Physical, mechanical, chemical and thermal properties of nanoscale graphene oxide-poly methylmethacrylate composites

2018 ◽  
Vol 52 (20) ◽  
pp. 2803-2813 ◽  
Author(s):  
Aftab A Khan ◽  
Eraj H Mirza ◽  
Badreldin A Mohamed ◽  
Nabeel H Alharthi ◽  
Hany S Abdo ◽  
...  

The purpose of this laboratory study was to formulate and characterize the graphene oxide-poly(methyl methacrylate) resin composite with an intended use as bone cement. Graphene oxide was fabricated through ultrasonication route. The autopolymerization resin (Eco Cryl Cold, Protechno, Vilamalla Girona, Spain) was used to prepare the specimens of required dimensions for different testing parameters. The control group (C-group) was prepared as such. However, for GO1-group, 0.024 wt/wt.-% of graphene oxide was incorporated in a resin matrix and GO2-group was a composite with 0.048 wt/wt.-% of graphene oxide in a resin matrix. TEM examination of graphene oxide sheets demonstrated them in the range of ∼500 nm to ∼2 µm. The mechanical properties were characterized using three-point bending and wear resistance, while material properties were assessed through transmission electron microscope, scanning electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, differential scanning calorimetry and thermo-gravimetric analysis. The results suggest that 0.024 wt/wt.-% and 0.048 wt/wt.-% of loading of GO have no effect on the physiochemical characteristics. However, thermal characteristics might slightly be improved. According to the analysis of variance results ( p < 0.05, n = 5), wear resistance and bending strength of both GO1 and GO2 groups significantly improved compared to C-group. The bending strength of GO2 improved to 87.0 ± 7.2 MPa from 65.9 ± 11.5 MPa of C-group. Scanning electron microscopy examination of the fractured surface demonstrated granule like structure where the graphene oxide sheets might be covered inside PMMA. The use of GO-PMMA composites favorably enhances the mechanical properties of bone cement.

2011 ◽  
Vol 56 (3) ◽  
pp. 805-812 ◽  
Author(s):  
B. Leszczyńska-Madej ◽  
M. Madej

The Properties of Babbitt Bushes in Steam Turbine Sliding BearingsThe analysis of the properties of babbitt bushes is presented in this article. Materials intended for examinations were charged from the TK-120 steam turbine of TG-8 turbosystem from the Power Station Stalowa Wola. The specimens were subsequently tested for Brinell hardness, microhardness, bending strength and wear resistance. The wear tests were carried out using the block-on-ring tester. The samples were also investigated by means of both light microscopy (LM) and scanning electron microscopy (SEM).


2007 ◽  
Vol 336-338 ◽  
pp. 1424-1425
Author(s):  
Sui Lin Shi ◽  
Ling Zhen Zhang

In this study, Al2O3-TiC composite was prepared at 1600°C for 1 h by hot-pressing using the Al2O3-TiC composite powder synthesized from self-propagating high-temperature synthesis (SHS) process. Mechanical properties of the composite were investigated, such as bulk density, Vickers hardness, fracture toughness and bending strength. The microstructure of the composite was also investigated by scanning electron microscopy (SEM).


2010 ◽  
Vol 148-149 ◽  
pp. 1571-1574
Author(s):  
Qing Li Hao ◽  
Jiao Tian ◽  
Hua Lan Wang ◽  
Xin Wang

The ordered polyaniline nanoarrays had dispersed homogeneously on the graphene oxide or reduced graphene oxide sheets without agglomeratation in isopropanol media. The composites were characterized by field emission scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, Raman spectroscopy and electrochemical tests. The electrochemical performance of the electrode material had been dramatically improved with the highest specific capacitance of 1351 F/g.


2012 ◽  
Vol 430-432 ◽  
pp. 327-330 ◽  
Author(s):  
Yong Qiang He ◽  
Hua Bin Chen ◽  
Hong Sun ◽  
Xiao Dong Wang ◽  
Jian Ping Gao

The pH and electric responsive composite hydrogels were prepared byin situpolymerization in the presence of graphene oxide (GO). Their structure and properties were characterized by scanning electron microscopy, Raman microscopy and mechanical testing. The results indicate that the GO is evenly dispersed in the composite hydrogels and the mechanical properties of the GO based composite hydrogels are significantly improved. Most importantly, the composite hydrogels were responsive to external stimuli such as pH and electric field.


2017 ◽  
Vol 52 (16) ◽  
pp. 2179-2188 ◽  
Author(s):  
Suneev Anil Bansal ◽  
Amrinder Pal Singh ◽  
Anil Kumar ◽  
Suresh Kumar ◽  
Navin Kumar ◽  
...  

