scholarly journals Characterization of Mechanical and Dielectric Properties of Silicone Rubber

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1831
Author(s):  
Eunyoung Cho ◽  
Loraine L. Y. Chiu ◽  
Mitchell Lee ◽  
Doshina Naila ◽  
Siddharth Sadanand ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dielectric Properties ◽  
Silicone Rubber ◽  
Material Properties ◽  
Dielectric Constants ◽  
Shear Moduli ◽  
Unique Material ◽  
Silicone Rubbers ◽  
Dielectric And Mechanical Properties

Silicone rubber’s silicone-oxygen backbones give unique material properties which are applicable in various biomedical devices. Due to the diversity of potential silicone rubber compositions, the material properties can vary widely. This paper characterizes the dielectric and mechanical properties of two different silicone rubbers, each with a different cure system, and in combination with silicone additives. A tactile mutator (Slacker™) and/or silicone thickener (Thi-vex™) were mixed with platinum-cured and condensation-cured silicone rubber in various concentrations. The dielectric constants, conductivities, and compressive and shear moduli were measured for each sample. Our study contributes novel information about the dielectric and mechanical properties of these two types of silicone rubber and how they change with the addition of two common silicone additives.

Microstructure, Mechanical and Dielectric Properties of Si3N4-BN Composites with Different Porosities

2015 ◽  
Vol 816 ◽  
pp. 40-47
Author(s):  
Kun Liu ◽  
Chang Rui Zhang ◽  
Bin Li ◽  
Si Qing Wang ◽  
Feng Cao
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Dielectric Properties ◽  
Flexural Strength ◽  
Dielectric Constants ◽  
Liquid Precursor ◽  
Die Pressing ◽  
Dielectric And Mechanical Properties

Si3N4-BN composites were prepared by die-pressing and precursor infiltration and pyrolysis (PIP) route using borazine as the precursor. The composition, microstructure, mechanical, and dielectric properties of the composites with different porosities were investigated. With the adoption of starch as pore forming substance, drawn the Si3N4preform from the liquid precursor borazine and decrease the pressure during curing, the porosity of the Si3N4-BN composites were effectively increased. Along with the increase of the porosity of the composites, the mechanical properties were decreased and the dielectric properties were improved. With 20 wt.% starch and drawn Si3N4preform from borazine before curing, the density, porosity, flexural strength and elastic modulus of the composites were 1.70 g·cm-3, 29.78%, 48.05MPa and 32.45GPa, respectively. The dielectric constants and loss tangents were 4.20~4.44 and 0.48~3.42×10-3at the frequency 7~ 18GHz. Composites with various dielectric and mechanical properties can be designed and prepared according to the application needs.

scholarly journals Preparation and Characterization of Intrinsic Low-κ Polyimide Films

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4174
Author(s):  
Yu Sun ◽  
Tao Li ◽  
Haiyang Dai ◽  
Manman Wang ◽  
Renzhong Xue ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dielectric Properties ◽  
Free Volume ◽  
Energy Gap ◽  
Volume Fraction ◽  
Tensile Modulus ◽  
Chain Structure ◽  
Dielectric Constants ◽  
Fluorinated Polyimide ◽  
Dielectric And Mechanical Properties

Three fluorinated polyimide (PI-FP, PI-FO and PI-FH) films with low dielectric constants and excellent comprehensive properties were successfully prepared using a polycondensation reaction method by incorporating p-phenylenediamine (PDA), 4-4′-diaminodiphenyl ether (ODA) and 4,4′-(Hexafluoroisopropylidene) bis (p-phenyleneoxy) dianiline (HFPBDA) into 4,4′-(Hexafluoroisopropylidene) diphthalic anhydride (6FDA), respectively. The effects of the diamine monomer structure on optical, dielectric and mechanical properties were investigated. Compared with PDA and ODA, HFPBDA can effectively improve the optical and dielectric properties of PI due to due to its special chain structure. Among the three PI films, PI-FH film presents the best optic transmission (highest transmittance = 90.2%) and highest energy gap (2.69 eV). The dielectric properties of PI-FH film improve the most. The dielectric constant and loss at 104 Hz are reduced to 2.05 and 0.0034 at 104 Hz, respectively, and remain stable up to 250 °C. The mechanical properties decrease in turn for PI-FP, PI-FO and PI-FH films due to the increase in free volume fraction. Nevertheless, PI-FH film still exhibits good mechanical properties with a tensile strength of 88.4 Mpa, a tensile modulus of 2.11 GPa and an elongation at break of 4.1%. The correlation between the dielectric and mechanical properties of PI films and their free volume characteristics is well explained with the help of positron annihilation spectroscopy.

