Elastomer Blends

2002 ◽  
Vol 75 (3) ◽  
pp. 365-427 ◽  
Author(s):  
Duryodhan Mangaraj
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Special Reference ◽  
Transport Properties ◽  
Commercial Application ◽  
Solution Properties ◽  
Polymer Miscibility ◽  
Mechanical Methods

Abstract Blending of elastomers is often used to enhance he performance characteristics of rubber products. This article reviews the thermodynamic principles underlying polymer-polymer miscibility, with special reference to elastomer blends. It discusses the distribution of fillers, additives and curatives in different phases of the blend and its effect on the properties of the vulcanizate. It describes the different methods used in preparing elastomer blends, with special emphasis on compatibilization. Characterization of blends using optical and electron microscopy, solution properties, thermal and dynamic mechanical methods have been described along with results. The effect of blending on mechanical properties, hysteresis, adhesion and tack, transport properties and electrical conductivity has been discussed. Past attempts for property enhancement by blending elastomers have been reviewed, followed by a discussion of commercial application of elastomer blends.

Mechanical Properties and Microstructure Evolution of Typical Over-Aging State Al-Zn-Mg-Cu Alloy during Thermal Exposure

2021 ◽  
Vol 1026 ◽  
pp. 84-92
Author(s):  
Tao Qian Cheng ◽  
Zhi Hui Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Electrical Conductivity ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Thermal Exposure ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Thermal Stability Of

Al-Zn-Mg-Cu alloy have been widely used in aerospace industry. However, there is still a lack of research on thermal stability of Al-Zn-Mg-Cu alloy products. In the present work, an Al-Zn-Mg-Cu alloy with T79 and T74 states was placed in the corresponding environment for thermal exposure experiments. Performance was measured by tensile strength, hardness and electrical conductivity. In this paper, precipitation observation was analyzed by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HREM). The precipitations of T79 state alloy were GPⅡ zone, η' phase and η phase while the ultimate tensile strength, hardness and electrical conductivity were 571MPa, 188.2HV and 22.2MS×m-1, respectively. The mechanical property of T79 state alloy decreased to 530MPa and 168.5HV after thermal exposure. The diameter of precipitate increased and the precipitations become η' and η phase at the same time. During the entire thermal exposure, T74 state alloy had the same mechanical property trend as T79 state alloy. The precipitate diameter also increased while the types of precipitate did not change under thermal exposure. The size of precipitates affected the choice of dislocation passing through the particles to affect the mechanical properties.

Electrodeposition of Nickel-Molybdenum (Ni-Mo) Alloys for Corrosion Protection in Harsh Environments

2016 ◽  
pp. 369-395 ◽  
Author(s):  
Teresa D. Golden ◽  
Jeerapan Tientong ◽  
Adel M.A. Mohamed
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Corrosion Protection ◽  
X Ray Diffraction ◽  
Molybdenum Alloys ◽  
Deposition Parameters ◽  
Iron Based ◽  
Electrodeposition Of Nickel ◽  
Scanning Electron

Electrodeposition of only molybdenum onto substrates is difficult, therefore molybdenum is typically deposited with iron-based alloys such as nickel. The deposition of such alloys is known as an induced codeposition mechanism. The electrodeposition of nickel-molybdenum alloys using alkaline plating solutions is covered in this chapter. The mechanism for deposition of nickel-molybdenum is reviewed, as well as the influence of the plating parameters on the coatings. Characterization of the coatings by scanning electron microscopy and x-ray diffraction is discussed and how deposition parameters affect morphology, composition, and crystallite size. Nickel-molybdenum alloys offer enhanced corrosion protection and mechanical properties as coatings onto various substrates. A survey of the resulting hardness and Young's modulus is presented for several research studies. Corrosion parameters for several studies are also compared and show the percentage of molybdenum in the coatings affects these values.

scholarly journals Characterization of the Corrosion Resistance of Composite Peened Aluminum

