Synthesis, Characterization and Biodegradation of Gum Arabic-based Bioplastic Membranes

Abstract

Gum Arabic (GA) collected from Acacia senegal trees was used with polyvinyl alcohol (PVA) to prepare a series biodegradable membranes. Great success was achieved for production of transparent bioplastic membranes by applying a novel casting method termed as free horizontal flow. The similarities between the six FTIR spectra in their principal peaks are due to their common functional groups. The broad pattern of the GA diffractogram obtained confirmed the amorphous nature of the GA, while the relatively sharpness of the PVA confirmed its semi-crystallinity.The crystallinity index (CI) values were increased with the increasing in the PVA allocation in the blend. Thermal degradation of the samples occurred at the higher temperatures (300-500°C) were greater than those for the lower temperatures (25-300°C). The PVA lost more weight than that for the GA at higher temperatures.The overall energy absorbed up to 500°C and subsequently thermal stability of the bioplastic membranes were increased as the PVA allocation in the blend is increased although the mass loss has the same trend. The GA membranes had the lowest nanometric particle size (NPS), while those for PVA had the highest ones. Increasing the PVA concentrations in the blends increased the NPS gradually. The bioplastic membranes were degraded by the isolated bacteria and fungi comparing with control samples. The major strains of isolated bacteria were Pseudomonas spp. and Bacillus spp., while Rhizobus spp was the major fungus. Addition PVA to GA enhanced the membranes formation and their properties such as crystallinity index, thermal stability and surface roughness.