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Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable molecular reconformation is feasible without breaking of covalent bonds. At ambient temperatures, such rubbers are thus relatively compliant (E ≈ 3 MPa) and deformable. [citation needed] IUPAC definition for an elastomer in polymer ...
The engineering stress (by definition) is the first derivative of the energy in terms of the extension ratio, which is equivalent to the concept of strain: = = and the Young's Modulus is defined as derivative of the stress with respect to strain, which measures the stiffness of the rubber in laboratory experiments.
where is the vacuum permittivity, is the dielectric constant of the polymer and is the thickness of the elastomer film in the current state (during deformation). Usually, strains of DEA are in the order of 10–35%, maximum values reach 300% (the acrylic elastomer VHB 4910, commercially available from 3M, which also supports a high elastic energy density and a high electrical breakdown strength.)
The phase transition temperature of an azo-liquid crystalline elastomer can be reduced due to the trans-cis isomerization of the azobenzenes during UV-irradiation and thus the liquid crystalline phase can be destroyed isothermally. For liquid crystalline elastomers with a high azo-concentration, a light-responsive change of the sample's length ...
In physics and materials science, elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed. Solid objects will deform when adequate loads are applied to them; if the material is elastic, the object will return to its initial shape and size after ...
Filled elastomers and biological tissues [3] [4] are also often modeled via the hyperelastic idealization. In addition to being used to model physical materials, hyperelastic materials are also used as fictitious media, e.g. in the third medium contact method .
On the other hand, for some materials, e.g., elastomers and polymers, subjected to large deformations, the engineering definition of strain is not applicable, e.g. typical engineering strains greater than 1%; [4] thus other more complex definitions of strain are required, such as stretch, logarithmic strain, Green strain, and Almansi strain.
Small vehicle suspensions using rubber (or other elastomers) can achieve the dual function of springing and damping because rubber, unlike metal springs, has pronounced hysteresis and does not return all the absorbed compression energy on the rebound. Mountain bikes have made use of elastomer suspension, as did the original Mini car.