scholarly journals Evaluating the Effects of Nanosilica on Mechanical and Tribological Properties of Polyvinyl Alcohol/Polyacrylamide Polymer Composites for Artificial Cartilage from an Atomic Level

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 76 ◽  
Author(s):  
Qinghua Wei ◽  
Yanen Wang ◽  
Yiwen Rao ◽  
Anguo Jiang ◽  
Kun Zhang ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Polymer Composites ◽  
Polymer Composite ◽  
Tribological Properties ◽  
Weight Ratio ◽  
Dynamics Simulation ◽  
Mechanical And Tribological Properties ◽  
Friction Models ◽  
Nanosilica Particle ◽  
Nanosilica Particles

Due to the superior performances of nanosilica particles, this research has been designed to study their effects on the mechanical and trigological properties of a PVA/PAM polymer composite by a molecular dynamics simulation method. To realize the research objectives mentioned above, the molecular models of amorphous cells and sandwiched friction models for pure polyvinyl alcohol (PVA)/polyacrylamide (PAM) (component weight ratio is 1:1) and PVA/PAM/nanosilica (component weight ratio is 5.75:5.75:1) polymer composites were constructed and simulated, respectively. The simulation results of the mechanical properties show increases about 31.6% in the bulk modulus, 53.1% in the shear modulus, and 50.1% in the Young’s modulus by incorporating a nanosilica particle into a pure PVA/PAM polymer composite. Meanwhile, the changes in Cauchy pressure, B/G ratio, and Poisson’s ratio values indicate that incorporating a nanosilica particle into pure PVA/PAM weakened the ductility of the composite. Incorporating a nanosilica particle into a pure PVA/PAM composite also showed a decrease about 28.2% in the abrasion rates and relative concentration distributions of polymer molecules in the final friction models. Additionally, the binding energy and the pair correlation functions between a nanosilica particle and the polymer chains in a cubic cell demonstrate that incorporating nanosilica into PVA/PAM polymer composites improves the internal binding strength between different components through the forming hydrogen bonds. As a result, the mechanical and tribological properties of PVA/PAM polymer composites can be enhanced by incorporating nanosilica particles.

scholarly journals Molecular dynamics simulation to enhance the mechanical and tribological properties of polyimide composites by graphene reinforcement

2021 ◽  
Vol 2083 (2) ◽  
pp. 022107
Author(s):  
Zhe Chen ◽  
Aijiao Li ◽  
Hong Liu
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Polymer Composites ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Dynamics Simulation ◽  
Mechanical And Tribological Properties

Abstract Background: Polyimide is one of the organic polymer materials with the best comprehensive performance. It has outstanding mechanical properties, excellent thermal stability and excellent corrosion resistance, but pure polyimide has high coefficient of friction and wear rate. By combining graphene with polyimide, the mechanical properties of the composite are significantly reformatived, and the friction coefficient and wear rate can be reduced. Objective: The molecular models were developed to study the mechanical and tribological properties of graphene as a reinforced material. Methods: In this paper, the mechanical properties and friction and wear mechanism of materials are studied by molecular dynamics method from the microscopic point of view. The Young’s modulus and hardness of composites were calculated using the strain constant method. Results: Molecular dynamics simulation results expressed that the Young’s modulus and hardness of polymer composites benefited by approximately 115% and 42%, respectively, after the addition of the graphene-reinforced material. The average friction coefficient and wear rate of polymer composites fall by 35% and 48%, respectively. Through the calculation and statistics of the micro-information in the process of friction simulation, the internal mechanism of various situations is revealed in the atomic dimension. Conclusions: Graphene can adsorb on the surface of polymer chain segment, a strong polymer matrix, through van der Waals and electrostatic forces and can effectively resist external loading.

The effect of environmental humidity/water absorption on tribo-mechanical performance of polymers and polymer composites – a review

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kawaljit Singh Randhawa ◽  
Ashwin Patel
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Tribological Properties ◽  
Fiber Reinforced Polymer ◽  
Content Type ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Water Conditions

Purpose The mechanical and tribological properties of polymers and polymer composites vary with different environmental conditions. This paper aims to review the influence of humidity/water conditions on various polymers and polymer composites' mechanical properties and tribological behaviors. Design/methodology/approach The influence of humidity and water absorption on mechanical and tribological properties of various polymers, fillers and composites has been discussed in this paper. Tensile strength, modulus, yield strength, impact strength, COF and wear rates of polymer composites are compared for different environmental conditions. The interaction between the water molecules and hydrophobic polymers is also represented. Findings Pure polymer matrices show somewhat mixed behavior in humid environments. Absorbed moisture generally plasticizes the epoxies and polyamides and lowers the tensile strength, yield strength and modulus. Wear rates of PVC generally decrease in humid environments, while for polyamides, it increases. Fillers like graphite and boron-based compounds exhibit low COF, while MoS2 particulate fillers exhibit higher COF at high humidity and water conditions. The mechanical properties of fiber-reinforced polymer composites tend to decrease as the rate of humidity increases while the wear rates of fiber-reinforced polymer composites show somewhat mixed behavior. Particulate fillers like metals and advanced ceramics reinforced polymer composites exhibit low COF and wear rates as the rate of humidity increases. Originality/value The mechanical and tribological properties of polymers and polymer composites vary with the humidity value present in the environment. In dry conditions, wear loss is determined by the hardness of the contacting surfaces, which may not effectively work for high humid environments. The tribological performance of composite constituents, i.e. matrix and fillers in humid environments, defines the overall performance of polymer composite in said environments.

