Surface modification of montmorillonite—MMT nanofiller: how it affects both the rigid amorphous fraction (RAF) and the physical properties of polyamide 66

Abstract

Studying the impact of type (organo-modified montmorillonite—MMT) into polyamide 66 (PA66) on the molecular motion of polymers within the space between polymer and nanoparticle is important to understand the improved properties of nanocomposites. The mechanical, thermal, and electrical properties have been examined employing Dynamical Mechanical Thermal Analysis, Differential Scanning Calorimetric, and Dielectric Relaxation Spectroscopy techniques. The results showed that the reinforcing effect of the PA66 matrix with MMT loading was justified by an 83% increase in the storage modulus (G′) with Cloisite 30B (C30B) MMT nanofiller. Furthermore, the glass transition temperature (T_g) decreased by 5.0 °C. A significant increase in the rigid amorphous fraction (RAF) was found due to the presence of filler, especially in the case of C30B-MMT nanocomposites, which comprised approximately 22% of the polymer. Moreover, it was observed that the dielectric constant (ε′) for all nanocomposites increased with temperature, particularly for Nanofil9 (N9)–MMT nanocomposites at relatively high temperatures (100 °C, 0.03 Hz). The conduction mechanism observed in all tested samples was confirmed to follow the correlated barrier hopping mechanism.