Effects of UV irradiation time on the molecular structure of typical engineering plastics and tribological properties under heavy load

2022 ◽  
pp. 095400832110665
Author(s):  
Lian Liu ◽  
Haitao Duan ◽  
Wen Zhan ◽  
Shengpeng Zhan ◽  
Dan Jia ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Wear Rate ◽  
Uv Irradiation ◽  
Tribological Properties ◽  
Irradiation Time ◽  
Heavy Load ◽  
Polyether Ether Ketone ◽  
Engineering Plastics ◽  
Ether Ketone ◽  
Heavy Loads

Exposing engineering plastics to UV irradiation can easily destroy the original molecular structure of the materials and consequently affect their tribological properties. This study investigated the effects of UV irradiation on the molecular structure of typical engineering plastics, such as polytetrafluoroethylene (PTFE) and polyether ether ketone (PEEK), and on their tribological properties under heavy loads (20 MPa). The surface morphology results showed that the appearance of PEEK changed significantly under UV irradiation. However, the change in PTFE was negligible. Under micromorphology, the processing lines of the two materials gradually became lighter with increasing UV irradiation time. The resulting infrared spectra showed that the molecular chains of both materials were broken, and new functional groups were formed under UV irradiation. Tribology testing demonstrated that with prolonged UV irradiation, the average PTFE coefficient of friction remained relatively stable, whereas that of PEEK was approximately 0.55. As the UV irradiation time increased, the wear rate of PTFE increased significantly, whereas that of PEEK showed no significant change.

Effects of potassium titanate whisker and glass fiber on tribological and mechanical properties of PTFE/PEEK blend

2017 ◽  
Vol 30 (6) ◽  
pp. 752-764 ◽  
Author(s):  
Xue Teng ◽  
Lefei Wen ◽  
Yunxia Lv ◽  
Wenge Tang ◽  
Xiaogang Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Glass Fiber ◽  
Tribological Properties ◽  
Reinforcing Effect ◽  
Potassium Titanate ◽  
Polyether Ether Ketone ◽  
Ether Ketone

Two series of 10% polytetrafluoroethylene (PTFE)/polyether ether ketone (PEEK) composites reinforced with potassium titanate whisker (PTW/PTFE/PEEK) and chopped glass fiber (GF/PTFE/PEEK) were prepared and characterized. We investigated the effects of the additives on thermal stability, tribological properties, mechanical properties, and rheological behavior. The results illustrated that the mechanical properties of 10% PTFE/PEEK blend can be dramatically improved by incorporating either PTW or GF; however, the reinforcing effect of GF was found to be superior. It was found that 1% additive resulted in blends with the best tribological properties. Compared to the unmodified blend, the friction coefficient and wear rate of the 1% PTW blend decreased by 7.2% and 21%, respectively, while the corresponding values of 1% GF blend decreased by 0.66% and 51%, respectively.

scholarly journals Effect of Surface Treatment With Er:YAG and CO2 Lasers on Shear Bond Strength of Polyether Ether Ketone to Composite Resin Veneers

2020 ◽  
Vol 11 (2) ◽  
pp. 153-159
Author(s):  
Yousef Jahandideh ◽  
Mehran Falahchai ◽  
Hossein Pourkhalili
Keyword(s):  
Surface Treatment ◽  
Co2 Laser ◽  
Shear Bond Strength ◽  
Composite Resin ◽  
Er:Yag Laser ◽  
Irradiation Time ◽  
Polyether Ether Ketone ◽  
Ether Ketone ◽  
Dunnett's Test ◽  
Effect Of Surface

Introduction: Polyether ether ketone (PEEK) has low surface energy and high resistance to chemical surface treatments. Therefore, different surface treatments such as laser conditioning should be investigated. There is a gap of information regarding the efficacy of laser irradiation in the surface treatment of PEEK, and the efficacy of several laser types needs to be evaluated for this purpose. This study aimed to assess the effect of surface treatment with erbium-doped yttrium aluminum garnet (Er:YAG) and carbon dioxide (CO2) lasers on shear bond strength (SBS) of PEEK to composite resin veneers. Methods: In this experimental study, 60 rectangular-shaped PEEK samples (7 x 7 x 2 mm) were used. The samples were mounted in auto-polymerizing acrylic resin in such a way that only one surface measuring 7x7 mm remained exposed. The samples were then randomly divided into 3 groups (n=20) of control, Er:YAG laser surface treatment (Power=1.5 W, energy density=119.42 J/cm2 , irradiation time=20 s) and CO2 laser surface treatment (Power=4 W, energy density=159.22 J/cm2 , irradiation time=50 s). The bonding agent and PEEK opaque were applied on the surface of samples and they were veneered with a composite resin using a hollow plastic cylinder with an internal diameter of 4 mm. The SBS was then measured and the data were analyzed using one-way ANOVA, Tukey HSD test and Dunnett’s test at 0.05 level of significance. Results: The SBS of the 3 groups was significantly different (P<0.001). The Tukey HSD test revealed that the Er:YAG laser had higher SBS than the CO2 laser group (P<0.001). The Dunnett’s test showed that both Er:YAG and CO2 laser groups yielded higher SBS than the control group (P<0.001). Conclusion: The Er:YAG and CO2 laser treatments can increase the SBS of PEEK to composite resin veneers, although the Er:YAG laser seems to be more effective for this purpose.

