\-tәr-mәr\ n [ elastic + - o- + - mer] (ca. 1939) Generally, a material that at room temperature can be stretched repeatedly to at least twice its original length and, immediately upon release of the stress, returns with force to its approximate original length (Harper CA (ed) (2002) Handbook of plastics, elastomers and composites, 4th edn. McGraw-Hill, New York). Stretchability and deformation with returnability is one criteria by which materials called plastics in commerce are distinguished from elastomers and rubbers. More explicitly, polymers that stretch and recover reproducibly without permanent change in dimensions (or deformation) are rubber or elastic materials. Elastomers are useful and diverse substances that easily form various rubbery shapes. Many industries rely on parts made from elastomers, especially automobiles, sports equipment, electronics, electrical equipment, and assembly line factories ( www.dupontelastomers.com). Another criterion is that, unlike thermoplastics...