Physicochemical Properties of Potato Starch-NCC Based Nanocomposites

This study investigated the effect of different concentrations of nanocrystalline cellulose (NCC) on the physical properties of starch-NCC nanocomposites. The nanoparticle distribution in the polymer matrix was investigated using x-ray diffraction. The heat resistance and mechanical properties of the film were measured by differential scanning calorimetry and tensile testing. Investigation of nanocomposite properties showed that the addition of NCC to starch film increased the moisture resistance of the film. With the addition of up to 9% NCC, the ultimate tensile strength of the nanocomposite samples increased from 5.9 to 7.64 MPa and the strain-to-break decreased from 34.82% to 20.66%. This trend was not significant for nanocomposite samples containing high concentrations of NCC (5%, 7%, 9%) because of their crystalline nature, the unique mechanical properties of the cellulose and the establishment of hydrogen bonds between the starch and cellulose nanoparticles. Investigation of thermal resistance of the nanocomposite samples showed that the addition of up to 9% NCC increased the melting point of the film from 218 to 251.5 °C. Increasing the NCC concentration decreased the glass transition temperature of the nanocomposite samples. The results show that the performance of the NCC differed in the amorphous and crystalline regions of the starch.