The formation of hybrid nanostructures improves the barrier properties significantly by increasing the path of diffusion of the permeant.

The present work provides an extensive insight on effect of hybrid nanofillers and its structure-property relationship in nanocomposites based on bromobutyl rubber (BIIR)/ polyepichlorohydrin rubber (CO) blends. TEM photomicrographs reveal high degrees of dispersion of nanoclay with the formation of hybrid nanostructures. Rheological behavior of the nanocomposites displays shear thinning nature and significant reduction of die swell (up to 13% reduction) is observed with increase in the dosage of nanoclay. The addition of the nanoclay drastically reduces the air permeability up to 17%, increases electrical conductivity and thermal conductivity of the rubber nanocomposites. Adhesion of rubber to the fabric ply is found to be good in the nanocomposite having a lower dosage of nanoclay. These unique attributes were found to stem from the fundamental viscoelastic characteristics i.e., increase in the entanglement density due to the hybrid nanostructures. The development of hybrid nanostructures and its significant contribution to the improvements of properties are schematically explained. Rubber formulations with such suitably tailor nanostructures will find their applications for next generation rubber based industrial products. 23to the low free path of the phonon and frequent phonon scattering effect at the rubber interface, the net thermal conductivity of B 90 H 10 CB 50 NC 0 is less. Scheme 5 explains the effect of hybrid nanostructure in enhancing the thermal conductivity of the nanocomposites. The dispersed hybrid nanostructures bridges between the BIIR-CO interface and acts as an extended path for the phonons to travel. The extended mean free path of phonons have now become to (λ+x) and (λ+y) from λ before it gets scattered. The increase in the mean free path corresponds to the increase in the thermal conductivity of the nanocomposites. However, relative decrease in the thermal conductivity of B 90 H 10 CB 50 NC 10 with increase in the temperature corresponds to the increase in the number of structural defects in the nanocomposites at higher temperatures. 32Scheme 5: Increase in the mean free path due to the formation of hybrid nanostructure in BIIR-CO nanocomposites 4.7. Adhesion Strength.Adhesion between the components is a basic requisite of any composite product when it is subjected to dynamic applications. The effect of nanoclay on the adhesion of the nanocomposites with neighboring fabric compound were analyzed and shown in Figure

The present work proposes a schematic model for predicting the water vapor transmissibility in hybrid nanocomposites based on bromobutyl (BIIR)/epichlorohydrin (CO) rubber blends. Morphology study reveals the exfoliation of nanoclay and development of hybrid nanostructures in the rubber nanocomposites. A unique correlation between water vapor transmissibility and gas (oxygen) permeability through the rubber nanocomposites has been systematically derived. The prediction of relative water vapor transmissibility was achieved by considering the polar path along with the existing tortuous path and has been validated. Interestingly, it is found that the water vapor transmissibility (TW) directly depends on the weight fraction of the polar rubber (ΦP) in the rubber blend and permeability to gas (PG) of the nanocomposites.

In the present work, a novel attempt has been proposed to simulate air permeability in tire inner liner based on bromobutyl (BIIR)/epichlorohydrin (CO) rubber blend nanocomposite. ANSYS ® software has been adopted for FEM analysis. It provides an essential insight into the prediction of air permeability using thermal/gas analogy. The simulated results are compared and successfully validated with the field tire results. It is found that the hybrid nanocomposite offers a substantial reduction in air permeability as compared to the standard inner liner compound. It signifies the impact of the nanostructures on enhancing the gas barrier of the tire inner liner with time. The prediction gives a possibility to improve proactively the quality of inner liner compound developed.