Effects of plasma treatment on amorphous and semicrystalline polymer

This study investigates the changes in morphology and wettability of amorphous and semicrystalline polyethyleneterephthalate (PET) polymers, which were treated in weakly ionized, highly dissociated RF oxygen plasma. The polymers were treated in glow region for different exposure times with the discharge power set to 250 W and the gas pressure set to 75 Pa. Results indicate that plasma modification has different effects on the surface properties of amorphous and semicrystalline polymers. The amorphous polymers are more sensitive to plasma treatment, as they can be quickly burned, while this is not the case for semicrystalline polymers. With the atomic force microscopy (AFM) different surface structures were observed, which become even more pronounced after plasma treatment. The measurements of water contact angle (WCA) on polymer surfaces also revealed different characters. The plasma treatment of amorphous polymer resulted in a lower hydrophilicity than was observed for the semicrystalline polymer at the some conditions.