Abstract
Biodegradable nanocomposite elastomers were produced from natural rubber (NR) latex, cassava starch and montmorillonite (MMT). NR/cassava starch mixtures by dry weight ratios of 100/30, 100/40 and 100/50 were mixed with organomodified MMT (OMMT) at 4 parts per hundred of dry rubber. The obtained homogeneous latex mixture was cast into 2 mm thick sheets, dried under an infrared lamp for 6 h, in an oven at 70 °C for 6 h and then cured at 110 °C for 3 h. After curing, samples were examined for their structures, tensile properties, water absorption, biodegradability and morphology. The X-ray diffractograms and transmission electron micrographs showed that the nanocomposites formed were exfoliated. Their tensile strength decreased with increasing cassava starch composition. However, enhancement of the tensile strength was observed when OMMT was incorporated. The water absorption also increased in proportion to the starch content in the nanocomposites. After soil burial for four weeks, the percent weight loss and biodegradability of the nanocomposites were both enhanced markedly as the proportion of starch in the composite increased.