Influence of organoclay dispersion on air retention and fatigue resistance of tyre inner liner compound

In a pneumatic tire, the contained air carries the load of the vehicle and also augments performance for other functional requirements, such as, rolling resistance, ride and handling, durability, and so on. The inner liner of the tire is responsible to ensure air retention by virtue of its high air impermeability. The present study focused on developing inner-liner compounds of improved air impermeability by utilizing platelet filler (layered silicate). The obtained organoclay was subjected to a pre-treatment process called exfoliation to increase the d spacing between the clay layers that further improved the morphological aspect of the compound. The inner-liner compound has been modified by partial replacement of carbon black with organically modified bentonite clay in 1:1 and 2.5:1 ratio. Air impermeability of rubber compounds was tested in a gas permeability tester. Field emission scanning electron microscope, transmission electron microscope, atomic force microscope, and x-ray diffraction were utilized to understand the distribution and dispersion of clay in the rubber compounds. Fatigue crack growth analysis was carried out to measure the fatigue life of the materials. The modified compounds exhibited air impermeability improvement from 7% to 30% vs the reference carbon-black filled compound with improved mechanical properties and filler dispersion.