A polymer blend from Gum Arabic and Sodium Alginate - preparation and characterization

An environmental friendly biopolymer blend has been fabricated with Gum Arabic (GA) and Sodium Alginate (SA). Three compositions of GA and SA blends coded GASA1 (GA:SA at 1:1), GASA2 (GA:SA at 2:1) and GASA3 (GA:SA at 1:2) has been synthesized. The two polymer phases form completely miscible, thermally stable amorphous multicomponent system which can be used as thermally stable polymeric material in electronic devices. The blends of GA and SA is casted to obtain thin films. Fourier Transform Infrared spectra (FTIR) confirms the formation of blend. The structural analysis and morphology of the synthesized blends has been studied with X- ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. XRD analysis shows that GA has amorphous and SA has semi crystalline nature. The diffraction pattern of the blends indicates that the semi crystalline nature of SA has been disturbed and an amorphous nature is obtained for the blend. SA has a spherical bead like structure and GA forms aggregates of high irregularity in the SEM image. Complete miscibility of the two polymers are seen in the SEM micrograph of the blends. Thermogravimetric-differential thermal analysis (TG-DTA) and differential thermal analysis (DSC) have been performed to study the thermal behavior of the prepared blends. From the TG-DTA analysis, higher onset decomposition temperature is reported for GASA2 which is 8% more than that for pure SA. The exothermic behavior of the blend has been discussed in details.