Nanocomposite Polyimide Materials

The transition to nanosized fillers allows to significantly improve the characteristics of composites while reducing their degree of filling, and in some cases to achieve new properties unattainable with the use of traditional fillers and modifiers. Polymeric nanocomposites have unique barrier properties, electrical conductivity, thermal conductivity, increased strength, heat resistance, and thermal stability, as well as reduced flammability. It is known that the addition of nanodispersed layered silicates and various forms of carbon nanofillers to polymeric matrices can significantly affect the mechanisms of thermal and thermooxidative destruction and burning of nanocomposites. In this chapter, we compare the properties of composite materials based on nanostructured silicon carbide and carbon nanotubes with modified and unmodified surfaces obtained on three types of polyimide matrices (matrix No. 1 based on pyromellitic dianhydride and 4,4′-oxydianiline, matrix No. 2 based on 3,3‘,4,4’-benzophenone tetracarboxylic acid dianhydride and p-phenylenediamine, and matrix No. 3 based on pyromellitic dianhydride and 4-[4-(4-aminophenoxy) phenoxy] phenylamine). The dynamic viscosity of polyamide acid, the physicomechanical characteristics of film polymer composite materials, the determination of thermal stability, and thermooxidative destruction mechanism of composites were determined

Conformational Analysis of Dibutylphosphorylacetic Acid N,N-Dibutylamide in Solution

Abstract: Polarity of N,N-dibutylamide of dibutylphosphorylacetic acid has been determined and its conformational analysis has been carried out by the methods of dipole moments and quantum chemistry [DFT B3PW91/6-311++G(df,p)+CPCM]. In solution, this acetamide exists as conformational equilibrium of several forms with staggered gauche- and trans-orientations of the substituents relative to the P=O bond, in which intramolecular contacts are formed involving hydrogen atoms of butyl substituents at the nitrogen atom and the oxygen atom of the P=O group