Which property primarily characterizes elastomers?

Elastomers are best characterized by their high elasticity, which allows them to undergo significant deformation when a force is applied and then return to their original shape once the force is removed. This unique property is due to the long, flexible polymer chains present in elastomers, which can easily stretch and bend. The organized yet loose structure of the polymers enables this reversible stretch, making elastomers ideal for applications that require flexibility and resilience, such as in rubber bands, seals, and tires.

While some elastomers may exhibit low tensile strength and low melting points, these characteristics are not defining features of elastomers as a class of materials. High thermal conductivity is also not a typical attribute of elastomers; in fact, many elastomers are good thermal insulators. Therefore, the defining characteristic lies in their remarkable elasticity, which enables them to perform effectively in various dynamic applications.