Artículos de revistas: "Entropic/rubber elasticity"

1

Weiner, J. H. y J. Gao. "TKIE ENTROPIC SPRING IN RUBBER ELASTICITY". Journal of Thermal Stresses 15, n.º 2 (abril de 1992): 329. http://dx.doi.org/10.1080/01495739208946140.

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2

Weiner, J. H. "Entropic versus kinetic viewpoints in rubber elasticity". American Journal of Physics 55, n.º 8 (agosto de 1987): 746–49. http://dx.doi.org/10.1119/1.15034.

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3

Pérez-Aparicio, Roberto, Arnaud Vieyres, Pierre-Antoine Albouy, Olivier Sanséau, Loïc Vanel, Didier R. Long y Paul Sotta. "Reinforcement in Natural Rubber Elastomer Nanocomposites: Breakdown of Entropic Elasticity". Macromolecules 46, n.º 22 (5 de noviembre de 2013): 8964–72. http://dx.doi.org/10.1021/ma401910c.

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4

Morawetz, Herbert. "History of Rubber Research". Rubber Chemistry and Technology 73, n.º 3 (1 de julio de 2000): 405–26. http://dx.doi.org/10.5254/1.3547599.

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Abstract After the discovery of the tapping of Hevea rubber trees in the middle of the eighteenth century and early technological applications of Hevea rubber, efforts to discover the chemical nature of rubber started with the determination of its elemental composition in 1826. Later it was shown that rubber pyrolysis yields low molecular weight chemicals with the identical elemental composition. It was long believed that these add to each other by “secondary valence bonds.” However Staudinger's work starting in 1920 proved that Hevea (H.) rubber consists of chains linked by covalent bonds. The utility of rubber increased dramatically with the discovery of vulcanization by Goodyear in 1844. However the nature of this process remained for many years controversial due to the influence of the “colloid school” of chemistry. The first observations on the nature of rubber elasticity date back to 1805, but more than a century passed before it was shown that the retractive force of stretched rubber is entropic. X-ray crystallographic studies not only provided the ultimate proof that natural rubber consists of covalently bonded chain molecules, but also gave evidence for its chemical structure. A century ago it was found that polymeric products other than H. rubber exhibited similar elastic properties. The race to produce synthetic rubbers was largely stimulated by the two World Wars. The availability of 14C labeled precursors led to the detailed description of the biosynthetic pathway by which rubber is produced in the Hevea plant.

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5

Drozdov, A. D. "Non-entropic theory of rubber elasticity: Flexible chains grafted on a rigid surface". International Journal of Engineering Science 43, n.º 13-14 (septiembre de 2005): 1121–37. http://dx.doi.org/10.1016/j.ijengsci.2005.03.010.

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6

Conrad, Nathaniel, Tynan Kennedy, Deborah K. Fygenson y Omar A. Saleh. "Increasing valence pushes DNA nanostar networks to the isostatic point". Proceedings of the National Academy of Sciences 116, n.º 15 (26 de marzo de 2019): 7238–43. http://dx.doi.org/10.1073/pnas.1819683116.

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The classic picture of soft material mechanics is that of rubber elasticity, in which material modulus is related to the entropic elasticity of flexible polymeric linkers. The rubber model, however, largely ignores the role of valence (i.e., the number of network chains emanating from a junction). Recent work predicts that valence, and particularly the Maxwell isostatic point, plays a key role in determining the mechanics of semiflexible polymer networks. Here, we report a series of experiments confirming the prominent role of valence in determining the mechanics of a model system. The system is based on DNA nanostars (DNAns): multiarmed, self-assembled nanostructures that form thermoreversible equilibrium gels through base pair-controlled cross-linking. We measure the linear and nonlinear elastic properties of these gels as a function of DNAns arm number, f, and concentration [DNAns]. We find that, as f increases from three to six, the gel’s high-frequency plateau modulus strongly increases, and its dependence on [DNAns] transitions from nonlinear to linear. Additionally, higher-valence gels exhibit less strain hardening, indicating that they have less configurational freedom. Minimal strain hardening and linear dependence of shear modulus on concentration at high f are consistent with predictions for isostatic systems. Evident strain hardening and nonlinear concentration dependence of shear modulus suggest that the low-f networks are subisostatic and have a transient, potentially fractal percolated structure. Overall, our observations indicate that network elasticity is sensitive both to entropic elasticity of network chains and to junction valence, with an apparent isostatic point 5<fc≤6 in agreement with the Maxwell prediction.

