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Li X, Zhang Z, Wang Y. Penetration resistance of graphene oxide/epoxy resin coating-A molecular dynamics investigation. J Mol Model 2023; 29:283. [PMID: 37606698 DOI: 10.1007/s00894-023-05691-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/11/2023] [Indexed: 08/23/2023]
Abstract
CONTEXT The functionalization of graphene is the best way to improve its interfacial compatibility and dispersibility in polymer matrix to obtain high-performance composites. In this study, three nanocomposite models with different salt layer thicknesses were established and simulated by molecular dynamics method to understand the effect of oxygen-containing functional groups on the impermeability of epoxy coatings. Molecular dynamics (MD) simulation results show that the nanocomposites have better impermeability than pure epoxy resin. The thickness of salt solution affects the permeation rate of salt solution and the interfacial properties of nanocomposites. The salt solution molecules trapped in the coating are mainly concentrated at the interface between graphene and epoxy resin, which is the main reason for the decrease in interface properties of epoxy coating. METHODS In this paper, Material Studio 8.0 was used to construct nanocomposite models with different salt layer thicknesses (GO/SW7Å, GO/SW10Å, and GO/SW13Å), and MD simulations were performed using a large-scale atomic and molecular parallel simulator (LAMMPS).
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Affiliation(s)
- Xian Li
- Zhengzhou Railway Vocational Technical College, Zhengzhou, 450052, China
| | - Zhichao Zhang
- Zhengzhou Railway Vocational Technical College, Zhengzhou, 450052, China
| | - Yijun Wang
- Henan Intelligent Safety Engineering Research Center for Rail Transit, Zhengzhou, 450018, China.
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2
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Samyn P, Bosmans J, Cosemans P. Benchmark Study of Epoxy Coatings with Selection of Bio-Based Phenalkamine versus Fossil-Based Amine Crosslinkers. Molecules 2023; 28:molecules28114259. [PMID: 37298736 DOI: 10.3390/molecules28114259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 06/12/2023] Open
Abstract
The phenalkamines (PK) derived from cardanol oil can be used as a bio-based crosslinker for epoxy coatings as an alternative for traditional fossil amines (FA). First, the reaction kinetics of an epoxy resin with four PK and FA crosslinkers are compared by differential scanning calorimetry, illustrating a fast reaction rate and higher conversion of PK at room temperature in parallel with a moderate exothermal reaction. Second, the performance of coatings with various concentrations of PK and PK/FA ratios indicates good mixing compatibility between crosslinkers resulting in higher hardness, scratch resistance, hydrophobicity, and abrasive wear resistance of coatings with PK. The superior performance is confirmed over a broad range of resin/crosslinker ratios, facilitating the processing with viscosity profiles depending on the PK type. Although fossil- and bio-based crosslinkers have different chemical structures, the unique linear relationships between intrinsic mechanical properties (i.e., ductility and impact resistance) and coating performance indicate that the degree of crosslinking is a primary parameter controlling coating performance, where PK simultaneously provides high hardness and ductility. In conclusion, the optimization of the processing range for bio-based PK as a crosslinker for epoxy coatings delivers suitable processing conditions and superior mechanical performance compared to traditional amine crosslinkers.
