Friction and wear behavior of polyimide matrix composites filled with nanographite

Abstract

In this study, nanographite (NG), as a lubricant additive, and polyimide (PI) were used to fabricate NG/PI composites via a hot compression molding process. The tribological properties of the NG/PI composites with different NG mass contents (0-10 wt%) were tested using a reciprocating ball-on-disc contact tribometer matched with a GCr15 rubbing pair. The thermal stability, surface hardness, and compression strength of the composites were discussed. The results revealed that a small quantity of nanofillers greatly reduced the friction coefficient and increased the wear resistance of the NG/PI composites. Despite a minor decrease in mechanical performance, the composite with 5 wt% of NG filler exhibited improved tribological properties; it showed a 55.63% reduction in the friction coefficient and a reduction of 97.39% in the wear rate compared with neat PI. Moreover, an increase in the glass transition temperature (T g ) of the NG/PI composites indicated the enhancement of their thermal stability and wear resistance. Scanning electron microscopy (SEM) analyses showed that the main wear mechanism of the composites was fatigue wear. These findings suggest that the 5 wt% NG/PI composite could be a significant contribution to the field of tribological engineering plastics.

Preparation and tribological behavior of high‐temperature oil‐containing porous polyimides

“…P84NT1 as a co-polymer benzophenone tetracarboxylic dianhydride, SEM morphology and chemical structure characterization can be referred to our previous work. [31,32] Polyalphaolefin 40 (PAO 40) with density of 0.82 g/cm 3 , a kinematic viscosity of 17.2 mm 2 /s at 40 C and 4.1 mm 2 /s at 100 C, was bought from Chevron Corporation.…”

“…The high-temperature pulverulent PIs are frequently applied to fabricate compacted bodies via a hot compressive molding process. A non-pore compact PI-based composite was prepared using the same raw material according to our articles published recently [31,32] to evaluate the evolution of mechanical and tribological properties accompanied by different filler content. As for high-temperature PPIs processing well below melting temperature, an understanding of the physical processes as well as the response to various process parameters during the fabrication process of polymer is necessary for obtaining reproducible and consistent products.…”

Insight into the role of debris in the formation of polytetrafluoroethylene film via molecular dynamic simulation of debris adhesion

“…[28] After minimization, PTFE molecules with 1, 2, …, 19, 20 chains were packed into periodic box, respectively. The initial density of PTFE model is 0.1 g/cm 3 and the final density is 2.2 g/cm 3 . Then, 200 ps MD simulation in NVT ensemble at 300 K was performed and the final model with five chains is shown in Figure 1A.…”

“…Self-lubricating polymer materials, such as polytetrafluoroethylene (PTFE) and polyimide (PI), are widely used in mechanical equipment because of their excellent selflubricating performance. [1][2][3][4] In the friction between selflubricating polymer materials and metal, polymer debris is generated inevitably, adheres on metal surface, and forms polymer transfer film. [5,6] Due to the formation of transfer film, the friction between polymer and metal will be converted to the friction between polymer and polymer film, so as to achieve antifriction.…”

Investigation of the way to enhance the synergistic effect between polyimide and graphene on the tribological performance of polytetrafluoroethylene composites

“…Polymer anti-friction materials are used extensively in bearing because of their excellent tribology performance, [1] such as polytetrafluoroethylene (PTFE) [2,3] and polyimide (PI). [4,5] Friction and wear performance of these polymers needs to be further improved. The improvement of tribology performance of polymer self-lubricating materials is always an important research topic.…”