Some Relations between Stress, Strain, and Temperature in a Pure-Gum Vulcanizate of Gr-S Synthetic Rubber

1945 ◽  
Vol 18 (2) ◽  
pp. 353-366
Author(s):  
Frank L. Roth ◽  
Lawrence A. Wood
Keyword(s):  
Natural Rubber ◽  
Work Stress ◽  
Low Temperatures ◽  
Experimental Information ◽  
Elastic Behavior ◽  
Stress Strain ◽  
Synthetic Rubber ◽  
Length Constant ◽  
Practical Information ◽  
High And Low Temperatures

Abstract Some relations between stress, strain and temperature have been investigated for a pure-gum vulcanizate of GR-S to furnish experimental information for use in theoretical consideration of its elastic behavior. The results of the work also yield some practical information about the tensile properties at high and low temperatures. In this work stress was studied as a function of temperature, with the elongation, or sometimes the length, constant. In this way effects of friction and flow accompanying changes in length of specimens were minimized. The general methods employed in this study were first outlined by Meyer and Ferri, who in common with other observers applied them to natural rubber. Peterson, Anthony, and Guth, in the only studies of this sort dealing with synthetic rubber, did not include GR-S or other butadienestyrene copolymers.

A Method of Testing the Elasticity of Synthetic Rubbers at Low Temperatures

1943 ◽  
Vol 16 (4) ◽  
pp. 888-896
Author(s):  
George D. Kish
Keyword(s):  
Natural Rubber ◽  
Low Temperatures ◽  
New Product ◽  
Elastic Behavior ◽  
Accurate Data ◽  
Synthetic Rubber ◽  
Rubber Compounds

Abstract With the appearance of many new synthetic rubber compounds, the need has arisen for quick and practical testing to determine their comparative applicability to uses formerly filled by natural rubber compounds. One of the most important points is the elastic behavior of synthetic rubbers at low temperatures, and such information is imperative when synthetics are to be introduced into the design of a new product. To obtain accurate data, an instrument termed an Elastensometer was devised.

Film from Mixtures of Natural and Synthetic Rubber Latex. Physical Properties

1952 ◽  
Vol 25 (4) ◽  
pp. 983-994
Author(s):  
R. M. Pierson ◽  
R. J. Coleman ◽  
T. H. Rogers ◽  
D. W. Peabody ◽  
J. D. D'Ianni
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Natural Rubber Latex ◽  
Synthetic Polymers ◽  
Rubber Latex ◽  
Stress Strain ◽  
Synthetic Rubber ◽  
Mooney Viscosity ◽  
The One ◽  
Rubber Stock

Abstract When tested in a single standardized procedure for cast latex films, the type of synthetic-rubber latex employed in latex blends containing 70 per cent or more natural-rubber latex had little effect on the stress-strain properties of the mixture. Cold-rubber latexes imparted higher stress-strain values to blends with natural rubber than did the corresponding hot-rubber latexes. The improvement was particularly noted on comparison of tensile product values. Low-conversion synthetic polymers produced higher stress-strain properties than high-conversion polymers in blends with natural rubber, even though their tensile strengths in 100 per cent synthetic stocks were approximately equal. Optimum physical properties were obtained by use of blends with synthetic polymers of medium Mooney viscosity. It is believed that the appearance of an optimum Mooney viscosity is tied in with the necessity of having quite high molecular weight on the one hand, and, on the other, the ability of the particles to knit well, the latter in turn requiring a comparative freedom from tight gel. Tensile product values increased with increasing styrene content in the synthetic polymer, but, correspondingly, the low-temperature stiffening increased. The physical properties of a natural rubber stock are far superior to those of any of the synthetic-rubber latexes tested to date. Cold-rubber latexes now in production are an improvement over high-temperature latexes, for example, in wet gel strength but do not approach natural rubber latex in stress-strain properties.

Relation between Stress Strain Behavior and Equilibrium Volume Swelling for Peroxide Vulcanizates of Natural Rubber and cis-1,4-Polyisoprene

1967 ◽  
Vol 40 (2) ◽  
pp. 673-678 ◽  
Author(s):  
G. M. Bristow
Keyword(s):  
Natural Rubber ◽  
Elastic Behavior ◽  
Stress Strain ◽  
Strain Behavior ◽  
Equilibrium Volume ◽  
Equilibrium Swelling ◽  
Tentative Evidence ◽  
Volume Swelling ◽  
Natural Rubber Vulcanizates

Abstract Data are reported for the elastic behavior, as described by the parameters C1 and C2, and the equilibrium swelling in n-decane, νr, for cumyl peroxide vulcanizates of natural rubber and cis-1, 4-polyisoprene. For natural rubber vulcanizates the correlation between C1 and νr can be described in terms of the original Flory Rehner equation with χ= 0.41. Tentative evidence is presented which favors this equation rather than the later modified form in which the term in νr1/3 is replaced by one in (νr1/3− νr/2).

