Preparation of Biodegradable Gradient Polymer by Microwave

2011 ◽  
Vol 236-238 ◽  
pp. 1949-1953 ◽  
Author(s):  
Ji Yan Liu ◽  
Xue Qing Liu
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Polymeric Membrane ◽  
Thickness Direction ◽  
Composition And Structure ◽  
Significant Difference ◽  
Gradient Variation ◽  
Percentage Ratio ◽  
Scanning Electron

A biodegradable gradient polymeric membrane based on chitosan (CS) and polyvinyl alcohol (PVA) has been prepared by microwave technique. The composition and morphology variation along the thickness direction in membrane were measured by elemental analysis and scanning electron microscope (SEM). The tensile properties of CS/PVA gradient membrane were tested. Results showed that the content of either polymer shows a gradient variation along the thickness direction. SEM photographs exhibit that morphology also evolves gradually with the varying percentage ratio of two polymers. As a result of such variations in composition and structure, the mechanical properties on both sides exhibit a significant difference. Compared with conventional isotropic membrane, gradient membrane has improved mechanical properties.

Effect of the Neodymium Content on Mechanical Properties of the Electro-Brush Plated Nano-Al2O3/Ni Composite Coating

2012 ◽  
Vol 525-526 ◽  
pp. 277-280
Author(s):  
Guo Jin ◽  
Xiu Fang Cui ◽  
Er Bao Liu ◽  
Qing Fen Li
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Composite Coating ◽  
Nanoindentation Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Small Cracks ◽  
Scanning Electron

The effect of the neodymium content on mechanical properties of the electro-brush plated nanoAl2O3/Ni composite coating was investigated in this paper. The microstructure and phase structure were studied with scanning electron microscope (SEM) and X-ray diffraction (XRD). The hardness and abrasion properties of several coatings with different neodymium content were studied by nanoindentation test and friction / wear experiment. Results show that the coatings are much finer and more compact when the neodymium was added, and the hardness and abrasion property of the coatings with neodymium were improved obviously. Besides, the small cracks conduced by the upgrowth stress in the coatings were ameliorated when the rare earth neodymium was added. The improvement mechanism was further discussed.

Scanning Electron Microscope in Rocks and their Comparison with Physical-Mechanical Properties

2020 ◽  
Vol 841 ◽  
pp. 114-118
Author(s):  
Marco Antonio Navarrete Seras ◽  
Francisco Javier Domínguez Mota ◽  
Elia Mercedes Alonso Guzmán ◽  
Wilfrido Martínez Molina ◽  
Hugo Luis Chávez García ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Tests ◽  
Structural Element ◽  
Concrete Mixtures ◽  
Hydraulic Concrete ◽  
Stone Materials ◽  
Historical Monuments ◽  
Scanning Electron

. Banks of stone materials from Michoacán, Mexico were characterized, since they are used in the construction of infrastructure in the area. With these materials are made hydraulic concrete mixtures or asphalt mixtures, foundations, paving stones and in restoration of historical monuments. The rocks analyzed and characterized, come from banks of volcanic stone materials and banks of crushed stone materials, which were subjected to mechanical tests such as uniaxial compression resistance (UCR), in addition was used scanning electron microscope (SEM), by means of which the characterization was carried out, obtaining morphological information of the material. The comparison of physical-mechanical properties with the elements they possess is important to estimate their behavior within ceramic matrices or as a structural element.

Microstructures, Tensile Properties and Forming Process of AZ31 Alloy Sheets

2007 ◽  
Vol 546-549 ◽  
pp. 241-244 ◽  
Author(s):  
Yun Qi Yan ◽  
H. Zhang ◽  
Q. Chen ◽  
H. Zhong ◽  
W.P. Weng
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tensile Properties ◽  
Cell Phone ◽  
Az31 Alloy ◽  
Forming Process ◽  
Fine Grained ◽  
Forming Temperature ◽  
Scanning Electron

Rolling and punching techniques of AZ31 alloy were investigated in this paper. Various rolling experiments were carried out to make fine-grained Mg sheets. Punching tests were conducted at the temperatures range from 70 to 300 oC. The analysis revealed that there existed an excellent warm forming temperature for as-rolled AZ31 alloy. A warm deep punching tool setup using heating elements was designed and manufactured to produce the cell phone. Microstructures were observed using optical and scanning electron microscope equipped with EBSD. The textures in as-rolled and as-annealed specimens attribute to different mechanical properties along the various direction.

Curing and Mechanical Properties of Bio-Based Hybrid Thermoset Resins from Unsaturated Polyester and Acrylated Epoxidized Palm Oil

2015 ◽  
Vol 1113 ◽  
pp. 23-27 ◽  
Author(s):  
Alireza Fakhari ◽  
Abdul Razak Rahmat ◽  
Mat Uzir Wahit ◽  
Amirali Khalili ◽  
Zyad Salem Alsagayar
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hybrid Systems ◽  
Palm Oil ◽  
Unsaturated Polyester ◽  
Thermoset Resins ◽  
Epoxidized Palm Oil ◽  
Flexural Tests ◽  
Scanning Electron

In this study a series of green thermoset resins have been produced from blending acrylated epoxidized palm oil (AEPO) and unsaturated polyester (UPE). The UPE/AEPO ratio was changed between 90/10 and 70/30 wt%. The curing behavior and morphology of hybrid systems were investigated by differential scanning calorimeter (DSC) and Scanning electron microscope (SEM). Moreover, studies on mechanical properties were performed by tensile and flexural tests. The results revealed that, these green thermoset resins exhibit thermo mechanical properties comparable to those of commercial unsaturated polyesters.

