Effect of glycerol on solution properties governing morphology, glass transition temperature, and tensile properties of electrospun zein film

An attempt was made to improve the tensile strength and elongation of electrospun zein film by addition of a plasticizer, namely, glycerol to the film forming solution. A surfactant viz. Tween®40 and NaCl were also added into the film solution to facilitate the electrospinning process. The effect of glycerol content on selected zein solution properties, i.e., surface tension, electrical conductivity, and viscosity, which in turn affect the mechanical property, morphology, and glass transition temperature (Tg) of the film were investigated. Morphology of the electrospun film was examined via scanning electron microscopy (SEM), whereas the film component was characterized by Fourier transform infrared (FTIR) spectroscopy. It was observed that as the glycerol content increased, the diameter of the electrospun fiber increased as a result of decreasing electrical conductivity with increasing surface tension of the solution. The flow‐behavior index of the solution indicated that glycerol had a significant impact on the solution flow property, hence improved fiber diameter uniformity. Besides, the tensile strength and elongation of the film were improved as glycerol content increased, but the reverse was noted at 10 wt %. Tg of the zein film decreased as the glycerol content increased.