Nature of Network, Carbon-Black-Rubber Interaction and Heat Aging of Polyethylacrylate Vulcanizates

1989 ◽  
Vol 62 (2) ◽  
pp. 357-366 ◽  
Author(s):  
N. Nakajima ◽  
R. A. Miller
Keyword(s):  
Carbon Black ◽  
Chemical Nature ◽  
Tensile Modulus ◽  
Large Strains ◽  
Molecular Architecture ◽  
Strain Measurements ◽  
Small Strains ◽  
Two Samples ◽  
Weight One ◽  
The Difference

Abstract Two commercial polyethylacrylate elastomers, having about 50 Mooney Index were selected. They were compounded with 50 parts of N330 carbon black per 100 parts of rubber by weight. One sample having epoxide (EP) crosslinking sites was crosslinked with ammoniumbenzoate. The other having double-bonds by copolymerizing with ethylidene norbornene (ENB) was crosslinked with a sulfur system. The vulcanizates were oven aged at 175°C for 70 h. Tensile stress-strain measurements were performed with the gum rubbers, uncured compounds, unaged vulcanizates, and heat-aged vulcanizates. The data presented as tensile modulus—strain curves revealed the following: at all strain levels, the moduli of ENB gum samples were lower than those of EP gums. After compounding with carbon black, the moduli of two samples became very similar. This indicates that ENB has more affinity with carbon black than EP has. The vulcanizates of two samples has matching moduli at 10% strain but a difference in network structure, since the molecular architecture of the gum rubbers were very different. After heat aging, moduli at small strains increased significantly but not at large strains. The increases were very similar for both samples. The heat-aging characteristics may be very similar for both samples, in spite of the difference in the chemical nature of the crosslinks.

Processing Ease and Rubber—Carbon-Black Interaction

1988 ◽  
Vol 61 (2) ◽  
pp. 362-376 ◽  
Author(s):  
N. Nakajima ◽  
R. A. Miller
Keyword(s):  
Carbon Black ◽  
Ethyl Acrylate ◽  
Dynamic Mechanical Properties ◽  
Strain Measurements ◽  
Carbon Blacks ◽  
Two Samples ◽  
History Of ◽  
The Difference ◽  
Particle Size And Structure ◽  
Size And Structure

Abstract Two samples of poly(ethyl acrylate) rubber, different in their mill processability and their manner of accepting carbon black were examined. This is a case history of how we differentiated Theological behavior of gum elastomers and how we characterized the rubber—carbon-black interaction in the compound. For the former objective, the dynamic mechanical properties were measured over the temperature range of interest. This information was used to interpret the difference in mill processability. For the latter objective, several carbon blacks in different particle size and structure were compounded with these samples. The effect of the different carbon blacks on these elastomers was examined with tensile stress-strain measurements. At least a part of the differences in behavior could be interpreted as the differences in the interaction between rubber and carbon black.

Strain Amplification of Elastomers Filled with Carbon Black in Tensile Deformation

1988 ◽  
Vol 61 (1) ◽  
pp. 137-148 ◽  
Author(s):  
N. Nakajima ◽  
J. J. Scobbo
Keyword(s):  
Carbon Black ◽  
Tensile Stress ◽  
Tensile Deformation ◽  
Molecular Architecture ◽  
Dynamic Shear ◽  
Treatment Procedure ◽  
Stress Strain ◽  
Strain Measurements ◽  
Unique Pattern ◽  
Data Treatment

Abstract This work is based on data previously obtained by the tensile stress-strain and dynamic-shear measurements with several gum rubbers and carbon-black-filled compounds. The gum rubbers were three NBR's of different molecular architecture and two SBR's, one of which was oil extended. The compounds contained 40 phr of N550 carbon black. Through the data treatment procedure developed in this work, the strain amplifications in the dynamic shear and tensile stress-strain measurements were evaluated with the uncrosslinked compounds. Each compound showed a unique pattern of strain amplification.

Dynamics of Nanoparticle Chain Aggregates of Carbon Under Tension

2003 ◽  
Vol 778 ◽  
Author(s):  
Rajdip Bandyopadhyaya ◽  
Weizhi Rong ◽  
Yong J. Suh ◽  
Sheldon K. Friedlander
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Polymer Film ◽  
Elastic Behavior ◽  
Small Strains ◽  
Transmission Electron ◽  
Chain Aggregates ◽  
Nanoparticle Chains ◽  
Reinforcing Filler

