Structure and Mechanical Properties of Porous Ultra-High Molecular Weight Polyethylene

2012 ◽  
Vol 466-467 ◽  
pp. 332-335 ◽  
Author(s):  
Jiu Mei Xiao
Keyword(s):  
Draw Ratio ◽  
Mechanical Test ◽  
Longitudinal Direction ◽  
Test Results ◽  
Machine Direction ◽  
Elongation At Break ◽  
Wet Process ◽  
Biaxial Stretching ◽  
Lower Elongation ◽  
Ultra High Molecular Weight

The porous UHMWPE were prepared by wet process and biaxial stretching. The scanning electron microscopy (SEM) experimental results indicated that there were two discernible components: microfibril bundles and microfibril networks in the porous biaxial UHMWPE. The higher draw ratio along the longitudinal direction (the machine direction) contributed more to orientation of the UHMWPE fibrils. Along the transverse direction, fibrils were torn, and more microfibrils network with larger size formed. The mechanical test results showed that along the longitudinal direction, the UHMWPE exhibited higher tensile strength and lower elongation-at-break.

scholarly journals Structure and mechanical properties of GR/UHMWPE nanocomposite ropes

2019 ◽  
Vol 131 ◽  
pp. 01127
Author(s):  
Wen Wen Yu ◽  
Jian Gao Shi ◽  
Yong Li Liu ◽  
Lei Wang
Keyword(s):  
Mechanical Properties ◽  
Melt Spinning ◽  
Mechanical Test ◽  
Reactive Extrusion ◽  
Breaking Load ◽  
Hot Water ◽  
Test Results ◽  
Screw Extruder ◽  
Elongation At Break ◽  
Ultra High Molecular Weight

Ultra-high molecular weight polyethylene (UHMWPE) and graphene (GR) was melt compounded by reactive extrusion. Nanocomposite monofilaments were prepared by melt spinning through a co-rotating screw extruder and drawing at hot water. GR/UHMWPE nanocomposite ropes were twisted using nanocomposite monofilaments. A structure and mechanical properties of the GR/UHMWPE nanocomposite monofilaments and its ropes had been characterized by scanning electron microscopy (SEM), and mechanical test. Results showed that the monofilaments surface of monofilaments became rougher with introducing of GR nanosheets, which could be related to stacking of GR. The breaking load of GR/UHMWPE nanocomposite ropes was remarkably improved upon nanofiller addition, with the decrease of the elongation at break.

The Sequential Analysis of Film Deformation Behavior during Successive Biaxial Stretching Process

2013 ◽  
Vol 747 ◽  
pp. 611-614 ◽  
Author(s):  
Yoshiyuki Kushizaki ◽  
Masayoshi Tokihisa ◽  
Hideki Tomiyama ◽  
Toshiro Yamada
Keyword(s):  
Constitutive Equation ◽  
Deformation Behavior ◽  
Draw Ratio ◽  
Sequential Analysis ◽  
Machine Direction ◽  
Material Constants ◽  
Biaxial Stretching ◽  
Experimental Deformation ◽  
Stretching Ratio ◽  
Stretching Process

The deformation behavior of Polypropylene (PP) film during successive biaxial stretching process which consists of machine direction (MD) stretching process with a roll drawing and transverse direction (TD) stretching with a tentering was analyzed sequentially by using a finite element method (FEM). In order to analyze it, stress-strain curves of casted PP film and uni-axially oriented PP film in MD were measured and fitted into the constitutive equation that the authors developed previously, respectively, and then, material constants for both films were obtained. Deformation behavior during successive biaxial stretching were calculated by applying the constitutive equation with the material constants of casted PP film for MD stretching and uni-axially oriented PP film in MD for TD stretching, respectively. Analytical conditions were the draw ratio of 5 for MD analysis and the stretching ratio of 9.5 for TD analysis. The authors also experimentally measured the thickness of film during and after MD and TD stretching using a pilot plant under the same conditions as analytical condition. Calculated results were able to express qualitatively the experimental deformation behavior of PP film such as the neck-in phenomena during MD stretching and the change of film thickness during MD and TD stretching.

scholarly journals Performance Study of Grass-Derived Nano-Cellulose and Polycaprolactone Composites for 3D Printing