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Affiliation(s)
- Pieter Samyn
- SIRRIS, Department of Innovations in Circular Economy and Renewable Materials, 3001 Leuven, Belgium
| | - Joey Bosmans
- SIRRIS, Department of Innovations in Circular Economy and Renewable Materials, 3001 Leuven, Belgium
| | - Patrick Cosemans
- SIRRIS, Department of Innovations in Circular Economy and Renewable Materials, 3001 Leuven, Belgium
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3
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Saleh SSM, Omar MF, Akil HM, Kudus MHA, Abdullah MMAB, Sandu AV, Vizureanu P, Halim KAA, Rasidi MSM, Mahamud SNS, Sandu I, Nosbi N. Preparation of Carbon Nanotubes/Alumina Hybrid-Filled Phenolic Composite with Enhanced Wear Resistance. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2772. [PMID: 37049066 PMCID: PMC10095878 DOI: 10.3390/ma16072772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/26/2023] [Accepted: 03/27/2023] [Indexed: 06/19/2023]
Abstract
Hybrid fillers can be produced via various methods, such as physical mixing and chemical modification. However, there is a limited number of studies on the effect of hybridisation on the mechanical performance of hybrid filler-reinforced polymer composites, especially in the context of wear performance. This study investigated the wear resistance of carbon nanotubes (CNTs)/alumina hybrid-filled phenolic composite, where two hybrid methods were used to produce the CNTs/alumina hybrid filler. The CNTs/alumina (CVD hybrid) was synthesised using the chemical vapour deposition (CVD) method, whereas the CNTs-/alumina (physically hybrid) was prepared using the ball milling method. The CNTs/alumina hybrid filler was then used as a filler in the phenolic composites. The composites were prepared using a hot mounting press and then subjected to a dry sliding wear test using a pin-on-disc (POD) tester. The results show that the composite filled with the CVD hybrid filler (HYB composite) had better wear resistance than the composite filled with physically hybrid filler (PHY composite) and pure phenolic. At 5 wt%, the HYB composite showed a 74.68% reduction in wear, while the PHY composite showed a 56.44% reduction in wear compared to pure phenolic. The HYB composite exhibited the lowest average coefficient of friction (COF) compared to the PHY composite and pure phenolic. The average COF decreased with increasing sliding speeds and applied loads. The phenolic composites' wear and average COF are in the order HYB composite < PHY composite < pure phenolic under all sliding speeds and applied loads.
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Affiliation(s)
- Siti Shuhadah Md Saleh
- Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis (UniMAP), Kangar 01000, Perlis, Malaysia
- Centre of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia
| | - Mohd Firdaus Omar
- Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis (UniMAP), Kangar 01000, Perlis, Malaysia
- Centre of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia
| | - Hazizan Md Akil
- School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal 14300, Pulau Pinang, Malaysia
| | - Muhammad Helmi Abdul Kudus
- School of Mechanical Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal 14300, Pulau Pinang, Malaysia
| | - Mohd Mustafa Al Bakri Abdullah
- Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis (UniMAP), Kangar 01000, Perlis, Malaysia
- Centre of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia
| | - Andrei Victor Sandu
- Faculty of Material Science and Engineering, Gheorghe Asachi Technical University of Iasi, 41 D. Mangeron St., 700050 Iasi, Romania
- Romanian Inventors Forum, Str. Sf. P. Movila 3, 700089 Iasi, Romania
- National Institute for Research and Development for Environmental Protection INCDPM, 294 Splaiul Independentei, 060031 Bucharest, Romania
| | - Petrica Vizureanu
- Faculty of Material Science and Engineering, Gheorghe Asachi Technical University of Iasi, 41 D. Mangeron St., 700050 Iasi, Romania
- Technical Sciences Academy of Romania, Dacia Blvd 26, 030167 Bucharest, Romania
| | - Khairul Anwar Abdul Halim
- Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis (UniMAP), Kangar 01000, Perlis, Malaysia
- Centre of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia
| | - Mohamad Syahmie Mohamad Rasidi
- Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis (UniMAP), Kangar 01000, Perlis, Malaysia
- Centre of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia
| | - Syarifah Nuraqmar Syed Mahamud
- Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis (UniMAP), Kangar 01000, Perlis, Malaysia
- Centre of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis, Kangar 01000, Perlis, Malaysia
| | - Ion Sandu
- Romanian Inventors Forum, Str. Sf. P. Movila 3, 700089 Iasi, Romania
- National Institute for Research and Development for Environmental Protection INCDPM, 294 Splaiul Independentei, 060031 Bucharest, Romania
- Arheoinvest Platform, Alexandru Ioan Cuza University of Iasi, Bd. Carol I, No. 22, Iasi 700506, Romania
