STRETCHING-INDUCED ORIENTATION TO IMPROVE MECHANICAL PROPERTIES OF ELECTROSPUN PAN NANOCOMPOSITES

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5913-5918 ◽  
Author(s):  
X. X. HOU ◽  
X. P. YANG ◽  
F. ZHANG ◽  
S. Z. WU ◽  
E. WACLAWIK
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Nanofibers ◽  
High Performance ◽  
Carbon Composites ◽  
X Ray Diffraction ◽  
Fiber Alignment ◽  
X Ray ◽  
Potential Precursor

Partially aligned and oriented polyacrylonitrile(PAN)-based nanofibers were electrospun from PAN and SWNTs/PAN in the solution of dimethylformamide(DMF) to make the carbon nanofibers. The as-spun nanofibers were hot-stretched in an oven to enhance its orientation and crystallinity. Then it were stabilized at 250 °C under a stretched stress, and carbonized at 1000 °C in N 2 atmosphere by fixing the length of the stabilized nanofiber to convert them into carbon nanofibers. With this hot-stretched process and with the introduction of SWNTs, the mechanical properties will be enhanced correspondingly. The crystallinity of the stretched fibers confirmed by X-ray diffraction has also increased. For PAN nanofibers, the improved fiber alignment and crystallinity resulted in the increased mechanical properties, such as the modulus and tensile strength of the nanofibers. It was concluded that the hot-stretched nanofiber and the SWNTs/PAN nanofibers can be used as a potential precursor to produce high-performance carbon composites.

Stretching-Induced Orientation for Improving the Mechanical Properties of Electrospun Polyacrylonitrile Nanofiber Sheet

2008 ◽  
Vol 47-50 ◽  
pp. 1169-1172 ◽  
Author(s):  
Si Zhu Wu ◽  
Feng Zhang ◽  
Xiao Xiao Hou ◽  
Xiao Ping Yang
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofibers ◽  
Molecular Orientation ◽  
High Performance ◽  
Carbon Composites ◽  
X Ray Diffraction ◽  
Fiber Alignment ◽  
X Ray ◽  
N2 Atmosphere ◽  
Potential Precursor

Partially aligned and oriented polyacrylonitrile(PAN)-based nanofibers were electrospun from PAN and CNTs/PAN in the solution of dimethylformamide(DMF) to manufacture the carbon nanofibers. The as-spun nanofibers were hot-stretched in a temperature controlled oven to enhance its crystallinity and molecular orientation. Therefore it were stabilized at 250 ( under a stress, and carbonized at 1000 ( in N2 atmosphere by fixing the length of the stabilized nanofiber to convert them into carbon nanofibers. With the hot-stretched process and with the content of CNTs, the mechanical properties will be enhanced correspondingly. The crystallinity of the stretched fibers confirmed by X-ray diffraction has also increased. For PAN nanofibers, the improved fiber alignment and crystallinity resulted in the increased mechanical properties, such as the modulus and tensile strength of the nanofibers. It was concluded that the hot-stretched nanofiber and the CNTs/PAN nanofibers can be used as a potential precursor to produce high-performance carbon composites.

scholarly journals Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
High Performance ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rubber Blends ◽  
Ft Ir ◽  
Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

Structure and properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/poly(L-lactic acid) quasi core/sheath melt-electrospun microfibers

2018 ◽  
Vol 89 (9) ◽  
pp. 1770-1781 ◽  
Author(s):  
Huaizhong Xu ◽  
Benedict Bauer ◽  
Masaki Yamamoto ◽  
Hideki Yamane
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Tensile Tests ◽  
Processing Parameters ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Diffraction Patterns

A facile route was proposed to fabricate core–sheath microfibers, and the relationships among processing parameters, crystalline structures and the mechanical properties were investigated. The compression molded poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH)/poly(L-lactic acid) (PLLA) strip enhanced the spinnability of PHBH and the mechanical properties of PLLA as well. The core–sheath ratio of the fibers was determined by the prefab strip, while the PLLA sheath component did not completely cover the PHBH core component due to the weak interfacial tension between the melts of PHBH and PLLA. A rotational target was applied to collect aligned fibers, which were further drawn in a water bath. The tensile strength and the modulus of as-spun and drawn fibers increased with increasing the take-up velocities. When the take-up velocity was above 500 m/min, the jet became unstable and started to break up at the tip of the Taylor cone, decreasing the mechanical properties of the fibers. The drawing process facilitated the crystallization of PLLA and PHBH, and the tensile strength and the modulus increased linearly with the increasing the draw ratio. The crystal information displayed from wide-angle X-ray diffraction patterns and differential scanning calorimetry heating curves supported the results of the tensile tests.

