Synthesis and thermal degradation characterization of novel poly(phosphazene-aryl amides)

Abstract

Polyamides are considered to be high-performance organic materials due to their outstanding thermal and mechanical properties [1-3]. Their properties arise from their aromatic structure and amide linkages. However, the poor solubility, high softening and melting temperatures caused by high crystallinity and high stiffness of polymer backbone hamper the processing of aromatic polyamides. What's more, the properties can be easily tailored through changing their molecular chain structure [4-6]. The strategies which have been employed for solubility increase in aromatic polyamides are lateral substitution and the distortion of the rigid character introducing non-planar, kinked or flexible parts in the main chain. Research efforts are there-fore underway to take advantage of their properties, enhance their machinability, solubility and incorporate new chemical functionalities in the polyamide backbone or lateral structure, so that their applicability is expanded and remains on the forefront of scientific research [7-9]. Vapor phase lubrication has been proposed as a scheme for lubrication of high efficiency engines operating at temperature outside the range in which any fluid lubricants can be used [10-16]. These applications include gas-turbines which operate with bearing temperatures in excess of 500C. The most commonly used vapor phase lubricants for these applications are the aryl phosphates and in particular tricresyl phosphate [17].