Nanostructured poly(lactic acid)/soy protein/HPMC films by electrospinning for potential applications in food industry

Abstract

As an alternative to oil based materials, there is a demand for easily degradable packaging materials. With this regard, the objective of this study is to produce bilayer nanofiber sheets composed of Poly (lactic acid) (PLA) and soy protein, hydroxypropyl methylcellulose (HPMC) and combination of them by using electrospinning. In addition, it was aimed to analyze morphological, optical, thermal properties of films and investigate permeability characteristics. Homogenous nanofibers were successfully collected onto PLA sheets. The solution containing HPMC had the highest viscosity and the lowest electrical conductivity values. Therefore, HPMC based nanofibers had the highest the average diameter values. Combining nanofibers with PLA sheets decreased transparency as compared to the transparency of neat PLA, it also did not improve permeability values. When the thermal properties of PLA/nanofibers were examined it was observed that while PLA sheet showed one stage degradation, bilayer films had two stage degradation. Soy protein containing nanofibers showed higher thermal stability. The FTIR spectrum of PLA/nanofiber sheets displayed the chemical characteristics of both PLA and nanofibers. PLA/nanofiber sheets obtained by electrospinning can be suggested in packaging of light sensitive foods.