Organo-modified nanoclays induce changes in the physical properties of polyamide 66

The effect of the addition of nanoparticulate (organo-modified montmorillonite—MMT) into polyamide 66 (PA66) on the glass transition temperature (T_g), storage modulus (G′), and the electrical properties has been elucidated employing differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA) and dielectric relaxation spectroscopy (DRS) techniques. The glass transition temperature decreases with the incorporation of clay nanoparticles. DMA technique is valuable and is the most sensitive thermal analysis technique for measuring T_g. It was noticed that as filler content increases the storage modulus increases meanwhile, it decreases as the temperature increases. Tested samples were formed to study the dielectric and conduction properties in the frequency range (10 mHz–10 MHz) at different temperatures in the range (+ 173 K to 503 K). One deduces that the dielectric constant (ε′) and ac electrical conductivity (σ_ac) increase with increasing filler content and temperature. Referring to the loss tangent (tan δ)–temperature curve for all samples, three different relaxations (α, β and γ) were detected and the calculated activation energy of these peaks were found to increase with organo-modified montmorillonite contents. The correlated barrier hopping conduction mechanism predominates the mechanism of neat polymer and its nanocomposites. Addition of 29.2 wt % filler shifted the mileage of hopping (R) toward lower value by approximately 40%. Different theoretical models were used to evaluate the effective dielectric constant (ε_e) of the nanocomposites.