Rheological Behaviour of Layered Silicate-Natural Rubber Latex Nanocomposites

The rheological behaviour of prevulcanised natural rubber (NR) latex nanocomposites based on layered silicates such as sodium bentonite and sodium fluorohectorite was studied. A typical commercial clay (non-layered version) was chosen as the reference. The effect of layered silicates on flow properties was analysed by investigating latex viscosity as a function of shear rate, temperature, and filler loading. In the presence of layered silicates, latex compounds show enhanced viscosity, probably owing to a network formation of silicate layers in the latex phase. The shear thinning behaviour exhibited by the nanocomposites at high temperature may be due to the network breakdown of silicate layers. Latex-layered silicate systems show pseudoplastic behaviour and increased zero shear viscosity and yield stress.