Elastomer
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.
Q81163
polymer
Concept
Q910483
viscoelasticity
Concept
Q128709
viscosity
Concept
Q62932
elasticity
Concept
Q245031
intermolecular force
Concept
Q2091584
Young's modulus
Concept
Q193514
failure strain
Concept
Q208674
portmanteau
Concept
Q6714735
rubber
Concept
Q188631
vulcanisates
Concept
Q178827
monomer
Concept
Q11344
elements
Concept
Q623
carbon
Concept
Q556
hydrogen
Concept
Q629
oxygen
Concept
Q670
silicon
Concept
None
amorphous polymer
UNK
Q825643
glass transition temperature
Concept
None
molecular reconformation
UNK
Q127920
covalent bonds
Concept
Q111092
ambient temperature
Concept
Q2091584
E
Concept
Q44395
Pa
Concept
Q17004810
seal
Concept
Q131790
adhesive
Concept
Q22676
soles for shoes
Concept
Q1127660
damping
Concept
Q918306
insulating
Concept
Q33438
IUPAC
ORG
Q81163
polymer
Concept
Q11369
intermolecular bonds
Concept
Q868477
thermoset
Concept
Q188631
vulcanization
Concept
Q380677
thermoplastic
Concept
Q146527
thermoplastic elastomer
Concept
Q898597
cross-link
Concept
Q904453
thermodynamic reasons
UNK
Q252266
Elastomer
Concept
Q252266
Elastomer
Concept
Q252266
Elastomer
Concept
2020-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
2020
DATE
+3^^http://www.w3.org/2001/XMLSchema#decimal
3
NUMBER
+56^^http://www.w3.org/2001/XMLSchema#decimal
56
NUMBER
+5^^http://www.w3.org/2001/XMLSchema#decimal
5
NUMBER
+700^^http://www.w3.org/2001/XMLSchema#decimal
700
NUMBER
subclass of
subclass of
instance of
instance of
instance of
instance of
measured physical quantity
instance of