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7

Zeng, Nianning y Henry W. Haslach. "Thermoelastic Generalization of Isothermal Elastic Constitutive Models for Rubber-Like Materials". Rubber Chemistry and Technology 69, n.º 2 (1 de mayo de 1996): 313–24. http://dx.doi.org/10.5254/1.3538375.

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Abstract Existing thermoelastic constitutive models are not able to predict important thermal properties of rubbers. For example, the modified entropic elasticity theory fails to predict that the temperature coefficient of stress, the energetic contribution to the stress, and the specific heat at constant deformation depend on both deformation and temperature. A class of thermoelastic constitutive equations is proposed that generalizes given isothermal models and predicts the temperature and deformation dependence. The Helmholtz free energy is written as the sum of the isothermal energy function, but with temperature-dependent material moduli, and a function of temperature. Conditions on the Helmholtz energy are given to ensure that three inversion effects which characterize rubber are predicted. As an application, an isotropic, homogeneous, mechanically incompressible thermoelastic constitutive equation is generalized from the isothermal Mooney-Rivlin model. The three uniaxial thermal inversion effects are successfully reproduced by this model.

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8

Dung, T. A., N. T. Nhan, N. T. Thuong, D. Q. Viet, N. H. Tung, P. T. Nghia, S. Kawahara y T. T. Thuy. "Dynamic Mechanical Properties of Vietnam Modified Natural Rubber via Grafting with Styrene". International Journal of Polymer Science 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/4956102.

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The dynamic mechanical behavior of modified deproteinized natural rubber (DPNR) prepared by graft copolymerization with various styrene contents was investigated at a wide range of temperatures. Graft copolymerization of styrene onto DPNR was performed in latex stage using tert-butyl hydroperoxide (TBHPO) and tetraethylene pentamine (TEPA) as redox initiator. The mechanical properties were measured by tensile test and the viscoelastic properties of the resulting graft copolymers at wide range of temperature and frequency were investigated. It was found that the tensile strength depends on the grafted polystyrene; meanwhile the dynamic mechanical properties of the modification of DPNR meaningfully improved with the increasing of both homopolystyrene and grafted polystyrene compared to DPNR. The dynamic mechanical properties of graft copolymer over a large time scale were studied by constructing the master curves. The value of bT has been used to prove the energetic and entropic elasticity of the graft copolymer.

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9

Wang, Run, Yanan Shen, Dong Qian, Jinkun Sun, Xiang Zhou, Weichao Wang y Zunfeng Liu. "Tensile and torsional elastomer fiber artificial muscle by entropic elasticity with thermo-piezoresistive sensing of strain and rotation by a single electric signal". Materials Horizons 7, n.º 12 (2020): 3305–15. http://dx.doi.org/10.1039/d0mh01003k.

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Artificial muscles are developed by using twisted natural rubber fiber coated with buckled carbon nanotube sheet, which show tensile and torsional actuations and sensing function via the resistance change by a single electric signal.

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10

Chen, Pinzhang, Yuanfei Lin, Jingyun Zhao, Lingpu Meng, Daoliang Wang, Wei Chen y Liangbin Li. "Reconstructing the mechanical response of polybutadiene rubber based on micro-structural evolution in strain-temperature space: entropic elasticity and strain-induced crystallization as the bridges". Soft Matter 16, n.º 2 (2020): 447–55. http://dx.doi.org/10.1039/c9sm02029b.

