Studies of Particle Dispersion in Elastomeric Polyurethane/Organically Modified Montmorillonite Nanocomposites

ABSTRACT Elastomeric polyurethane (PU) was mixed with 1, 3, 5, 7, and 10 wt% of Cloisite 20A to obtain PU-based nanocomposites. The thermal stabilities of the obtained products were characterized by thermal analysis using a thermogravimetric analyzer (TGA), which showed that addition of 5 wt% of organoclay to the PU increased its stability, whereas thermal stabilization was less efficient at 10 wt%. The electrical conductivities of these composites were studied as a function of temperature, and it was found that the conductivity of PU was enhanced upon using 5 wt% of organoclay. The tensile strength, elongation (%), and Young's modulus were considerably enhanced upon increasing the organoclay content to 5 wt%, but were then decreased to some extent upon further increase of the nanoparticle loading to 10 wt%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study these nanocomposite structures, and it was found that the organoclay is fully exfoliated in the PU matrix when 5 wt% o...