Comparative Study of Physical Properties of Polymer Composites Reinforced with Uncarbonised and Carbonised Coir

This study involved the use of uncarbonised and carbonised coir in preparing composites of a given polymer. In this case natural rubber (NR) was used. Uncarbonised coir (UC) and carbonised coir (CC) were separately used to prepare the polymer composites. Carbon black (CB) was also used differently and the filler loadings for all varied between 0 and 50 phr. Before using the uncarbonised coir and carbonised coir, they were characterised on the basis of moisture content, pH, particles size and surface area. The properties of the various composite samples prepared were then investigated. The results of the tests obtained for the NR-UC composites were compared with those of NR-CC and also with those of NR-CB composites. It was observed that for hardness, the results obtained from composites of UC and CC fillers showed similar trends with those of carbon black (CB) reinforced composites, increasing with increase in filler volume. For the tensile strength and modulus a trend of slight rise was observed. There were no sharp rises in values as filler volumes were increased. UC and CC fillers were observed to impart very poorly on the tensile strength and modulus relative to the CB reinforced composites. The results from test for elongation, compression set and flex fatigue showed a falling trend for all the fillers to a comparable level with CB. It was generally observed that the uncarbonised coir presented better potentials for reinforcement than the carbonised coir.