Elasticity rubberlike

Problem 2-25. Complex fluids. Consider a suspension consisting of a Newtonian suspending fluid and micrometer-sized particles in which Brownian motion is a factor. The particles are spherical at equilibrium but are made of a Hookean elastic (rubberlike) material. Assume that the suspension is dilute (the motion of each particle is independent of the fact that other particles are present). Discuss whether this material can be described at a continuum level as a Newtonian fluid. Does this depend on the magnitude of the elastic modulus On the shear rate ... 

If a fluid does not follow Eq. (3.5-1), it is a non-Newtonian fluid. Then a plot of t versus —dv/dr is not linear through the origin for these fluids. Non-Newtonian fluids can be divided into two broad categories on the basis of their shear stress/shear rate behavior those whose shear stress is indejjendent of time or duration of shear (time-independent) and those whose shear,stress is dependent on time or duration of shear (time-dependent). In addition to unusual shear-stress behavior, some non-Newtonian fluids also exhibit elastic (rubberlike) behavior which is a function of time and results in... 

Queslel JP, Mark JE. Elasticity, rubberlike. In Mark ME, editor. Encyclopedia of polymer... 

Elastomers. Elastomers is a generic name for polymers that exhibit rubberlike elasticity. Elastomers are soft yet sufficiently elastic that they can be stretched several hundred percent under tension. When the stretching force is removed, they retract rapidly and recover their original dimensions. 

Many other parepistemes were stimulated by the new habits of precision in theory. Two important ones are the entropic theory of rubberlike elasticity in polymers, which again reached a degree of maturity in the middle of the century (Treloar 1951), and the calculation of phase diagrams (CALPHAD) on the basis of measurements of thermochemical quantities (heats of reaction, activity coefficients, etc.) here the first serious attempt, for the Ni-Cr Cu system, was done in the Netherlands by Meijering (1957). The early history of CALPHAD has recently been... 

Treloar, L.R.G. (1958) The Physics of Rubberlike Elasticity (Oxford University Press, Oxford). 

Thermoelasticity Rubberlike elasticity that a rigid plastic displays ... 

Mark,J.E. The Use of Model Polymer Networks to Elucidate Molecular Aspects of Rubberlike Elasticity. Vol. 44, pp. 1 —26. 

Small deformations of the polymers will not cause undue stretching of the randomly coiled chains between crosslinks. Therefore, the established theory of rubber elasticity [8, 23, 24, 25] is applicable if the strands are freely fluctuating. At temperatures well above their glass transition, the molecular strands are usually quite mobile. Under these premises the Young s modulus of the rubberlike polymer in thermal equilibrium is given by ... 

The statistical distribution of r values for long polymer chains and the influence of chain structure and hindrance to rotation about chain bonds on its root-mean-square value will be the topics of primary concern in the present chapter. We thus enter upon the second major application of statistical methods to polymer problems, the first of these having been discussed in the two chapters preceding. Quite apart from whatever intrinsic interest may be attached to the polymer chain configuration problem, its analysis is essential for the interpretation of rubberlike elasticity and of dilute solution properties, both hydrodynamic and thermodynamic, of polymers. These problems will be dealt with in following chapters. The content of the present... 

These deductions from basic facts of observation interpreted according to the rigorous laws of thermodynamics do not alone offer an insight into the structural mechanism of rubber elasticity. Supplemented by cautious exercise of intuition in regard to the molecular nature of rubberlike materials, however, they provide a sound basis from which to proceed toward the elucidation of the elasticity mechanism. The gap between the cold logic of thermodynamics applied to the thermoelastic behavior of rubber and the implications of its... 

Before proceeding further it is desirable to point out that dH/dL)T,p will differ indiscernibly from dE/dL)T,p in any likely application to rubberlike elastic phenomena. This may be seen by observing that the second term on the right-hand side of the relation... 

Mark JE, Erman B (1988) Rubberlike elasticity - a molecular primer. John Wiley, New York... 

J.E. Mark and B. Erman, Rubberlike Elasticity A Molecular Primer, Wiley-Intersdence, New York, 1988. 

B. Erman and J.E. Mark, The molecular basis of rubberlike elasticity. In J.E. Mark, B. Erman and... 

J.E. Mark, Illustrative modeling studies on elastomers and rubberlike elasticity. In M. Laudon, and B. Romanowiczs (Eds.), International Conference on Computational Nanoscience. Computational Publications, Boston, Hilton Head Island, SC, 2001, p. 53. 

The strain is given by the relative length or elongation a = L/L where L and are the lengths of the sample in the deformed and undeformed states, respectively. Dividing the stress f/A by the strain function (a - a- ) indicated in the simplest molecular theories of rubberlike elasticity (38,39) then gives the elastic modulus or reduced stress (38-42)... 

Evaluation of Non-Gaussian Elasticity Theories. There are now numerous theories of rubberlike elasticity which use non-Gaussian distribution functions to take into account limited... 

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