2021 ◽  
Author(s):  
Malte L. Flachmann ◽  
Michael Seitz ◽  
Wilfried V. Liebig ◽  
Kay A. Weidenmann
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Chloride Solution ◽  
Base Material ◽  
Surface Modifications ◽  
Metallic Base ◽  
Corrosion Properties ◽  
Scanning Electron

AbstractComposite peening offers the opportunity to introduce ceramic blasting particles into metallic base material. By embedding Al2O3 particles, mechanical properties of aluminum can be improved. However, those surface modifications might negatively impact corrosion resistance and thus shorten the lifetime of components. This study analyzes corrosion properties of peened aluminum in chloride solution via immersion, scanning electron microscopy and polarization. The data of observed microstructures indicate that peening accelerates corrosion and that intergranular corrosion is the main force of degradation in contrast with pitting corrosion of monolithic aluminum.

scholarly journals Preparation of Multicomponent Biocomposites and Characterization of Their Physicochemical and Mechanical Properties

2020 ◽  
Vol 4 (1) ◽  
pp. 18
Author(s):  
Yuriy A. Anisimov ◽  
Duncan E. Cree ◽  
Lee D. Wilson
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Physicochemical Properties ◽  
In Situ Polymerization ◽  
Structural Parameters ◽  
Dye Adsorption ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Swelling Properties

This work focused on a mutual comparison and characterization of the physicochemical properties of three-component polymer composites. Binary polyaniline–chitosan (PANI–CHT) composites were synthesized by in situ polymerization of PANI onto CHT. Ternary composites were prepared by blending with a third component, polyvinyl alcohol (PVA). Composites with variable PANI:CHT (25:75, 50:50 and 75:25) weight ratios were prepared whilst fixing the composition of PVA. The structure and physicochemical properties of the composites were evaluated using thermal analysis (thermogravimetric analysis (TGA), differential scanning calorimetry (DSC)) and spectroscopic methods (infrared (IR), nuclear magnetic resonance (NMR)). The equilibrium and dynamic adsorption properties of composites were evaluated by solvent swelling in water, water vapour adsorption and dye adsorption isotherms. The electrical conductivity was estimated using current–voltage curves. The mechanical properties of the samples were evaluated using dynamic mechanical analysis (DMA) and correlated with the structural parameters of the composites. The adsorption and swelling properties paralleled the change in the electrical and mechanical properties of the materials. In most cases, samples with higher content of chitosan exhibit higher adsorption and mechanical properties, and lower conductivity. Acid-doped samples showed much higher adsorption, swelling, and electrical conductivity than their undoped analogues.

Multiwalled Carbon Nanotubes-Incorporated Polyurethane Nanocomposites

2008 ◽  
Vol 47-50 ◽  
pp. 1109-1112
Author(s):  
Ye Seul Kim ◽  
Rira Jung ◽  
Hun Sik Kim ◽  
Hyoung Joon Jin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Multiwalled Carbon Nanotubes ◽  
Physical And Mechanical Properties ◽  
High Reactivity ◽  
Multiwalled Carbon ◽  
Contact Points ◽  
Conductive Fillers

Polyurethane was used as adhesive due to high reactivity, high flexibility, and mechanical properties. Electrically conductive adhesives (ECAs) are an alternative to tin-lead solder in order to provide conductive paths between two electrical device components, which typically consist of a polymeric resin that contributes physical and mechanical properties, and conductive fillers. However, ECAs have low electrical conductivity and unstable network due to large contact points of the few micrometer-sized metal particles. In order to overcome these restrictions, multiwalled carbon nanotubes (MWCNTs) with high aspect ratio and smaller nanometer scale can be used as conductive fillers. In this study, ECAs were based on polyurethane filled with two kinds of fillers, raw MWCNTs and acid treated MWCNTs, respectively. Electrical conductivity was measured by using four-point probe. Morphology and dispersibility of fillers were observed by scanning electron microscopy and transmission electron microscopy.