2021 ◽  
Vol 11 (3) ◽  
pp. 1273
Author(s):  
Chen Feng ◽  
Jiping Zhou ◽  
Xiaodong Xu ◽  
Yani Jiang ◽  
Hongcan Shi ◽  
...  
Keyword(s):  
3D Printing ◽  
Mechanical Test ◽  
Chemical Properties ◽  
Test Results ◽  
Performance Study ◽  
Compression Process ◽  
Ansys Fluent ◽  
Nano Cellulose ◽  
Physical And Chemical ◽  
And Chemical Properties

In recent years, 3D printing has received increasing attention from researchers. This technology overcomes the limitations of traditional technologies by printing precise and personalized scaffold with arbitrary shapes, pore structures, and porosities for the applications in various tissues. The cellulose nanocrystal (CNC) is extracted from Humulus Japonicus (HJS) and mixed with poly(ε-caprolactone) (PCL) to prepare a series of CNC/PCL composites for printing. Based on the analysis of the physical and chemical properties of the series of the CNC/PCL composites, an optimal mass ratio of CNC to PCL was obtained. The Solidworks was used to simulate the stretching and compression process of the scaffolds with three different patterns under an external force. The flow of nutrient solution in the scaffolds with different patterns was simulated by ANSYS FLUENT, and then a new optimization scaffold pattern with a concave hexagon shape was advised based on the simulation results. Collectively, the mechanical test results of the material and scaffold confirmed that the optimal filling amount of the CNC was 5%, and the scaffold pattern with concave hexagon shape exhibited better mechanical properties and suitable for the transport of cells and nutrients, which is expected to be more widely used in 3D printing.

Transient liquid phase bonding of Cu and Al using metallic particles interlayers

2021 ◽  
pp. 095440542098823
Author(s):  
Alireza Zaheri ◽  
Mohammadreza Farahani ◽  
Alireza Sadeghi ◽  
Naser Souri
Keyword(s):  
Liquid Phase ◽  
Mechanical Test ◽  
Transient Liquid Phase ◽  
Transient Liquid Phase Bonding ◽  
Joint Interface ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metallic Particles ◽  
Powder Interlayer

The bonding strength, and microstructures of Cu and Al couples using metallic powders as interlayer during transient liquid phase bonding (TLP bonding) were investigated. The interfacial morphologies and microstructures were studied by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and X-ray diffraction. First, to explore the optimum bonding time and temperature, nine samples were bonded without interlayers in a vacuum condition. Mechanical test results indicated that bonding at 560°C in 20 min returns the highest bond strength (84% of Al). This bonding condition was used to join ten samples with powder interlayers. Powders were prepared by mixing different combinations of Cu, Al (+Fe nanoparticles) and Zn. In the bonding zone, different Cu9Al4, CuAl, and CuAl2 intermetallic co-precipitate. The strongest bonding is formed in the sample with the 70Al (+Fe)-30Cu powder interlayer. Powder interlayers present thinner and more uniform intermetallic layers at the joint interface.

The effect of long-term annealing simulating the parameters of dry storage of VVER-1000 fuel rods on the mechanical properties of E110 alloy shells in the longitudinal direction

2021 ◽  
Vol 4 ◽  
pp. 42-49
Author(s):  
G. P. Kobylyansky ◽  
◽  
А. О. Mazaev ◽  
Е. А. Zvir ◽  
S. G. Eremin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Relative Elongation ◽  
Mechanical Test ◽  
Longitudinal Direction ◽  
Radiation Defects ◽  
Thermal Tests ◽  
Fuel Rods ◽  
Dry Storage

Presented are the results of mechanical tensile tests of longitudinal (segmental) samples cut from the midsection of claddings spent as VVER-1000 FA during one- and six-year campaigns and subject to thermal tests in helium at 480 °С during 468 full days. An average burnup of these fuel rods achieved ~ 20 and ~ 70 (MW·day)/kg U, respectively. The tests followed the examinations for cladding mechanical properties performed using the tests results for ring samples cut from the specified fuel rods. These fuel rods were tested in the experiments to determine impact of long-term thermal tests that model dry storage conditions on mechanical properties of Zr E110 claddings. Based on mechanical tests results at room temperature and at 380 °С there was determined as follows: ultimate strength sв, yield strength s0,2 and total relative elongation d0 of claddings length-wise on the fuel rod segments at the fuel column midsection. The obtained characteristics were compared to corresponding values for initial (unirradiated) cladding tubes and mechanical test results of the ring samples in the transverse direction. Long-term thermal tests have led to partial return to initial (before operation) values sв, s0,2 and d0 of radiation-hardened claddings; this return was more prominent in the longitudinal direction than in the transverse one. A radiation hardening decrease was accompanied with an increase in total relative elongation values in both cladding directions. Anisotropy of yield strength has changed as well. These changes can be explained by partial annealing of radiation defects, which are obstacles to dislocation movements during cladding strain. The morphology of above radiation defects is different in various sliding planes in texturized grains of cladding material.

