scholarly journals Effect of Powder on Tribological and Electrochemical Properties of Nylon 66 and Ultra-High Molecular Weight Polyethylene in Water and Seawater Environments

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2874
Author(s):  
Wanxing Xu ◽  
Tian Yang ◽  
Shengpeng Zhan ◽  
Dan Jia ◽  
Lixin Ma ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Synergistic Effect ◽  
Tribological Properties ◽  
Pure Water ◽  
Water Environment ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Polymer Materials ◽  
Nylon 66 ◽  
Ultrahigh Molecular Weight ◽  
Seawater Environment

Polymer materials are used increasingly in marine machinery and equipment; their tribological properties and effect on the water environment have garnered significant attention. We investigate the effect of water or seawater environment containing powder on tribology and electrochemistry of polymer materials. A friction test involving nylon 66 (PA66) and an ultrahigh molecular weight polyethylene (UHMWPE) pin–disc (aluminum alloy) is performed in seawater or water with/without polymer powder, and the solution is analyzed electrochemically. The results show that the tribological properties of the UHMWPE improved by adding the powder to the solution, whereas the PA66 powder demonstrates abrasive wear in a pure water environment, which elucidates that the synergistic effect of powder and seawater on UHMWPE reduces the wear, and the synergistic effect of pure water and powder aggravates the wear. The results of electrochemical experiments show that after adding powder in the friction and wear tests, the powder can protect the pin by forming a physical barrier on the surface and reducing corrosion, and the changes are more obvious in seawater with powder in it. Through electrochemical and tribological experiments, the synergistic effect of solution environment and powder was proved.

Biomimetic surface design for ultrahigh molecular weight polyethylene to improve the tribological properties

2012 ◽  
Vol 226 (8) ◽  
pp. 705-713 ◽  
Author(s):  
Bo Zhang ◽  
Wei Huang ◽  
Xiaolei Wang
Keyword(s):  
Molecular Weight ◽  
Tribological Properties ◽  
Articular Surface ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Industrial Applications ◽  
Wear Depth ◽  
Surface Design ◽  
Area Density ◽  
Ultrahigh Molecular Weight ◽  
Average Wear

Tribological problem is a major obstacle that limits the using of ultrahigh molecular weight polyethylene (UHMWPE) in industrial applications and orthopedic surgeries. Many efforts have been made to improve the tribological properties of UHMWPE, such as promoting the structure, morphology, and mechanical properties of the polymer. Inspired by the features of articular surface, micro-scaled texture is introduced to improve the tribological properties of UHMWPE using micro-imprint lithography. Friction and wear experiments are conducted on textured and untextured specimens using ring-on-disc test apparatus under water lubrication. The experimental results demonstrate that the micro-scaled surface texture can remarkably improve the tribological properties of UHMWPE. Friction force can be effectively reduced by selecting suitable dimple parameters. Compared with an untextured UHMWPE, the textured one with optimum parameters shows a reduction in the friction coefficient as much as 66.7–85.7% on different load–speed conditions. The optimized area density of surface textured UHMWPE ranges from 22.9% to 29.9%, which is obviously higher than that of stiff materials such as metals and ceramics. The textured UHMWPE with area density 29.9%, diameter 50 µm, and depth 15 µm presents a significant effect of wear resistance. The average wear depth of textured UHMWPE is 35.5% of that of untextured one.

Biodegradation behavior and tribological properties of ultrahigh molecular weight polyethylene stabilized with α-tocopherol

2019 ◽  
Vol 71 (3) ◽  
pp. 494-498
Author(s):  
Xueqin Kang ◽  
Chi Yao ◽  
Shirong Ge
Keyword(s):  
Molecular Weight ◽  
Tribological Properties ◽  
Design Methodology ◽  
Experimental Studies ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Tribological Test ◽  
Pressing Method ◽  
Content Type ◽  
Ultrahigh Molecular Weight ◽  
One Year

Purpose This paper aims to investigate the effect of simulated body fluid (SBF) on biodegradation and tribological properties of ultrahigh molecular weight polyethylene (UHMWPE) and UHMWPE stabilized with α-tocopherol. Design/methodology/approach The samples of UHMWPE and UHMWPE stabilized with α-tocopherol were prepared by a hot-pressing method, and then immersed in SBF for one year. Tribological test was performed on a UMT-2 tribometer. Findings The crystallinity and tribological properties increased slightly after UHMWPE stabilized with α-tocopherol, whereas the O/C ration decreased slightly. The crystallinity and O/C ratio increased after all samples immersed in SBF for one year. This resulted in the deterioration of tribological properties and the wear mechanism change. The tribological properties change was smaller in UHMWPE stabilized with α-tocopherol than that in UHMWPE, because the oxidation resistance of UHMWPE was increased by α-tocopherol. Originality/value The results of the experimental studies demonstrated and compared the biodegradation behavior and tribological properties of UHMWPE, UHMWPE stabilized with α-tocopherol, and after they immersed in SBF for one year.

scholarly journals Elongational Flow Field Processed Ultrahigh Molecular Weight Polyethylene/Polypropylene Blends with Distinct Interlayer Phase for Enhanced Tribological Properties

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1933
Author(s):  
Xiaochuan Chen ◽  
Xiaotong Wang ◽  
Changlin Cao ◽  
Zhongke Yuan ◽  
Dingshan Yu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Shear Flow ◽  
Flow Field ◽  
Tribological Properties ◽  
Elongational Flow ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Wear Loss ◽  
Fatigue Wear ◽  
Ultrahigh Molecular Weight ◽  
Processing Modes

Herein, we produced a series of ultrahigh molecular weight polyethylene/polypropylene (UHMWPE/PP) blends by elongational-flow-field dominated eccentric rotor extruder (ERE) and shear-flow-field dominated twin screw extruder (TSE) respectively and presented a detailed comparative study on microstructures and tribological properties of UHMWPE/PP by different processing modes. Compared with the shear flow field in TSE, the elongational flow field in ERE facilitates the dispersion of PP in the UHMWPE matrix and promotes the interdiffusion of UHMWPE and PP molecular chains. For the first time, we discovered the presence of the interlayer phase in blends with different processing modes by using Raman mapping inspection. The elongational flow field introduces strong interaction to enable excellent compatibility of UHMWPE and PP and induces more pronounced interlayer phase with respect to the shear flow field, eventually endowing UHMWPE/PP with improved wear resistance. The optimized UHMWPE/PP (85/15) blend processed by ERE displayed higher tensile strength (25.3 MPa), higher elongation at break (341.77%) and lower wear loss of ERE-85/15 (1.5 mg) compared to the blend created by TSE. By systematically investigating the microstructures and mechanical properties of blends, we found that with increased content of PP, the wear mechanism of blends varies from abrasive wear, fatigue wear, to adhesion wear as the dominant mechanism for two processing modes.

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