Surface treatments using plasma and vacuum ultraviolet radiation (VUV) were used to introduce oxygen-containing functional groups in samples of polypropylene, in order to modify its wettability. ATR-FTIR, AFM and contact angle (CA) measurements were used to analyze the chemical and physical changes on the PP surface as a function of time. The results showed changes in wettability of the VUV-treated samples mainly due to chemical modification of the surfaces. For plasma-treated samples, aging occurred faster than for the VUV-treated ones. For both treatments, a rearrangement of the polymer chains during aging has probably occurred, with possible crosslinking of surface macromolecules for the VUV-treated samples.
Polypropylene; UV; plasma; aging