Effect of AlN on Microstructure and Mechanical Properties of Mg-Al-Zn Alloy

2011 ◽  
Vol 704-705 ◽  
pp. 1095-1099
Author(s):  
Peng Liu ◽  
Hao Ran Geng ◽  
Zhen Qing Wang ◽  
Jian Rong Zhu ◽  
Fu Sen Pan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Tensile Testing ◽  
Cast Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Microstructure And Mechanical Properties ◽  
Zn Alloy

Effects of AlN addition on the microstructure and mechanical properties of as-cast Mg-Al-Zn magnesium alloy were investigated using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and tensile testing. Five different samples were made with different amounts of AlN(0wt%, 0.12wt%, 0.30wt%, 0.48wt%, 0. 60wt%). The results show that the phases of as-cast alloy are composed of α-Mg,β-Mg17Al12. The addition of AlN suppressed the precipitation of the β-phase. And, with the increase of AlN content, the microstructure of β-phase was changed from the reticulum to fine grains. When AlN content was up to 0.48wt% in the alloy, the β-phase became most uniform distribution. After adding 0.3wt% AlN to Al-Mg-Zn alloy, the average alloy grain size reduced from 102μm to 35μm ,the tensile strength of alloy was the highest. The average tensile strength increased from 139MPa to 169.91MPa, the hardness increased from 77.7HB to 98.4HB, but the elongation changes indistinctively. However, when more amount of AlN was added, the average alloy grain size did not reduce sequentially and increased to 50μm by adding 0.6wt% AlN and the β-phase became a little more. Keywords: Al-Mg-Zn alloy; AlN; β-Mg17Al12; Tensile strength

Studies on mechanical properties, dielectric behavior and DC conductivity of neodymium oxide/poly (butyl methacrylate) nanocomposites

2020 ◽  
pp. 096739112096065
Author(s):  
K Suhailath ◽  
Meenu Thomas ◽  
MT Ramesan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Neodymium Oxide ◽  
Dielectric Behavior ◽  
Dc Conductivity ◽  
Butyl Methacrylate ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Uniform Dispersion

The current article aims to develop poly (butyl methacrylate) (PBMA) nanocomposites with enhanced electrical and mechanical properties by incorporating neodymium oxide (Nd2O3) nanoparticles between the PBMA chains. The morphological, thermal and structural profiles of the PBMA nanocomposites reinforced with different loading of Nd2O3 nanoparticles were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The SEM images revealed that the morphology of the PBMA was significantly influenced by the insertion of Nd2O3. The uniform dispersion of Nd2O3 in the polymer composite was visible at 5 wt% loading of nano-filler. The main crystalline peaks of Nd2O3 nanoparticles in the amorphous PBMA structure were revealed by the X-ray diffraction analysis. The thermal stability of PBMA was greatly enhanced by the dispersion of Nd2O3 in the PBMA matrix. The tensile strength and elongation at break of the composites were measured and both results showed the enhanced mechanical properties of PBMA due to the reinforcement of Nd2O3 nanoparticles. The various parameters affecting the increased tensile strength of composite by the incorporation of nanoparticles were studied by different theoretical modeling. The electrical properties such as dielectric constant and the dielectric loss tangent (tan δ) of PBMA nanocomposites were enhanced with the addition of nanoparticles. Also, the DC conductivity of polymer composites was estimated and the applicability of different theoretical models for predicting the conductivity properties of PBMA/Nd2O3 nanocomposites were examined.

Influence of B4C on enhancing mechanical properties of AA2014 aluminum matrix composites

2021 ◽  
pp. 095440622110585
Author(s):  
Memduh Kara ◽  
Tolga Coskun ◽  
Alper Gunoz
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Aluminum Matrix ◽  
Good Method ◽  
Aluminum Matrix Composites ◽  
Phase Identification ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
X Ray

Aluminum is a material with advantageous properties such as lightness, good conductivity, high plastic deformation ability, and superior corrosion resistance. However, aluminum and many aluminum alloys have disadvantages in terms of mechanical properties such as hardness, tensile strength, and wear resistance. To overcome this disadvantage of aluminum, it is a good method to add ceramic particles to the matrix. For this purpose, in this study, B4C (boron carbide)-reinforced AA2014 aluminum matrix composites were fabricated at 3%, 5%, and 7% reinforcement ratios using the stir casting method. Tensile tests, wear tests, cutting force measurements, and microhardness measurements were performed to determine the fabricated composite materials’ mechanical properties. Scanning electron microscopy and optical microscopy were used to analyze the microstructure of composite. X-ray diffraction analysis was utilized to study the phase identification. As a result of the study, it was observed that with the increase in the B4C reinforcement ratio, the mechanical properties of the aluminum matrix composite material, such as wear resistance, cutting strength, and hardness, increased. On the other hand, the change in tensile strength did not occur in this way. Tensile strength first increased and then decreased. The highest value of tensile strength was achieved at 5% B4C reinforcement. X-ray diffraction results showed that AA2014 and B4C were the fundamental elements in composites and are free from intermetallics.