- Academy of Romanian Scientists AOSR, 54 Splaiul Independentei St., Sect 5, 050094 Bucharest, Romania
| | - Norlin Nosbi
- Department of Mechanical Engineering, Centre for Corrosion Research (CCR), Institute of Contaminant Management for Oil and Gas (ICM), Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak, Malaysia
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Jiao C, Cai T, Chen H, Ruan X, Wang Y, Gong P, Li H, Atkin R, Yang F, Zhao H, Nishimura K, Jiang N, Yu J. A mucus-inspired solvent-free carbon dot-based nanofluid triggers significant tribological synergy for sulfonated h-BN reinforced epoxy composites. NANOSCALE ADVANCES 2023; 5:711-724. [PMID: 36756511 PMCID: PMC9890617 DOI: 10.1039/d2na00689h] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 12/08/2022] [Indexed: 06/18/2023]
Abstract
Nano-filler reinforced polymer-based composites have attracted extensive attention in tribology; however, to date, it is still challenging to construct a favorable lubricating system with excellent compatibility, lubricity and durability using nano-filler reinforced polymer-based composites. Herein, sulfonated boron nitride nano-sheets (h-BN@PSDA) are prepared and used as nano-fillers for epoxy resins (EPs), to improve friction and wear along with thermal conductivity. Furthermore, inspired by the lubricating principle and structure of snail mucus, a solvent-free carbon dot-based nanofluid (F-CDs) is fabricated and used for the first time as the lubricant for h-BN@PSDA/EPs. Both poly (4-styrene sulfonate) and polyether amine grafted on the surface of F-CDs contribute to branched structures and multiple interfacial absorption effects. Extraordinarily low friction and wear are detected after long-term sliding. The average coefficient of friction and wear rate of h-BN@PSDA/EPs composites are reduced by 95.25% and 99.42% respectively, in the presence of the F-CD nanofluid, compared to that of EPs. Besides, the added h-BN nano-sheets increase the thermal conductivity (TC) of EPs from 0.178 to 0.194 W (m-1 K-1). The distinguished lubrication performances are likely due to the formation of a hybrid nanostructure of 0D F-CDs and 2D h-BN@PSDA together with the "rolling-sliding" and "self-mending" effects of added F-CDs.
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Affiliation(s)
- Chengcheng Jiao
- School of Materials Science and Engineering, Shenyang University of Chemical Technology Shenyang 110142 China
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
| | - Tao Cai
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
| | - Huanyi Chen
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
| | - Xinxin Ruan
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
| | - Yandong Wang
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
| | - Ping Gong
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
| | - Hua Li
- School of Molecular Sciences, University of Western Australia Perth Western Australia Australia
| | - Rob Atkin
- School of Molecular Sciences, University of Western Australia Perth Western Australia Australia
| | - Feng Yang
- School of Materials Science and Engineering, Shenyang University of Chemical Technology Shenyang 110142 China
| | - Haichao Zhao
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
| | - Kazuhito Nishimura
- Advanced Nano-Processing Engineering Lab, Mechanical Engineering, Kogakuin University Tokyo 192-0015 Japan
| | - Nan Jiang
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
| | - Jinhong Yu
- Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
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5
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Influence of Maleinized Polybutadiene on Adhesive Strength and Toughness of Epoxy Resins. INT J POLYM SCI 2022. [DOI: 10.1155/2022/9517467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This study explored the effect of maleinized polybutadiene (MPB) on the mechanical properties of epoxy resins. Diglycidyl ether of bisphenol-A, an epoxy resin, was modified by incorporating MPB having different molecular weights in order to improve the fracture toughness and peel strength. MPB was mixed with epoxy resin at several concentrations (5, 10, and 15 phr), with the epoxy resin as the major phase and MPB as the minor phase. A comparative study was performed to investigate the influence of MPB on epoxy resins based on their molecular weight difference. Lap shear test results showed that the shear strength of the MPB-modified epoxy resins was superior to that of the neat epoxy resin. At 10 wt% MPB loading, the modified epoxy resin exhibited an 87% enhancement in T-peel strength relative to that of the neat epoxy resin. Moreover, the fracture energy of the modified epoxy system increased proportionally with the amount of MPB in the epoxy matrix. These results indicate that MPB incorporation is a simple and effective method for designing multifunctional epoxy resins, thus facilitating their industrial application in various spheres.
