Encapsulation in Ternary Elastomer Blends

1999 ◽  
Vol 72 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Yasuaki Koseki ◽  
Moo Sung Lee ◽  
C. W. Macosko
Keyword(s):  
Electron Microscopy ◽  
Butadiene Rubber ◽  
Spreading Coefficient ◽  
Blend Ratio ◽  
Chlorinated Polyethylene ◽  
Blend Morphology ◽  
Transmission Electron ◽  
Dispersed Phases ◽  
Encapsulated Structures ◽  
Comonomer Content

Abstract Ternary elastomer blends of acrylonitrile-butadiene rubber (NBR), chlorinated polyethylene (CM), and ethylene-propylene rubber (EP) have been investigated using transmission electron microscopy (TEM). Especially the effect of comonomer content, chlorine in CM and acrylonitrile in NBR, on blend morphology is studied. The blend ratio of NBR/CM/EP is fixed at 10/20/70 by weight: EP acts as matrix and NBR and CM comprise dispersed phases. TEM observation is possible without staining due to a natural contrast between NBR and CM. From TEM micrographs it is clear that NBR/CM/EP blends show encapsulated structures. Which component will be the encapsulating layer depends on comonomer contents. For blends containing high acrylonitrile content (NBR46), CM forms the encapsulating layer; whereas, for blends with low acrylonitrile (NBR16), NBR16 encapsulates CM. The encapsulation behavior of NBR/CM/EP blends is interpreted in terms of a spreading coefficient concept combined with solubility parameter and melt viscosity differences between NBR and CM. Our calculation based on simple thermodynamic considerations explains the morphology observed in this study except for the NBR16/CM29/EP blend.

Blends of Nylon 6/66 and Acrylonitrile-Butadiene Rubber: Effects of Blend Ratio and Dynamic Vulcanization on Morphology and Properties

2005 ◽  
Vol 21 (4) ◽  
pp. 277-297 ◽  
Author(s):  
C. Radhesh Kumar ◽  
I. Aravind ◽  
R. Stephan ◽  
Peter Koshy ◽  
J. Jose ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Butadiene Rubber ◽  
Dynamic Vulcanization ◽  
Blend Ratio ◽  
Acrylonitrile Butadiene Rubber ◽  
Electron Microscopies ◽  
Blend Morphology ◽  
Transmission Electron ◽  
The Stability ◽  
Morphology And Mechanical Properties

The morphology and mechanical properties of nylon (copolyamide 6/66)/ acrylonitrile-butadiene rubber (NBR) blends have been studied with special reference to the effect of blend ratio and crosslinking systems. Morphological investigations of the blends using scanning and transmission electron microscopies show that a uniform and finer dispersion of the elastomer phase is achieved by dynamic crosslinking. The effects of various crosslinking systems such as sulphur and dicumyl peroxide on the morphology and mechanical properties of these blends were analysed. Morphological stability of the blends upon annealing has been investigated and the mechanical properties of the blends have been discussed. Attempts have been made to correlate the morphology with the mechanical properties of the dynamically vulcanized blends. The stability of the blend morphology during annealing has been examined.

Silica and Silane Coupling Agent for in Situ Reinforcement of Acrylonitrile-Butadiene Rubber

1999 ◽  
Vol 72 (1) ◽  
pp. 119-129 ◽  
Author(s):  
K. Murakami ◽  
S. Osanai ◽  
M. Shigekuni ◽  
S. Iio ◽  
H. Tanahashi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Silica Particles ◽  
Butadiene Rubber ◽  
Acrylonitrile Butadiene Rubber ◽  
In Situ Silica ◽  
Transmission Electron ◽  
Dispersion Agent ◽  
The Relationship

Abstract In situ silica reinforcement for the acrylonitrile-butadiene rubber (NBR) vulcanizates, which were premixed with a conventional silica (VN-3) and γ-mercaptopropyltrimethoxysilane (γ-MPS), was achieved by the sol-gel reaction of tetraethoxysilane (TEOS) using ethylenediamine. It was observed that the reinforcement efficiency tended to increase with the increase of mechanically premixed conventional silica. From the observations of transmission electron microscopy and scanning electron microscopy, the simultaneous use of VN-3 and γ-MPS was found to promote the formation of large silica particles and clusters with a relatively good dispersion by the sol-gel reaction of TEOS in the NBR vulcanizate. The results of hysteresis measurements supported this promotion. It was considered to be due to the surface modification of VN-3 by the sol-gel reaction of TEOS and the presence of γ-MPS which worked as a dispersion agent for silica particles. The relationship between the mechanical properties and the morphology of the in situ silica filled vulcanizates is discussed.

