Tribological behavior of graphite oxide reinforced polyethersulfone composite under drying sliding condition

Wang³

et al. 2020

Polymer International

Self Cite

Because of high wear rate and low thermal deformation temperature, the generalization and application of polytetrafluoroethylene (PTFE) in the field of tribology is restrained to a certain extent. In order to improve the wear resistance and thermal stability of this self‐lubricating polymer, organic montmorillonite (OMMT) nanoparticle reinforced polyethersulfone (PES) and PTFE ternary composites were prepared by the cold molding and vacuum sintering technology. The effects of sodium montmorillonite (Na‐MMT) and OMMT on the microstructures, thermal stabilities and tribological properties of PTFE composites were comparatively studied. The results show that the thermal stability of the PES/PTFE composites is clearly improved by the incorporation of OMMT nanoparticles. Not only the friction coefficients but also the wear rates of OMMT/PES/PTFE composites are less than those of Na‐MMT/PES/PTFE composites under identical tribological tests. Of all these PTFE composites, the PES/PTFE composite containing 10.0 wt% OMMT nanoparticles exhibits the best friction and wear properties (μ = 0.14, k = 5.78 × 10−15 m3 N–1 m−1). This can be attributed to the existence of a polymer multicomponent layer consisting of PTFE, PES and OMMT on the composite surface as well as the formation of uniform PTFE transfer film on the worn surfaces of metal counterparts.

V = B ((), \frac{π}{180} R^{2} \arcsin \frac{b}{2 R} - \frac{b}{2} \sqrt{R^{2} - \frac{b^{2}}{4}})

k = \frac{V}{FL}

where k is the specific wear rate (m 3 N –1 m –1 ), F is the load (N) and L is the sliding distance (m).…”

Section: Methodsmentioning

confidence: 99%

Retracted: Influence of organic montmorillonite nanoparticles on the microstructures and thermal and tribological properties of polyethersulfone and polytetrafluoroethylene composites

Wang³

et al. 2020

Polymer International

Self Cite

“…Hunke et al used lowpressure microwave plasma functionalization of PTFE powders to enhance the mechanical and tribological properties of PES composites [30]. Yan et al added graphite oxide and 3-aminopropyltriethoxysilanemodified graphite oxide to the PES resin to improve the mechanical, thermal, and tribological properties of this polymer [31,32]. Exploratory efforts have been made to greatly improve the friction and wear properties of PTFE matrix ternary composites by incorporating various types of nanofillers.…”

Section: Introductionmentioning

confidence: 99%

RETRACTED ARTICLE: Thermal, mechanical, and tribological properties of sodium-montmorillonite-nanoparticle-reinforced polyethersulfone and polytetrafluoroethylene ternary composites

et al. 2020

Friction

Self Cite

Polyethersulfone (PES) and polytetrafluoroethylene (PTFE) blend composites reinforced with sodiummontmorillonite (Na-MMT) nanoparticles were prepared by cold molding and vacuum sintering. The effects of the Na-MMT content on the thermal, nanomechanical, and tribological properties of the Na-MMT/PES/PTFE ternary composites were investigated in detail. The results indicate that at the optimal content, Na-MMT nanoparticles can be uniformly dispersed in the PES/PTFE binary blend composites and generate strong interfacial bonding with the polymeric matrix. Both the thermal stability and the nanomechanical properties of the PES/PTFE binary blend composites are clearly improved by the incorporation of Na-MMT nanoparticles. Among these PTFE-based composites, the Na-MMT/PES/PTFE ternary composite containing 10.0 wt% of Na-MMT nanoparticles exhibits the optimal friction and wear performance. Compared with those of the PES/PTFE blend composite, the friction coefficient (μ = 0.16) and wear rate (k = 2.63 × 10 −14 m 3 /(N•m)) of the 10.0 wt% Na-MMT/PES/PTFE ternary composite are 19.1% and 97.2% lower, respectively. The significant enhancement of the wear resistance of the Na-MMT/PES/PTFE ternary composite is attributable to the formation of PTFE self-lubricating transfer films. The transfer films generated on the worn surfaces of GCr15 steel balls can prevent direct contact between the PTFE composites and their metal counterparts, thereby protecting the polymer composites from damage.

“…The applied load was adjusted to 10 N, while the sliding velocity was set to 0.10 m/s. The stroke amplitude was 5 mm, and the test distance was 100 m. The wear rate k was calculated according to the following formula [29,30] :…”

Section: Tribological Testsmentioning

confidence: 99%

Surface wettability, tensile mechanical performance, and tribological behavior of polyimide/polytetrafluoroethylene blends enhanced with hydroxylated multiwalled carbon nanotubes at high relative humidity

2021

Polymer Composites

Multiwalled carbon nanotubes were hydroxylated (MWCNTs-OH) by a strong acid mixture and then used as a reinforcement nanofiller in blends of polytetrafluoroethylene (PTFE) and polyimide (PI) to fabricate MWCNTs-OH/ PTFE/PI nanocomposites. The influences of MWCNTs-OH additions on the surface wettability, tensile mechanical property, and tribological behaviors of MWCNTs-OH/PTFE/PI nanocomposites under different relative humidity were investigated. Test results indicate that the introduction of MWCNTs-OHcan dramatically decrease the static water contact angles and increase the tensile strengths and elastic moduli of the PTFE/PI polymer blends. This is largely due to the existence of numerous hydrophilic functional groups on the surfaces of MWCNTs-OH and its ultrahigh mechanical characteristics. The relative humidity has a much weaker impact on the friction coefficients of the MWCNTs-OH/PTFE/PI nanocomposites than on the wear rates. Of all composites, the 0.8 wt% MWCNTs-OH/PTFE/PI nanocomposite possesses the lowest friction coefficient (0.11) and wear rate (2.97 Â 10 À15 m 3 /(Nm)) at a high relative humidity of 90%. The conspicuous increase in wear resistance is attributable to the enhancement effect of MWCNTs-OH and the generation of homogeneous polymer self-lubricating tribofilms.