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Guo L, Chen Z, Han H, Liu G, Luo M, Cui N, Dong H, Li MZ. Advances and outlook in modified graphene oxide (GO)/epoxy composites for mechanical applications. APPLIED NANOSCIENCE 2022. [DOI: 10.1007/s13204-022-02653-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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7
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Liu C, Xue X, Yuan Q, Lin Y, Bao Y, He Y, Zhang W. Preparation and Tribological Properties of Bismaleimide Matrix Composites Reinforced with Covalent Organic Framework Coated Graphene Nanosheets. Polymers (Basel) 2022; 14:polym14163289. [PMID: 36015546 PMCID: PMC9416587 DOI: 10.3390/polym14163289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/06/2022] [Accepted: 08/07/2022] [Indexed: 11/16/2022] Open
Abstract
The poor compatibility between the polymer matrix and complex modification processes greatly affects the excellent tribological properties of graphene in the polymer matrix. In this study, a covalent organic framework (COF)-coated graphene hybrid lubricating filler (G/COFs) was synthesized in situ using a sample one-step mechanochemical synthesis process. This was used to improve the tribological properties of bismaleimide (BMI) resin. The morphology and microstructure of the G/COFs hybrid were characterized, and the effect of the added amount on the tribological properties of the G/COFs/BMI composites was studied. The results showed that the G/COFs hybrid could improve the stability of the friction coefficient and decrease the volume wear rate of BMI composites. Compared to the neat BMI, the 0.6 wt% G/COFs/BMI composites showed optimal tribological performance, with the friction coefficient and volume wear rate decreasing from 0.35 to 0.14 and from 48 × 10-6 to 10.6 × 10-6 mm3/(N‧m), respectively. In addition, the G/COFs/BMI composites showed lower friction coefficient fluctuations and volume wear rates than G/BMI composites. This is mainly attributed to the fact that the deposition of COFs can not only effectively prevent the aggregation of graphene nanosheets, but can also significantly improve the compatibility and interfacial bond between the graphene and BMI matrix. Moreover, the good synergistic effect between the lamellar COFs and graphene nanosheets can generate high-quality self-lubricating transfer films during the friction process. The excellent dispersibility, efficient chemical functionalization, better friction reduction and wear-resistance properties, and facile preparation method make graphene/COFs hybrid nanoparticles promising as an excellent lubricating filler.
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Affiliation(s)
- Chao Liu
- Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and Technology, Shaanxi University of Science and Technology, Xi’an 710021, China
- College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China
- Correspondence:
| | - Xin Xue
- College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China
| | - Qiming Yuan
- College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China
| | - Yang Lin
- College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China
| | - Yan Bao
- College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China
| | - Yinkun He
- College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China
| | - Wenbo Zhang
- Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and Technology, Shaanxi University of Science and Technology, Xi’an 710021, China
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8
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Yue R, Liu Y, Xia S, Xu S, Cao S. Raman Imaging Evidence for Mechanical/Tribological Quasi-Steady State in GO-Strengthening Polyurethane/Epoxy Interpenetrating Polymer Network. Macromol Res 2022. [DOI: 10.1007/s13233-022-0055-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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Zhu C, Wei N, Zhao J. Coarse-Grained Potentials of Poly(vinyl alcohol)/Graphene Oxide Interfaces. Macromolecules 2022. [DOI: 10.1021/acs.macromol.1c02117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chunhua Zhu
- Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology, Jiangnan University, Wuxi 214122, P. R. China
| | - Ning Wei
- Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology, Jiangnan University, Wuxi 214122, P. R. China
| | - Junhua Zhao
- Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology, Jiangnan University, Wuxi 214122, P. R. China
- Institute of Mechanics and Advanced Materials, School of Mechanical Engineering, Jiangnan University, Wuxi 214122, P. R. China
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Liu Y, Gao G, Jiang D, Yin Z. Enhancement of the Water-Lubricated Tribological Properties of Hybrid PTFE/Nomex Fabric Laminate Composite via Epoxy Resin and Graphite Filler. MATERIALS 2021; 15:ma15010062. [PMID: 35009208 PMCID: PMC8746200 DOI: 10.3390/ma15010062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/08/2021] [Accepted: 12/09/2021] [Indexed: 11/25/2022]
Abstract
This paper studied a hybrid polytetrafluoroethylene (PTFE)/Nomex fabric composite with lower friction coefficient (COF) and high underwater wear resistance. A pin-on-disk tribometer was used to test tribological properties under different applied loads and rotation speeds. The wear surface, transfer film and cross-section were analyzed by scanning electron microscope (SEM) and optical microscope. The results showed enhanced underwater tribological properties because of excellent self-lubricating properties of PTFE fibers and a good lubricating effect and load-carrying capacity of graphite fillers. Improved underwater mechanical strength was connected to the high strength of epoxy resin and high bonding force between Nomex and epoxy resin.
