POLYPROPYLENE ARTICLE HAVING MONOMER GRAFTED THEREON BY IRONIZING RADIATION

摘要

Polypropylene articles are provided. The polypropylene articles comprise non-crystalline mesomorphous polypropylene having olefinic unsaturation-containing monomers graft-polymerized thereon by ionizing radiation in a dosage sufficient to degrade crystalline polypropylene. The irradiated polypropylene articles retain useful tensile properties after storage periods of as long as at least about four months. Further provided is a method for preparing irradiated polypropylene articles having olefinic unsaturation-containing monomers graft-polymerized thereon comprising the steps of melt extruding polypropylene; quenching the extruded polypropylene immediately after extrusion to provide non-crystalline mesomorphous polypropylene; coating the non-crystalline mesomorphous polypropylene with an ionizing radiation graft-polymerizable monomer; and irradiating the coated non-crystalline mesomorphous polypropylene with a dosage of ionizing radiation sufficient to degrade crystalline polypropylene and sufficient to effect graft-polymerization of the monomer onto the surface of the polypropylene.