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11

Le Cam, J. B., J. R. Samaca Martinez, X. Balandraud, E. Toussaint y J. Caillard. "Thermomechanical Analysis of the Singular Behavior of Rubber: Entropic Elasticity, Reinforcement by Fillers, Strain-Induced Crystallization and the Mullins Effect". Experimental Mechanics 55, n.º 4 (25 de julio de 2014): 771–82. http://dx.doi.org/10.1007/s11340-014-9908-9.

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12

Karlinsky, J. B., J. T. Bowers, J. V. Fredette y J. Evans. "Thermoelastic properties of uniaxially deformed lung strips". Journal of Applied Physiology 58, n.º 2 (1 de febrero de 1985): 459–67. http://dx.doi.org/10.1152/jappl.1985.58.2.459.

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We examined the temperature dependence of small degassed hamster lung strip mechanics to develop insights into the molecular basis of lung elasticity. Quasi-static length-tension curves of adapted lung strips were generated at 10, 23, 37, 50, and 80 degrees C; quasi-static tension-temperature plots (QSTT) at strains of 0.5, 0.75, and 1.0 were then formulated. Static tension-temperature (STT) plots at strain 1 were independently generated from other strips. Stress relaxation was evaluated as a function of temperature at different strains; hysteresis ratio was calculated as a parameter of mechanical efficiency. Between 23 and 37 degrees C, the slopes of the QSTT plots at the different strains were close to zero. The slope of the STT plot was slightly positive, indicating that the tension developed by a stretched strip was primarily due to entropic changes with length, suggesting that strips behave like rubber polymers near physiological temperature. Between 10 and 23 degrees C, the slope of the QSTT curve was zero at the two lowest strains but was negative at strain 1; and slope of the STT curve was zero at strain 1. These data indicated that collagen fiber and possibly glycosaminoglycan function was abnormally affected at 10 degrees C. Between 50 and 80 degrees C at strain 1, the slopes of both the QSTT and STT plots at all strains were positive. These data suggested that elastic fiber function was altered between 50 and 80 degrees C such that both internal energetic and entropic contributions to the tension were changed. Stress relaxation and hysteresis data were consistent with these findings.

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13

Kato, Kazuaki, Daisuke Matsui, Koichi Mayumi y Kohzo Ito. "Synthesis, structure, and mechanical properties of silica nanocomposite polyrotaxane gels". Beilstein Journal of Organic Chemistry 11 (16 de noviembre de 2015): 2194–201. http://dx.doi.org/10.3762/bjoc.11.238.

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A significantly soft and tough nanocomposite gel was realized by a novel network formed using cyclodextrin-based polyrotaxanes. Covalent bond formation between the cyclic components of polyrotaxanes and the surface of silica nanoparticles (15 nm diameter) resulted in an infinite network structure without direct bonds between the main chain polymer and the silica. Small-angle X-ray scattering revealed that the homogeneous distribution of silica nanoparticles in solution was maintained in the gel state. Such homogeneous nanocomposite gels were obtained with at least 30 wt % silica content, and the Young’s modulus increased with silica content. Gelation did not occur without silica. This suggests that the silica nanoparticles behave as cross-linkers. Viscoelastic measurements of the nanocomposite gels showed no stress relaxation regardless of the silica content for <20% compression strain, indicating an infinite stable network without physical cross-links that have finite lifetime. On the other hand, the infinite network exhibited an abnormally low Young’s modulus, ~1 kPa, which is not explainable by traditional rubber theory. In addition, the composite gels were tough enough to completely maintain the network structure under 80% compression strain. These toughness and softness properties are attributable to both the characteristic sliding of polymer chains through the immobilized cyclodextrins on the silica nanoparticle and the entropic contribution of the cyclic components to the elasticity of the gels.

