Properties of Natural Rubber Nanocomposites Reinforced with Carbon Nanotubes

2015 ◽  
Vol 1109 ◽  
pp. 195-199 ◽  
Author(s):  
Abd Aziz Azira ◽  
Dayang Habibah Abangismawi I. Hassim ◽  
D. Verasamy ◽  
Abu Bakar Suriani ◽  
M. Rusop

In order to achieve improvements in the performance of rubber materials, the development of carbon nanotube (CNT)-reinforced rubber composites was attempted. The CNT/epoxidised natural rubber (ENR) nanocomposite was prepared through latex technology. Physical and mechanical properties of the CNT/ENR nanocomposites were characterized in contrast to the carbon black (CB)/ENR composite. The dispersion of the CNTs in the rubber matrix and interfacial bonding between them were rather good; monitored transmission electron microscopy and scanning electron microscopy. The mechanical properties of the CNT-reinforced ENR showed a considerable increase compared to the neat ENR and traditional CB/ENR composite. The storage modulus of the CNT/ENR nanocomposites greatly exceeds that of neat ENR and CB/ENR composites and a maximum conductivity of about 1 S m-1 can be achieved. The approach presented can be adapted to other CNT/polymer latex systems.

2013 ◽  
Vol 86 (2) ◽  
pp. 205-217 ◽  
Author(s):  
Hedayatollah Sadeghi Ghari ◽  
Zahra Shakouri

ABSTRACT Research was undertaken on natural rubber (NR) nanocomposites with organoclays. A double-network (DN) structure is formed when a partially cross-linked elastomer is further cross-linked during a state of strain. Two methods were used in the preparation of NR/organoclay nanocomposites: the ordinary method (single-network NR nanocomposite) and double-networked NR (DN-NR) nanocomposites. The single-networked NR nanocomposites were used for comparison. The effects of organoclay (5 phr) with a different extension ratio on curing characteristics, mechanical properties, hardness, swelling behavior, and morphology of single- and double-networked NR nanocomposites were studied. The results showed that double-networked NR nanocomposites exhibited higher physical and mechanical properties. The tensile strength of DN-NR nanocomposites increased up to 33 MPa (more than four times greater than that of pure NR) and then decreased with an increasing extension ratio. Modulus and hardness continuously increased with an increased extension ratio. The microstructure of the NR/organoclay systems was studied by X-ray diffraction and field emission scanning electron microscopy. The effects of different extension ratios on the dispersion of organoclay layers in the nanocomposites were investigated. Generally, results showed that the optimized extension ratio in DN nanocomposites was equal (or about or around) to α= 2.


Author(s):  
Robert C. Rau ◽  
Robert L. Ladd ◽  
John Moteff

As part of a program investigating the effects of neutron irradiation on the physical and mechanical properties of body centered cubic refractory metals, transmission electron microscopy has been carried out on irradiated tungsten after tensile and creep-rupture testing. These observations have shown the existence of a fluence threshold region between 5.9 × 1018 and 3.8 × 1019 nvt (E < 1 MeV) over which both microstructure and mechanical properties undergo abrupt changes.A series of specimens irradiated at pile ambient temperature (∼ 70°C) to various fast neutron fluences and subsequently tensile tested at 400°C showed dramatic evidence of the build-up of defect clusters with increasing exposure. The starting microstructure present in undeformed button heads of unirradiated control specimens consisted of large tungsten grains divided into many small subgrains by hexagonal dislocation networks, as shown in Figure 1. Irradiation to neutron fluences of 4.0 and 5.9 × 1018 nvt produced tiny dot clusters in the matrix, as shown in Figure 2.


Author(s):  
M. Kirn ◽  
M. Rühle ◽  
H. Schmid ◽  
L.J. Gauckler

It is expected that Si-Al-O-N alloys are important high temperature construction materials. The phase diagrams for Si-Al-O-N alloys were studied systematically mainly by X-ray diffraction work (for a summary see). Different stable phases were found. For the understanding of the physical and mechanical properties it is of great interest to know for the different stable phases the microstructure and the morphology, which can be obtained by TEM observations. Results of some TEM studies are reported here utilizing not only the conventional TEM but also the lattice fringe imaging technique.Specimens of the different phases were produced as described in They were prepared for TEM observations. For high resolution work a Siemens ELMISKOP 102 (operating voltage 125 kV) was used fitted with a double tilting stage (± 45°), for conventional TEM studies the specimens were examined in an AEI EM7 high voltage EM operated at 1 MeV.