Study of Microstructure and Mechanical Properties of Extrued Spray Forming Al-8.5Fe-1.3V-1.7Si Alloy

2013 ◽  
Vol 750-752 ◽  
pp. 671-674
Author(s):  
Rong Hua Zhang ◽  
Yong An Zhang ◽  
Bao Hong Zhu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Yield Strength ◽  
Scanning Electron Microscope ◽  
Room Temperature ◽  
Extrusion Process ◽  
Spray Forming ◽  
Microstructure And Mechanical Properties ◽  
Scanning Electron

In this paper, the Al-8.5Fe-1.3V-1.7Si alloys were fabricated by spray forming and extrusion process. The microstructure and mechanical properties of the alloy were investigated by means of metallographic, scanning electron microscope and tensile test. The results indicate that the tensile strength of the extrued alloys can reach 353MPa, the yield strength 300MPa, elongation 19.12%, at room temperature. At 250°C, the tensile strength of the extrued alloys can reach 221MPa, the yield strength 208MPa, elongation 13.33%.

Influence of prophylaxis on the microleakage of sealants: in vitro study

2002 ◽  
Vol 26 (4) ◽  
pp. 371-375 ◽  
Author(s):  
Ana Beatriz Alonso Chevitarese ◽  
Orlando Chevitarese ◽  
Ivete Pomarico Ribeiro de Souza ◽  
Roberto Braga de Carvalho Vianna
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
In Vitro Study ◽  
Optical Microscope ◽  
Vitro Study ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Scanning Electron

The aim of this study was to evaluate the influence of prophylaxis on the sealants microleakage in 30 premolars divided into: Group A, Group B and Group C. The teeth were analyzed using the optical microscope (OM) and at scanning electron microscope (SEM). There was a statitical significant difference among the groups regarding the presence of microleakage, but not with the presence of tags.

scholarly journals Experiment on Strength and Failure Behavior of Sandstone Containing Pre-Existing Cracks Under Brazilian Compression

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaojian Cao ◽  
Han Zhang ◽  
Jun Yu ◽  
Tianchong Yu ◽  
Yuxing Qing
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Failure Process ◽  
Experimental Results ◽  
Failure Behavior ◽  
Axial Deformation ◽  
Scanning Electron

Determination of the mechanical properties of rock containing pre-existing cracks under tension condition is of great significance to understand the failure process of rock in engineering. This paper presents the experimental results of sandstone containing pre-existing cracks under Brazilian compression. The characteristics of the microcracks were analyzed by a scanning electron microscope. The results show that the rock containing pre-existing cracks has an obvious anisotropic characteristic. When the crack inclination is 45°, the rock has the minimum tensile strength and the weakest axial deformation resistance.

Effect of polyamide 6 on the mechanical behavior of thermoplastic polyurethanes/polyamide 6 blends

2021 ◽  
pp. 095440542110406
Author(s):  
Nga Thi-Hong Pham
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Behavior ◽  
Thermoplastic Polyurethane ◽  
Polyamide 6 ◽  
Thermoplastic Polyurethanes ◽  
Microscope Images ◽  
Scanning Electron

Ductility and tensile strength are among the basic mechanical properties of polymers. Generally, it is difficult to enhance the ductility without significantly reducing the tensile strength. In this study, thermoplastic polyurethane (TPU) is mixed with 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% polyamide 6 (PA6). The results show that the sample containing 100% TPU has the largest elongation of 690.5%. When PA6 is added, the elongation decreases gradually to 635.0%, 623.1%, 529.5%, 476.0%, 391.3%, and 242.8%, corresponding to 2.5%, 5%, 7.5%, 10%, 12.5%, and 100% PA6, respectively. The tensile strengths are 36.7, 33.8, 29.4, 26.5, 23.1, and 24.9 MPa, corresponding to 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% PA6 samples, respectively. The tensile strength decreases gradually when the PA6 content is increased. Notably, the tensile strength of the 12.5% PA6 sample increases compared to the 10% PA6 sample. In addition, the hardness of the TPU/PA blend increases slightly as the PA6 ratio is increased. Finally, scanning electron microscope images demonstrate that PA6 particles act as particles dispersed or dissolved in TPU/PA blends.

scholarly journals Evaluation of two different root-end cavity preparation techniques: A scanning electron microscope study

2013 ◽  
Vol 07 (02) ◽  
pp. 186-190 ◽  
Author(s):  
Seda Aydemir ◽  
Hale Cimilli ◽  
Afife Binnaz Hazar Yoruç ◽  
Nevin Kartal
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Control Group ◽  
Laser Materials ◽  
Cavity Preparation ◽  
Scanning Electron Microscope Study ◽  
Yag Laser ◽  
Significant Difference ◽  
Laser Group ◽  
Scanning Electron

ABSTRACT Objective: In this study, we aimed to evaluate and compare the dentinal walls of root-end cavities for the presence of cracks after cavity preparation using US retrotips and Er: YAG laser. Materials and Methods: Fifty single-rooted teeth were prepared by Protaper NiTi rotary system and obturated by lateral condensation. Three milimeters of root-end was resected. Twenty teeth were prepared with US retrotip (Group 1), 20 teeth with Er: YAG laser (Group 2), and 10 teeth without retropreparation (control group). The root-end surfaces were examined under a scanning electron microscope (SEM). Then the cracks of the resected root surfaces were evaluated on microphotographs. Results: No statistically significant difference was detected between US Group and Laser Group for complete, incomplete, intradentinal, and total number of cracks (P = 0.47, P = 0.80, P = 0.69, P = 0.869, respectively). Conclusion: Statistical analysis revealed no significant effect of retropreparation technique on the development of apical cracks (P > 0.05).

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