Epoxy resins have been extensively utilized for mechanical strength applications in the field of aerospace, automobiles, marine, defence, etc. Improving the strength as well as fracture behaviour of the light weight materials is challenging. Present work is an attempt to enhance elastic modulus, hardness and fracture resistance simultaneously by reinforcing the epoxy (bisphenol-A) matrix with a new-age two-dimensional atomically thin graphene oxide filler. Wet chemical oxidation method was used to prepare graphene oxide sheets. Morphological study of the synthesized graphene oxide was carried out using scanning electron microscopy. Fourier-transformed infrared, ultraviolet–visible and Raman spectroscopic techniques were also employed to ascertain the synthesis of graphene oxide. The results confirmed the synthesis of well oxidized graphene oxide sheets. The prepared graphene oxide sheets were then sonicated in acetone solution to ensure better dispersion in the bisphenol-A graphene oxide nano-composite using 0.25, 0.5, 1.0 and 1.5 wt.% graphene oxide reinforcement. Solution mixing method was used to synthesize the polymer nano-composite. Scanning electron microscopy results revealed the smooth dispersion of graphene oxide in the bisphenol-A matrix. Nano-indentation of the bisphenol-A graphene oxide nano-composite showed a considerable jump in elastic modulus at 1 wt.% and hardness at 0.50 wt.% of graphene oxide reinforcement. Fracture resistance of bisphenol-A graphene oxide composite as represented by ratio of elastic modulus to hardness was enhanced by 24% as compared to the pristine bisphenol-A. Our results demonstrate a promising way to improve the mechanical characteristics of epoxy resins through graphene oxide reinforcement at low weight percentages.


Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2174
Author(s):  
Diana Gregor-Svetec ◽  
Mirjam Leskovšek ◽  
Blaž Leskovar ◽  
Urška Stanković Elesini ◽  
Urška Vrabič-Brodnjak

Polylactic acid (PLA) is one of the most suitable materials for 3D printing. Blending with nanoparticles improves some of its properties, broadening its application possibilities. The article presents a study of composite PLA matrix filaments with added unmodified and lignin/polymerised lignin surface-modified nanofibrillated cellulose (NFC). The influence of untreated and surface-modified NFC on morphological, mechanical, technological, infrared spectroscopic, and dynamic mechanical properties was evaluated for different groups of samples. As determined by the stereo and scanning electron microscopy, the unmodified and surface-modified NFCs with lignin and polymerised lignin were present in the form of plate-shaped agglomerates. The addition of NFC slightly reduced the filaments’ tensile strength, stretchability, and ability to absorb energy, while in contrast, the initial modulus slightly improved. By adding NFC to the PLA matrix, the bending storage modulus (E’) decreased slightly at lower temperatures, especially in the PLA samples with 3 wt% and 5 wt% NFC. When NFC was modified with lignin and polymerised lignin, an increase in E’ was noticed, especially in the glassy state.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Divine Sebastian ◽  
Chun-Wei Yao ◽  
Lutfun Nipa ◽  
Ian Lian ◽  
Gary Twu

In this work, a mechanically durable anticorrosion superhydrophobic coating is developed using a nanocomposite coating solution composed of silica nanoparticles and epoxy resin. The nanocomposite coating developed was tested for its superhydrophobic behavior using goniometry; surface morphology using scanning electron microscopy and atomic force microscopy; elemental composition using energy dispersive X-ray spectroscopy; corrosion resistance using atomic force microscopy; and potentiodynamic polarization measurements. The nanocomposite coating possesses hierarchical micro/nanostructures, according to the scanning electron microscopy images, and the presence of such structures was further confirmed by the atomic force microscopy images. The developed nanocomposite coating was found to be highly superhydrophobic as well as corrosion resistant, according to the results from static contact angle measurement and potentiodynamic polarization measurement, respectively. The abrasion resistance and mechanical durability of the nanocomposite coating were studied by abrasion tests, and the mechanical properties such as reduced modulus and Berkovich hardness were evaluated with the aid of nanoindentation tests.


2012 ◽  
Vol 184-185 ◽  
pp. 1380-1383
Author(s):  
Yong Ping Niu ◽  
Xiang Yan Li ◽  
Jun Kai Zhang ◽  
Ming Han ◽  
Yong Zhen Zhang

Polybutyl acrylate (PBA) grafted alumina nanoparticles were synthesized. Polytetrafluoroethylene (PTFE) nanocomposites reinforced with PBA grafted nanoparticles were prepared by compression molding. The effects of PBA grafted nanoparticles on the tribological behavior of the PTFE nanocomposites were investigated on a tribometer. The abrasion mechanisms of the PTFE nanocomposites were investigated by scanning electron microscopy (SEM) of the abraded surfaces. The results show that the addition of PBA grafted nanoparticles maintains low friction coefficient and improves the wear resistance of the PTFE nanocomposites.


2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


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