Surface modification of polypropylene by plasmas

Polypropylene (PP) is a polymer with good mechanical properties which has been used in a wide range of applications. However, due to its inertness and low surface energy, PP has to be surface treated for applications in coatings, bonding, printing and metallization. The frequently used surface treatments for PP include plasma, corona and flame treatments. Plasma treatment of polymer surfaces has been studied extensively for many years [1]; however, it has not been used as extensively as corona and flame treatment in industry. Plasma treatments must be carried out in a vacuum and the cost of industry-scale equipment for such treatment is very high. The process parameters are highly system-dependent; the optimal processing conditions developed for one system usually cannot be adopted by another system.