Preparation and characterization of STRG/PI composite films with optimized dielectric and mechanical properties

Polymer ◽  
2015 ◽  
Vol 65 ◽  
pp. 262-269 ◽  
Author(s):  
Pengtu Zhang ◽  
Jianjie He ◽  
Zhong-Kai Cui ◽  
Xinxin Li ◽  
Xiaoyun Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Films ◽  
Dielectric And Mechanical Properties

scholarly journals Compatibility Study of Silicone Rubber and Mineral Oil

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5899
Author(s):  
Smitha Karambar ◽  
Stefan Tenbohlen
Keyword(s):  
Dielectric Properties ◽  
Moisture Content ◽  
Silicone Rubber ◽  
Mineral Oil ◽  
Acid Number ◽  
Compatibility Study ◽  
Total Acid ◽  
Silicone Rubbers ◽  
Conductive Silicone Rubber ◽  
Solid Insulation

In this study, three types of silicone rubbers, namely, insulative silicone rubber, conductive silicone rubber and silicone rubber with conductive as well as insulative layers are investigated for their compatibility with mineral oil. Mineral oil with different silicone rubber samples is thermally aged at 130 °C for 360 h, 720 h and 1080 h and at 23 °C, 98 °C and 130 °C for 360 h. At the end of each ageing interval, mineral oil and oil-impregnated silicone rubbers are investigated for their dielectric properties. Aged mineral oil samples are investigated for their moisture content, breakdown voltage, colour number, dissolved gases and total acid number, whereas solid insulation samples are investigated for their moisture content. Additionally, pressboard samples in mineral oil and mineral oil without any solid insulation materials are also aged under the same conditions and are investigated for their dielectric properties. From the obtained results, it can be assessed that the presence of carbon particles in conductive silicone rubber negatively impacts the dielectric properties of mineral oil. Among the investigated silicone rubbers, the insulative silicone rubber exhibits good compatibility with mineral oil and a strong potential for being used in mineral oil.

scholarly journals Synthesis, Characterization, and Applications of ZnO Nanowires

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Yangyang Zhang ◽  
Manoj K. Ram ◽  
Elias K. Stefanakos ◽  
D. Yogi Goswami
Keyword(s):  
Environmental Protection ◽  
Material Properties ◽  
Zno Nanowires ◽  
Synthesis Methods ◽  
Special Focus ◽  
Wide Range ◽  
Unique Material ◽  
Photocatalytic Applications

ZnO nanowires (or nanorods) have been widely studied due to their unique material properties and remarkable performance in electronics, optics, and photonics. Recently, photocatalytic applications of ZnO nanowires are of increased interest in environmental protection applications. This paper presents a review of the current research of ZnO nanowires (or nanorods) with special focus on photocatalysis. We have reviewed the semiconducting photocatalysts and discussed a variety of synthesis methods of ZnO nanowires and their corresponding effectiveness in photocatalysis. We have also presented the characterization of ZnO nanowires from the literature and from our own measurements. Finally, a wide range of uses of ZnO nanowires in various applications is highlighted in this paper.

Effect of Temperature and Freezing On Human Adipose Tissue Material Properties Characterized by High-Rate Indentation-Puncture Testing

2021 ◽  
Author(s):  
Zhaonan Sun ◽  
Bronislaw Gepner ◽  
Sang-hyun Lee ◽  
Michelle Oyen ◽  
Josh Rigby ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Adipose Tissue ◽  
Material Properties ◽  
Injury Risk ◽  
Seat Belt ◽  
Human Adipose Tissue ◽  
High Rate ◽  
Effect Of Temperature ◽  
Frozen Tissue

Abstract The characterization of human subcutaneous adipose tissue (SAT) under high-rate loading is valuable for development of biofidelic finite element human body models (FE-HBMs) to predict seat belt-pelvis interaction and injury risk in vehicle crash simulations. While material characterization of SAT has been performed at 25°C or 37°C, the effect of temperature on mechanical properties of SAT under high-rate and large-deformation loading has not been investigated. Similarly, while freezing is the most common preservation technique for cadaveric specimens, the effect of freeze-thaw on the mechanical properties of SAT is also absent from the literature. Therefore, the aim of this study was to determine the effect of freezing and temperature on mechanical properties of human SAT. Fresh and previously frozen human SAT specimens were obtained and tested at 25°C and 37°C. High-rate indentation and puncture tests were performed, and indentation-puncture force-depth responses were obtained. While the chance of material failure was found to be different between temperatures and between fresh and previously frozen tissue, statistical analyses revealed that temperature and freezing did not change the shear modulus and failure characteristics of SAT. Therefore, the results of the current study indicated that SAT material properties characterized from either fresh or frozen tissue at either 25°C or 37°C could be used for enhancing the biofidelity of FE-HBMs.