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14

Li, Xu, Yi Dong, Ziran Li y Yuanming Xia. "EXPERIMENTAL STUDY ON THE TEMPERATURE DEPENDENCE OF HYPERELASTIC BEHAVIOR OF TIRE RUBBERS UNDER MODERATE FINITE DEFORMATION". Rubber Chemistry and Technology 84, n.º 2 (1 de junio de 2011): 215–28. http://dx.doi.org/10.5254/1.3577534.

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Abstract The hyperelastic behavior of unfilled natural rubber and some kinds of filled rubbers used in tire industry is tested by applying automated grid method. More accurate stress–strain data of tested rubber specimens at different temperatures are obtained. Test results show that different from the unfilled natural rubber whose stiffness increases linearly with temperature rising, the filled tire rubber has a tendency first to become soft and then to become stiff through its “critical temperature.” And this trend shift could be qualitatively interpreted by the joint action of two kinds of mechanisms, namely, the “energy elasticity” and the “entropy elasticity” effect. Besides, based on consideration of the relationship between model parameters and environmental temperature, the modified Arruda–Boyce model is extended to its explicit temperature-dependent form. Fitting results illustrate that this new model could take the temperature effect on hyperelastic behavior of tire rubbers into account well, and with an easy form, it is of convenient and practical usefulness in some relevant engineering application.

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15

Manning, Gerald S. "Construction of a Universal Gel Model with Volume Phase Transition". Gels 6, n.º 1 (27 de febrero de 2020): 7. http://dx.doi.org/10.3390/gels6010007.

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The physical principle underlying the familiar condensation transition from vapor to liquid is the competition between the energetic tendency to condense owing to attractive forces among molecules of the fluid and the entropic tendency to disperse toward the maximum volume available as limited only by the walls of the container. Van der Waals incorporated this principle into his equation of state and was thus able to explain the discontinuous nature of condensation as the result of instability of intermediate states. The volume phase transition of gels, also discontinuous in its sharpest manifestation, can be understood similarly, as a competition between net free energy attraction of polymer segments and purely entropic dissolution into a maximum allowed volume. Viewed in this way, the gel phase transition would require nothing more to describe it than van der Waals’ original equation of state (with osmotic pressure Π replacing pressure P). But the polymer segments in a gel are networked by cross-links, and a consequent restoring force prevents complete dissolution. Like a solid material, and unlike a van der Waals fluid, a fully swollen gel possesses an intrinsic volume of its own. Although all thermodynamic descriptions of gel behavior contain an elastic component, frequently in the form of Flory-style rubber theory, the resulting isotherms usually have the same general appearance as van der Waals isotherms for fluids, so it is not clear whether the solid-like aspect of gels, that is, their intrinsic volume and shape, adds any fundamental physics to the volume phase transition of gels beyond what van der Waals already knew. To address this question, we have constructed a universal chemical potential for gels that captures the volume transition while containing no quantities specific to any particular gel. In this sense, it is analogous to the van der Waals theory of fluids in its universal form, but although it incorporates the van der Waals universal equation of state, it also contains a network elasticity component, not based on Flory theory but instead on a nonlinear Langevin model, that restricts the radius of a fully swollen spherical gel to a solid-like finite universal value of unity, transitioning to a value less than unity when the gel collapses. A new family of isotherms arises, not present in a preponderately van der Waals analysis, namely, profiles of gel density as a function of location in the gel. There is an abrupt onset of large amplitude density fluctuations in the gel at a critical temperature. Then, at a second critical temperature, the entire swollen gel collapses to a high-density phase.

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16

Shaw, M. C. y E. Young. "Rubber Elasticity and Fracture". Journal of Engineering Materials and Technology 110, n.º 3 (1 de julio de 1988): 258–65. http://dx.doi.org/10.1115/1.3226046.