2007 ◽  
Vol 80 (4) ◽  
pp. 690-700 ◽  
Author(s):  
Atsushi Kato ◽  
Shinzo Kohjiya ◽  
Yuko Ikeda

Abstract Usual rubber products are a composite from rubber and nano-filler (e.g. silica, carbon black, etc.), and it is believed that the good dispersion of the nano-filler is the most important issue determining the performance of rubber vulcanizates. So far, transmission electron microscopy (TEM) has been the most useful tool for evaluation of the dispersion. However, it affords images of the sample projected on an x, y-plane, and the information along the thickness (z-axis) direction is missing. Three-dimensional (3D) visualization of nanometer structure of nano-filler dispersion in a rubber matrix is what all rubber technologists have been dreaming of. This dream is at last realized, and described in this paper. Use of TEM combined with computerized tomography (abbreviated as 3D-TEM in this paper, which is sometimes called electron tomography) enabled us to reconstruct 3D images of nano-filler (silica or carbon black) aggregates in rubbery matrix. It is said that nano-filler aggregate is a structure of size from 10 nm to 1000 nm, and agglomerate is an even larger structure. The 3D-TEM results on silica aggregates in natural rubber were presented in this paper. Silica aggregates were characterized by combining the 3D images of the vulcanizates. Furthermore, density of silica loaded natural rubber as an example of physical properties, was measured, and explained by the structure elucidated by 3D-TEM.


2012 ◽  
Vol 164 ◽  
pp. 142-145 ◽  
Author(s):  
Qian Zhang ◽  
Yu De Zhang ◽  
Yan Wang

Nanoomposites consisting of natural rubber (NR) reinforced with the modified kaolin were fabricated. The effect of modified kaolin loading on the mechanical properties of the vulcanizates was examined by varying its incorporation (20–50 phr). The NR-based nanocomposites were characterized using the transmission electron microscopy (TEM), Instron tensile machine and thermal analyser. These filled NR composites exhibit outstanding mechanical properties and much higher thermal stability compared to the pure NR. The hardness and tensile properties increased with increasing filler loading and an optimum of tensile strength was achieved at 50 phr of modified kaolin. The morphological studies by TEM revealed that kaolinite layers were finely dispersed into the natural rubber matrix and orientationally arranged in parallel


2014 ◽  
Vol 9 (3) ◽  
pp. 155892501400900
Author(s):  
Shima Shayestehfar ◽  
Mohammad Esmail Yazdanshenas ◽  
Ramin Khajavi ◽  
Abo-Saeed Rashidi

In this study, the effect of titanium dioxide particles (TiO2 micro and nano) on the physical and mechanical properties of Nylon 6–based multifilament yarns was investigated. For this reason, master-batches of Nylon 6/TiO2 micro and nano-particles were prepared by melt compounding before spinning and then multifilament composites incorporating 0.03, 0.33, 0.5 and 0.7% TiO2 micro and nano-particles were successfully spun in a melt-spinning machine. Characterization of these composite multifilament yarns was carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray (EDX), and X-ray diffraction (XRD) analysis. Characterization of mechanical strength properties including tenacity and elongation at break of the resultant composites are discussed as a function of filler loading. Through the application of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), it was found that incorporating micro titanium dioxide caused severe aggregation at the nylon fiber surface. By contrast, the diffusion of nano-particles within bulk of multifilament yarns was much more consistent, although aggregation of the titanium dioxide nano-particles still appeared. The results manifested the improvement of mechanical properties of the nano-composites containing TiO2 nano-particles.


2014 ◽  
Vol 87 (1) ◽  
pp. 10-20 ◽  
Author(s):  
M. J. Azizli ◽  
G. Naderi ◽  
G. R. Bakhshandeh ◽  
S. Soltani ◽  
F. Askari ◽  
...  

ABSTRACT The effects of organoclay loading and chloroprene rubber (CR) concentration on the cure characteristics, microstructure, and mechanical and rheological properties of isobutylene–isoprene rubber (IIR)/CR blend were investigated. Different compositions of CR (10, 20, and 40 wt%) with Cloisite15A as organo modified nanoclay (1, 3, 5, and 7 wt%) were used for blends by a two-roll mill. Samples were vulcanized at 175 °C using a hot press. The cure and scorch times and also the maximum torque of the composites increased with the incorporation of organoclay. Mechanical properties such as tensile strength, elongation at break, modulus (100%, 200%, and 300%), and resilience improved with increasing nanoclay loading. The structure of the nanocomposites was characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). XRD results of nanocomposites indicated that the intercalation of polymer chains into the clay gallery was deduced from increasing the interlayer distance of silicate layers. TEM and SEM also directly confirmed XRD results.


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