Surface Modification of Organic Polymer Materials with Unipolar Pulse Glow Plasma

We experimentally addressed the surface modification of organic polymer materials, such as epoxy-resin (EP), cyanate-ester (CY) and polytetrafluoroethylene (PTFE) materials, with unipolar and bipolar plasma discharges.The influence of the plasma discharge on the wettability was investigated with infrared spectroscopy, X-ray photoelectron spectroscopy and contact angle measurement.The results show that the surface modification with unipolar and bipolar plasma discharges had a major impact.To be specific, when it comes to significant improvement of wettability, bipolar plasma discharge outperforms unipolar one.The plasma discharge accounted for the creation of quite a few polar bonds by breaking surface non-polar bonds, for instance O-H and C-O-C bonds for EP; C-H and -COOH bonds for CY; and C-C, C-F, C-F₂, C-F₃ and C-O bonds for PTFE.However, as the storage time increased in air, the hydrophilicity decreased simply because the surface density of polar bonds decreased.