Radiation Resistant Polypropylene- New Developments

Abstract

For health care packaging applications, polypropylene (PP) has the advantages of being nontoxic and inert to liquids and drugs. Its low cost and the ease with which it can be extruded or shaped are also important. For medical purposes, it is necessary to sterilize these materials using gamma radiation to ensure total and reliable sterility. However, gamma-irradiated polypropylene is subject to degradation or embrittlement over time. Radiation causes degradation of the polymer by direct energy transfer and subsequent ox idation. The need for radiation sterilizable plastics which are resistant to this type of degradation is important because of the increased use of gamma irra diation as a preferred sterilization method. To retard degradation in polypro pylene, it is important to control these reaction kinetics. Methods to improve polypropylene's resistance to such degradation are focused on the relationships of morphology and radiation effects. New developments in this area are dis cussed regarding methods to make PP film radiation resistant.