Influence of the cohesive energy density of polymers and of the nature of metal-polymer interface on the contact charging of polymers

An attempt is made to show that there is a relation between the amount of transferred charge and the free energy (per equivalent) of oxide formation on the metal at a metal-polymer interface. The authors show that there is an approximate linear relation between the amount of charge transferred to polymers and their cohesive energy density (CED), for a given metal electrode. It is suggested that existing data can be described with two empirical linear relations. They imply that there is a triboelectric series among polymers, with negatively charged polymers having the lowest CED and those with high CED being positively charged; and the charge transfer mechanism is partially controlled by the oxide layer on the metal electrode. This means that noble metals (such as gold) are less affected by this phenomenon and therefore are more likely to give the true charge transferred to the polymer