PSAs Tenaciously Bond to Non-Stick Film After Plasma Surface Treatment
The virtues of chemical inertness and low surface energy that make polytetrafluoroethylene (PTFE) and its copolymers valuable engineering polymers also account for the difficulty in achieving chemical bonds. These materials are typically etched or flame treated to enable physical bonding to an adhesive. These methods create temporary changes to the surface that do not bond well to a respective adhesive upon exposure to UV, moisture, chemicals and/or thermal stresses. This inability to produce permanent, strong bonding between an adhesive and the etched or flamed surface has limited the way these very useful base polymers have been used in industry.
In the late 1980s, researchers at SUNY at Buffalo discovered that radio frequency (rf) glow discharge (cold gas plasma) of hydrogen in combination with vaporized liquids provided unique surface modification of fluoropolymer materials. Through the use of hydrogen plasma as a fluorine scavenger in conjunction with vaporized liquids, oxygen incorporation into the surface matrix of PTFE could be well controlled. The modified surfaces retained morphology, chemical resistance and hydrophobic properties to degrees similar to those of the original, unmodified material.