Effect of silanizion on mechanical and tribological properties of kenaf-carbon and kenaf-glass hybrid polymer composites

2020 ◽  
Vol 26 ◽  
pp. 2094-2098
Author(s):  
Kartik Singh ◽  
Diptikanta Das ◽  
Ramesh Kumar Nayak ◽  
Sourav Khandai ◽  
Ramanuj Kumar ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Tribological Properties ◽  
Hybrid Polymer ◽  
Mechanical And Tribological Properties

ANALYSIS OF TRIBOLOGICAL PROPERTIES OF SELECTED PTFE-BASED POLYMER COMPOSITES IN A SLIDING INTERACTION WITH ALUMINIUM OXIDE (Al2O3)

Tribologia ◽  
2018 ◽  
Vol 280 (4) ◽  
pp. 107-112 ◽  
Author(s):  
Władysław SKONECZNY ◽  
Sławomir KAPTACZ ◽  
Adrian BARYLSKI ◽  
Tomasz KMITA
Keyword(s):  
Mechanical Properties ◽  
Service Life ◽  
Polymer Composites ◽  
Tribological Properties ◽  
Mechanical Parameters ◽  
Reciprocating Motion ◽  
Graphite Content ◽  
Mechanical And Tribological Properties ◽  
Ptfe Composite ◽  
Bronze Powder

The paper presents the microstructure and mechanical and tribological properties of polymer composites based on polytetrafluoroethylene (PTFE) intended for use in friction couples where reciprocating motion is performed, e.g., in compressors or actuators. Micromechanical tests carried out using the Oliver-Pharr method showed that the PTFE composite with a 40% bronze content (T8B) had the most advantageous mechanical properties (hardness H, Young’s modulus E). In turn, tribological tests that were conducted using a ballon- disc tester in the linear (reciprocating) motion showed that the polytetrafluoroethylene composite with a mixture of 25% bronze powder and 15% graphite (T4GM) had the lowest tribological wear. The tribological properties of composite T5W with 25% graphite content were not much worse. Despite the most favourable mechanical parameters, the tribological wear of composites T8B and PTFE with glassy carbon (T3Ws) was nearly twice higher due to the absence of grease formed by a graphite filling. The results show that the use of composites containing a bronze-graphite filling improves the service life of lubricant-free friction couples that perform reciprocating motion.

scholarly journals A review on the mechanical properties for thin film and block structure characterised by using nanoscratch test

2019 ◽  
Vol 8 (1) ◽  
pp. 628-644
Author(s):  
Xianfeng Wang ◽  
Ping Xu ◽  
Rui Han ◽  
Jun Ren ◽  
Longyuan Li ◽  
...  
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Polymer Composite ◽  
Tribological Properties ◽  
Block Structure ◽  
Mode Selection ◽  
Deep Understanding ◽  
Single Layer ◽  
Adhesion Properties ◽  
Mechanical And Tribological Properties

AbstractThe nanoscratch test has been identified as one of the important tools for evaluating the mechanical and tribological properties of materials. This paper reviews the current researches on the nanoscratch test using to characterise the mechanical properties of three typical materials, including thin film, polymer composite and concrete, from the perspectives of the Berkovich indenter, parameter selection, mode selection, and analysis of resulting data. In addition, to provide a deep understanding on the test from different magnitude, a comparison between the microscratch test and nanoscratch test on the evaluation of tribological performance is also provided in this paper. The characterisation by nanoscratch test of two structural samples, in terms of layered film structures (thin film and coating sample) and single layer block structure (polymer composite sample and concrete samples) are also described in this paper, which aims to provides a deep understand on the evaluation the adhesion, tribological and interfacial properties of the typical materials samples by nanoscratch test. Finally, the coefficient of friction and critical load are discussed, which are two important parameters in tribological properties and adhesion properties.

Development of Antifriction Materials Based on Polytetrafluoroethylene with Carbon Fibers and Tungsten Disulfide

2020 ◽  
Vol 992 ◽  
pp. 745-750
Author(s):  
A.P. Vasilev ◽  
T.S. Struchkova ◽  
A.G. Alekseev
Keyword(s):  
Wear Resistance ◽  
Polymer Composites ◽  
Carbon Fibers ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Relative Elongation ◽  
Tungsten Disulfide ◽  
Degree Of Crystallinity ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction

This paper presents the results from the investigation of effect the carbon fibers with tungsten disulfide on the mechanical and tribological properties of PTFE. Is carried out a comparison of mechanical and tribological properties of polymer composites PTFE-based with carbon fibers and PTFE with complex filler (carbon fibers with tungsten disulfide). It is shown that at a content of 8 wt.% CF+1 wt.% WS2 in PTFE, wear resistance increases significantly while maintaining the tensile strength, relative elongation at break and low coefficient of friction at the level of initial PTFE. The results of X-ray analysis and investigation of SEM supramolecular structure and friction surfaces of PTFE and polymer composites are presented. It is shown that the degree of crystallinity of polymer composites increases in comparison with the initial PTFE. The images of scanning electron microscope reveal that particles of tungsten disulfide concentrating on the friction surface is likely responsible to a reduction in the coefficient of friction and increase the wear resistance of PTFE-based polymer composites with complex fillers.

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