SURFACE SILANIZATION OF POLYETHYLENE FOR ENHANCED ADHESION

Low density polyethylene has been treated using a novel surface treatment process ''SICOR'' (''SIlaneon-CORona'' treated polymer) in order to enhance adhesion with a range of adhesives including polyurethane, methacrylate and cyanoacrylate. The process comprises two steps, i.e. corona discharge followed by application of an organo-functional silane. The incorporation of surface hydroxyl groups onto the polymer surface enables organo-silane to create the hydrogen or covalent bonds with the oxidized polymer surface. The possibility of the creation of these bonds has been investigated using FTIR, XPS and wettability studies. The adhesion enhancement due to the new process is significant. Frequently, the strength increase exceeds 200% compared with the corona discharge treatment and more than 300% compared with LDPE priming using the ''Loctite 770'' polyolefin primer. The process is shown to be as good as, or better than, plasma treatment in terms of the strength increase following substrate treatment prior to adhesive bonding.