Mechanical and dielectric properties of cobalt–zinc nanoferrite/nitrile butadiene rubber composites

2016 ◽  
Vol 31 (1) ◽  
pp. 3-22 ◽  
Author(s):  
AA Sattar ◽  
DE El-Nashar ◽  
WR Agami ◽  
M Adel Aly
Keyword(s):  
Electron Microscopy ◽  
Ftir Spectroscopy ◽  
Ferrite Nanoparticles ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
Rubber Composites ◽  
Dielectric Parameters ◽  
Nitrile Butadiene Rubber ◽  
Transmission Electron ◽  
Zn Ferrite

Nitrile butadiene rubber (NBR) samples filled with cobalt–zinc (Co-Zn) ferrite nanoparticles (Co1− xZn xFe2O4, where x = 0, 0.2, 0.4, 0.6, 0.8, 0.9, 0.95 and 1) were prepared. The structure and morphology of Co-Zn ferrite nanoparticles were investigated using X-ray diffraction, transmission electron microscopy, and Fourier transform infrared (FTIR) spectroscopy, while the structure of the Co-Zn nanoferrite-filled NBR composites was studied using scanning electron microscopy and FTIR spectroscopy. The influence of ferrite composition on cure characteristics, mechanical properties and hardness showed an improvement up to x = 0.8. Dielectric parameters showed an enhancement with ferrite composition.

PREPARATION AND PROPERTIES OF HNT–SiO2COMPOUNDED SHEAR THICKENING FLUID

NANO ◽  
2014 ◽  
Vol 09 (08) ◽  
pp. 1450100 ◽  
Author(s):  
YAN WANG ◽  
YAOFENG ZHU ◽  
YAQIN FU
Keyword(s):  
Electron Microscopy ◽  
Dispersion Medium ◽  
High Speed ◽  
Shear Thickening ◽  
Halloysite Nanotube ◽  
Shear Thickening Fluid ◽  
Transmission Electron ◽  
Polyethylene Glycol 200 ◽  
Dispersed Phases ◽  
Scanning Electron

A novel shear thickening fluid (STF) obtained from a halloysite nanotube (HNT) and SiO2compounded system was successfully prepared using HNT and nano- SiO2as dispersed phases and polyethylene glycol 200 (PEG200) as the dispersion medium. The steady rheological behavior of the STF was investigated using a high-speed rotational rheometer, and the dispersion states of SiO2and HNT in PEG200 were characterized by field emission scanning electron microscopy and transmission electron microscopy. Results show that HNT and SiO2coexisted in the compounded system, and presented a special state that was both uniformly dispersed and partially enriched. The shear thickening effect of the STF was significantly enhanced by the enrichment of SiO2loaded on the surface of HNTs in the compounded system.

Preparation of NBR/Expanded Graphite Nanocomposites by Simple Mixing

2005 ◽  
Vol 13 (8) ◽  
pp. 815-821 ◽  
Author(s):  
D.W. Liu ◽  
X.S. Du ◽  
Y.Z. Meng
Keyword(s):  
Electron Microscopy ◽  
Ball Mill ◽  
Expanded Graphite ◽  
Mechanical Analysis ◽  
Butadiene Rubber ◽  
Melt Mixing ◽  
Remarkable Improvement ◽  
Transmission Electron ◽  
Lower Glass Transition Temperature ◽  
Graphite Nanocomposites

