A framework for a consistent description of the correlation effects along polymer chains subject to flow is proposed. The formalism shows how correlations between chain segments in the flow can be incorporated into a hierarchy of distribution functions for tangent vectors. The present description allows to take into account all the relevant relaxation mechanisms for slow flows. Special cases of the derived set of equations are shown to yield some existing models and shed some light on the connection between them.
Stepanyan, R., Slot, J. J. M., & Molenaar, J. (2004). On the microscopic approach to the nonlinear dynamics of entangled polymer melts. Europhysics letters, 68(6), 832-838. https://doi.org/10.1209/epl/i2004-10277-3