Zahra Rafiee - Department of Chemistry, Yasouj University, Yasouj 75914-353, I. R. Iran.
Shadpour Mallakpour - Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan, 84156-83111, I. R. Iran.

Polyimides are among the most heat-resistant polymers and are widely applied in high temperature plastics, adhesives, dielectrics, photoresists, nonlinear optical materials,membrane materials for separation, and Langmuir–Blodgett (LB) films, among others. Additionally, polyimides are usedin a diverse range of applications, including the fields ofaerospace, defense, and opto-electronics; they are also used in liquid crystal alignments, composites, electroluminescentdevices, electrochromic materials, polymer electrolyte fuel cells, polymer memories, fiber optics, etc [1]. The chemistryof polyimides is itself a vast field, and it includes a large variety of available monomers and different synthetic methodologies. However, there has been considerable debateabout the various reaction mechanisms involved in the different synthetic methods. The properties of polyimides canbe dramatically altered by minor variations in structure. Subtle changes in the structures of the dianhydride and/or diaminecomponents will have significant effects on the properties of the final polyimide [2-5].