Degradation Behaviour of Natural Rubber Layered Silicate Nanocomposites

Abstract

The degradation behaviour of natural rubber latex nanocomposites employing various degrading agents viz. thermal, gamma and UV radiations, chlorination, sterilization, ozone and solvents, was studied in detail. It was found that the layered silicate nanocomposite performed well in the presence of most of the degrading agents and such materials are suitable for processes such as chlorination, sterilization etc. It was observed that the degrading action was arrested either due to the hindrance exerted by the clay layers against crack propagation or due to the barrier effect against the degrading agents. A better interaction of nanosilicates was found with a polymer matrix due to their higher surface area, making the matrix stiffer and the diffusion of heat and gases through the bulk more difficult hence, retarding the degradation of the composite. These points were illustrated using XRD, TEM, SEM and TGA studies. Kraus plot showed a strong filler-rubber interface in rubber nanocomposites. Schematic representation of the degradation of the nanocomposite demonstrated the effect of nanofillers in chain scission or crosslinking, which may occur during degradation.