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11
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Recent advances in the study of structure and properties of fiber composites with an epoxy matrix. JOURNAL OF POLYMER RESEARCH 2021. [DOI: 10.1007/s10965-021-02783-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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12
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Shirani A, Li Y, Eryilmaz OL, Berman D. Tribocatalytically-activated formation of protective friction and wear reducing carbon coatings from alkane environment. Sci Rep 2021; 11:20643. [PMID: 34667195 PMCID: PMC8526829 DOI: 10.1038/s41598-021-00044-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/01/2021] [Indexed: 11/09/2022] Open
Abstract
Minimizing the wear of the surfaces exposed to mechanical shear stresses is a critical challenge for maximizing the lifespan of rotary mechanical parts. In this study, we have discovered the anti-wear capability of a series of metal nitride-copper nanocomposite coatings tested in a liquid hydrocarbon environment. The results indicate substantial reduction of the wear in comparison to the uncoated steel substrate. Analysis of the wear tracks indicates the formation of carbon-based protective films directly at the sliding interface during the tribological tests. Raman spectroscopy mapping of the wear track suggests the amorphous carbon (a-C) nature of the formed tribofilm. Further analysis of the tribocatalytic activity of the best coating candidate, MoN-Cu, as a function of load (0.25–1 N) and temperature (25 °C and 50 °C) was performed in three alkane solutions, decane, dodecane, and hexadecane. Results indicated that elevated temperature and high contact pressure lead to different tribological characteristics of the coating tested in different environments. The elemental energy dispersive x-ray spectroscopy analysis and Raman analysis revealed formation of the amorphous carbon film that facilitates easy shearing at the contact interface thus enabling more stable friction behavior and lower wear of the tribocatalytic coating. These findings provide new insights into the tribocatalysis mechanism that enables the formation of zero-wear coatings.
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Affiliation(s)
- Asghar Shirani
- Department of Materials Science and Engineering, University of North Texas, Denton, TX, 76203, USA
| | - Yuzhe Li
- Department of Materials Science and Engineering, University of North Texas, Denton, TX, 76203, USA
| | | | - Diana Berman
- Department of Materials Science and Engineering, University of North Texas, Denton, TX, 76203, USA.
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Bhatia S, Khan S, Angra S. Effect of the content of silane-functionalized boron carbide on the mechanical and wear performance of B4C reinforced epoxy composites. HIGH PERFORM POLYM 2021. [DOI: 10.1177/09540083211031129] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This article presents the mechanical, physical, and tribological properties of the boron carbide (B4C) reinforced epoxy matrix composites (BEMCs). The BEMC samples were prepared with various B4C concentration of 0%, 1%, 2%, 3%, and 5%. B4C particles were treated with a silane coupling agent to ensure efficient adhesion with epoxy. The influence of a range of parameters (particle loading, sliding speed, sliding distance, and normal load) on the wear and friction behavior of BEMCs were evaluated by conducting wear tests under dry sliding conditions on a pin-on-disc wear test set-up. The addition of B4C to the epoxy polymer improved the wear resistance of the composites. Maximum wear resistance and coefficient of friction were observed for the composite with the highest percentage of B4C (5%). The specific wear rate was reduced on increasing load and sliding distance and increased with the sliding velocity. Mechanical properties including compression strength, flexural strength, and impact energy, along with physical properties such as density and hardness, were also evaluated. B4C particles improved the hardness, density, flexural and compression strength, and impact resistance of the composites. Scanning electron microscope (SEM) analysis of the worn-out surfaces and flexural fractured surfaces was carried out to predict the possible wear and fracture mechanisms. Micro-ploughing, abrasion, and adhesion were the wear mechanisms in BEMCs. Under the flexural loads, particulate de-bonding, pull-out, and brittle fracture of the matrix were the governing failure mechanisms.