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Rubber is an amorphous elastomer of high entropy that is normally treated by statistical thermodynamics instead of molecular modeling. A pseudo-amorphous model is introduced that is useful in extending true stress-true strain uniaxial tensile results to other more complex states of stressing. While the statistical thermodynamic approach is still needed to deal with thermal aspects of rubber elasticity, the new approach represents a simpler, more accurate method of dealing with mechanical properties. Fracture of rubber follows a criterion of constant engineering strain (or constant extension ratio) in the resultant principal stress direction which is consistent with the proposed model and the experimental results presented.

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17

Shadwick, Robert E. y John M. Gosline. "Physical and Chemical Properties of Rubber-Like Elastic Fibres from the Octopus Aorta". Journal of Experimental Biology 114, n.º 1 (1 de enero de 1985): 239–57. http://dx.doi.org/10.1242/jeb.114.1.239.

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We investigated the physical and chemical properties of highly extensible elastic fibres from the octopus aorta. These fibres are composed of an insoluble rubber-like protein which we call the octopus arterial elastomer. The amino acid composition of this protein is different from that of other known protein rubbers, being relatively low in glycine and high in acidic and basic residues. Up to extensions of 50%, mechanical data from native elastic fibres fit a theoretical curve for an ideal Gaussian rubber with elastic modulus G = 4.65 × 105 N m−2, and this is unchanged by prolonged exposure to formic acid. Thermoelastic tests on this protein indicate that the elastic force arises primarily from changes in conformational entropy, as predicted by the kinetic theory of rubber elasticity. Analysis of the non-Gaussian behaviour of the elastic fibres at extensions greater than 50% suggests that the molecular chains in this octopus protein are somewhat less flexible than those in resilin or elastin. Some speculations on the molecular design of these protein rubbers are made.

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18

Hoei, Yoshio. "MOLECULAR TREATMENT OF RUBBER-LIKE ELASTICITY FOR ACTIVE FILLER–LOADED NETWORKS". Rubber Chemistry and Technology 88, n.º 4 (1 de diciembre de 2015): 640–59. http://dx.doi.org/10.5254/rct.15.84884.

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ABSTRACT Prior comparison of experimental observations and model predictions for natural rubber/styrene–butadiene rubber carbon black–filled systems has indicated a need for further development of tubelike constraint-based entropy models. In particular, systems incorporating active fillers introduce constraints whose effects should be considered. This contribution extends the finite-extension single-chain model proposed originally by Teramoto, via consideration of the bound rubber layer surrounding a filler particle as well as filler-cluster breakup and strain-amplification effects. The resulting model includes descriptors of the entropy state of the polymer matrix, the affine and phantomlike chain deformation, and tube diameter. The model produced a more accurate prediction of the shape of observed stress–strain curves, particularly at moderate and high strains.

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19

YAMASHITA, Yoshihiro y Sueo KAWABATA. "Non-Entropy Elasticity of a Highly Stretched Pure Rubber." NIPPON GOMU KYOKAISHI 74, n.º 5 (2001): 191–95. http://dx.doi.org/10.2324/gomu.74.191.

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20

Holzapfel, G. A. y J. C. Simo. "Entropy elasticity of isotropic rubber-like solids at finite strains". Computer Methods in Applied Mechanics and Engineering 132, n.º 1-2 (mayo de 1996): 17–44. http://dx.doi.org/10.1016/0045-7825(96)01001-8.

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21

Urry, D. W., T. Hugel, M. Seitz, H. E. Gaub, L. Sheiba, J. Dea, J. Xu y T. Parker. "Elastin: a representative ideal protein elastomer". Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 357, n.º 1418 (28 de febrero de 2002): 169–84. http://dx.doi.org/10.1098/rstb.2001.1023.

