Role of chain ends in coil deformation of driven single polymer

Nonlinear elasticity of coil deformation is profound in polymer rheology. The structural asymmetry between the middle part of the chain and the chain end is supposed to be the origin of internal tension for coil deformation of driven single linear polymers. We performed dynamic Monte Carlo simulations on driven single ring polymers without the abovementioned asymmetry, and compared their deformation behavior to that of the linear counterparts of the same chain length. The comparison proved that the chain ends are not the cause of internal tension for coil deformation, and rather, their relatively high mobility suppresses the coil-stretch transition upon large coil deformation. Therefore, the "cracking-the-whip" effect, as an integration of local acceleration caused by dynamic heterogeneity of nearby monomers on the polymer chain, is the sole origin of internal tension for the observed coil deformation of driven single linear and ring polymers. This study opens an extensive investigation on the intramolecular source of nonlinearity for nonequilibrium polymer dynamics.