Toughened and water-resistant starch/TiO2 bio-nanocomposites as an environment-friendly food packaging material

Poor mechanical properties and moisture sensitivity limit the application of starch-based bio-material. Starch/titanium dioxide (TiO2) bio-nanocomposites were prepared by blending. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) results stated that more stable hydrogen bonds formed between nano-TiO2 and starch with increased nano-TiO2 content, which was explained by schematic diagrams. The moisture content reduced from 23% to 13% and the contact angle increased from 43° to 85°, indicating that nano-TiO2 brought better water-resistance and higher hydrophobicity to starch/TiO2 bio-nanocomposites. The onset temperature of thermal degradation shifted from 119 °C to 174 °C, which exhibited the improved thermal stability of starch/TiO2 bio-nanocomposites. The results of x-ray diffraction (XRD) showed the recrystallization of starch molecular was restricted. Besides, there was a big growth of elongation at break from 109% to 293%, proving a better mechanical property. The starch/TiO2 bio-nanocomposite could be used as an eco-friendly food packaging material with simple preparation technology and better performance.