Energy Contribution to Rubber Elasticity

1968 ◽  
Vol 39 (11) ◽  
pp. 4937-4943 ◽  
Author(s):  
Mitchel Shen ◽  
Paul J. Blatz
Keyword(s):  
Rubber Elasticity ◽  
Energy Contribution

Internal Energy Contribution to the Elasticity of Natural Rubber

1970 ◽  
Vol 43 (2) ◽  
pp. 270-281 ◽  
Author(s):  
Mitchel Shen
Keyword(s):  
Natural Rubber ◽  
Elastic Stress ◽  
Tensile Elongation ◽  
Relative Energy ◽  
Rubber Elasticity ◽  
Energy Contribution ◽  
Constant Length ◽  
Shear Moduli ◽  
Energetic Stress ◽  
Apparent Strain

Abstract It has recently been noted by a number of workers that the relative energy contribution, fe/f, to the elastic stress of rubberlike materials appears to depend on the extension ratio at which thermoelastic measurements were carried out. This apparent strain dependence is in contradiction to the free energy additivity principle of the statistical theory of rubber elasticity. In this paper we resolve this problem by determining fe/f from the temperature coefficient of shear moduli. The shear moduli were not directly determined from measurements of shear, but calculated from tensile elongation data. This method circumvents the difficulty encountered in directly obtaining the relative energy contribution from stress—temperature data. Both constant length and constant stress thermoelastic measurements were used to obtain fe/f. A series of natural rubber samples, crosslinked in the presence of various amounts of n-hexadecane, were investigated. It is found that the relative energy contribution to the elasticity of natural rubber is 0.18. Changes in inter-molecular interactions, brought about by the incorporation of diluents, produce no variation in the value of fe/f. This observation supports the hypothesis that the energetic stress in rubber elasticity is wholly attributable to intrachain energies of the network chains.

Structures and Properties of Rubberlike Networks

1997 ◽  
Author(s):  
Burak Erman ◽  
James E. Mark
Keyword(s):  
Subject Matter ◽  
Rubber Elasticity ◽  
Polymer Science ◽  
Strong Emphasis ◽  
Present Book ◽  
Structures And Properties

Rubber elasticity is an important sub-field of polymer science. This book is in many ways a sequel to the authors' previous, more introductory book, Rubberlike Elasticity: A Molecular Primer (Wiley-Interscience, 1988), and will in some respects replace the now classic book by L.R.G. Treloar, The Physics of Rubber Elasticity (Oxford, 1975). The present book has much in common with its predecessor, in particular its strong emphasis on molecular concepts and theories. Similarly, only equilibrium properties are covered in any detail. Though this book treats much of the same subject matter, it is a more comprehensive, more up-to-date, and somewhat more sophisticated treatment.

scholarly journals Solar energy contribution to an electric vehicle needs on the basis of long-term measurements

2018 ◽  
Vol 10 ◽  
pp. 203-210 ◽  
Author(s):  
Em. Kostopoulos ◽  
G. Spyropoulos ◽  
K. Christopoulos ◽  
J.K. Kaldellis
Keyword(s):  
Solar Energy ◽  
Electric Vehicle ◽  
Energy Contribution

Rubbery Ormosils

1990 ◽  
Vol 180 ◽  
Author(s):  
Young J. Chung ◽  
Su-Jen Ting ◽  
John D. Mackenzie
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Model ◽  
Rubber Elasticity ◽  
New Technique ◽  
Polydimethyl Siloxane ◽  
Gelation Process ◽  
Organically Modified Silicates ◽  
Organically Modified ◽  
A New Technique

ABSTRACTA new technique which permits the successful preparation of ORMOSILS (Organically Modified Silicates) with rubbery elasticity has been developed. Common alkoxides were reacted with polydimethyl siloxane (PDMS) and the microstructures were carefully controlled. Large monoliths of the porous rubbery ORMOSILS have been prepared. Gelation process was studied by 29Si liquid NMR spectroscopy. A structural model for rubber elasticity of ORMOSILS was proposed.

