Diffusion and transport through nanocomposites of natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their blends

Solvent resistance properties of nano-structured layered silicates filled natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their 70/30 latex blend were investigated by equilibrium swelling method using benzene, toluene and p-xylene. The layered nano-structured sodium bentonite and sodium fluorohectorite were used in the present study. The impact of concentration of filler, temperature and penetrant size on the transport properties of aromatic solvents through layered silicates reinforced latex membranes were analysed. The transport properties of filled latex membranes was analysed as a function of extent of exfoliation of the layered silicate in the rubber matrix. The morphology of filler dispersion in the rubber matrix was analysed from transmission electron micrographs. More exfoliated structure was found in sodium-fluorohectorite filled latex membrane. The extent of intercalation of polymer chain into the layers of silicates was estimated using X-ray diffraction technique. The enhanced d-spacing in latex nanocomposite indicated the intercalated structure. Nanocomposite of natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their blends showed reduced swelling rate due to the tortuosity of the path and the reduced transport area in polymeric membrane.