Morphology, Isothermal Crystallization Kinetics and Mechanical Properties of Polyvinyl Alcohol/Aloe Vera Electrospun Nanofibers

The present research aims to determine the morphology, crystallization kinetic of PVA with the addition of aloe vera and its relation to mechanical behaviour. PVA/AV membranes were examined under a field emission scanning electron microscope (FESEM). Mechanical properties of PVA/Aloe vera blending systems were studied via tensile test and isothermal crystallization kinetics of PVA in the blends was investigated by means of differential scanning calorimetry (DSC). FESEM micrographs showed that all types of nanofibers produced were smooth, continuous, and free of beads. PVA + 10%AV produced finest fiber size at about 150 nm. The incorporation of Aloe vera into PVA has resulted in decreasing the tensile strength of the PVA/AV nanofibres. By incorporating 5% Aloe vera, the strength has reduced 49%, from 5.93 MPa to 3.01 MPa. Further increments of Aloe vera loading at 10% and 15% have reduced the strength to 2.02 MPa and 1.12 MPa, respectively. At 10 wt% of Aloe vera loading, however, elongation at break was improved. DSC results show that the Avrami equations are applicable to describe the isothermal crystallization kinetics of the PVA and the blend systems. The addition of Aloe vera generally reduces the Avrami index for all crystallization temperatures. Thus, Aloe vera acts as a promoting agent for the axial crystal growth direction by increasing the thermal gradient, however does not show linear correlation with mechanical properties.