Treatment of polymer surfaces by low pressure microwave plasmas

Abstract

Improved wettability and adhesion are obtained for polypropylene after brief exposure to a low pressure microwave cold nitrogen plasma which optionally may contain fluorine compounds. This process is used to create adhesion of epoxy resins on polypropylene surfaces for the fabrication of electronic components. It has to take the place of a very expensive and polluting industrial treatment requiring high temperatures for about seven hours. Energy cost is divided by 700. The surfaces of polypropylene have been examined by means of electronic microscopy and XPS. Incorporation of nitrogen in the first surface layers is observed after the plasma treatment with an apparent N/C atomic stoichiometry of about 0.22