the unmodified gum. From turbidity measurement, ethanol modified (EGL) gum appears more turbid than both acetic anhydride modification (AAN) and pure gum (PGM). In salinity, conductivity and total dissolved solid (TDS) tests, acetic anhydride (AAN) sample higher values than other samples. The melting point of ethanol modified (EGL) and PGM are only slightly different, 242oC and 245oC respectively while that of AAN was 229oC. The mechanical properties of the samples were measured using Honsfield Tensometer. The AAN sample has the highest modulus at 10, 20, 30 and 40% gum composition. For PGM the modulus drops from 10-30% gum composition then finally increases. The acetolysis (ACT) modification shows decrease in modulus as the percent of gum increases. Modulus of PGM drops at 20, 40, 60 and 80% gum composition. It was found that the tensile strength of the chemical modification formulations reinforced the polyvinyl chloride matrix at 10%/90%, 20%/80% and 30%/70% gum/PVC compositions for AAN and at 10%/90% and 20%/80% gum/PVC compositions. Though EGL showed increase at 30%/70% composition, its tensile strength is similar to that of the unmodified gum (PGM), decreasing with increasing gum concentration.