Nanocomposites of acrylonitrile-butadiene rubber (NBR) and expanded graphite (EG) were synthesised by melt mixing. Before being mixed with the NBR, the expanded graphite was first sonicated for 10 h, and the powders obtained were then grounding in a ball mill for another 10 h. Scanning electron microscopy (SEM) of the sonicated graphite layers revealed that the expanded graphite was completely torn into nanoscale sheets. Transmission electron microscopy (TEM) of the NBR/EG composites indicated nanoscale dispersion of the EG within the NBR matrix. The mechanical properties of the NBR/EG nanocomposites showed a remarkable improvement in tensile strength. Dynamic mechanical analysis (DMA) showed that the EG imparted a higher storage modulus and lower glass transition temperature to the NBR matrix. The expanded graphite was effective in increasing the electrical conductivity of the composites.

Structure and Properties of BR Nanocomposites Reinforced with Organoclay

2005 ◽  
Vol 13 (4) ◽  
pp. 371-384 ◽  
Author(s):  
Shaohui Wang ◽  
Zonglin Peng ◽  
Yong Zhang ◽  
Yinxi Zhang
Keyword(s):  
Electron Microscopy ◽  
Ammonium Salts ◽  
Butadiene Rubber ◽  
Structure And Properties ◽  
Reinforcement Effect ◽  
X Ray Diffraction ◽  
Melt Mixing ◽  
Elongation At Break ◽  
X Ray ◽  
Transmission Electron

Butadiene rubber (BR)/organoclay nanocomposites were prepared by direct melt mixing of BR and clay modified with different primary and quaternary ammonium salts. BR/pristine clay composite and BR/organoclay nanocomposites were analysed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis. The vulcanization characteristics and the mechanical properties of the BR/pristine clay and BR/organoclay composites were investigated. The results showed that the interlayer distance of the organoclays was expanded, which indicated that intercalated BR/organoclay nanocomposites had been prepared. Organoclay effectively accelerated the vulcanization of BR, which was attributed to the intercalatant used to modify the clay. The tensile strength, elongation at break and tear strength of BR/organoclay nanocomposites are much higher than those of gum BR vulcanizate and BR/pristine clay composites. The organoclay modified with dimethyl dihydrogenated tallow ammonium chloride (DDAC) gave the best reinforcement effect in BR of all the organoclays.

NR/SBR composites reinforced with organically functionalized MWCNTs: simultaneous improvement of tensile strength and elongation and enhanced thermal stability

2016 ◽  
Vol 36 (8) ◽  
pp. 813-818 ◽  
Author(s):  
Minghua Li ◽  
Weixiao Tu ◽  
Xinfeng Chen ◽  
Huihui Wang ◽  
Jinyang Chen
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Mechanical And Thermal Properties ◽  
Butadiene Rubber ◽  
Transmission Electron ◽  
Styrene Butadiene

Abstract Butyl acrylate-α-methyl methacrylate-glycidyl methacrylate (BA-MMA-GMA) terpolymer was successfully grafted onto carbon nanotubes (CNTs) via a facile grafting functionalization approach, affording an organically functionalized multiwalled CNTs (O-MWCNTs), which show improved mechanical and thermal properties in natural rubber/styrene-butadiene rubber (NR/SBR) composites. Under optimized conditions, the result of elongation at break of NR/SBR composites combined with 1.5 parts per hundred rubber (phr) O-MWCNTs is 450% compared to 376% of pristine NR/SBR composites, which is proportional to tensile strength due to the mixed O-MWCNTs in the rubber matrix. Transmission electron microscopy study shows that O-MWCNTs (1.5 phr) can disperse uniformly in NR/SBR/O-MWCNT composites. A scanning electron microscopy study on the fractured surface morphology of the optimized composites reveals that a BA-MMA-GMA terpolymer can interact with the rubber matrix strongly. The decreased height of the maximum tanδ peak shows that O-MWCNTs can reduce the heat buildup and damping capability of NR/SBR/O-MWCNT composites. The largest enhancement observed in the thermal degradation curves of composites is, for the first time, about 70°C, which can be attributed to enhanced interfacial interaction between MWCNTs and the rubber matrix.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

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