scholarly journals Chiral phase-coexistence in compressed double-twist elastomers

Soft Matter ◽  
2021 ◽  
Author(s):  
Matthew P Leighton ◽  
Laurent Kreplak ◽  
Andrew David Rutenberg
Keyword(s):  
Liquid Crystal ◽  
Biological Systems ◽  
Phase Coexistence ◽  
Rubber Elasticity ◽  
Chiral Phase

We adapt the theory of anisotropic rubber elasticity to model cross-linked double-twist liquid crystal cylinders such as exhibited in biological systems. In mechanical extension we recover strain-straightening, but with an...

scholarly journals Chain Configurations and Rubber Elasticity

1954 ◽  
Vol 11 (6) ◽  
pp. 604-605
Author(s):  
Ei Teramoto
Keyword(s):  
Rubber Elasticity

scholarly journals Physiological factors affecting performance in elite distance runners

2016 ◽  
Vol 22 ◽  
pp. 7 ◽  
Author(s):  
Leif Inge Tjelta ◽  
Shaher A. I. Shalfawi
Keyword(s):  
Oxygen Uptake ◽  
Energy System ◽  
Running Economy ◽  
Distance Runners ◽  
Energy Contribution ◽  
Physiological Factors ◽  
Factors Affecting ◽  
Air Resistance ◽  
Factors Affecting Performance ◽  
Response To Exercise

Running distances from 3000 m to the marathon (42 195 m) are events dominated by energy contribution of the aerobic energy system. The physiological factors that underlie success in these running events are maximal oxygen uptake (VO2max), running economy (RE), the utilization of the maximum oxygen uptake (%VO2max) and velocity at the anaerobic threshold (vAT). VO2max for distance runners competing on an international level has been between 70 and 87 ml/kg/min in men, and between 60 and 78.7 ml/kg/min in women, respectively. Due to lack of air resistance, laboratory testing of RE and vAT are recommended to be conducted on treadmill with 1% slope. %VO2max are in most studies expressed as the average fractional utilization of VO2max at vAT. Much of the current understanding regarding the response to exercise is based on studies of untrained and moderately trained individuals. To use this knowledge to give training recommendations to elite runners is hardly valid. Researchers should therefore exercise caution when giving training recommendations to coaches and elite distance runners based on limited available research.

Unsteady Aerodynamic Forces Measured on a Fluttering Profile

2014 ◽  
Author(s):  
Igor Zolotarev ◽  
Václav Vlček ◽  
Jan Kozánek
Keyword(s):  
Mach Number ◽  
Flow Field ◽  
Degrees Of Freedom ◽  
Air Flow ◽  
Optical Measurements ◽  
Energy Contribution ◽  
Aerodynamic Forces ◽  
Unsteady Aerodynamic ◽  
New Information ◽  
Drag And Lift

The study presents evaluation of optical measurements of the air flow field near the fluttering profile NACA0015 with two-degrees of freedom, Mach number of the flutter occurrence were M=0.21 and M=0.45. Aerodynamic forces (drag and lift components) were evaluated independently on the upper and lower surfaces of the profile. Using the mentioned decomposition, the new information about mechanism of flutter properties was obtained. The forces on the upper and lower surfaces are phase shifted and are partially eliminated as a result of the circulation around the profile. The cycle changes of these forces cause the permanent energy contribution from the airflow to the vibrating system.

Theory of Rubber Elasticity for Development of Synthetic Rubbers

1943 ◽  
Vol 16 (2) ◽  
pp. 286-289
Author(s):  
Hubert M. James ◽  
Eugene Guth
Keyword(s):  
Long Range ◽  
Characteristic Property ◽  
Raw Materials ◽  
Rubber Elasticity

Abstract Two cardinal problems exist in connection with the production of synthetic rubbers: (1) choice of the type of synthetics, necessary raw materials, and methods of production, and (2) evaluation of the products obtained. The most important and characteristic property of synthetics (and of natural rubbers) is their long-range reversible elasticity.

Sign in / Sign up

Export Citation Format

Share Document