Elasticity of rubber Assignment Example | Topics and Well Written Essays - 1500 words

snap of no-account - Assignment ExampleRubber substances ar not confined to natural rubber, however. They take rate of a great variety of synthetic polymers of comparable properties. An elastomer is considered as a polymer that shows evidence of rubber flexible properties, i.e. materials that can be possibly stretched to a number of times its original length with out(p) breaking and which, upon spark of the stress, instantaneously returns to their original lengths. A rubber is more or less an elastic material, since its deformation is instantaneous and it further shows almost no slither (Bjork, 1988). The distinctive nature of rubbers was ascertained by John Gough in 1305, and described his findings and experiments as shown in this subsequent paragraph. A person has to clasp one end of the carving of a rubber between the thumb and forefinger of each hand get the central flow of the piece into slight contact with the lips further lengthen the slip swiftly and you get out inst antly wee-wee out a feeling of warmth in that section of the mouth that is in contact with stretched rubber. For this rosin evidently grows warmer the further it is lengthened and the edges of the lips possess a higher degree of sensibility, which facilitates them to discover these changes with great facility than other parts of the body. The augment in temperatures, which is recognized in the event of extending some(prenominal) pieces of Caoutchouc, whitethorn be obliterated in on the spot, by allowing the slip to contract again which it will do quickly by desirable quality of its own spring, as soft as the stretching forces blockade to act as soon as it has been fully exerted. Gough made these comments regarding his second experiment In any case one end of a slip of Caoutchouc is fastened to a rod of forest or metal, and some weight is fixed (added) at the other extremity/end the thong will be seen to become longer with cold and shorter with heat (Mark, 1984). To make certai n this concept, it is necessary for a self experimentation. One will only need a strip of rubber, a weight and a hair-dryer. Gough presented no better explanations to the unexpected findings, such as that the expected stiffness increments with rising temperatures and that heat is progressive throughout stretching duration. It took approximately fifty years prior to the formulation of thermodynamics of the rubber pushover. Rubbers exhibit predominantly entropy-driven elasticity through measurements of force and specimen length at varied temperature levels. Thermo-elastic effects of rubber shows that stretched rubber samples which are subjected to constant uniaxial load contract reversibly on heating, and the same sample can give out heat reversibly if stretched. These two observable concepts are true and consistent with the view that the entropy of the rubber decreased on stretching. Molecular picture of the entropic forces is dated back to the theoretical work of 1930s, when it wa s suggested that the covalently bonded polymer chains had been lie during extension (Gumbrell, Rivlin, &, Mullins, 1953, p. 1495). Methods and procedures This study involved an investigation in the thermo-elastic behaviors and thermodynamics, with regards to the energetic and entropic elastic forces. At minimum strains, characteristically less than ? = L L 0 1.1 (where L and L0 are the dimensions of the unstressed and stressed specimens, respectively), the stress at