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During the last half century, identification of an ideal (predominantly entropic) protein elastomer was generally thought to require that the ideal protein elastomer be a random chain network. Here, we report two new sets of data and review previous data. The first set of new data utilizes atomic force microscopy to report single-chain force-extension curves for (GVGVP) 251 and (GVGIP) 260 , and provides evidence for single-chain ideal elasticity. The second class of new data provides a direct contrast between low-frequency sound absorption (0.1-10 kHz) exhibited by random-chain network elastomers and by elastin protein-based polymers. Earlier composition, dielectric relaxation (1-1000 MHz), thermoelasticity, molecular mechanics and dynamics calculations and thermodynamic and statistical mechanical analyses are presented, that combine with the new data to contrast with random-chain network rubbers and to detail the presence of regular non-random structural elements of the elastin-based systems that lose entropic elastomeric force upon thermal denaturation. The data and analyses affirm an earlier contrary argument that components of elastin, the elastic protein of the mammalian elastic fibre, and purified elastin fibre itself contain dynamic, non-random, regularly repeating structures that exhibit dominantly entropic elasticity by means of a damping of internal chain dynamics on extension.

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22

Froelich, D., R. Muller y Y. H. Zang. "New Extensional Rheometer for Elongational Viscosity and Birefringence Measurements: Experimental Results and Interpretation". Rubber Chemistry and Technology 59, n.º 4 (1 de septiembre de 1986): 564–73. http://dx.doi.org/10.5254/1.3538218.

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Abstract This study shows that by using the recoverable strain, one can represent the elongational viscosity ηe=σe/˙ε as a linear function of the quantity λr2−λr−1, characteristic of a neo-Hookian material. The elongational viscosity is then the sum of two contributions: One is related to the entropic elasticity of the chains through the recoverable deformation of the sample. The other is related to the shear viscosity at a shear rate equivalent to the extensional strain rate. In absence of a simple theoretical justification for such an equation, more experiments are being undertaken with different polymers and rubbers in order to understand how the recoverable strain is related to the chemical structure of the chain and to check the generality of the equation.

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23

Göritz, D. y R. Grassler. "Melting Temperatures as a Function of the Strain of Oriented Polymer Networks". Rubber Chemistry and Technology 60, n.º 2 (1 de mayo de 1987): 217–26. http://dx.doi.org/10.5254/1.3536126.

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Abstract The reduction in conformational entropy on stretching elastomers causes an increase in melting point of the temperature-induced crystallisation. The dependence of the melting point on degree of deformation is relatively weak. The high melting points of the strain-induced crystallites must be caused by regions whose orientation is markedly higher than that which corresponds to the macroscopic strain. Such a bimodal orientation distribution is explained by an inhomogeneous deformation of the rubber. There exist either regions in the specimen which do not participate in the deformation or regions with very low strength. Stretching leads to an affine deformation of a part of the specimen. If one lets this crystallize, temperature-induced crystallites find themselves in surroundings whose orientation is describable with the assumption of a Gaussian network. Correspondingly, the increase in melting point as a function of strain can be calculated with the aid of the statistical theory of entropy elasticity, in the way Roe and Krigbaum did. The other, essentially smaller part of the sample contains the inhomogeneities. They cause locally highly oriented fibrillar-like regions which lie in the deformation direction. The strain-induced crystallites are formed within these regions of exceptionally low entropy. The simultaneous existence of temperature- and strain-induced crystallisation is interpreted as evidence for inhomogeneous deformation in elastomers.

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24

Gosline, John M. "Structure and Mechanical Properties of Rubberlike Proteins in Animals". Rubber Chemistry and Technology 60, n.º 3 (1 de julio de 1987): 417–38. http://dx.doi.org/10.5254/1.3536137.

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Abstract Polymer networks formed from protein molecules that adopt kinetically-free, random-coil conformations are found in many animals, where they play a number of important roles. The 5 rubberlike proteins isolated and studied to date indicate that animal rubbers, like their synthetic counterparts, contain random networks which are usually stabilized by covalent crosslinks. Long-range elasticity in rubberlike proteins is based on changes in the conformational entropy of random-coil molecules. Further, these protein networks show viscoelastic glass transitions similar to all other amorphous polymer networks. Future research on protein sequences should increase our understanding of how polypeptide chains can function as random-coil molecules, and studies into the mechanical state of elastin in arterial tissues may provide important clues about the mechanisms of some forms of human disease.

