Previous studies have discussed the kinetics involved in the reduction in surface tension of ethyl(hydroxyethyl)cellulose (EHEC) at the air/aqueous solution interface in terms of configuration changes involved in the transfer of individual polymer segments between soluted and adsorbed states. It was suggested that the process kinetics were governed by a substantially high activation barrier. In the present study, based on molecular mechanic simulations, it is shown. that a nearly activation-free path between configurations exists for EHEC due to the extreme flexibility of the polymer chain. Hence, the relatively slow kinetics of the process should rather be attributed to a stepwise transformation between conformations which is expressed as a sequence of elementary processes involving a considerable number of intermediate isomers. This occurs over an extended time period. Also, the configuration changes involved in the uncoiling of the polymer at the interface are related to the hydration effects.