Preparation And Characterization Of PTGE Cross-linking Enhanced Soy Protein-based Film

Plastic packaging materials aredifficult to be degraded, causing environmental pollution easily. Interest has recently arisen in developing alternative packaging materials with good performance and pollution-free property. As a new and green packaging film material, soy protein isolate film (SPI) material has many advantages including good biodegradation and superior film-forming capacity. However, the weak water resistance and poor mechanical properties of the SPI films limited their applications. In order to address these drawbacks, SPI based films were prepared using PTGE as a crosslinking agent, together with PVA or PAM. The properties of the films were examined by the Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TG) and Scanning electron microscope (SEM). The results were drawnas follows:(1)The introductionof PVA reduced the amino content of composite films, improved the crystallinity, formedhydrogen bond between soyprotein isolate and PVA, thus the thermal stability, mechanical properties and water resistence of the film was improved. After adding PVA and PTGE, the crosslinking reaction happened between SPI, PVA and PTGE, the thermal stability and the surface hydrophilicity increased significantly, as the mechanical properties and water resistance.(2)PAM had good compatibility with soy protein isolate, which could form hydrogen bond, so that the thermal stability, mechanical properties and water resistance increased significantly; PAM and PTGE caused a larger influence on the structure of the composite film. The crystallization peakof composite film became sharp and narrow, the crosslinking reaction happened between SPI, PAM and PTGE, whichmadethe thermal stability, mechanical properties and water resistance improved.