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25

Hanson, David E., John L. Barber y Gopinath Subramanian. "The entropy of the rotational conformations of (poly)isoprene molecules and its relationship to rubber elasticity and temperature increase for moderate tensile or compressive strains". Journal of Chemical Physics 139, n.º 22 (14 de diciembre de 2013): 224906. http://dx.doi.org/10.1063/1.4840096.

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26

Gannoruwa, Asangi, Yuanbing Zhou, Kenichiro Kosugi, Yoshimasa Yamamoto y Seiichi Kawahara. "ORIGIN OF ENERGETIC ELASTICITY AND ENTROPIC ELASTICITY OF NATURAL RUBBER WITH NANODIAMOND NANOMATRIX STRUCTURE". Rubber Chemistry and Technology, 14 de junio de 2021. http://dx.doi.org/10.5254/rct.21.79923.

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ABSTRACT The origin of energetic elasticity in conjunction with the entropic elasticity for natural rubber with a nanodiamond nanomatrix structure was investigated in terms of bound rubber formed between nanodiamonds, based on the interaction between natural rubber and nanodiamonds inside the nanomatrix. The natural rubber with a nanodiamond nanomatrix structure was prepared by reacting nanodiamonds with deproteinized natural rubber in the presence of tert-butylhydroperoxide/tetraethylenepentamine at 30 °C in the latex stage followed by drying. Morphology of the products was observed by two-dimensional and three-dimensional transmission electron microscopies. The effect of bound rubber on the mechanical properties of the products was investigated by measurements of the dynamic mechanical properties and differential scanning calorimetry. The contribution of bound rubber was estimated by combining the Takayanagi equation and modified Guth–Gold equation. A significant increase in complex modulus was attributed to the effect of the bound rubber.

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27

Paul, Jinu. "Thermoelastic characterization of carbon nanotube reinforced PDMS elastomer". Journal of Polymer Engineering, 16 de noviembre de 2020. http://dx.doi.org/10.1515/polyeng-2020-0118.

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AbstractInternal energy and entropy contribution to the elasticity of carbon nanotube reinforced polydimethylsiloxane (PDMS) is evaluated using statistical theory of rubber elasticity. Stress–temperature measurements were performed and the data was used to calculate the internal energy contribution to elastic stress. Interesting aspects such as increase in energy and low entropy contribution to the elasticity of carbon nanotube reinforced PDMS is observed. This can be related t o the deformation behavior of the network chains of pristine elastomers and the directional reorientation of nanotube entanglements. While the entropy change is associated with reorientation or directional preference of the carbon nanotube entanglements, the internal energy change is associated with structural bending or stretching of the nanotubes. A reversible deformation of nanotube entanglements complements rubber like elasticity and the present study gives insights into the thermoelasticity of reinforced elastomers as well as the elastic behavior of carbon nanotube entanglements inside a polymer matrix.

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28

Darwis, Roziha, Norma Alias, Nazeeruddin Yaacob, Mohamed Othman, Nurashikin Abdullah y Teh Yuan Ying. "Temperature Behavior Visualization on Rubber Material Involving Phase Change Simulation". Malaysian Journal of Fundamental and Applied Sciences 5, n.º 1 (5 de agosto de 2014). http://dx.doi.org/10.11113/mjfas.v5n1.287.

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Material engineers are excited with the design of a new rubber product through the development of a new composite of the rubber product. Our research contributes in developing the mathematical simulation based on Gauss-Seidel Red-Black and Gauss-Seidel method to solve the temperature behavior of the rubber elasticity, strength, entropy and classical experiments through reference publications and stimulating rubber physics research elsewhere. The temperature behavior leads to the partial differential equation of heat transfer problems involving phase change simulation. The prototype of the algorithm implemented on Linux operating systems using C language.

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Artículos de revistas sobre el tema "Entropic/rubber elasticity"

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