Thermal and Mechanical Properties of Natural Rubber and Starch Nanobiocomposites

Large-scale starch nanoparticles of about 10–50 nm were obtained by acidic hydrolysis of amylopectin-rich cornstarch (waxy starch). They were used to prepare nanobiocomposites with natural rubber by mastication technique. Up to 30 phr (parts per hundred of rubber) of the filler was successfully incorporated leading, to an enhancement in thermo-mechanical properties. Tensile and elongation were even higher than those of conventional composites of untreated waxy starch and amylose-rich starch as well as carbon black at all loadings. SEM revealed single-phase morphology of nanocomposites, indicating extremely uniform mixing. It was observed that starch could be a potential substitute for carbon black as filler.