What is Elastomer: Definition and 12 Discussions

An elastomer is a polymer with viscoelasticity (i.e., both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus and high failure strain compared with other materials. The term, a portmanteau of elastic polymer, is often used interchangeably with rubber, although the latter is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually a compound of several elements among carbon, hydrogen, oxygen and silicon. Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable molecular reconformation, without breaking of covalent bonds, is feasible. At ambient temperatures, such rubbers are thus relatively compliant (E ≈ 3 MPa) and deformable. Their primary uses are for seals, adhesives and molded flexible parts. Application areas for different types of rubber are manifold and cover segments as diverse as tires, soles for shoes, and damping and insulating elements. The importance of these rubbers can be judged from the fact that global revenues are forecast to rise to US$56 billion in 2020.IUPAC defines the term "elastomer" as a "polymer that displays rubber-like elasticity."Rubber-like solids with elastic properties are called elastomers. Polymer chains are held together in these materials by relatively weak intermolecular bonds, which permit the polymers to stretch in response to macroscopic stresses.

Elastomers are usually thermosets (requiring vulcanization) but may also be thermoplastic (see thermoplastic elastomer). The long polymer chains cross-link during curing, i.e., vulcanizing. The molecular structure of elastomers can be imagined as a 'spaghetti and meatball' structure, with the meatballs signifying cross-links. The elasticity is derived from the ability of the long chains to reconfigure themselves to distribute an applied stress. The covalent cross-linkages ensure that the elastomer will return to its original configuration when the stress is removed. As a result of this extreme flexibility, elastomers can reversibly extend from 5–700%, depending on the specific material. Without the cross-linkages or with short, uneasily reconfigured chains, the applied stress would result in a permanent deformation.
Temperature effects are also present in the demonstrated elasticity of a polymer. Elastomers that have cooled to a glassy or crystalline phase will have less mobile chains, and consequentially less elasticity, than those manipulated at temperatures higher than the glass transition temperature of the polymer.
It is also possible for a polymer to exhibit elasticity that is not due to covalent cross-links, but instead for thermodynamic reasons.

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  1. Twigg

    What is the most incompressible elastomer?

    Hi all! Usually, one would model a rubber as incompressible (##\nu \rightarrow \infty## or equivalently ##\kappa \rightarrow \infty##, where ##\nu## is Poisson ratio and ##\kappa## is bulk compressibility). However, I am trying to use rubber in an application where performance will improve the...
  2. AlexVY

    Ways to measure elastomer swell

    Summary: Cost-effective ways to measure the swell of elastomers of submersible pumps after they are pulled from wells Dear Physics Community! I am working for an energy company and we are using progressive cavity pumps (PCPs) for producing water from our wells. This is a youtube video...
  3. N

    Elastomer on top of a bending beam

    I'm trying to understand differences between two setups. In one setup I put a thin metal layer on top of a rigid plastic film, which I then bend to a certain radius. The metal is not very prone to crack in itself but with very small bending radius you are able to crack the surface. If I have...
  4. M

    Medical EPDM Food grade / non food grade

    Hi all We are having a debate regarding peroxide cured EPDM where we a few employees are saying peroxide cured EPDM is food safe and can used as an FDA compliant material; the other group are saying that peroxide curing does not make it food safe. I lean more towards it is because the peroxide...
  5. S

    Conformability elastic material compressed on a wavy surface

    Hey there, I'm struggling in finding the useful equations to determine some conformability parameters for a finite elastic material (EPDM) compressed on a rigid slightly wavy surface. I would like to optimize the thickness of the elastic material in terms of indentation depth and thus contact...
  6. R

    Coefficient of friction of elastomer on steel

    I need to measure the co-efficient of friction of rubber (elastomer) seal on steel. How can I do this by experimentally ? I appreciate your any kinds of help regarding this issue. Thanks in advance.
  7. T

    Basic Vibration Damping and Isolation

    Hello, I am studying and trying to understand Powertrain / Engine mounts used in automotive such as these: http://images.gasgoo.com/MiMwMDRfMDA0Izc4MDA3NzIwMA--/auto-part-engine-torque-strut-mount-engine-mounting-for-buick-enclave-chevrolet-traverse-gmc-acadia-25840458.jpg...
  8. S

    Elastomer pressure vessel?

    Hello Physics Forum. I'm looking to use the vapor pressure of a liquid to apply a constant pressure to a piston. The vapor pressure of the liquid is higher than the pressure I'm looking to exert (vapor pressure is ~16psi and I need to push with a pressure of 5.5psi). I'm thinking of using an...
  9. T

    Elastomer stretched in tension and elongation

    Homework Statement A strip of elastomer was stretched in tension and elongation and was held constant. After 10 minutes the tensile stress in the specimen dropped by 12%. Assuming that the elastomer behaves in accordance with the maxwell model: (i) Calculate the relaxation time (to the...
  10. A

    Elastomer Mechanical Properties

    Specifically I'm looking for a resource that can provide me with basic material property information for common elastomers such as Neoprene(R) for the purposes of flat gasket joint analysis. Stress/strain curves and other such data would be very helpful. I understand that elastomers material...
  11. W

    Elastomer Tear Testing Guide

    Hello - I am working on a test for different neoprene mixtures. The set up is two jaws that clamp across the width of a strip of neoprene. One jaw is attached to a stationary post, the other is attached to a cylinder able to apply a variable pulling force. The problem I am having is...
  12. A

    Find the yield strength for an elastomer

    Hey, Just wondering, how would you find the yield strength for an elastomer just from the engineering stress-strain curve. My professor said its complix and different books have different ways of finding it. Any ideas?