Characterization of Polypropylene Nanocomposite Structures

2006 ◽  
Vol 129 (1) ◽  
pp. 105-112 ◽  
Author(s):  
K. Kanny ◽  
V. K. Moodley
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Material Properties ◽  
Melt Blending ◽  
Transmission Electron ◽  
Low Weight ◽  
Static Tensile ◽  
Exfoliated Nanocomposite ◽  
Nanocomposite Structures

This study describes the synthesis, mechanical properties, and morphology of nanophased polypropylene structures. The structures were manufactured by melt-blending low weight percentages of montmorillonite nanoclays and polypropylene thermoplastic. Both virgin and infused polypropylene structures were then subjected to quasi-static tensile, flexural, hardness and impact tests. Analysis of test data show that the mechanical properties increase with an increase in nanoclay loading up to a threshold of 2wt.%; thereafter, the material properties degrade. At low weight nanoclay loadings the enhancement of properties is attributed to the lower percolation points created by the high aspect ratio nanoclays. The increase in properties may also be attributed to the formation of intercalated and exfoliated nanocomposite structures formed at these loadings of clay. At higher weight loading, degradation in mechanical properties may be attributed to the formation of agglomerated clay tactoids. Results of transmission electron microscopy studies and scanning electron microscopy studies of the fractured surface of tensile specimens verify these hypotheses.

The Effect of Additives on the Microstructure and Properties of BaTiO3 Ceramics

2013 ◽  
Vol 787 ◽  
pp. 152-156
Author(s):  
A. Lara ◽  
P. Yuan ◽  
F. Ghezzo ◽  
X. Miao ◽  
Z. Zhao
Keyword(s):  
Mechanical Properties ◽  
Dielectric Properties ◽  
Relative Density ◽  
Slip Casting ◽  
Holding Time ◽  
Theoretical Density ◽  
Microstructure And Properties ◽  
Conventional Furnace ◽  
Effect Of Additives ◽  
Dielectric And Mechanical Properties

Doped BaTiO3 powders were sintered by slip casting. Sintering was performed at the temperature of 1300oC, for 180 min holding time, in a conventional furnace. Additives were varied to study their effect on the densification and both dielectric and mechanical properties. The relative density of the obtained material was high, up to 96.5 0.6 % the theoretical density for the BaTiO3-Al2O3 composition. For these samples, their mechanical and dielectric properties have been studied.

scholarly journals Brillouin and Raman Micro-Spectroscopy: A Tool for Micro-Mechanical and Structural Characterization of Cortical and Trabecular Bone Tissues

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6869
Author(s):  
Martina Alunni Cardinali ◽  
Assunta Morresi ◽  
Daniele Fioretto ◽  
Leonardo Vivarelli ◽  
Dante Dallari ◽  
...  
Keyword(s):  
Trabecular Bone ◽  
Material Properties ◽  
Label Free ◽  
Tissue Remodelling ◽  
First Choice ◽  
Unique Material ◽  
Specialized Tissue ◽  
Non Destructive ◽  
Abnormal Tissue

Human bone is a specialized tissue with unique material properties, providing mechanical support and resistance to the skeleton and simultaneously assuring capability of adaptation and remodelling. Knowing the properties of such a structure down to the micro-scale is of utmost importance, not only for the design of effective biomimetic materials but also to be able to detect pathological alterations in material properties, such as micro-fractures or abnormal tissue remodelling. The Brillouin and Raman micro-spectroscopic (BRmS) approach has the potential to become a first-choice technique, as it is capable of simultaneously investigating samples’ mechanical and structural properties in a non-destructive and label-free way. Here, we perform a mapping of cortical and trabecular bone sections of a femoral epiphysis, demonstrating the capability of the technique for discovering the morpho-mechanics of cells, the extracellular matrix, and marrow constituents. Moreover, the interpretation of Brillouin and Raman spectra merged with an approach of data mining is used to compare the mechanical alterations in specimens excised from distinct anatomical areas and subjected to different sample processing. The results disclose in both cases specific alterations in the morphology and/or in the tissue chemical make-up, which strongly affects bone mechanical properties, providing a method potentially extendable to other important biomedical issues.

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