Stress-Strain Behavior of Natural Rubber Vulcanized in the Swollen State

1971 ◽  
Vol 44 (3) ◽  
pp. 744-749 ◽  
Author(s):  
Colin Price ◽  
G. Allen ◽  
F. de Candia ◽  
M. C. Kirkham ◽  
A. Subramaniam
Keyword(s):  
Statistical Theory ◽  
Natural Rubber ◽  
Theory Of Elasticity ◽  
Elastic Behavior ◽  
Force Extension ◽  
Stress Strain ◽  
Strain Behavior

Abstract Samples of natural rubber were vulcanized in the presence of n-decane, decalin and o-chlorobenzene. The diluents were then removed, and the force-extension characteristics of the samples studied over the range 1.1<α<2.0. The elastic behavior of the solution-vulcanized elastomers appear to be in much closer agreement with the statistical theory of elasticity than is the case for vulcanizates prepared in the dry state.

Simple Systems

2017 ◽  
Author(s):  
Jochen Rau
Keyword(s):  
Magnetic Field ◽  
Low Temperatures ◽  
General Framework ◽  
Gibbs State ◽  
Macroscopic System ◽  
Basic Model ◽  
System A ◽  
Paramagnetic Salt ◽  
High And Low Temperatures ◽  
Simple Systems

Even though the general framework of statistical mechanics is ultimately targeted at the description of macroscopic systems, it is illustrative to apply it first to some simple systems: a harmonic oscillator, a rotor, and a spin in a magnetic field. These applications serve to illustrate how a key function associated with the Gibbs state, the so-called partition function, is calculated in practice, how the entropy function is obtained via a Legendre transformation, and how such systems behave in the limits of high and low temperatures. After discussing these simple systems, this chapter considers a first example where multiple constituents are assembled into a macroscopic system: a basic model of a paramagnetic salt. It also investigates the size of energy fluctuations and how—in the case of the paramagnet—these fluctuations scale with the number of constituents.

scholarly journals Processes of hypernuclei formation in relativistic ion collisions

2018 ◽  
Vol 171 ◽  
pp. 13001
Author(s):  
Alexander Botvina ◽  
Marcus Bleicher
Keyword(s):  
Experimental Research ◽  
Statistical Models ◽  
Low Temperatures ◽  
Particle Physics ◽  
Broad Distribution ◽  
High Energies ◽  
Intermediate Energies ◽  
Ion Collisions ◽  
High And Low Temperatures

The study of hypernuclei in relativistic ion collisions open new opportunities for nuclear and particle physics. The main processes leading to the production of hypernuclei in these reactions are the disintegration of large excited hyper-residues (target- and projectile-like), and the coalescence of hyperons with other baryons into light clusters. We use the transport, coalescence and statistical models to describe the whole reaction, and demonstrate the effectiveness of this approach: These reactions lead to the abundant production of multi-strange nuclei and new hypernuclear states. A broad distribution of predicted hypernuclei in masses and isospin allows for investigating properties of exotic hypernuclei, as well as the hypermatter both at high and low temperatures. There is a saturation of the hypernuclei production at high energies, therefore, the optimal way to pursue this experimental research is to use the accelerator facilities of intermediate energies, like FAIR (Darmstadt) and NICA (Dubna).

scholarly journals Stress-strain curve of concretes with recycled concrete aggregates: analysis of the NBR 8522 methodology

2017 ◽  
Vol 10 (3) ◽  
pp. 547-567 ◽  
Author(s):  
D. A. GUJEL ◽  
C. S. KAZMIERCZAK ◽  
J. R. MASUERO
Keyword(s):  
Test Procedure ◽  
Strain Curve ◽  
Recycled Concrete ◽  
Load Test ◽  
Recycled Aggregates ◽  
Elastic Behavior ◽  
It Use ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Brazilian Standard

ABSTRACT This work analyses the methodology "A" (item A.4) employed by the Brazilian Standard ABNT 8522 (ABNT, 2008) for determining the stress-strain behavior of cylindrical specimens of concrete, presenting considerations about possible enhancements aiming it use for concretes with recycled aggregates with automatic test equipment. The methodology specified by the Brazilian Standard presents methodological issues that brings distortions in obtaining the stress-strain curve, as the use of a very limited number of sampling points and by inducing micro cracks and fluency in the elastic behavior of the material due to the use of steady stress levels in the test. The use of a base stress of 0.5 MPa is too low for modern high load test machines designed do high strength concrete test. The work presents a discussion over these subjects, and a proposal of a modified test procedure to avoid such situations.

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