Answer: Option (c) is the correct answer.
Explanation:
Due to the structure of linear polymers they are highly ductile in nature. And, more is the number of strains present in a polymer more will be its brittleness.
Time dependent stress with respect to some strain level measure remains constant is known as relaxation modulus.
Mathematically, [tex]E_{r}(t) = \frac{\sigma(t)}{\epsilon_{o}}[/tex]
More cross-linking is present in thermosets whereas there is low degree of cross-linking in elastomers. Therefore, it means that an elastomer will have some amount of cross-linking but not as thermosets.
Thus, we can conclude that the statement relaxation modulus is a representative of stress drop with respect to the initial stress, is false.