Novel poly(ether-imide) and sepiolite nanocomposites were synthesized based on a unique diamine monomer with the aim of improving physical and mechanical properties of final polyimide films. The diamine was polycondensed with 4,4′-(hexafluoroisopropylidene) diphthalic anhydride to produce related poly(ether amic acid) prepolymer. Pure poly(ether-imide) and nanocomposite films were prepared via thermal imidization process of poly(ether amic acid). Coexistence of ether, pyridine, and phenylene functional groups in the diamine chemical structure resulted in flexible polyimide films with significant thermal, physical, and mechanical properties. Thermal stability, glass-transition temperature, dimensional stability, and tensile properties of polymer and nanocomposites were studied and compared. Morphology of nanocomposites was also investigated using scanning and transmission electron microscopic methods to study the distribution and dispersion behavior of sepiolite nanofibers in the polyimide matrix. By introduction of sepiolite nanoparticles, overall improvement of properties was observed in respect to pure polyimides.

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A new poly(sulfone ether imide) was prepared, and related nanocomposites were produced through introduction of sepiolite nanoparticles into the matrix of polymer. Inherent viscosity, thermal and mechanical features of pristine poly(sulfone ether imide), and nanocomposite samples were evaluated and compared. The crystallinity was also investigated. Dispersion and distribution behaviors of nanocomposite samples and cross‐sectional morphology of nanocomposite films were also studied. Also, the optimized amounts of sepiolite nanoparticles in the matrix of polymer were determined by microscopic techniques (scanning electron microscope and transmission electron microscope). By introduction of 3 wt% of sepiolite, superior thermal and mechanical properties were observed. Copyright © 2016 John Wiley & Sons, Ltd.

Over time human needs have been changing. Science and technology are responsible for providing these needs. One of these needs, especially in high‐tech technology is a polymer that can tolerate high temperatures. Progress in this field is due to meet the requirements of the aerospace industry, where heat‐resistant polymers with low weights and suitable formability and processability are needed to substitute many high weight metals. In this article, a brief introduction covers some basic information about heat‐resistant characteristics, factors influencing it, and some well‐established analytical methods for estimating heat‐resistant features of polymeric materials. In the following sections, a number of most important commonly used heat‐resistant polymers are selected and their overall properties are reviewed particularly focusing on their heat resistance. These polymers include polyimides and their copolymers, polyamides and related copolymers, polyesters, aromatic polyethers and their derivatives, benzimidazoles, and ladder polymers. It should be noted that a number of other heat‐resistant synthetically developed or commercially successful polymers (less important) are not included in this category, which are fully described in other books and review papers.