Synthesis and property evaluations of highly filled polyimide composites under thermal cycling conditions from-190 °C to+200 °C

This paper presents data on the synthesis of composites based on polyimide and modified tungsten (IV) oxide (WO2). The resulting, highly filled, polyimide/WO2 composites were investigated by electron microscopy and thermal analysis in a gas environment of oxygen and argon. The maximum content of modified WO2, in the studied composites, was 60 wt%. The introduction of WO2 increases the thermal stability of the composites. For pure polyimide, the upper limit of the operating temperature is 507 degrees C; for a composite with a content of 30 wt% WO2 - 526 degrees C, and for 60 wt% WO2 - 554 degrees C in a gas environment of Ar. The change in the physico-mechanical properties of highly filled polyimide composites was studied under the conditions of thermal cycling from -190 degrees C to + 200 degrees C. The time of one cycle was 22 min. The thermal cycle was repeated 5, 10 and 20 times. The following parameters were determined: tensile strength, modulus of tensile elasticity and elongation under tension. The introduction of WO2 slightly reduces the initial strength characteristics of the composites.