The results of molecular dynamics simulations of poly(ethylene oxide) (PEO) NaI polymer electrolytes are presented. We focus on the influence of the electrostatic and polarization interactions on the dynamics of the polymer segments. This is done by calculating the mean square displacement of the CH2 groups and the corresponding incoherent intermediate scattering functions. The latter are compared with results from neutron spin-echo (NSE) experiments. Two different compositions were studied: a pure PEO melt and a PEO-NaI polymer electrolyte. It is shown that inclusion of polarization interactions lead to a slowing down of segmental relaxation in the polymer electrolyte compared to more simplified models for electrostatic interactions.