Cellulose/Soy Protein Isolate Blend Films Prepared via Room-Temperature Ionic Liquid

An ionic liquid (IL), 1-ally-3-methylimidazolium chloride (AmimCl), was used as cosolvent for cellulose and soy protein isolate (SPI) to prepare different compositions of cellulose/SPI blend films, which were coagulated under a nonsolvent condition. The structures of the blend films were investigated by Fourier transform infrared (FTIR) spectrum, X-ray diffraction (XRD), scanning electron microscope (SEM), and transparence analysis, and the physical properties of the films such as mechanical properties, water resistance, water vapor permeability, gas permeability, and thermal stability were also examined. The results indicate that cellulose/SPI blends have excellent miscibility in all weight ratios of cellulose to SPI. With the increase of cellulose content in blend films, the tensile strength, elongation at break, water resistance, and thermal stability of the cellulose/SPI blend films all increase. The addition of the cellulose results in a decrease in the water vapor permeability values. In addition, all films have high gas barrier capacities. These films appear to have the potential as packing and/or coating materials, replacing synthetic polymer films.