Preparation and characterization of poly(vinyl alcohol) and 1,2,3-propanetriol diglycidyl ether incorporated soy protein isolate-based films

Novel biodegradable films were prepared from soy protein isolate (SPI), poly(vinyl alcohol) (PVA), glycerol, and 1,2,3-propanetriol diglycidyl ether (PTGE). The mechanical, hydrophilic, and compatible properties of the films were investigated. The influence of PTGE as a crosslinker on the properties of the SPI/PVA/PTGE films was examined with Fourier transform infrared spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis, mechanical analysis, contact angle measurements, and scanning electron microscopy. XRD and contact angle examination confirmed that the addition of PTGE altered the film microstructure to a crystalline one. The mechanical properties and water resistance of the SPI/PVA/PTGE films increased notably compared with those of the unmodified SPI films. All results indicate that the networks were formed between SPI and PTGE and played an important role in forming a homogeneous structure in the obtained films. The novel biodegradable films provide a convenient and promising way for preparing environmentally friendly film materials. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42578.