AbstractCarbon black in the form of nanoparticle chains is used as a reinforcing filler in elastomers. However, the dynamics of the filler particles under tension and their role in the improvement of the mechanical properties of rubber are not well understood. We have studied experimentally the dynamics of isolated nanoparticle chain aggregates (NCAs) of carbon made by laser ablation, and also that of carbon black embedded in a polymer film. In situ studies of stretching and contraction of such chains in the transmission electron microscope (TEM) were conducted under different maximum values of strain. Stretching causes initially folded NCA to reorganize into a straight, taut configuration. Further stretching leads to either plastic deformation and breakage (at 37.4% strain) or to a partial elastic behavior of the chain at small strains (e.g. 2.3% strain). For all cases the chains were very flexible under tension. Similar reorientation and stretching was observed for carbon black chains embedded in a polymer film. Such flexible and elastic nature of NCAs point towards a possible mechanism of reinforcement of rubber by carbon black fillers.

scholarly journals Finite Pure Plane Strain Bending of Inhomogeneous Anisotropic Sheets

Symmetry ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 145
Author(s):  
Sergei Alexandrov ◽  
Elena Lyamina ◽  
Yeong-Maw Hwang
Keyword(s):  
Plane Strain ◽  
Yield Criterion ◽  
Large Strains ◽  
Rigid Plastic ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Starting Point ◽  
The Difference ◽  
Inside Radius ◽  
Elastic Unloading

The present paper concerns the general solution for finite plane strain pure bending of incompressible, orthotropic sheets. In contrast to available solutions, the new solution is valid for inhomogeneous distributions of plastic properties. The solution is semi-analytic. A numerical treatment is only necessary for solving transcendent equations and evaluating ordinary integrals. The solution’s starting point is a transformation between Eulerian and Lagrangian coordinates that is valid for a wide class of constitutive equations. The symmetric distribution relative to the center line of the sheet is separately treated where it is advantageous. It is shown that this type of symmetry simplifies the solution. Hill’s quadratic yield criterion is adopted. Both elastic/plastic and rigid/plastic solutions are derived. Elastic unloading is also considered, and it is shown that reverse plastic yielding occurs at a relatively large inside radius. An illustrative example uses real experimental data. The distribution of plastic properties is symmetric in this example. It is shown that the difference between the elastic/plastic and rigid/plastic solutions is negligible, except at the very beginning of the process. However, the rigid/plastic solution is much simpler and, therefore, can be recommended for practical use at large strains, including calculating the residual stresses.

scholarly journals The Use of Heap Bioleaching as a Pre-Treatment for Platinum Group Metal Leaching

2017 ◽  
Vol 262 ◽  
pp. 151-154
Author(s):  
James M. Mwase ◽  
Jochen Petersen
Keyword(s):  
Platinum Group Metal ◽  
Metal Leaching ◽  
Flotation Concentrate ◽  
Group Metal ◽  
Two Samples ◽  
Heap Bioleaching ◽  
Mineral Recovery ◽  
The Difference ◽  
Pre Treatment

Two samples, a Platreef flotation concentrate and coarse ore (<6 mm), were column bioleached at 65°C using a culture dominated by Metallosphaera hakonensis. Based on solution assays, extractions in excess of 90% Cu and Ni were achieved from the flotation concentrate, while from the coarse ore 96% Cu and 67% Ni extractions were achieved. The difference in extraction levels and leaching patterns despite identical conditions used for both samples is discussed, as is the performance of the samples during a follow-up leach step using cyanide to extract the PGMs in a separate column leach experiment. While the recovery of Pd and Au was excellent during these steps, recovery of Pt was limited to 35% after 45 days for the concentrate and 56% after 60 days for the whole ore material, primarily due to the presence of a refractory Pt mineral. Recovery from a concentrate without pre-treatment was substantially lower.

scholarly journals Kenaf Fibre Reinforced Polypropylene Composites: Effect of Cyclic Immersion on Tensile Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
W. H. Haniffah ◽  
S. M. Sapuan ◽  
K. Abdan ◽  
M. Khalid ◽  
M. Hasan ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Room Temperature ◽  
Tap Water ◽  
Tensile Modulus ◽  
Polypropylene Composites ◽  
Preliminary Results ◽  
Kenaf Fibre ◽  
The Difference ◽  
Number Of Cycles

This research studied the degradation of tensile properties of kenaf fibre reinforced polypropylene composites due to cyclic immersion into two different solutions, as well as comparison of the developed composites’ tensile properties under continuous and cyclic immersion. Composites with 40% and 60% fibre loadings were immersed in tap water and bleach for 4 cycles. Each cycle consisted of 3 days of immersion and 4 days of conditioning in room temperature (28°C and 55% humidity). The tensile strength and modulus of composites were affected by fibre composition, type of liquid of immersion, and number of cycles. The number of immersion cycles and conditioning caused degradation to tensile strength and modulus of kenaf fibre reinforced polypropylene composites. Continuous and cyclic immersion in bleach caused tensile strength of the composites to differ significantly whereas, for tensile modulus, the difference was insignificant in any immersion and fibre loadings. However, continuous immersion in the bleach reduced the tensile strength of composites more compared to cyclic immersion. These preliminary results suggest further evaluation of the suitability of kenaf fibre reinforced polypropylene composites for potential bathroom application where the composites will be exposed to water/liquid in cyclic manner due to discontinuous usage of bathroom.

