Surface Modification of PET and PP by Atmospheric Pressure Cold Plasma in Argon Environment

This paper presents a DBD system used to generate plasma at atmospheric pressure in argon environment. The discharge was produced by applying high voltage power supply (7kV) to the electrodes separated by distance of 3 mm. The lower electrode was covered by a glass plate of thickness 1.5mm which served as the dielectric barrier. Argon was supplied at a flow rate of 2liter per minute. Two types of polymer samples, PET and PP were treated for different time ranging from 5sec1minute.Contact angle of both the samples before and after treatment were measured. In our experimental results, it has been shown that plasma treatment produces remarkable improvement in wettability. The change in surface morphology of the sample was investigated by SEM analysis. SEM images showed that roughness of the sample increases appreciably after the treatment in plasma for both the polymers. The stability of plasma modified sample was also studied by measuring the hydrophobic recovery of the sample up to several days after the treatment.