Organically modified nanosized starch derivatives as excellent reinforcing agents for bionanocomposites

Organic modification of starch nanoparticles was carried out at room temperature to obtain nanosized hydrophobic derivatives. The particle size of the modified starch nanoparticles obtained by transmission electron microscopy (TEM) and X-ray diffraction (XRD) was found out to be around 50 nm. The hydrophobic starch derivatives were used to prepare bionanocomposites of natural rubber by mastication process. The properties were compared with composites obtained from untreated starch nanoparticles and carbon black. Up to 30 phr of the fillers were successfully incorporated leading to an enhancement in mechanical as well as thermal properties. Scanning electron microscopy (SEM) revealed single phase morphology of nanobiocomposites indicating compatibility of the filler and matrix. Dynamic mechanical properties were seen as a broad tan delta peak over a large range of temperature. It was observed that modified starch nanoparticles could be a potential substitute for carbon black as reinforcing agents and as promising materials for vibration damping applications.