A Study on Copper Alloy C194 Lead Frame Grain Size Correlation to the Mechanical Properties Variations in Microelectronic Assembly Line

2012 ◽  
Vol 516-517 ◽  
pp. 1902-1905 ◽  
Author(s):  
Abd Rashid Amirul ◽  
Yusoff Mahani
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Copper Alloy ◽  
Assembly Line ◽  
Lead Frame ◽  
X Ray Diffraction ◽  
X Ray ◽  
Die Attach ◽  
Typical Performance

Copper alloy C194 lead frame occasionally has been observed creates non-sticking defect at wire bond process in typical microelectronic assembly line. The effect was significantly assessed as process variation during die attach. In this study, microstructure and mechanical properties of copper alloy lead frames were investigated. The copper alloy lead frames were selected from different batches in the production line that produced sticking (typical performance) and non-sticking defect. The micro structural and structural properties were investigated by means of optical microscopy (OM) and X-ray diffraction (XRD), respectively. The hardness and tensile strength were also determined. The result revealed that non-sticking lead frame has larger grain size of 43.8 nm than typical performance lead frame. Due to lower dislocation density, tensile strength and hardness of typical lead frame with smaller grain size were higher than that of defect lead frame. Elongation of defect lead frame was reached above 10% as compared to typical performance lead frame groups with the value below 4%.

scholarly journals The Effect of Incorporating Silica Stone Waste on the Mechanical Properties of Sustainable Concretes

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3832 ◽  
Author(s):  
Saeid Abbasi ◽  
Mohammad Hemen Jannaty ◽  
Rabar H. Faraj ◽  
Shahriar Shahbazpanahi ◽  
Amir Mosavi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Sustainable Construction ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Sem Images ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
The Matrix ◽  
First Time

Incorporating various industrial waste materials into concrete has recently gained attention for sustainable construction. This paper, for the first time, studies the effects of silica stone waste (SSW) powder on concrete. The cement of concrete was replaced with 5, 10, 15, and 20% of the SSW powder. The mechanical properties of concrete, such as compressive and tensile strength, were studied. Furthermore, the microstructure of concrete was studied by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy analysis (EDX), Fourier transformed infrared spectroscopy (FTIR), and X-Ray diffraction (XRD) tests. Compressive and tensile strength of samples with 5% SSW powder was improved up to 18.8% and 10.46%, respectively. As can be observed in the SEM images, a reduced number of pores and higher density in the matrix can explain the better compressive strength of samples with 5% SSW powder.

Microstructures and Properties of W-26Re Alloy by SPS

2012 ◽  
Vol 236-237 ◽  
pp. 113-117
Author(s):  
Song Wang ◽  
Ming Xie
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Test Results ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tester ◽  
Fine Grain ◽  
Plasma Sintering ◽  
Spark Plasma

W-26Re alloy was fabricated by spark plasma sintering (SPS) technology. The phases, microstructures and mechanical properties of the alloy were investigated by X-ray diffraction, optical light microscope, scanning electron microscope, energy dispersion spectroscope, digital display micro-hardness tester and tensile test. Results show that, using SPS technique can prepare W-26Re alloy with high density, fine grain and excellent mechanical properties. The relative density of W-26Re alloy was 96.2%. The main phases in the alloy were determined by the amount of (W) solid solution and the intermetallic  phases. The micro-hardness was 729HV, the ultimate tensile strength was 1680MPa, yield tensile strength was 1143MPa and elongation of alloy was 8.7%.

Sintering Effect on Mechanical Properties of Composites of Bovine Derived Hydroxyapatite (BHA) with Titanium

2006 ◽  
Vol 309-311 ◽  
pp. 359-362 ◽  
Author(s):  
L.S. Ozyegin ◽  
Oguzhan Gunduz ◽  
Faik N. Oktar ◽  
B. Oz ◽  
Simeon Agathopoulos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
High Performance ◽  
X Ray Diffraction ◽  
Metallic Titanium ◽  
Load Bearing ◽  
X Ray ◽  
Properties Of Composites ◽  
Sintering Effect

The aim of this study was to prepare high performance biomaterials suitable for use at load bearing applications with high bioactivity. The hydroxyapatite (HA) was prepared from bovine bones via calcination technique. The bovine derived HA (BHA) was mixed with 5 and 10 wt% metallic titanium (Ti) and the obtained homogenous mixtures were pressed to produce the test samples. The compacts were sintered at temperatures between 1000 and 1300°C. Compression strength, density, and microhardness were measured. SEM and X-ray diffraction studies were also made. The best mechanical properties were obtained between after sintering at 1200-1300°C.

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