Effects of UV Irradiation on the Molecular Structure and Tensile Properties of Nucleated Polypropylene

2014 ◽  
Vol 905 ◽  
pp. 82-87 ◽  
Author(s):  
You Ji Tao ◽  
Gan Xin Jie ◽  
Xiao Dong Zhang ◽  
Li Fen Hu ◽  
Jian Peng ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Uv Irradiation ◽  
Irradiation Time ◽  
Relative Content ◽  
Carbonyl Index ◽  
Relationship Of ◽  
The Relationship ◽  
Strength Retention

A sorbitolum compound and an aryl amide compound were applied to prepare α-nucleated PP (α-PP) and β-nucleated PP (β-PP), respectively. Effects of UV irradiation on the molecular structure and tensile properties of pure PP, α-PP and β-PP were investigated. The relationship of tensile strength with carbonyl index was discussed. The change of relative content of β-modification in β-PP during photodegradation was examined by WAXD. The carbonyl index calculated from FTIR spectra arranged as α-PP > PP > β-PP, however, the tensile strength retention at the UV irradiation time of 792h arranged as PP > β-PP > α-PP. The relative content of β-crystal nearly unchanged during the photodegradation.

scholarly journals Biological tribology properties of the modified polyether ether ketone composite materials

2020 ◽  
Vol 59 (1) ◽  
pp. 399-405
Author(s):  
Li Ning ◽  
Chen Deqiang ◽  
Gao Xiyan ◽  
Lu Lirong ◽  
Chen Weizeng
Keyword(s):  
Tribological Properties ◽  
Blood Compatibility ◽  
Biological Properties ◽  
Nano Particles ◽  
Orthopaedic Implant ◽  
In Vivo Experiments ◽  
Polyether Ether Ketone ◽  
Medical Materials ◽  
Ether Ketone

AbstractModification of poly-ether-ether-ketone (PEEK) to adapt to the biological properties of materials is currently the key point in the research of medical materials. The tribological properties and biocompatibility of the PEEK composites modified by carbon fiber (CF), potassium titanate whisker(PTW) and nano-particles were discussed in this paper. The results show the modified PEEK composites by a certain length to diameter ratio of CF show the best using effect in vivo experiments in good blood compatibility, which is suitable for orthopaedic implant materials. A large number of experiments show that the PEEK composites would be modified with a certain ratio of CF (about 30%wt.), whisker (about 15%wt.) and HA (about 5%wt.) particle with better biological tribological properties, more important value in medical research.

scholarly journals Encapsulation of Capacitive Micromachined Ultrasonic Transducers (CMUTs) for the Acoustic Communication between Medical Implants

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 421
Author(s):  
Jorge Oevermann ◽  
Peter Weber ◽  
Steffen H. Tretbar
Keyword(s):  
Data Security ◽  
Ultrasonic Transducers ◽  
Surrounding Tissue ◽  
Center Frequency ◽  
Medical Implants ◽  
Research Groups ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Polyether Ether Ketone ◽  
High Bandwidth ◽  
Ether Ketone

The aim of this work was to extend conventional medical implants by the possibility of communication between them. For reasons of data security and transmitting distances, this communication should be realized using ultrasound, which is generated and detected by capacitive micromachined ultrasonic transducers (CMUTs). These offer the advantage of an inherent high bandwidth and a high integration capability. To protect the surrounding tissue, it has to be encapsulated. In contrast to previous results of other research groups dealing with the encapsulation of CMUTs, the goal here is to integrate the CMUT into the housing of a medical implant. In this work, CMUTs were designed and fabricated for a center frequency of 2 MHz in water and experimentally tested on their characteristics for operation behind layers of Polyether ether ketone (PEEK) and titanium, two typical materials for the housings of medical implants. It could be shown that with silicone as a coupling layer it is possible to operate a CMUT behind the housing of an implant. Although it changes the characteristics of the CMUT, the setup is found to be well suited for communication between two transducers over a distance of at least 8 cm.

Experimental study on the effect of surface texture on tribological properties of nanodiamond films under water lubrication

2021 ◽  
pp. 135065012110334
Author(s):  
Ying Yan ◽  
Xuelin Lei ◽  
Yun He
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Surface Texture ◽  
Diamond Film ◽  
Diamond Films ◽  
Nanocrystalline Diamond ◽  
Water Contact ◽  
Texture Density ◽  
Short Run

The effect of nanoscale surface texture on the frictional and wear performances of nanocrystalline diamond films under water-lubricating conditions were comparatively investigated using a reciprocating ball-on-flat tribometer. Although the untreated nanocrystalline diamond film shows a stable frictional state with an average friction coefficient of 0.26, the subsequent textured films show a beneficial effect on rapidly reducing the friction coefficient, which decreased to a stable value of 0.1. Furthermore, compared with the nanocrystalline diamond coating, the textured films showed a large decreasing rate of the corresponding ball wear rate from 4.16 × 10−3 to 1.15 × 10−3 mm3/N/m. This is due to the fact that the hydrodynamic fluid film composed of water and debris can provide a good lubrication environment, so the entire friction process has reached the state of fluid lubrication. Meanwhile, the surface texture can greatly improve the hydrophilicity of the diamond films, and as the texture density increases, the water contact angle decreases from 94.75° of the nanocrystalline diamond film to 78.5° of the textured films. The proper textured diamond film (NCD90) exhibits superior tribological properties among all tested diamond films, such as short run-in period, low coefficient of friction, and wear rate.

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