Influence of the Degree of Crystallinity on the Mechanical and Tribological Properties of High-Performance Thermoplastics Over a Wide Range of Temperatures: From Room Temperature up to 250°C

The mechanical characteristics of block-shaped samples of a number of thermally stable thermoplastics for structural applications are investigated over a wide range of temperatures: from the room temperature (RT) up to 250 degrees C. Together with several commercially available materials, namely, polyetheretherketone, polyphenylene sulfide, and a polyetherimide Ultem-1000; a number of polyimide thermoplastics designed at the Institute of Macromolecular Compounds RAS having both semicrystalline and amorphous structures were studied. The tribological behavior of these thermoplastics was investigated in the tribometers of different types using polymer-steel couples with the variation of both the temperature (from RT to 250 degrees C) and the contact pressure. The experimental determination of the overheating values of the contact surface of the polymer sample was carried out during the friction process at different medium temperatures. The possibilities of obtaining a maximally broad temperature range for applications of thermoplastic polymeric material by regulating the degree of its structural ordering are analyzed.