Question

what happens to thermoplastic polymer when some stress are applied and removed​

Answer 1

STRESS-STRAIN BEHAVIOR OF POLYMERS

One of the most important characteristics of polymers is their inherent toughness and resistance to fracture (crack propagation). It is not coincidence that the name plastic, which describes any kind of polymeric material, is similar to the word plasticity which is the propensity of a solid to undergo permanent deformation under stress.