Preparation and Characterization of Modified Corn Bract Cellulose/Nano Talcum Powder/Pea Starch Composite Film

The study aimed to develop green degradable food packaging materials. Here, the composite film was prepared by tape casting method, which pea starch (PS) was used as the main film-forming matrix, modified corn bract cellulose (MCBC) and nano talcum powder (NTP) were used as reinforcing material and glycerin was used as plasticizer. The properties of the composite membrane were determined, and the composite membrane was characterized by scanning electron microscope and Fourier infrared spectroscopy. Finally, the thermogravimetric analysis and degradation analysis were carried out. Results showed that, the optimal preparation conditions of composite film including PS 8%, glycerol 2.5%, MCBC 0.8%, NTP 0.15% by using the method of single factor experiments and orthogonal experiment. Under these conditions, the thickness of composite film was 0.042 mm, the transmittance was 32.58%, the tensile strength was 32.48 MPa, the elongation at break was 33.61%, the water vapor transmission was 0.19×10⁻¹⁰ g/(m·s·Pa), the oil permeability coefficient was 0.006 g·mm/m²d, the water absorption rate was 55.79% and the solubility was 18.04%. The results of scanning electron microscopy (SEM) showed that the surface of the composite film was smooth and uniform, and the structure was compact. The results of fourier transform infrared spectroscopy (FTIR) showed that MCBC, NTP and PS were compatible well, and the intermolecular hydrogen bond of them were enhanced. Moreover, the results of thermal gravimetric analyzer (TGA) showed that the decomposition temperature of composite film was 318.12 ℃, and the heat stability of composite film was improved. Degradation analysis also showed that the natural degradation rate of composite film was 96.47% after being buried in soil for 8 days, therefore, the composite film could be biodegraded completely. The study would provide a reference for the application of MCBC/NTP/PS composite film in food industry.