Influence of corona treatment energy and storage time on the changes of the contact angle of activated polystyrene film

Corona treatment was applied to modify surface of general purpose polystyrene (GPPS) film to improve its molecular interaction with lacquers, paints and adhesives. Results of corona treatment unit energy (E) effect on changes in the contact angle of the film using water, glycerol, diiodomethane and a-bromonaphthalene as well as results of changes in the contact angle occuring during six weeks storage after corona treatment have been presented. The significant influence of Ej on the contact angle changes, especially when tested with water and glycerol (polar liquids) has been found. It turns out from presented results that the wettability suitable for technical purposes can be obtained when Ej values reach ca. 1.2 kJ/m(2). Due to gradual disappearance of the activation process effects, storage time of the tested film can not be longer than 2 weeks.