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Affiliation(s)
- Sunny Bhatia
- Mechanical Engineering Department, National Institute of Technology Kurukshetra, Faridabad, India
- Automobile Engineering Department, Manav Rachna International Institute of Research and Studies, Faridabad, India
| | - Sabah Khan
- Mechanical Engineering Department, Jamia Millia Islamia, New Delhi, India
| | - Surjit Angra
- Mechanical Engineering Department, National Institute of Technology Kurukshetra, Faridabad, India
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14
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Wang Y, Zhu Y, Wu H. Formation and topological structure of three-dimensional disordered graphene networks. Phys Chem Chem Phys 2021; 23:10290-10302. [PMID: 33903875 DOI: 10.1039/d1cp00617g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Disordered graphene networks (DGNs) can be regarded as the three-dimensional (3D) assembly of graphene-like fragments at the nanoscale, in which some intrinsic topological features are usually hidden in these formless fragments without clear understanding. Although some high-resolution structural patterns have been observed in pyrolytic carbons and flash graphene experimentally, it is still hard to characterize the topology and texture of DGNs considering continuous 3D connectivity. Toward this end, starting from the annealing process, we herein performed molecular dynamics simulations to investigate the formation and topological structure of DGNs. Three typical stages are found during the formation of DGNs, that is, the formation of polyaromatic fragments, formation of a disordered framework, and further graphitization. The topology of the obtained DGNs was then investigated, including topological defects, stacking behavior, and global curvature. Several typical in-plane and out-of-plane topological defects are found to connect the 3D network of graphene-like layers. The computed X-ray diffraction and angular defects demonstrate that a high-density DGN tends to form a randomly stacked structure with more connections, while a low-density DGN exhibits more bowl-shaped layers and a less distorted curvature. At low annealing temperatures, the local curvature of DGNs is highly distorted, and the structure seems to lack graphitization compared to high-temperature ones.
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Affiliation(s)
- YongChao Wang
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, CAS Center for Excellence in Complex System Mechanics, University of Science and Technology of China, Hefei 230027, China.
| | - YinBo Zhu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, CAS Center for Excellence in Complex System Mechanics, University of Science and Technology of China, Hefei 230027, China.
| | - HengAn Wu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, CAS Center for Excellence in Complex System Mechanics, University of Science and Technology of China, Hefei 230027, China.
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15
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Li J, Ren C, Sun Z, Ren Y, Lee H, Moon KS, Wong CP. Melt Processable Novolac Cyanate Ester/Biphenyl Epoxy Copolymer Series with Ultrahigh Glass-Transition Temperature. ACS APPLIED MATERIALS & INTERFACES 2021; 13:15551-15562. [PMID: 33755416 DOI: 10.1021/acsami.0c20537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The rapid progress in silicon carbide (SiC)-based technology for high-power applications expects an increasing operation temperature (up to 250 °C) and awaits reliable packaging materials to unleash their full power. Epoxy-based encapsulant materials failed to provide satisfactory protection under such high temperatures due to the intrinsic weakness of epoxy resins, despite their unmatched good adhesion and processability. Herein, we report a series of copolymers made by melt blending novolac cyanate ester and tetramethylbiphenyl epoxy (NCE/EP) that have demonstrated much superior high-temperature stability over current epoxies. Benefited from the aromatic, rigid backbone and the highly functional nature of the monomers, the highest values achieved for the copolymers are as follows: glass-transition temperature (Tg) above 300 °C, decomposition onset above 400 °C, and char yield above 45% at 800 °C, which are among the highest of the known epoxy chemistry by far. Moreover, the high-temperature aging (250 °C) experiments showed much reduced mass loss of these copolymers compared to the traditional high-temperature epoxy and even the pure NCE in the long term by suppressing hydrolysis degradation mechanisms. The copolymer composition, i.e., NCE to EP ratio, has found to have profound impacts on the resin flowability, thermomechanical properties, moisture absorption, and dielectric properties, which are discussed in this paper with in-depth analysis on their structure-property relationships. The outstanding high-temperature stability, preferred and adjustable processability, and the dielectric properties of the reported NCE/EP copolymers will greatly stimulate further research to formulating robust epoxy molding compounds (EMCs) or underfill for packaging next-generation high-power electronics.
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Affiliation(s)
- Jiaxiong Li
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Chao Ren
- School of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu, Anhui 241000, China
| | - Zhijian Sun
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Yanjuan Ren
- Department of Materials Science and Engineering, CAPT/HEDPS/LTCS, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Engineering, Peking University, Beijing 100871, China
| | - Haksun Lee
- School of Electrical and Computing Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Kyoung-Sik Moon
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ching-Ping Wong
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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