Characterization of Ti-xNb (x = 25 – 35) Alloys in as Melt and Annealed States

2019 ◽  
Vol 946 ◽  
pp. 287-292
Author(s):  
Alexander Thoemmes ◽  
Ivan V. Ivanov ◽  
Alexey Ruktuev
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase ◽  
Nb Content ◽  
Scanning Electron

The effect of Nb content on microstructure, mechanical properties and phase formation in as-melt and annealed binary Ti-Nb alloys were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analysis. The content of Nb varied in the range 25-35 mass % leading to significant changes in the microstructure. The annealed and furnace-cooled binary Ti-Nb samples exhibited HCP martensitic α` phase at a Nb content below 27.5 mass % and metastable BCC β phase at higher contents of Nb. The mechanical properties of alloys depended strongly on the Nb content and type of the dominating phase.

Electron Microscopy of Nanodevices: In Situ and Ex Situ Characterization of Structure and Transport Properties of Carbon Nanotubes

2008 ◽  
Vol 14 (S2) ◽  
pp. 188-189
Author(s):  
JM Zuo ◽  
T Kim ◽  
Q Chen ◽  
LM Peng ◽  
EA Olson
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
New Mexico ◽  
Transport Properties ◽  
Ex Situ

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

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.

X-ray Tomographic Characterization of Natural Polymer Composites and Correlation of Bulk Mechanical Properties

2009 ◽  
Vol 1219 ◽  
Author(s):  
Anahita Pakzad ◽  
Paul Mainwaring ◽  
Patricia A. Heiden ◽  
Reza Shahbazian Yassar
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Clear Correlation ◽  
Natural Polymer ◽  
Microscopy Imaging ◽  
X Ray ◽  
Nanomechanical Properties ◽  
The Matrix ◽  
A New Technique

AbstractIn this research, cellulose micro-crystals (CMC) were used to reinforce a bio-polymer, polycaprolactone (PCL). Mechanical properties were tested using nanoindentation. Electron microscopy imaging and a new technique called x-ray ultra microscopy and microtomography (XuM) were used to investigate the distribution of the filler in the matrix. We could demonstrate a clear correlation between the spatial distribution of CMC-PCL composites and their nanomechanical properties.

Crack Repairing of Aluminum Alloy 6061 by Reinforcement of Al2O3 and B4C Particles Using Friction Stir Processing

2021 ◽  
Vol 875 ◽  
pp. 238-247
Author(s):  
Zunair Masroor ◽  
Ahsan Abdul Rauf ◽  
Faisal Mustafa ◽  
Syed Wilayat Husain
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Microstructural Analysis ◽  
Hardness Test ◽  
X Ray Diffraction ◽  
Crack Line ◽  
Friction Stir ◽  
Mechanical Methods ◽  
Weld Parameters

Crack repairing of aluminum alloys is done using conventional welding techniques or mechanical methods, which results in the redundancy of mechanical properties due to defects formation. Friction Stir Welding/Processing (FSW/FSP) is a solid-state joining technique which is used to join various different similar and dissimilar metals, along with the fabrication of surface composites to cater the mentioned problem. The objective of this study is to repair the crack produced in 6061 aluminum alloy by the reinforcement of ceramic particles, Al2O3 and B4C, to further increase the efficiency of the joint along the crack line. Weld parameters, equipment used and the processing conditions are emphasized. The mechanical testing and the characterization of the weld as well as base metal was done and compared using tensile testing, micro hardness test and microstructural analysis. X-Ray Diffraction (XRD) was performed for crystallinity and intermetallic study. The dispersion of the particles was investigated using Field Emission Scanning Electron Microscope (FESEM). The crack in the Al-6061 was effectively repaired using FSP. The reinforced samples showed improved mechanical properties as compared to non-reinforced ones.

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