Effect of fibrous TiO2 filler on the structural, mechanical, barrier and optical characteristics of biodegradable maize starch/PVA composite films

The work focuses on producing and evaluating "green" multifunctional film materials based on a mixed eco-friendly starch/PVA matrix and filled with fibrous TiO2 particles formed by the ultrasound-assisted biotemplate method. Starch/PVA/TiO2 film-forming dispersions were prepared by heating and intensively mixing the components at the same time, and then composite films were obtained by the casting method. The influence of the TiO2 filler content on the morphological and structural characteristics of the composites was studied by the optical microscopy, X-ray diffraction, DSC and FTIR spectroscopy methods. The compatibility of the polymer components was improved by incorporating a small amount of the filler (0.01 and 0.05 wt% of the dry polymer weight). The dependence of tensile strength and water vapor permeability on the filler content was shown to have a maximum at the TiO2 concentration of 0.05 wt%. The UV- protective ability of the composite films rose as the TiO2 concentration increased. The presence of TiO2 in the biodegradable starch/PVA matrix had little effect on the soil burial biodegradation rate of the composite films. Thus, the obtained results show that fibrous TiO2 particles at optimum concentration of 0.01 and 0.05 wt% can improve starch/PVA films properties and extend their functionality.