Preparation and Properties Research of Anti-Fogging Polypropylene Packaging Films

2012 ◽  
Vol 262 ◽  
pp. 581-585 ◽  
Author(s):  
Xiao Jin Gao ◽  
Li Qiang Huang ◽  
Xin Li
Keyword(s):  
Silica Sol ◽  
Range Analysis ◽  
Machine Direction ◽  
Polypropylene Film ◽  
Mixture Ratio ◽  
Elongation At Break ◽  
Coated Film ◽  
Span 80 ◽  
Optimum Formula ◽  
The Relationship

The anti-fogging properties of a new anti-fogging agent containing silicon sprayed on polypropylene were discussed. The anti-fogging agent was prepared by using silicone hydride and silica sol, the new anti-fogging agent with different consistency was daubed on the polypropylene film .The contact angle, first dripping time and ten drippings time of the anti-fogging PP films were tested. According to the range analysis, the best mixture ratio, which was just the optimum formula was found. The relationship between the anti-fogging agent consistence and the anti-fogging performance was discussed too. The result showed that the anti-fogging properties of the coated film were better and the mechanical properties of the coated film enhanced in some sort. The mixture ratio of the anti-fogging agent was that the silica sol was 12phr; the span 80 was 15%; the pH was 5.5. After the film was coated, the tensile strength of machine direction raised by 109.14% than the contrast. The elongation at break of transverse direction raised by 32.51MPa and that of machine direction raised by 17.95MPa. This anti-fogging agent containing silicon was preferable to polypropylene.

scholarly journals Structural Formation of UHMWPE Film Tracked by Real-Time Retardation Measurements during Uniaxial/Biaxial Stretching

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2292 ◽  
Author(s):  
Yoshinori Hashimoto ◽  
Shotaro Nishitsuji ◽  
Takashi Kurose ◽  
Hiroshi Ito
Keyword(s):  
Tensile Testing ◽  
X Ray Diffraction ◽  
Structural Formation ◽  
X Ray ◽  
Amorphous Phases ◽  
Analysis Techniques ◽  
Biaxial Stretching ◽  
Thermal Analysis Techniques ◽  
Ultra High Molecular Weight ◽  
Order Structures

This work reports on an experimental study of the stretching of ultra-high molecular weight polyethylene (UHMWPE) film in various uniaxial/biaxial stretching modes at various temperatures and stretching speeds. We examined the stress-birefringence relationship as a stress-optical rule (SOR) under uniaxial stretching and evaluated the stress-optical coefficient (SOC). Wide-angle X-ray diffraction (WAXD) measurements were applied to evaluate the contribution to birefringence of the crystalline and amorphous phases and to characterize stretching modes. In simultaneous biaxial stretching, the melting temperature (Tm) proved critical to structural formation. We applied thermal analysis techniques and tensile testing to evaluate higher order structures after each stretching mode.

Characterization of EVA Residues from the Shoe Industry and Post-Consumer Urban-Waste Polyethylenes

2005 ◽  
Vol 24 (3) ◽  
pp. 139-158 ◽  
Author(s):  
A.J. Zattera ◽  
O. Bianchi ◽  
R.V.B. Oliveira ◽  
L.B. Canto ◽  
C.A. Ferreira ◽  
...  
Keyword(s):  
Tensile Modulus ◽  
Urban Waste ◽  
Elongation At Break ◽  
Shoe Industry ◽  
Izod Impact ◽  
Lower Elongation ◽  
Mechanical Tensile ◽  
High Degree ◽  
Tga And Dsc

