There have been numerous reports describing the preparation and characterization of polymer-based clay nanocomposites. Typically, this involves reinforcing a polymer with modified clay (ceramic type filler). The degree of homogeneity and adhesion between the organic (polymer) and inorganic (clay) components can be improved using reactive organoclay, which results in greatly improved properties of the hybrid materials. The enhanced properties for these nanocomposites include mechanical [1–7], thermal [1–4], barrier [8, 9], flammability [4, 10–12] and are related to the dispersion and nanostructure of the layered silicate in the polymer matrix. The greater advantages come from the delaminated samples with the exception of flammability, where both delaminated and intercalated nanocomposites behave in the same way [10, 11]. Three preparative approaches are generally applied to obtain these hybrid materials: in situ polymerization intercalation, solution intercalation, and melt intercalation. Shen et.al.  have compared the solution and melt intercalation of polymer clay composites. Solution intercalation is a solvent-based technique in which polymer is soluble and clay is swellable. When they are both mixed, the polymer chains intercalate and displace the solvent within the interlayer of the silicate. Upon solvent removal, the intercalated structure remains, resulting in hybrids with nanoscale morphology. Morgan and Gilman  described factors affecting the nanostructure of composites, especially in melt intercalation. The most important point that they emphasized is the organic treatment, without which the dispersion of hydrophilic clay into hydrophobic polymer is impossible. Secondly, the importance of thermal stability of the organic modifier was also pointed out by the same group, particularly in melt blending or curing the nanocomposites at high temperature. The commonly employed alkyl ammonium ion as modifier for layered silicates is thermally unstable, degrading at temperatures of 200 °C or less. When this degradation takes place, the silicate layers lose their organophilicity becoming hydrophilic again, and their ability to positively affect the physical properties may be reduced. The advantages expected from the nanocomposites usually deteriorate under these conditions. To overcome this difficulty, we have prepared an amine terminated aromatic amide oligomer (modifier), which is thermally stable and can also produce the interactions among the two phases. These nanocomposites find their applications in aerospace, automobile, and packaging industries.
Polyamides, the most versatile class of engineering polymers, display a wide range of properties. Aliphatic polyamides (nylons) find many industrial and textile applications due to their high mechanical strength and durability. Many studies on nylon-based clay nanocomposites have been reported previously [15–20]. Aromatic polyamides (aramids) are being used in industry because of their outstanding properties. However, poor solubility in common organic solvents and high melting temperatures are the limiting factors for the processing of these materials. A lot of attempts have been made to solubilize these polymers in order to prepare their composites using different techniques [21–25]. Aliphatic–aromatic polyamides (glass clear nylons) offer a wide range of properties including transparency, thermal stability, good barrier, and solvent resistant properties. These commercial polyamides have been reinforced with various ceramic phases [26–29]. There are numerous references to polyamides from aliphatic diamines and aromatic diacids and a far lesser number to polyamides from aromatic diamines and aliphatic diacids [30–38]. Probably the reason that aliphatic–aromatic polyamides have been studied in greater detail than the aromatic–aliphatic is that many of the former group can be made by melt and plasticized melt methods [32, 33, 39] or by standard interfacial procedures [35, 37, 40]. The aromatic–aliphatic polyamides, on the other hand are difficult to prepare by interfacial and solution methods [30, 41] and when prepared by melt methods, frequently are discolored and may have branched or network structures. Recently, excellent nanocomposites obtained from pectin–ZnO and ethylene vinylacetate–carbon nanofiber have been reported [42, 43]. Metal nanoparticle embedded conducting polymer–polyoxometalate composites and ionic liquid assisted polyaniline–gold nanocomposites for biocatalytic application have also been investigated [44, 45].
Keeping in view the importance of these polyamides, we have prepared the aromatic–aliphatic polyamide containing sulfone linkages by low temperature polycondensation method that could offer a balance of properties between those of tractable aliphatic nylons and the virtually insoluble and non-melting wholly aromatic polyamides. This aromatic–aliphatic polyamide is soluble in DMF, DMSO, and DMAc which can be attributed to the flexible sulfone linkages that provide a polymer chain with a lower energy of internal rotation . This polyamide was reinforced with reactive, thermally stable montmorillonite intercalated with oligomeric species. The nanocomposites obtained by solution intercalation technique were characterized for XRD, SEM, TEM, mechanical testing, TGA, DSC, and water uptake measurements.