scholarly journals Effects of alkanolamide addition on cure characteristics, crosslink density and tensile properties of carbon-black-filled styrene-butadiene rubber compounds

2018 ◽  
Vol 197 ◽  
pp. 12006 ◽  
Author(s):  
Indra Surya ◽  
Hanafi Ismail
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Tensile Properties ◽  
Crosslink Density ◽  
Density Measurement ◽  
Tensile Modulus ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Cure Characteristics ◽  
Styrene Butadiene

By using a semi-efficient sulphur vulcanisation system, the effects of alkanolamide (ALK) addition on cure characteristics, crosslink density and tensile properties of carbon black (CB)-filled styrene-butadiene rubber (SBR) compounds were investigated. The ALK was prepared from Refined Bleached Deodorized Palm Stearin and diethanolamine and added into the CB-filled SBR compounds. The ALK loadings were 1.0, 3.0, 5.0 and 7.0 phr. It was found that ALK decreased the scorch and cure times of the CB-filled SBR compounds. ALK also improved the tensile modulus and tensile strength; especially up to a 5.0 phr of loading. The crosslink density measurement proved that the 5.0 phr of ALK exhibited the highest degree of crosslink density which caused the highest in tensile modulus and tensile strength. Due to its plasticity effect, ALK increased the elongation at break of the CB-filled SBR vulcanisates.

EFFECT OF CELLULOSE FIBER SURFACE TREATMENT TO REPLACE CARBON BLACK IN NATURAL RUBBER HYBRID COMPOSITES

2021 ◽  
Author(s):  
Hossein Kazemi ◽  
Frej Mighri ◽  
Keun Wan Park ◽  
Slim Frikha ◽  
Denis Rodrigue
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Surface Treatment ◽  
Hybrid Composites ◽  
Tensile Modulus ◽  
Fiber Surface ◽  
Cellulose Fiber ◽  
Cellulose Fibers ◽  
Infrared Spectrometry ◽  
Hybrid Filler

ABSTRACT In recent years, cellulose fibers have attracted considerable attention as biofillers for natural rubber (NR) composites. However, neat cellulose cannot be used as a substitute for conventional fillers due to its poor compatibility with NR. Therefore, a new surface treatment via maleic anhydride grafted to polyisoprene (MAPI) in solution was developed to improve the filler–matrix interaction. Different contents of carbon black (CB) and cellulose fibers (before and after modification) were used as a hybrid filler system to investigate the possibility of CB substitution in NR composites. First, contact angle, Fourier transformed infrared spectrometry (FTIR), and scanning electron microscopy (SEM) techniques were used to confirm the successful cellulose surface treatment. Second, morphological analysis, Payne effect, and swelling behavior of the rubber compounds in toluene confirmed the effect of cellulose treatment on improving the interfacial filler–matrix adhesion. Finally, the results showed that the composite filled with 20 phr modified cellulose and 20 phr CB (50% replacement of CB) exhibited even better results than the composite filled with 40 phr of CB, since the tensile strength was only 7% lower, but the elongation at break, tensile modulus at 100%, and storage modulus at 25 °C were respectively 35%, 24%, and 22% higher.

An NMR Investigation of the Interaction between Carbon Black and Cis-Polyisoprene

1980 ◽  
Vol 53 (4) ◽  
pp. 975-981 ◽  
Author(s):  
L. G. Svensson ◽  
S. E. Svanson
Keyword(s):  
Carbon Black ◽  
Main Part ◽  
Chemical Nature ◽  
Physical Nature ◽  
Surface Interaction ◽  
Carbon Blacks ◽  
Irreversible Effects

Abstract Attempts have been made to change the methods of preparation of samples of IR filled with various carbon blacks. Considering experiments where reliable results have been obtained hitherto we have drawn the following conclusions: 1. For solution-mixed and short-milled samples, a large broadening is observed, which is reduced by extraction, heating the samples above 50°C, and by prolonged milling. It is assumed that this broadening is due to interactions of a physical nature. The remaining broadening effect is assigned to irreversible effects of a chemical nature. 2. For dry-milled samples, where prolonged milling is always needed to achieve reasonable mixing, the main part of the broadening effects is not changed by the above treatments. 3. By heating the products to temperatures above 180°C a pronounced broadening develops. We believe that the largest surface interaction is attained by this treatment.

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