This paper presents a characterization of a crosslinked EVA residue (EVA-c) from expanded sheets used in the shoe industry and post-consumer urban-waste polyethylenes regarding their molecular (FTIR), mechanical (tensile and impact tests), morphological (SEM), thermal (DSC, TGA) and dynamic-mechanical (DMTA) properties. For comparison, the properties of the EVA-c and recycled polyethylenes are compared to respective virgin polymers. The recycled polyethylenes generally presented similar properties to the virgin ones. On the other hand, some EVA-c properties differed from virgin ones since it has a high degree of crosslinking and it therefore has a higher tensile modulus and lower elongation at break, notched Izod impact strength and hardness. Additionally, crosslinking was also found to modify the thermal properties (TGA and DSC) of EVA-c.

Effects of cross-linking by MgCl2 as an initiator on the properties of EVOH

2020 ◽  
pp. 089270572091331
Author(s):  
Bin Wang ◽  
Chong Lu ◽  
Jing Hu ◽  
Weixin Lu
Keyword(s):  
Mechanical Test ◽  
Barrier Properties ◽  
Thermomechanical Properties ◽  
Cross Linking ◽  
Resonance Spectroscopy ◽  
Test Results ◽  
Ethylene Vinyl Alcohol ◽  
Ftir Spectrometry ◽  
Stretching Vibration ◽  
C Nmr

Ethylene vinyl alcohol (EVOH) with excellent barrier properties has insufficient thermomechanical properties. The introduction of magnesium chloride (MgCl2) as an initiator in EVOH blends improved its properties by cross-linking. Torque behavior and gel experiment analysis indicated that a cross-linking in EVOH was formed. The cross-linking mechanism was confirmed through 13C nuclear magnetic resonance spectroscopy (13C NMR) and Fourier-transform infrared (FTIR) spectrometry. In 13C NMR spectra, the splitting peaks of CH carbon and CH2 carbon tended to disappear, and the stretching vibration peak of –C=C– was observed in the FTIR spectra. The formation of hydrogen bond between MgCl2 and EVOH destroyed the intramolecular and intermolecular hydrogen bonds of EVOH, which contributed to the dehydration of –OH to form –C=C–, and –C=C– was the basis for a cross-linking reaction. The thermal analysis of blends demonstrated that the melting temperature and crystallization temperature decreased, and the crystallinity gradually disappeared when the MgCl2 content increased. Glass transition temperature significantly increased as the intermolecular force enhanced. Thermogravimetric analysis showed that a cross-linked structure could improve the thermostability of EVOH with an increase in the MgCl2 content. Mechanical test results revealed a remarkable increase in the tensile strength of EVOH as the MgCl2 content increased.

scholarly journals Preparation and Properties of Chitosan/Graphene Modified Bamboo Fiber Fabrics

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1540 ◽  
Author(s):  
Yan Wu ◽  
Yuqing Bian ◽  
Feng Yang ◽  
Yang Ding ◽  
Kexin Chen
Keyword(s):  
Control Sample ◽  
Antimicrobial Properties ◽  
Longitudinal Direction ◽  
Bamboo Fiber ◽  
Great Promise ◽  
Detergent Solution ◽  
Optical Brightener ◽  
Elongation At Break ◽  
Finishing Agent ◽  
Impregnation Modification

Chitosan (CS) and graphene (Gr) were used to modify bamboo fiber fabrics to develop new bamboo fiber fabrics (CGBFs) with antimicrobial properties. The CGBFs were prepared by chemical crosslinking with CS as binder assistant and Gr as functional finishing agent. The method of firmly attaching the CS/Gr to bamboo fiber fabrics was explored. On the basis of the constant amount of CS, the best impregnation modification scheme was determined by changing the amount of Gr and evaluating the properties of the CS/Gr modified bamboo fiber fabrics. The results showed that the antibacterial rate of CGBFs with 0.3 wt% Gr was more than 99%, and compared with the control sample, the maximum tensile strength of CGBF increased by 1% in the longitudinal direction and 7.8% in the weft direction. The elongation at break increased by 2.2% in longitude and 57.3% in latitude. After 20 times of washing with WOB (without optical brightener) detergent solution, the antimicrobial rate can still be more than 70%. Therefore, these newly CS/Gr modified bamboo fiber fabrics hold great promise for antibacterial application in home decoration and clothing textiles.

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